JSF no dog fighter

[yak2]

Clever link there FN. For mine the EE Lightning was a pretty neat weapon for its time.
My candidate for ugliest aircraft is the Airspeed Ferry.
Should have been struck by lightning

[Leyland P75]

The P-38 wasn't exactly pretty either was it?

Don't get me wrong re: EE/BAC Lightning.

Any 50's era design that can accelerate and climb to the best part of 90,000 as fast as any modern fighter (and faster than most), supercruise and hit Mach 2.5 - reportedly easily and smoothly - is alright in my book.

Wikipedia actually has a pretty good article, particularly stories of U-2 and Concorde interceptions....

[FlyNavy]

Well the Lightning 50's era had a 15 minute flight time under above conditions - hence the oberwing tanks which gave it another five min? Did you ever follow up the story of the RAF engineer who went flying in one by mistake during an engine run? He was not strapped in in an ejection seat that was not going to work - because he was doing an engine run that got out of hand! It is nice that he survived - but it was touch and go - boomboom. ;D

[Leyland P75]

Fair dinkum? Goes to show anyone can be a pilot eh?

Do you have a link?

[FlyNavy]

Well peter75 I guess you can be excused because you have not read the story and I did not reveal that the engineer was a private pilot. Sorry - NOT! ;D As for the link. It is on these forums somewhere but perhaps not obviously a stand out topic. Searching on this forum is fraught.

P75 here is a Lightning F-15 pilot impression:
www.thunder-and-lightnings.co.uk/lightning/memories.php
____________________

Link to the story via this link?

www.lightning.org.uk/archive/0303.php

"I well remember the Wg Cdr Spry version of Wg Cdr Walter Holden's ‘flight’ without canopy or flying equipment when, on testing the engines at the end of the runway at Lyneham, he found himself in full reheat and airborne. Managing to control what must have been a very difficult aircraft to fly in that configuration and after four attempts, he put it down safely with only slight damage to the tail end. The aircraft, XM135, is a Mk1 - the first Lightning to go into service. Its proud record before retirement following its last flight into the Imperial War Museum at Duxford on 24 November 1974 was 1,634 flights. I wonder whether they included Wg Cdr Holden's trip? Another incident was the famous RAF Coltishall accident when a Lightning taxied into the crew room. Spry had fun with that one."
______________________

forum.keypublishing.co.uk/showthread.php?t=20807

"It happened on July 22nd 1966 while XM135 was at 33 MU at Lyneham. The aircraft had a persistant electrical problem that only showed itself under aceleration. So Wg Cdr Walter "Taff" Holden decided to undertake some ground tests to see if he could find the problem. The canopy was removed and the ground locks were in place Taff had a set of pilots notes with him in the cockpit he was strapped in but the safty pins were in. A couple of short bursts down the run way showed nothing so taff decided to give it a bit more speed. As he opened the throttels he accidentally pushed them through the gate into reheat. At first he thought the trottles had jammed but by the time he figured out what was happeneing he was out of runway and was left with only one choice to take XM135 for a quick spin round the airfield. This wouldnt be too much of a problem except that Taff had only done a few hours on a tiger moth. He couldnt call the tower as he only had on ear defenders and he couldnt eject as the seat was safe. After a couple of failed attempts after 12 minutes he landed."

[Leyland P75]

No canopy?!?!? Sheesh! It keeps getting better!

Let me guess, he also went supersonic as well?

[FlyNavy]

Bhell this story is elusive - anyway from the mouth of horses:

forum.keypublishing.co.uk/showthread.php?s=69f485ce93f87c36716009cdfe73e706&t=20807&page=2

The flight in Taffy's own words

"This story is well known in Lightning circles but it is great to be able to hear the real facts 'from the horses mouth' as it were."

Lightning XM135 Inadvertent Flight

Some Background Considerations
In attempting to write a more detailed personal account of my unfortunate flight in Lightning XM135 back in July 1966, I think I should add some of the reasoning and reason why I attempted the test in the first place. This might remove some of the erroneous facts, misapprehensions and misconceptions which I have seen in some accounts of the event.

First I should explain that I was a qualified pilot, even although I was an R.A.F. Engineer Branch officer. I joined the R.A.F. as an apprentice in 1943, from where I gained a cadetship to university. At the university I read mechanical engineering and learnt to fly on Tiger Moths, with the University Air Squadron. On graduation, I was given the option to continue with an engineering career or to follow a General Duties (Flying) career. I chose the former path and the Air Ministry at that time, considered that there was merit in allowing me to qualify to 'wings' standard as a pilot, in the belief that an engineering officer with a pilot qualification, could more easily see the pilots point of view in aircraft maintenance matters. I too, thought this was a very good idea.

I qualified on Harvards, but my early engineering duties only allowed me to keep in flying practice on Chipmunks. Whilst I was at Kinloss, I managed to get checked out on Oxfords and on occasions assisted a qualified test pilot, to air test twin engine Neptunes. My only jet aircraft experience was as a passenger in the second seat of a Javelin T3 and again in the 'rumble' seat of a Canberra. In my service, one of my postings took me to 33MU Lyneham where as the C.O of a civilian manned aircraft storage unit, I had Canberra, Meteor and Lightning types, which were gradually being prepared for despatch to various flying unit tasks. When the Meteor and Canberra types had been cleared, the powers that be, decided that the MU should close after the last Lightning's had been despatched. Up until the last Canberra, I had a qualified and current test pilot on my staff for those aircraft, but he was not a current Lightning pilot. When a Lightning needed test flying, I had to call for any available pilot with a current test pilot rating. Most times I would find one who could be spared within a 24 or 36 hour period. So much for my personal and R.A.F unit background.

Lightning Mk 1A XM135
XM 135 was being prepared for despatch to a Target Facilities Flight, but over a period of weeks, it had been giving no end of trouble. Each time it was being flight tested, the pilot found that on the initial few yards of a take off run, the inverter, supplying power to the primary flight instruments, would cut out and the stand by inverter would have to cut in, clearly an unsatisfactory state of affairs. Electricians were using every trick in their trade to establish the cause, each time thinking that they had removed, replaced and tightened every likely component. With nothing out of order, they would seek another test flight. It was a Boscombe Down pilot who next attempted to fly the aircraft, found the same problem persisting and refused to fly until a more positive explanation could be determined.

Back to the drawing board, electricians decided to devise some tests which might isolate the fault and indicate roughly where and which component was at fault. They intended to ask the next test pilot to switch in and out parts of circuits, using trailing wires from the likely circuits to temporary switches in the cockpit and to do these electrical switchings before and after each few yards of a simulated take off run, when the fault was manifest. The temporary wires from internal circuitry required the cockpit canopy to be removed and in this state the aircraft was made ready for another air test. Being a pilot, it was easiest for me, as CO, to request the services of a qualified test pilot, from wherever I could find one, but for the next test on XM135, no pilot was available for at least another week. With my unit closing down, many civilians being made redundant, a timetable of clearance being upset with this 'rogue' aircraft, there was much tetchiness and irritation amongst my staff. The intended Boscombe Down pilot, knowing I was a pilot, suggested I might try the test myself. He suggested using an out of use runway (Runway36) as I would only be using 30 or 40 yards at a time. He suggested using a Land Rover to communicate with Air Traffic Control and to get their clearance for each movement of the aircraft. However, there was one remaining minor problem. I had only sat in a Lightning cockpit once before and I had no idea how to start its two Rolls Royce Avon engines! The Foreman of engine trades gave me a 5 minute briefing on how to do this and XM135 was towed out to Runway 05 on 22July 1966 for my electrical tests.

