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Post by Radialicious on Apr 21, 2008 22:15:52 GMT 12
Thanks Dave, I know why there is still a Bristol wing and two engines lying round. Each one is so muntingly big, heavy, awkward and immovable that I'm not surprised. It is only when you are up on your stepladder looking directly at a B-170 leading edge you realise how deep the wing is. A good friend of mine today told me of the time he helped to re-spar a Bristol as an apprentice. Apparently you can slither around inside the wing almost to the tip. He was a small bugger so that helped.
Today started with a look at the spark plugs that had been soaking in kero for the last few days. They cleaned up quite well. Or so I thought...... When I looked closely at the first one that had been through the Champion abrasive blasting and cleaning thingamy, it appeared that the gap had closed up. I tweaked the fine wire electrode with my thumbnail and it broke clean off! The electrode is only about 30 thou across and I'm not sure how it is attached to the body of the spark plug. When the second one broke off in a similar manner it was clear that I should put them all down and do something else. The weld that holds them on is extremely fine. A few phone calls tonight has probably unearthed a source of replacement sparkplugs - hopefully new.
Soundsair again lent me a 28V lead acid battery which can now be quickly hooked into the Freighter to provide power to test systems. I wanted to find out why the port engine wasn't recieving any fuel via the priming system that worked so well on the STBD side. I traced the plumbing that went from the pump in the STBD cave and up into the wingroot. It was clear via a junction placed just outboard of the wingroot that there was a blockage somewhere along the line. There wasn't much I could inspect inside of that only to hope that I could attack things when it reappeared on the port side. I traced the pipeline back from the solenoid on the other side to a tee intersection. One side of the tee went to the port primer solenoid and the other was blanked off. Compressed air was blown back through this line to see if any obstruction could be felt from the port side. None at all. In fact when the air was blown into this side, there was a definite click from within the tee junction. I was obvious that I had stumbled across a shuttle valve that was somehow installed incorrectly. I took the valve out and sussed out that there was a free flow in one direction but none in the other. Why it was there in the first place intrigues me because I know that these engines have been run as they are now. How the port engine could be primed in this configuration is a mystery.
As of today, the priming system works as advertised. Phew! I only hope that the outlet nozzles deep inside the induction systems aren't blocked also. Their plumbing disappears into darkness. Only Mr and Mrs Bristol know where it ends up. Tonight I can only assume that to check the fact that the induction system is operational, I need to prime the engines to the point that when turned by hand, raw fuel comes out of the exhausts. If not I'll be looking for a volunteer to lie on the nacelle pointing a can of CRC easy-start down her throat as I press the button..... ;D
There isn't a great deal of difficult jobs left to do now just all the small ones. If we can find some new sparkplugs, most things are sorted. I spoke with one of our founding committee members tonight regarding the most difficult bit - Gasoline! A battle plan was soon developed for that.
Back to Bristolville on Wednesday arvo after a West Coast overnight.
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802gwr
Warrant Officer
Posts: 30
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Post by 802gwr on Apr 23, 2008 4:17:48 GMT 12
Hi Al, The double 'clunk' you hear while turning the prop! l bet a box of beer it is the harmonic balance weight inside the crank counter weights. lt'not an impulse coupling,.... there are none !!
Paul
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Post by Radialicious on Apr 23, 2008 22:01:43 GMT 12
Hi Paul, Thanks for that. I had wondered if she had any such counterweights. It is interesting that you can 'feel' them through the propeller tips. Hopefully its a good sign that all is well inside. I spent time today cleaning up the STBD prop, hub, spinner and backplate. All good there. I'm curious as to whether the blades are still free to turn inside the hubs. By this I mean if they are able to feather and will react to the CSU. For the purpose of my project, it doesn't really matter if they are frozen. In saying that, there would be more 'impact' as a public event if they could be exercised during a run up. The de-ice boots on each blade begin with a cuff at the root that appears to shield the blade bearings in the hub. We'll soon find out. The prop, throttle and fuel cutoff controls are responding nicely to a bit of lubrication. They are now smooth enough that you can feel the microswitches deep inside the mechanisms. Today I found that the more I waterblasted the prop and cowls etc, the more dirt I saw elsewhere. It became quite addictive and before I knew it, I was dealing to the whole STBD fuselage. I used to fly Piper Aztecs and BN Islanders up north. They did so much work that they didn't get cleaned very often. It was only when you washed them, that you realised how dirty they had become. Big Bird was sadly, quite clearly dirty but it was amazing how well she cleaned up. Today was not one of technical triumphs and Bristol breakthroughs but the good old waterblaster really gave her a facelift. Big Bird has a shed-load of spare parts on the airfield through which I am going to comb through on the weekend. Hopefully our stash of sparkplugs will be unearthed. I'm still chipping away at the STBD haybale and soon want to mow around her. There are two reasons for this. One is a mid project clean up and the other is to try and mulch up as much of the hay that is lying around as is possible. Feathered Vandal Society Inc is still hell bent on putting as much back as they can! I have kept a foot long 'twig' that I pulled out from deep inside one engine as a mark of how intent these birds are to set up shop. No shit, it was one foot long. Match that to the bird that dragged it in. I imagine it to be similar to a human holding a power pole or lamp post in his/her (probably his) teeth and dragging it up a fire escape and through a forth floor window. Full credit to the bird. How it got airborne in the first place with that in its beak is a miracle of Barnes Wallis proportions. BUT, to fly,approach, land in the gap of an aluminium cowling that might be three inches across and smuggle in the lamp post that you have in your mouth.... Again full credit.