It was by way of extraordinary good fortune that my engine Foreman explained that, although I would not be needing reheat, that reheat needed the throttles to be pushed past a reheat 'gate' and one had to feel for the gate keys, behind the throttle, to unlock. My only other knowledge of the Lightning was what I could remember from pilot's notes. At each test flight by the qualified pilot, I would be in ATC with a copy pilot's notes, should he need any aircraft figures to be relayed to him. One or two figures stuck in my mind, namely that the undercarriage had a maximum speed before it should be retracted and I had an even vaguer figure of about 150 knots for a landing speed. Some extra knots would be required for each 1000 lbs. of unused fuel, but I did not need to bother with any such figures for the test, which I was to undertake.

The Ground Test
I was correctly strapped into the cockpit (seated on the in situ parachute and ejector seat) and after starting the engines and holding the aircraft static, on the brakes, I did the necessary preliminaries for the electrical checks in the cockpit, checking the notes I had scribbled on a notepad which lay on the coaming in front of me. All seemed ready for the first test and I indicated to the Land Rover to obtain ATC clearance for use of the short 30 or 40 yards of runway. Holding the brakes I gradually opened the throttles to about 90%. My feeling at the time was the unexpected heavy vibration of Avon power held against the brakes. I did a quick check of the temporary electrical switches and circuitry lights, then released the brakes. That initial punch from the thrust was quite remarkable and I moved the expected 30 to 40 yards before I throttled back and applied the brakes. So far so good. I made some notes, altered some more switch positions, noted the on/off lights and prepared for the next test. This was done in a similar fashion and I was leaving the 'fault' diagnosis to my electrical staff who would have to interpret my notes. I needed to do one more test and ATC had noted that I had only used about 100 yards total, so they were quite happy to clear me for a similar short distance. ATC had also been holding up a fuel bowser and trailer with 3600 gallon of AVTAG for awaiting C130 aircraft refuelling, they decided to allow the bowser to cross the runway. On opening the throttles for that final test, I obviously pushed them too far, misinterpreting the thrust, because of the unexpected heavy vibration and they got locked into reheat. Yes, I did use some expletives but I had no time to think of getting out of reheat, because in front of me, the bowser and trailer had just crossed the runway, from right to left, so my thoughts were to make sure I was missing them by sufficient margin. No, I couldn't steer to clear them; reheat takes you in a straight path like a bullet out of a gun. The time between finding myself in reheat and just missing the bowser was less than half the time I have taken to write this sentence.

Before my thoughts could again return to getting myself out of reheat, I was gathering speed and about to cross the main duty runway, where a Comet had just passed on its take off run. I then had no time to look for reheat gate keys, my eyes were on what next lay ahead. Two things, the end of the short runway 07 and just beyond was the small village of Bradenstoke which I just had to miss. There was no chance of stopping, non whatsoever. I had gained flying speed (that is what reheat is for, short sharp take offs) and I had no runway left. I did not need to heave it off the runway, the previous test pilot had trimmed it exactly for take off and only a slight backward touch on the stick and I was gathering height and speed. Then my thought was to get my speed back in case I should damage the undercarriage. Incidentally, I could not have raised the undercarriage; the ground servicing locks were in place for safety reasons. With only clear blue sky in front of me, I could then search and feel for those gate keys. Yes, I found them and thanked my lucky stars that my engine foreman had quite incidentally told me of their location and I was soon able to get the speed back to (I am guessing now) about 250knots. My next thoughts were to keep Lyneham airfield in sight and where had the Comet got to, the one I had missed a few seconds ago? Then I asked myself, should I eject and where and when? No, I could not; the safety pins were in the ejection seat and safe for servicing, not for flying. My only alternative then was to attempt a landing, but how does one interpolate or extrapolate Tiger Moth, Chipmunk, Harvard flying to a two engined, 11 ton, beast like the Lightning?

After regaining my bearings, a little composure and simply by observation, making sure that the Comet had been warned away, I decided I should attempt a landing on the duty runway and direction. I was trying to combine all my limited flying experience into a few minutes of DIY flight 'training' on a Lightning. It wasn't easy, but I must admit that some of the elementary rudiments of my proper flying training and flight theory were coming in useful. I needed to get the feel of the aircraft, if I was to get it back on the ground. My first approach was ridiculous, I could tell that my speed, height, rate of descent, even alignment wasn't correct and my best plot was to go round again. This time making sure that my throttles would be well below reheat position. A second approach was no better, I had some aspects better, but as the duty runway 25 is on the lip of an escarpment, with a valley floor beyond, my rate of descent took me below runway height and I found myself adding power to get back to the right level. More power also meant more speed and I was trying to get to something like 150 knots for landing, but the uncoordinated attempt was becoming a mess so I abandoned it, took myself away on a very wide circuit of Lyneham and decided to land in the opposite direction. This I thought would give me more time to get the 'feel' right and if I made a mess of the landing, I would overrun the runway and just drop (crash) into the valley beyond. In that direction, with a messed up landing, I would have no fear of crashing into Lyneham village.

The long final leg of this approach gave me the thinking time that I needed and I gradually got the feel that speed, alignment, rate of descent, height and approach angle were better. I plonked it down at about the right position off the runway threshold, but just forgot that I was in a nose wheel aircraft and emulated my best three wheelers in a Chipmunk or Harvard. The result was that I crunched the rubber block which encases the brake parachute cables. However, I had got down, but I then had to stop. I obviously knew the Lightning had a brake parachute, but where was the 'chute lever, button or knob? There, I found it marked Brake Chute and I pulled it and I could then look ahead and concentrate on keeping straight and somewhere near the centre line. I hung on to the brake lever, I wasn't slowing as much as I would like, so I just kept up my hand pressure on the brakes. I had about 100 yards of runway left when I stopped and even then, I didn't know that the brake parachute had dropped off as soon as it was deployed, because the cable had been severed as a result of my super tail wheel three pointer.

Events Immediately after the Flight
XM 135 was towed back to the hangar and I was taken to see the medical officer who gave me some pills to calm my nerves. I felt reasonably calm because I had almost killed myself on five occasions in that 12 minute flight, yet I had miraculously survived. What is more, I would see my wife and young family again. Two or three times in that same 12 minutes, I thought I would never ever see them again. My only priority was to save my own skin, I was not thinking about the non insured loss of a Lightning Mk 1A aircraft. The minor damage to the aircraft was repaired with a new set of brake shoes and a new rubber chute block. As a memento, I have kept that rubber block, one day it might be returned to XM135 at Duxford.

The Fault
Although the tests I did and the ensuing flight did not immediately provide a reason for the initial electrical fault, my electrical staff, with additional assistance from English Electric, Salmesbury eventually did. Apparently, in early versions of the Lightning, there was to be a ground test button fitted into the standby inverter circuit. It was never fitted to the Mk1A but the wires were left in the looms. It was one of these redundant wires which shorted on to the UHF radio as it moved on its trunnions when the aircraft nudged forward on take off. Who would have thought I should risk my life to find it, in the way I did?

Events Subsequent to the Flight
There was a subsequent Inquiry to find out what had happened and why and to make recommendations for it never to happen again. As I was the Commanding Officer of the Unit, I was responsible for my own as well as the service actions of all my staff. I was not acting against any orders in the Flight Order Book which I religiously kept up to date. But those orders did not cater for engineering officers doing investigative type checks on Lightning's. They were later amended. After the Unit Inquiry I had to go up in front of the Commander-in-Chief. That was when I thought my career would be placed in jeopardy. I even thought that my coveted 'wings' would be taken from me; I had no idea how the incident was being regarded by Command or indeed Air Ministry. But, as I stood in front of Air Marshal Sir Kenneth Porter, he read the proceedings, asked me if I agreed with his view that "With the limited flying experience that I had, the test would have been better left to an experienced and current Lightning test pilot." I agreed of course. He then told me to remove my hat, sit down and proceeded to tell me some of his unfortunate flying incidents in Mesopotamia in the Middle East. I was thankful that nothing more was to become of the incident and that I still had a job to do back at 33 Maintenance Unit, Lyneham.

I coped with all the official communications regarding the incident, but what I was unprepared for was the release of the story to the public. I had had very little experience of working with the press, certainly none with radio, TV, national and world press. I had no training in how to deal with their quest for news. My Command Headquarters suggested I went away on leave before press releases were made by Air Ministry. This I did and took my family off camping to Jesola, in Italy. Imagine my complete surprise when, on the first day of camp, on my way to find some ice, someone shouted "Hello Taffy, I've just been reading about your Lightning flight!!" The world seemed a very small place. On returning to the U.K. I was overwhelmed to find that the incident was still front line news. People wanted to write articles in newspapers, books, magazines, interviews on TV and radio and underhand attempts to hear my account of what had happened. Having admitted that I had made an unwise decision to do the ground tests, I decided that the unwanted publicity that I had attracted was in no way going to be for financial gain. I steadfastly refused offers although for a two page article in the Sunday Express, I requested the editors to make a contribution to the R.A.F. Benevolent Fund. Despite prompts, no moneys were ever handed over and I became very disillusioned with all publicity media. Some friends thought I had gained reward for an article in 'Mayfair'; it was written without my knowledge and authority, but, because it was factually correct, I had no redress from the Press Complaints Board. Nonetheless, I was extremely annoyed.

Some years after the incident, my hidden fears of high speed flight came to the surface and I had to spend two periods in hospital. I had not come to terms with the emotional side of the event. To return to my wife and family after five close encounters with death, was indeed a miraculous experience, but I had not been honest with myself, to accept it as such, so I needed psychiatric help. I could recall the technicalities of the flight without any hang-ups, but was unwilling to talk about that emotional side of the ordeal until I was placed under medical drugs and to bring those emotions to the surface. That was a rewarding experience and it gave me a much better understanding of people who might need that same kind of help, after similar unfortunate occurrences.

Forty Years On
I am now retired and living with my wife in Cheshire. Apart from being an active DIY plumber, carpenter, electrician handyman, my main pastime is involvement with family history. My inadvertent flight is still very vivid and in writing this personal account, I needed little prompting. Over the intervening years, I have received many letters and reminders from people whom I did not know, all praising my efforts to return myself and aircraft back to the ground safely. Yes, I have basked in some glory, when accounts of what happened, have been retold in social gatherings. I have never sought publicity, but whenever it became impossible to suppress, I have had to live with it. I enjoyed my career in the Royal Air Force, but not because of XM135!

Best regards Taffy Holden"

[FlyNavy]

Taffy speaks via Utube here:



Lightning XM135 inadvertant flight by W/Cdr "Taffy" Holden

"http://www.lightningpilots.com/ I have met Taffy twice,once unknowingly when he was my commanding officer at RAF Halton and once a few years ago at my neighbour's BBQ, he turned out to be the host's Uncle!

It all started when XM135 had a wiring loom changed in its electrical utility system (generation) as part of a more major overhaul. The replacement loom came from a flight test aircraft, at high engine power levels and "brakes off", both the engine generator dolls eyes indicators would drop out supposedly indicating a double generator failure. The problem had first showed up on the post overhaul test flight and had necessitated a priority landing at Lyneham due to suspected total electrical generation failure. A team from the support unit were dispatched to recover the aircraft. Two attempts where made to resolve the problem, both times the test pilot drove some distance only to conduct a high speed abort when the problem reappeared. By this time the test pilot was getting a bit cheesed off and said that he would only make another attempt when the problem was unquestionably solved. Hence intrepid engineering officer "Taffy" Holden found himself performing high speed taxi tests.

Taffy had to carry out a series of high power taxi acceleration tests to simulate the forces imposed during a take off roll as that was the time where the electrical fault manifested itself. The thrust lever on the Lightning can control both engines and when pushed fully forward can be made to go through a gate which in doing so activates the After-Burners (Re-heat). On Taffy's last run, this is what he inadvertently did. The speed of the taxing aircraft with both engines in after-burn built up very quickly while he struggled to remember how to dis-engage the after-burners, (a pair of piano like keys have to be depressed while retarding the throttle).
After a few seconds he observed a fuel tanker crossing the intersection on the taxiway that the Lightning was using, he figured that he would not be able to avoid the tanker an so the only option left to him was to lift the aircraft off the ground.
Taffy was a ground engineering officer and although he had been trained to fly Tiger Moths and Harvards he had never flown a jet let alone a Lightning!

In W/Cdr Holdens own words about after the incident;
"XM 135 was towed back to the hangar and I was taken to see the medical officer who gave me some pills to calm my nerves. I felt reasonably calm because I had almost killed myself on five occasions in that 12 minute flight, yet I had miraculously survived. What is more, I would see my wife and young family again. Two or three times in that same 12 minutes, I thought I would never ever see them again. My only priority was to save my own skin, I was not thinking about the non insured loss of a Lightning Mk 1A aircraft. The minor damage to the aircraft was repaired with a new set of brake shoes and a new rubber chute block. As a memento, I have kept that rubber block, one day it might be returned to XM135 at Duxford.

The Fault
Although the tests I did and the ensuing flight did not immediately provide a reason for the initial electrical fault, my electrical staff, with additional assistance from English Electric, Salmesbury eventually did. Apparently, in early versions of the Lightning, there was to be a ground test button fitted into the standby inverter circuit. It was never fitted to the Mk1A but the wires were left in the looms. It was one of these redundant wires which shorted on to the UHF radio as it moved on its trunnions when the aircraft nudged forward on take off. Who would have thought I should risk my life to find it, in the way I did?"

BBC radio interview with John Dunn."

[Peter Lewis]

A recent internet poll voted the PL-11 Airtruck as the ugliest aircraft ever.

"If it's wacky it's British, if it's ugly it's French, and if it's both wacky and ugly it's Russian".
Could only be said by an American!

[FlyNavy]

F-35B Ready to Begin Stovl Testing Mar 3, 2009
By Graham Warwick and Guy Norris

www.aviationweek.com/aw/generic/story.jsp?id=news/F35B030309.xml&headline=F-35B%20Ready%20to%20Begin%20Stovl%20Testing&channel=defense

Tied down over the hover pit, doors open and nozzles deployed, the Joint Strike Fighter is entering its most challenging phase of testing. Over the month ahead, Lockheed Martin will fully exercise the propulsion system in powered-lift mode to clear the F-35B to begin short-takeoff-and-vertical-landing (Stovl) flight testing.

Built around a shaft-driven lift fan, the Stovl propulsion system was a key discriminator in the JSF competition. On a single mission in July 2001, Lockheed Martin’s X-35B concept demonstrator completed a short takeoff, supersonic dash and vertical landing—an unprecedented accomplishment that Boeing’s direct-lift X-32B could not match.

Seven years into development of the F-35, the lift system has been tested only on the ground, and in the aircraft only at low power. In the coming weeks on the hover pit, tests will build up to full power and include manual and automatic conversions between conventional and powered-lift modes.