Yesterday I bumped into Captain Bob Guard in CHCH. Bob is the (I think) Fleet Operations Manager for Air Nelson. They operate Bombardier Q300's (Dash 8's to the rest of us) on our regional feeder routes. He was the Captain who delivered ZK-CPT to the Marlborough Aero Club in June 1986. Like many Bristol vets, he was more than interested in my project. I can see a bit of a reunion coming up for these Gentlemen when she can taxi under her own power again.
Next on the project list is to completely huck out the hay from the STBD bale, remove, clean and refit the many oil screens and filters on both sides, and get deep into the fuel system. That is a bit of an unknown. I plan to run both engines from one 100 gallon auxilliary tank selected to crossfeed. There are two of these tanks and it is anybodies guess as to whether they or their plumbing is still up to it. Thankfully the tanks are alloy so any problems should be easy fixes. Touch wood..... With petrol prices as they are, there is incentive to find and fix any leak super quick.
Bristol, Out.
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Post by kiwi on Apr 23, 2008 22:20:28 GMT 12
I think that wing has its origins way back in the Bristol Bombay .
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Post by Dave Homewood on Apr 23, 2008 23:02:52 GMT 12
Al, given the amount of hay and nesting material you've found in the engines, do you think once you have it runnable that some sort of engine covers will need to be fitted when static to keep birds out? The Harvard NZ1050 at Wigram's gate has a clear perspex front fitted inside the cowl to keep birds out. Maybe that would be a good idea.
As for the bird with the stick, maybe he started at the top of the tree and glided down. Or perhaps he had help from a possum. :-)
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802gwr
Warrant Officer
Posts: 30
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Post by 802gwr on Apr 24, 2008 14:36:26 GMT 12
Al, You can check fuel flow to the engine at the engine driven fuel pump. With the idle shut off in the off position swich on a boost pump or both then crack a line at a 'T' conection at the engine driven fuel. You should be getting fuel pressure there. The primer pump injects fuel directly into each side of the supercharger case by two very small jets that can be removed to clean. Or crack the line at the jet to see if you have fuel there. You will have to follow the primer supply pipes to find the jets,.......... good luck !
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Post by Radialicious on Apr 26, 2008 21:17:39 GMT 12
Thanks for the info Paul. It is real good to have a heads up on what needs attention and where. I've yet to test the fuel booster pumps because we haven't yet put fuel in the system. That is likely to be a bit of a headache for many reasons. ZK-CPT is one of the few survivors to have alloy tanks. Hopefully this will make this task a whole lot easier. It is still my plan to lock out all but one of the tanks and use the crossfeed to run both engines. This afternoon I caught up with Brian Morland who along with his wife Wendy, are founding members of the 'Friends of the Bristol'. They have played a large part in promoting ZK-CPT in the 22 years that she has been at Omaka. Brian and I had a fossick this afternoon in our shed of goodies. One of the important finds were a fuel collector tank complete with its two fuel booster pumps. It's good to know we have spares if the others give me problems. Much of SAFE Air's spares were secured by the Friends of the Bristol after the fleet was retired. We have boxes and boxes of brand new items. Many are relevant only to the B-170 and get deep into the nitty gritty. By this I mean we are likely to be able to replace the bracket that supports the gusset that strengthens the attachment to the doubler that stiffens the whojameewotzit on both port and starboard thingamy's if said thingamy is found to be in need of replacement.
I have checked the primer lines as far forward as their outlets on the firewall. Where those lines go after reaching the supercharger is anyones guess as they completely disappear into darkness. Hopefully I have missed some access panel to make them more accessible. I'd like to completely flush the priming system with it disconnected from the nozzles just in case any rubbish ends up blocking the business end.
As you suggest Dave, keep the birds out will be a focus of my activities once Big Bird has her voice back. Some sort of seal for the intake between the cowl and the spinner and the cowl outlets will be produced in the short term. It is important that these seals are easily removed as it seems that there is more of a focus on keeping her alive than waking her up and putting her back to sleep again. Periodic public engine run events as seen overseas with Lancasters and Shackletons is the best way of maintaining interest and possibly income for this old machine. The success of the first engine runs will dictate where we head from here.
Tomorrow is a day off for me so watch this space....