The F-35B’s lift system includes the aft three-bearing swivel nozzle, which vectors engine thrust downward; roll posts in the wing fed with bypass air diverted from the engine; and the liftfan housed behind the cockpit and driven via shaft and gearbox from the main powerplant. Together they produce a maximum of at least 40,550 lb. of thrust in the hover.

Conversion from CTOL to Stovl mode takes about 15 sec. In the first 6 sec., doors open for the liftfan inlet and exhaust, dorsal auxiliary intake, underwing roll posts and aft nozzle. Over the next 7 sec., the clutch engages to drive the liftfan gearbox. When spun up, solid bolts lock into place to take the torque and unload the clutch. Thrust split between engine and liftfan and roll split between wing posts is then used to control the aircraft in jetborne flight.

The ability to combine supersonic speed and vertical flight in a single airframe is a crucial attribute of the JSF, and while the U.S. Marine Corps, the U.K. Royal Air Force and Royal Navy are in the minority among JSF customers, their need for Stovl capability has been a driver of the program from the outset. The Marines’ urgent need to replace the Harrier has put the F-35B in pole position for flight testing, ahead of the numerically more important conventional takeoff F-35A for the U.S. Air Force.

Aircraft BF-1, the first F-35B, has been on the hover pit before, in May 2008, but at testing was limited to 30% thrust to avoid exciting vibration that caused turbine blade failures in two F135 engines during powered-lift ground tests at Pratt & Whitney. Those tests demonstrated manual and automatic conversion between CTOL and Stovl modes, albeit at low power, says J.D. McFarlan, air vehicle integrated product team lead.

Now the engine has been redesigned, reinstalled in BF-1 and the propulsion and flight control systems upgraded to the latest software release, which will be used from hover pit testing through to the first vertical landing around midyear “unless we learn something and need to change it,” he says.

Designed to collect the exhaust and duct it away from the aircraft to simulate operation in free air, the hover pit at Lockheed Martin’s Fort Worth, Tex., plant is 150 X 75 ft. and 80 ft. of its length is covered with steel grating. Lift-system exhaust flows through the grating, is deflected aft and ejected upward at the rear of the pit.

The aircraft is tied down to struts that connect to the nose and main gear axles and are anchored to the floor of the pit 14 ft. below. Load cells measure forces on the struts in all three axes and allow the overall forces and moments on the aircraft to be calculated and correlated with computer models of the propulsion and control systems.

The majority of testing will be conducted over the open pit, but for the final series of runs steel panels will be fitted over the grating to allow the ground environment during vertical takeoff and landing to be measured. “Our area of interest is under the three-bearing nozzle, which should be similar to a Harrier exhaust,” says McFarlan.

The outwash environment will also be measured to determine the impact on maintainers. In addition, tests over the plated pit will indicate the extent to which hot exhaust gas is recirculated and ingested by the engine, potentially reducing vertical thrust. An inlet rake will measure pressures and temperatures going into the engine.

During the concept demonstration phase it was shown that the lift fan reduces recirculation by creating a “dam” of cooler air that blocks hot exhaust flowing forward from the aft nozzle. “We don’t expect to see any hot gas ingestion on the pit,” says McFarlan, who adds that the inlet rake will remain in place for Stovl flight tests.

Pit tests will begin by stepping through the conversion process—opening the doors; prepositioning, engaging and locking the liftfan clutch; blocking the bypass duct and diverting air to the roll posts; and swinging the three-bearing nozzle down. “We’ll run though these steps manually, then do automatic conversions,” he says.

Propulsion system checkout will follow and include tests to measure forces and moments and time delays between the pilot making a control request and lift system responding; to verify that a particular nozzle angle produces the thrust angle expected; throttle transients and control sweeps to dynamically change thrust and roll split; and demonstrating the control mode to abort conversion, “which we can do at any time,” says McFarlan.

Pit tests are expected to take about a month, and generate the data needed to obtain clearance to fly BF-1 with the lift-system engaged. “We should begin initial Stovl flight work in the April/May timeframe,” says McFarlan. Initial Stovl transition work will be conducted from Fort Worth. After repeating an earlier doors-open flight test to check the updated control software, the lift fan will be engaged.

Flights from Fort Worth will focus on handling qualities and propulsion testing during Stovl transition at speeds from 250 kt. down to 100 kt., all above 20,000 ft. altitude. After a few flights with a KC-135 tanker for aerial refueling qualification, BF-1 will ferry to NAS Patuxent River, Md., in the “early summer” to continue Stovl testing at lower and lower speeds and altitudes.

Tests there will begin with Stovl-mode rolling landings at speeds from 130 kt. down to 70 kt. The F-35B will then transition from semi-jetborne to jetborne flight at speeds from 60 kt. down to 40 kt. where it will rely totally on the propulsion system for lift. The first hovers will be conducted in free air at several hundred feet for station-keeping work before proceeding to the first vertical landing on Patuxent River’s hover pit.

McFarlan says BF-1 will complete “probably a dozen” flights between arriving at Patuxent River and performing the first vertical landing, which is expected to be accomplished in June-July. This will be followed by about a year of envelope-expansion flying at the Navy’s flight test center, which will include Stovl operation in crosswinds and tailwinds, and with and without stores.

Loaded with flight-test instrumentation, BF-1 weighs in close to an operational F-35B and will have a similar thrust margin in vertical flight, says McFarlan. With a hover weight of 39,000 lb. and thrust of 40,550 lb., the F-35B is expected to operate at a nominal maximum hover weight ratio of 97%, providing a thrust margin of 3%. “BF-1 will probably have a little more margin,” he says.

Weight is not the issue it once was for the F-35B. “We are right on track to the weight plan set forth on exit from the SWAT phase,” says McFarlan. SWAT—the 18-month Stovl Weight Attack Team redesign completed in 2004—reduced the F-35’s weight by more than 3,000 lb. “We are no longer approving design changes for weight reduction—we don’t need to,” he says. The emphasis is on design improvements for affordability, with weight reduction seen as a bonus.

Lockheed Martin is waiting to measure the F135’s installed thrust on the hover pit before deciding whether any further weight reduction is needed, but with 40,550 lb. as the minimum vertical thrust expected from any engine in the fleet, McFarlan is confident the F-35B will meet its Stovl performance requirements.

Pratt & Whitney shipped the first redesigned Stovl flight-test engine to Lockheed Martin at the end of January, meeting the schedule agreed last spring following the turbine blade failures. “They did a good job getting the propulsion system to us on time,” he says.

While the turbine-blade problem delayed the start of powered-lift testing by four to six months, it has not extended the overall flight-test program, says Bill Gostic, vice president F135 program. The engine, meanwhile, is meeting its requirements for thrust, temperature and stall margin. The CTOL powerplant is on its weight target and the Stovl version is 6 lb. over, he says.

The F135 has its origins in the F119 engine powering Lockheed Martin’s F-22, with a larger fan and additional turbine stage to provide higher thrust. The increased-diameter two-stage fan has redesigned aerodynamics and the first stage is an integrally bladed rotor with hollow blades inertia-welded to the hub.

Compared with the F119, there are aerodynamic tweaks, material changes and manufacturing improvements in the compressor, which uses blisks throughout. The combustor has the same aerodynamics, with more advanced cooling allowing higher temperatures.

The single-stage high-pressure turbine has improved cooling, but the aerodynamics of the first and second turbine stages are unchanged from the F119. The biggest change is the addition of a third turbine stage to drive the liftfan. Pratt opted for an unshrouded third stage, Gostic says, because it was impractical to produce a cooled and shrouded single-crystal blade of the size required.

That design decision came under scrutiny after third-stage turbine blades failed in two Stovl engines during powered-lift ground testing, one in August 2007 and one in February 2008. The cause was a fatigue crack that initiated at the same internal cooling hole in both blades.

“The root cause was high-cycle vibratory stress,” says Gostic. “The pressure wakes from the third-stage vanes upstream of the turbine were exciting the blades.” The result was a stress concentration at a cooling hole near the base of a rib inside the blade close to its leading edge. The wakes are stronger in Stovl mode because the turbine is working harder to drive liftfan.

“The pressure ratio in CTOL is very different,” says Gostic. “We extract much more energy in Stovl and the pressure drop is much greater. This results in a higher vibratory response.” Increasing engine speed by 50-100 rpm. to get more Stovl thrust as part of the SWAT redesign effort also exacerbated the vibration excitation problem.

Pratt had not seen the problem before because the F119 has much smaller turbine blades and does not have the F135’s variable cycle. “There has never been a turbine blade like this that can instantly go from up-and-away flight to producing 28,000 shp.,” says Gostic. “Engage the liftfan and you effectively double the size of the fan. There is a sudden increase in load on the turbine.”

The fix has been to introduce asymmetry to disrupt the excitation causing the vibration. Asymmetry is already used in the F135 fan, alternate blades having different shapes. In the redesigned third turbine stage, instead of 54 evenly spaced vanes the lower half now has 28, the upper half 24. “This breaks up the timing of the excitation,” says Gostic.

The second part to the fix is to redesign the turbine blade itself to get rid of the stress concentration. This is achieved by eliminating the holes where the crack started, so this high-stress area is now solid and cooling air is redirected through slots above and below.

The fix was evaluated first in a ground-test engine with redesigned vanes and unchanged third-stage rotor. This showed a reduction in vibratory stress of up to 48% with just the vane redesign alone. “It gave us sufficient margin to survive with the old blade,” Gostic says. Another engine test over 500 tactical cycles showed no change to cooling effectiveness.

A redesigned flight-test engine was then subjected to a proof test intended to uncover any susceptibility to high-cycle fatigue. Previous tests involved stepping up engine speed in 50-rpm. increments and holding each test point for 10 X 6 vibration cycles. In the proof test devised for the F135, speed is increased in 25-rpm. steps from idle to the 9,000-rpm. redline and each is held for 10 X 7 cycles—the test takes about 30 hr.

“It’s an unprecedented proof test, 2-10 times more difficult than any previous test,” says Gostic, explaining that “high-cycle fatigue modes are peaky and otherwise we could miss them.” Pratt plans to proof test “a couple more” Stovl engines to be sure the fix is working.

Rolls-Royce provides the lift system components, meanwhile, and is testing elements of a lighter system for the initial service release (ISR) powerplant for production F-35Bs. The company plans to conduct system-level tests at Indianapolis in third-quarter 2009 before handing over to Pratt & Whitney for propulsion system tests. The Block 3.5 final production standard will incorporate a hollow second-stage ‘blisked’ liftfan rotor; hollowed-out first-stage rotor; titanium instead of aluminum liftfan case; and inlet guide-vane ice protection system.

These improvements cut an additional 39 lb. from the Block 3 development configuration, itself 150 lb. lighter than the original lift-system design. The complete system includes the three-bearing swivel nozzle, roll posts, gearbox, clutch, driveshaft and variable-area vane-box nozzle (VAVBN). Deliveries of the production-standard VAVBN have already begun to Northrop Grumman, which builds the F-35B forward fuselage.

The VAVBN vectors the lift-fan exit flow as well as back-pressuring the fan to control stall margin and is an integral part of the Stovl aircraft’s structure and one of the earliest modules to be delivered. By contrast the liftfan is almost the last to be delivered. “We won’t be delivering the first [production] liftfan until March 2010,” says Rolls-Royce Defense North America President Dennis Jarvi.

Six lift systems will be produced for the low-rate initial production Lot 2 (LRIP-2) batch of F-35Bs, with deliveries continuing through 2010. Rolls expects to finalize details of the 12-shipset LRIP-3 contract imminently. This calls for delivery of the first VAVBN in June 2009, and first lift-fan module in September 2010. Discussions have begun on long-lead items for LRIP-4, which is to include the first U.K. buy. “The rate is starting to move up,” he says.

While cost continues to be a concern across the F-35 program, Jarvi says Rolls-Royce is “making a lot of progress” on its part of the propulsion system. Further cost-reduction initiatives are planned, with potential changes to some materials and manufacturing tolerances. “We have identified some funding to do additional cost-reduction work and make it more affordable,” he says.

Rolls-Royce has also studied several advanced materials for the liftfan clutch aimed at ensuring it meets the required life of 1,500 engagements. While ultimately only flight tests will prove the durability of the present design, which uses aerospace-standard carbon-carbon brake material, “we still believe we will want to go after improved clutch life,” says Rolls-Royce liftfan program director Gregg Pyers.

Pratt is projecting a 1,350-engagement lift for a “minimum” clutch, says McFarlan. This is based on a usage spectrum that includes engagements in ground idle, in flight at various engine speeds, and while decelerating, maneuvering and in other stressing conditions. While research is underway on advanced materials, Gostic says these could be more specialized and expensive than the material now used. Another option, he says, is to monitor how the clutch is actually used in flight tests and see whether it could get to 1,500 engagements without change.

In 2006, Rolls surveyed more than 30 materials and narrowed the list to three finalists. “We’d like to do further experiments and downselect to one,” says Pyers, who adds the finalists include hybrids of existing brake materials.

[FlyNavy]

F-35 Air Combat Skills Analyzed Mar 5, 2009 By Andy Nativi {Where is Koppalotta? Carlo?}

www.aviationweek.com/aw/generic/story_generic.jsp?channel=defense&id=news/F35-030509.xml&headline=F-35 Air Combat Skills Analyzed

The F-35’s ability to win an air-to-air engagement is drawing increased attention as the U.S. military and industry’s focus includes expanding the Joint Strike Fighter’s customer base beyond the core purchasing nations.

For years, prime contractor Lockheed Martin seemed content to promote the F-35’s “strike fighter” capabilities, if only to avoid competing against its other major fighter program, the F-22 Raptor. But with the F-22 not exportable, Lockheed Martin seems keen to talk up the F-35’s air combat skills to bolster its chances for new foreign military sales—namely, to Japan, Turkey and Greece.

The contractor tells Aviation Week that the JSF’s combination of stealth, multisensor situational awareness, advanced pilot-machine interface and basic aeromechanical performance make it a credible fighter aircraft, too. That is key to several other customers, who cannot afford the so-called high-low fighter mix on which the U.S., U.K. and Italian air forces are planning.

But Lockheed Martin is focusing largely on the beyond-visual-range fight, with ranges greater than 18 naut. mi. that executives say will represent 62% of all aerial combat. Another 31% of engagements would fall into the 8-18-naut.-mi. transition range, and just 7% of fighting would be close-in combat where the airframe is stressed the most.

Lockheed Martin says it ran the F-35 through the Pentagon’s TAC Brawler simulation for air combat systems analysis, using what would be the “ideal” air combat configuration, taking the conventional-takeoff-and-landing F-35A, the only model designed to perform full 9g maneuvers.

The aircraft can also reach a 55-deg. angle of attack in trimmed flight, while most fighters, excluding the F/A-18, are limited to 30 deg. The exact performance of the current F-35A configuration—also known as the 240-4—are classified. But a similar earlier standard (240-3) was credited with a maximum speed of Mach 1.67; acceleration from Mach 0.8 to Mach 1.2 at 30,000 ft. in 61 sec.; a top turning speed of 370 kt. at 9g and 15,000 ft.; and a sustained turn capability of 4.95g at Mach 0.8 and 15,000 ft. Moreover, an aircraft with those performance figures would carry two beyond-visual-range AIM-120 Advanced Medium-Range Air-to-Air Missiles (Amraams) in the internal weapons bay.

Yet, such performance numbers appear to leave the F-35 short of the kind of air-to-air capabilities provided by other combat aircraft, such as the Russian Su-30MKI or the European Typhoon. And even Lockheed Martin test pilots concede that the F-35—although offering very high initial acceleration due to its powerful 42,000-lb.-thrust F135 engine—could start losing advantage at higher speed and altitude. This might be partly due to the aircraft’s large frontal area, which is designed to allow internal weapons carriage—meaning in a traditional quick-reaction intercept role, the F-35 may not be able to match rivals.

Nevertheless, Brawler modeling showed the F-35 could achieve a loss-exchange ratio better than 400% against its nearest “competitor,” according to Lockheed Martin executives. They demur about naming the competitor, but their comparison charts indicate it is the Sukhoi Su-30 or Typhoon.

That engagement ratio comes from the combination of F-35 characteristics, executives argue, including stealth, the performance of the APG-81 active electronically scanned array radar, sensor fusion using data links and the 360-deg. situational awareness afforded by the distributed aperture system of infrared and electro-optical sensors and electronic support measures.

In the meantime, and without discussing specific performance characteristics, Italian air force fighter pilots involved with the F-35 program tell Aviation Week that the aircraft’s performance falls “between the F-16 and the F/A-18 in terms of flight envelope—and is actually closer to the F/A-18, considering its high angle of attack and slow-speed maneuvering capabilities.”

The F-35A, with an air-to-air mission takeoff weight of 49,540 lb., has a thrust-to-weight ratio of 0.85 and a wing loading of 110 lb. per sq. ft.—not ideal for a dog-fighter. The F135 engine delivers 42,000 lb. thrust, and industry officials suggest that an F-35 entering an air-to-air engagement with 40%—or more than 7,275 lb.—of internal fuel will have a thrust-to-weight ratio of 1.09 and a wing loading of 83 lb. per sq. ft. Those figures describe an agile, albeit not top-end, fighter.

Still, one key feature, Lockheed Martin executives stress, is the very low observability designed into the JSF. Whereas the F-35 would carry its weapons internally, the Typhoon, Su-30, Saab Gripen or Dassault Rafale carry their missiles externally, thus increasing their radar signatures and degrading their on-paper air-to-air performance. The F-35 also accommodates more internal fuel, 8.3 tons, giving it greater endurance potential without external fuel tanks that would affect radar signatures.

Nevertheless, the F-35 may have notable weaknesses for pure air-to-air combat. For one, it is not designed to conduct engagements in a high-speed, high-altitude, sustained turning environment. Its high-speed cornering capability should help it to dodge an adversary’s beyond-visual-range missiles, though, particularly if German and U.K. air-to-air simulations on the kill probability of modern medium-range air-to-air missiles are accurate.

Those figures are part of the rationale for countries pursuing the ramjet-powered MBDA Meteor missile to supplant Amraams. Yet even in the Amraam world, Typhoons may have an edge over the F-35, since they could launch the missile at higher speed. Sukhoi Su-30s and the future T-50 are also being designed to maximize air-to-air missile performance that way.

Finally, while Lockheed Martin touts F-35 stealth as an advantage, it has its drawbacks, as well. The aircraft’s payload is limited as long as it wants to preserve its low-observable signature through internal carriage. That means having only four AIM-120s at its disposal. A study now underway could boost that total to six Amraams. Other weapons, including infrared-guided air-to-air missiles, would be carried externally, with plans for a “stealthy” JSF adaptation using a low-signature pylon design. Still, the radar signature would increase, as would drag, further reducing the F-35’s potential.

It is not clear how critical such perceived shortcomings truly are. Some pilots argue that in a dogfight, the air-to-air missile has more to do with the engagement’s outcome than does the aircraft."

[FlyNavy]

Behind You Posted by Douglas Barrie at 3/5/2009

www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3a04156245-0caa-48d6-b111-50f6c836bafb

"The MBDA Asraam imaging infrared-guided air-to-air missile has been tested by the Royal Australian Air Force in an over-the-shoulder shot using the lock-after launch mode. The missile hit the target, with the engagement carried out at a range in excess of 3.1 miles.

The shot – the first in-service lock-after launch firing - was carried out from a RAAF F/A-18. The missile entered Australian service in 2004.

The shot was intended to simulate a “chase down” engagement with the threat aircraft closing to the rear of the launch aircraft. The launch aircraft was flying at “low-level and typical fighter speed.”

There is increasing interest in this kind of shot for self-defense, with some intended Joint Strike Fighter customers also looking at the utility of this kind of engagement."

sitelife.aviationweek.com/ver1.0/Content/images/store/4/13/7418dd64-3590-45b0-bd00-e66cb829e24c.Large.jpg



Picture Credit Australian Defense Organization
_______________________

www.neptunuslex.com/2009/03/06/asraam-arriving/#comments
NeptunusLex:
"It’d be tempting to say that a shoot’em-off-your-six missile was a unique requirement of the RAAF, but that (alas) would come back around and bite me. I’ve flown against Australian fighter pilots in FA-18s, and they know they trade as well anyone, in a close-in brawl."
_____________________

s98.photobucket.com/albums/l261/SpazSinbad/?action=view¤t=RussianJetCA_SU-30.flv (8.5Mb)

SU-30MK



As seen on: rnzaf.proboards43.com/index.cgi?board=avfilms&action=modifypost&thread=8706&post=69018

[FlyNavy]

Photos: Lockheed Martin

www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3a48045786-570e-467b-b017-f3dbc1b50863

PICTURES: F-35 Opens Weapon Bay Doors Posted by Graham Warwick
Lockheed Martin's first F-35, which is not structurally representative of the production aircraft and was due to be retired after some 70 flights, has been given a stay, of execution of sorts. Aircraft AA-1 is to complete about a dozen extra flights, then will be sent down the Eglin AFB in Florida for live-fire testing. One of the first milestones achieved after AA-1 was put back in the air in late February was opening the weapons bays in flight.

AA-1 has subsequently flown with dummy weapons in the bays - one 2,000lb JDAM and one AIM-120 AMRAAM in each. The extra flights are expected to include noise tests at Eglin, which is the location for the first JSF joint training center. Concerns over noise have led the Pentagon to cap the initial deliveries to Eglin at 59 aircraft, well short of the 107 F-35As, Bs and Cs planned."

[FlyNavy]

Harrier Matches JSF-B Range - Official Posted by Bill Sweetman at 3/6/2009
[Hair splitting on a grand scale - what is the point of this? Remember the aircraft has not flown/been tested in real world with this kind of load. Yes computer simulation will get figures and these numbers can be changed in an infinity of ways so picking one scenario is pretty stupid for comparison in my book. I betcha there is another comparison where the JSF will clearly outrange the Harrier. So what? All this B/S nitpicking is going to kill us all. ;D]

www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3a5d2a261e-b62a-4f5e-979b-d11c5dcbfa33

Commenter Solomon Shorter's assertion that the F-35B Joint Strike Fighter has more than twice the payload and range of the Harrier started me thinking. Popular sites and standard fact sheets say one thing, my 1996 Jane's something else.

How about the US Navy's official aircraft characteristics manual? Fortunately, someone decided that the Harrier was so old, that had to be historic, so they put it on the web. www.history.navy.mil/planes/av-8b.pdf (1.5Mb)

OK, this is not an entirely fair comparison. The JSF is stealthy and supersonic and has an integrated sensor suite, and this is the original AV-8B, which had a piece of chewing gum stuck to the windshield as a bombsight.

But on the other side of things, the JSF is a brand-new airplane supported by tens of billions of dollars in investment. Today's Harrier is, essentially, an upgraded version of the original Hawker P.1127, which was ordered five years after the RAF retired its last front-line Spitfires. The P.1127 was a purely experimental aircraft (at the time, the RAF had no requirement for it) and Bristol had cobbled the engine together from Olympus and Orpheus parts.

Most of the Harrier's evolution took place in two programs, both of which were cheap substitutes for more ambitious projects that had been canceled. The original RAF Harrier GR.1 incorporated bits and pieces of the avionics developed for the supersonic HS.1154, scrapped in 1964. Around 1975, British Aerospace and McDonnell Douglas proposed a much improved aircraft with a bigger engine - but both the UK government and the US Navy choked on the price tag and the result was the re-winged AV-8B. The Pegasus engine has likewise been upgraded piecemeal-fashion along the way.

But the bottom line is this: with 2,500 pounds of weapons, plus the gun pod, the AV-8B has a hi-lo-hi operational radius of 508 nm. The F-35B's design radius, with no gun, two 1,000-pound bombs and two AMRAAMs, is 450 nm: the most recent numbers (from 2007) show it exceeding that and just about equalling the AV-8B's range.

Of course that comparison does not allow the F-35B the use of external fuel, which would add 70 nm or so to the radius if F-35A figures supplied to Norway are correct. But that gives away one of the JSF's two key advantages over its veteran predecessor.

In part this shows the price of stealth (which tends to increase empty weight) and supersonic speed (subsonic aircraft, like the Buccaneer, A-4, A-6 and A-7, have always tended to out-range the competition).

But from an operational point of view, it's important: the premise behind a STOVL-equipped carrier is that it can operate on its own, without air support from another carrier or from land (and the latter includes tankers).

So the offensive and defensive reach of the air wing is determined by two factors: how far the fleet needs to stand off from land, which determined by the threat from missiles or submarines, and the combat radius of its aircraft. And without tankers, there needs to be a solid margin between combat radius and mission distance, because there's nowhere to divert. You don't want two un-anticipated minutes of burner use to cost you a ditched aircraft.

And all of this is not to say that JSF is not projected to meet its requirements: but you do wonder why they were written that way in the first place."

[FlyNavy]

JSF Leadership Reins in EW Speculation Mar 6, 2009 By David A. Fulghum

www.aviationweek.com/aw/generic/story_channel.jsp?channel=defense&id=news/F35EW030609.xml&headline=JSF%20Leadership%20Reins%20in%20EW%20Speculation

The long debate about whether non-U.S. users can modify or replace the classified software that runs the electronic warfare (EW) detection, identification, self-defense and attack systems of the F-35 is over.

The answer is “no,” says U.S. Air Force Maj. Gen. Charles Davis, program executive officer for the Joint Strike Fighter.

Elbit and Elta, Israeli companies, are railing against being left out of the F-35 program and the ban on competing for a specialized EW system. Israel has completely different threat priorities than the U.S., the companies argue, and they have experience modifying EW packages for both the F-15I and the F-16I.

“They are going to buy aircraft that have basically the same capability as all the others,” Davis says. Israel is conducting a requirements analysis for future EW missions and capabilities offered by the Joint Strike Fighter to determine if gaps exist. Customization “is doable through software. It is not doable by Israelis sticking boxes in the airplane,” Davis says.

The Israel Defense Forces are looking at an initial buy of 25 F-35As with an option for 50 more. They abandoned the idea of a short-takeoff-and-vertical-landing force when they saw its price, weight, range and payload penalties compared to a conventional takeoff aircraft.

In the U.S., among the various services, there has been an open question—given that the design can be modified to carry an electronic warfare officer—about whether some future variant of the F-35 would be transformed into a specialized electronic warfare/attack (EW/A) specialty aircraft. It is being studied, but the likelihood seems to be diminishing.

“I think electronic [warfare] will simply be a mission area [each] airplane performs,” says Marine Corps Brig. Gen. David Heinz, deputy program executive officer for the JSF. “I do not believe I’m [moving toward] special variant type airplanes. Holistically, the requirements guys are looking at how can they can meet the [EW/A] requirement within the number of aircraft that will be available jointly.” Electronics techniques amplified through the advanced radar of the F-35 will already be able to cover some bands in the spectrum, he adds.

“There will be podded additions [like the Next Generation Jammer] that can go on the aircraft,” Heinz says. “But, we’re surmising a technical solution without knowing the requirement. Today, we have a pretty good understanding of the bands that need to be covered. NGJ as it grows will have several applications, including boxes that go inside an airplane or small pods that can go on the exterior of a number of platforms.

“I’m going to build to the gap that the requirements people believe exists today,” Heinz says. “It may be a multiplatform solution and not one dedicated to an individual platform for a specific mission. We’re still going through that.”

Specialists are also still ironing out the threat and target set for F-35s.

By 2014, the F-35 community will begin establishing its relationship with the Air Armament Center at Eglin AFB, Fla., where the service develops its new kinetic and nonkinetic weapons and studies the introduction of new missions. For example, all the initial F-35 Block 0.5 aircraft, because of their advanced electronically scanned array radars, will arrive capable of training for cruise-missile defense.

But Davis points out that “it’s not just weapons threats. You have to decide where you’re going to attack that kill chain with electronic warfare. We’re ready to penetrate and do electronic warfare; we [just] need a program to go do it and people need to tell us their requirements. We’re not there yet.”

Davis goes on to say that “if you are attacking an anti-access area, you have all kinds of forces coming from all kinds of directions and not just the F-22s all by themselves.” He adds, “Operation Desert Storm [in 1991] is probably the last time that you’ll see something quite of the nature of sending the F-117s [stealth aircraft] in all by themselves. The battlefields will be so dynamic and complex—S-300s, S-400s, whatever [enemy advanced missile systems]—you’ll have to bring up very dynamic and complex forces against them.”

That leads into the discussion of linking the stealth fleet of F-22s, B-2s, F-35s and, possibly, unmanned combat aircraft.

“There’s been a lot of discussion about [communications] links,” Davis says. “That discussion is nowhere near done. There’s also a lot more discussion on how to link to the F/A-18E/F and EA-18G. There’s a long way to go to understand how the elements of the air wing of the future will work together.”

The narrowband Link 16 data link was being examined for its applicability to air-to-air communications, but its lack of bandwidth was soon recognized as problem.

“As the guys start understanding what [intelligence and targeting data] they can get from the F-35, pretty soon there’s no bandwidth left on Link 16,” Heinz says. “We need to come up with who needs it, when, why and does it need to be raw data or can it be some fusion of data? The dialog is getting better. But it will still be happening five years from now as we migrate through unmanned air vehicles and other platforms.”

The Multifunction Advanced Data Link solves the bandwidth communications problems for F-22s, F-35s and B-2s. But it doesn’t help them link to F-18s, F-16s and other legacy platforms.

“We know we want to share targeting, data, threat or EW information with or from a UAV,” Davis says. “The issue is not if we can do it. We’ve got the software. But it is a pretty big gorilla in terms of the number of aircraft that will have the capability. . . . How do I want [information] to go from node to node? They haven’t solved it, but it has highlighted the problems with a future networking system.”

[FlyNavy]

F-35 May Need Thermal Management Changes Mar 12, 2009 By Bradley Perrett

www.aviationweek.com/aw/generic/story_generic.jsp?channel=defense&id=news/F35-031209.xml&headline=F-35 May Need Thermal Management Changes

MELBOURNE, Australia – The Lockheed Martin F-35 Lightning II may be redesigned to improve its ability to absorb heat from its electronics and systems.

The aircraft is meeting the specification for thermal management, but the Joint Strike Fighter program’s deputy executive officer, Maj. Gen. David Heinz (select), says he is asking contractors to assess the costs of changes to give it a bigger margin over the requirement.

“We meet that requirement but it is a very tough requirement,” Heinz says, adding that, while he has asked for studies for an improved margin, “at the moment I don’t need it.”

The F-35 is designed to transfer heat from its powerful electronics and systems to its fuel, to keep the aircraft cool and make it less detectable by infrared cameras.

Under most conditions, that presents no challenge, but if the aircraft is at the end of a mission, it will have little fuel aboard to absorb the heat energy, says Tom Burbage, Lockheed Martin’s executive vice president for F-35 program integration. And the toughest part of the specification is to distribute the heat into the remaining fuel while operating in the tropics in hot and high conditions.

While Heinz says the aircraft can do that, his interest in finding ways of increasing the margin – for example, by circulating the fuel faster and reducing the amount of generated heat – implies that the aircraft is only just meeting its specification without much room for comfort.

High fuel temperature would not result in critical failure, Burbage says, speaking at the Australian International Airshow here. The limit on the temperature is set by the heat tolerance of the full-authority digital engine control unit submerged in a fuel tank, he says. Overly hot fuel will shorten the unit’s life, but not cause it to suddenly fail.

Apart from a design change, there is an operational way to work around excess fuel temperature: fly higher, to reach cooler air.

That method may not suit every mission, however, and it will obviously be unavailable at the end of a flight, when the small volume of remaining fuel presents the greatest challenge but the pilot must descend for landing. This is particularly an issue for the F-35B, the vertical-takeoff-and-landing version that must hover and land at high power at the end of a mission without exceeding fuel temperature limits.

Meanwhile, extensive testing by Lockheed Martin and the Royal Australian Air Force, an intended customer, has found that the F-35 is not as noisy as feared. That issue has threatened to disrupt basing plans and potentially presents health risks to ground personnel.

The F-35 is only about as noisy as an F-16 fitted with a Pratt & Whitney F100-PW-200 engine, Burbage says. It is quieter than the Lockheed Martin F-22 Raptor and the Boeing F/A0-18E/F Super Hornet. “It is noisier than a classic Hornet [F/A-18A-D] but not much noisier,” says Air Vice Marshal John Harvey, manager of Australia’s New Air Combat Capability program.

Moreover, the F-35 often will be able to minimize airfield noise by taking off without afterburner, partly due to its internal weapons and fuel stowage."

[Leyland P75]

I take it the highlighting is your own FN?

[FlyNavy]

The original link is there for to see the original 'unhighlighted' text. Nice to see the RAAF pro-active regarding noise problem. People in US think JSF is too noisy so KUDOS to the RAAFie Chappies.

There is an huge amount of text material on this thread. I post it here as storage for the inevitable debate about value of JSF. This debate has started way too early IMHO because not a lot is publicly known about JSF capabilities (at least those facts to even begin to satisfy critics). All I see is a lot of disputing LockMart press releases which is a little odd but let the battle begin. ;D

As for myself as we have agreed amongst ourselves (p75 & me) we await the reality checks down the track. Until then I'm willing to give LockMart the benefit of the doubt to live up to its promises, keeping in mind our Guvmnt has not made the inevitable order so far. This is the key: 'how many to buy and when'.

As I see it there is no choice - we will buy JSFs - unless they are absolutely SUPA DUPA DOGGIES unable to CLUB SEALS at will. ;D

AND I don't see that the US Guvmnt will allow the JSF to fail. Geez they have not allowed capitalism to fail so there is hope for the JSF.

[FlyNavy]

VERY long article about 'training' for the JSF with complex ground facilities augmented by computers including touch screen laptops for pilots (article too long to reproduce here):

www.flightglobal.com/articles/2007/11/16/219642/training-central-lockheed-martin-prepares-for-f-35-jsf.html
_____________________

"Australia has awarded Lockheed a separate contract to analyse throughput and sizing of an ITC." (integrated training centre)

www.flightglobal.com/articles/2007/08/17/216086/f-35-pilot-training-system-passes-review.html
____________________

FLIGHT TEST: F-35 Simulator - Virtual fighter By Mike Gerzanics

"While the F-35 is several years away from entering service, Lockheed and its partners appear to be well on the way to fielding a highly integrated fifth-generation fighter. The F-35 may not supercruise or have the manoeuv­rability of an F-22, but its stealth is on par with its high-priced stablemate. Combined with fused tactical information from both on- and off-board sensors, stealth should allow the F-35 to engage a wide range of targets - some having no idea what hit them."

www.flightglobal.com/articles/2007/07/31/215810/flight-test-f-35-simulator-virtual-fighter.html

[FlyNavy]

AVALON 2009: Lockheed confident on Australian F-35 By Siva Govindasamy

www.flightglobal.com/articles/2009/03/12/323696/avalon-2009-lockheed-confident-on-australian-f-35.html

Lockheed Martin is confident that it will be able to deliver Australia's first F-35 Joint Strike Fighter in 2013. But continuing worries about possible delays to the aircraft have resulted in Canberra keeping its options open about ordering additional Boeing F/A-18Fs to plug potential capability gaps.

"We expect to take delivery of the first F-35 in 2013 and a few more in 2014. We will be working to achieve initial operational clearance in 2015," Air Vice-Marshal John Harvey, F-35 programme manager for the New Air Combat Capability at Australia's Defence Material Organisation. "The F-35 continues to make good progress, and the defence ministry and Australian industry are working closely with their international partners to make the programme a success."

Seeking to ally worries about delays, Tom Burbage, Lockheed's executive vice-president and general manager for F-35 programme integration, says that flight tests were on track. "The aircraft and its systems are proving to be significantly more mature at this stage of testing than those of past programmes. The programme is achieving established milestones and retiring technical risk according to plan."

Both Harvey and Burbage add that even if there is a fresh delay to the F-35, which has faced several setbacks since its inception, this will not affect Australia's procurement as the country is due to receive its first aircraft later in the production schedule. Canberra has already ordered 24 Boeing F/A-18Fs to plug a possible capability gap between the retirement of its General Dynamics F-111s and the introduction of the F-35s.

Grp Capt Steve Robertson, the head of Australia's Air Combat Transit Office, says that the country has not ruled ordering even more Super Hornets if there are further delays to the F-35. In addition, if Canberra converts 12 of the 24 F/A-18Fs into E/A-18G Growlers as it has indicated it might, it may need to order additional Super Hornets to boost its strike capability regardless of the progress on the F-35.

"Additional Super Hornets may be necessary under a number of scenarios, but this has not been decided yet," says Robertson. "We have to wait for the Defence White Paper before we know where we are heading in this regard."

The White Paper will be the blueprint for Australia's future defence policy, setting out the government's plans for the size, capacity and shape for the next 20 years or more. This will include the Air Combat Capability Review, which looks at Australia's air combat requirements up to 2045. The first part of the review, looking at requirements up to 2015, was released last year and led to a government decision to stick with its predecessor's order for 24 F/A-18Fs to replace the F-111s."