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Post by Radialicious on Apr 27, 2008 21:06:52 GMT 12
I didn't get a huge amount done this afternoon because the weather in Blenheim wasn't all that flash. In saying that, I did manage to spend a bit of time on the oil system. Each tank has a bolder-catcher mesh screen that filters out the big rubbish as oil leaves the tank. These fiters are attached to a rod about 70cm long and are secured by a threaded lid at the top of the tank. Inside the screens was a pretty chewy mix of debris that took a bit of removing. In the end they cleaned up quite well and have now been refitted. Before filling up the tanks I decided to nip up the hose clips on the inlet and outlet pipes just in case they bacame the source of an oil leak. Shortly afterwards I poured 10 gallons of W-100 into the port tank. I haven't filled the tank completely yet just in case it decides to leak out overnight. In saying that, even 10 gallons will make quite a puddle! The dipsticks are calibrated in both litres and gallons. I prefer to read the gallons side because 19 gallons isn't quite such a scary thought as the 90 litres that is on the other side. My work schedule has me fairly busy this week but I am keen to do the same to the STBD tank and system.
I have been reading a bit from a Bristol Siddley aero engine school textbook recently and stumbled across a section on Bristol Hercules sleeve valve mechanisms. It describes how the mechanism works and concludes with the following gem that explains in simple British terms how they achieve the speed of the sleeve drive gears.
"The 63 toothed crankshaft gear drives the 42 toothed layshaft gears at 1 1/2 time crankshaft speed. Fixed to the layshaft gears are the 21 toothed layshaft pinions, which in turn drive the 63 toothed sleeve driving gears, giving a ratio of 63/42 x 21/63 which equals half crankshaft speed in the same direction of rotation as the crankshaft."
It's as simple as that! I hope that wasn't an exam question at the end of the course.
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Post by Radialicious on Apr 27, 2008 21:17:13 GMT 12
Here is an oldy but a goody that reflects the charm and personality of the radial engine....
We gotta get rid of those turbines, they're ruining aviation and our hearing...
A turbine is too simple minded, it has no mystery. The air travels through it in a straight line and doesn't pick up any of the pungent fragrance of engine oil or pilot sweat.
Anybody can start a turbine. You just need to move a switch from "OFF" to "START" and then remember to move it back to "ON" after a while. My PC is harder to start.
Cranking a round engine requires skill, finesse and style. You have to seduce it into starting. It's like waking up a horny mistress. On some planes, the pilots aren't even allowed to do it...
Turbines start by whining for a while, then give a lady-like poof and start whining a little louder.
Round engines give a satisfying rattle-rattle, click-click, BANG, morerattles, another BANG, a big macho FART or two, more clicks, a lot more smoke and finally a serious low pitched roar. We like that. It's a GUY thing...
When you start a round engine, your mind is engaged and you can concentrate on the flight ahead. Starting a turbine is like flicking on a ceiling fan: Useful, but, hardly exciting.
When you have started his round engine successfully your crew chief looks up at you like he'd let you kiss his girl too!
Turbines don't break or catch fire often enough, leading to aircrew boredom, complacency and inattention. A round engine at speed looks and sounds like it's going to blow any minute. This helps concentrate the mind !
Turbines don't have enough control levers or gauges to keep a pilot's attention. There's nothing to fiddle with during long flights.
Turbines smell like a Boy Scout camp full of Coleman Lamps. Round engines smell like God intended machines to smell.
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Post by Radialicious on Apr 27, 2008 21:39:23 GMT 12
Here is a short portion of the Wikipedia response to an inquiry to the Bristol B-130 Bombay....
The Bombay was built to Air Ministry Specification C.26/31 for a monoplane aircraft capable of carrying bombs or 24 troops. Bristol's early experience with monoplanes was dismal — both the 1922 racer prototype and the 1927 Bristol Bagshot fighter suffered from lack of torsional rigidity in the wings. Based on this experience, Bristol over-engineered the Bombay's wing to include no less than seven spars made from high-strength steel. Not surprisingly, the end product was a very heavy aeroplane.
Seven STEEL spars? In each wing?
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Post by Barnsey on Apr 30, 2008 15:00:23 GMT 12
There's at least 2 current or former S&S types hanging around here.... They're known to be handy with an industrial sewing machine!!
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Post by corsair67 on Apr 30, 2008 15:07:59 GMT 12
And some people wonder why the British avaition industry died out! ;D
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Post by Dave Homewood on Apr 30, 2008 15:34:12 GMT 12
There's at least 2 current or former S&S types hanging around here.... They're known to be handy with an industrial sewing machine!! There's actually more of us than just two here. I don't have a sewing machine however otherwise I'd gladly offer to make covers.
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Post by Gavin Conroy on Apr 30, 2008 20:07:25 GMT 12
Good work Al, you are doing a great job and I will be out for a look at the weekend to check on any progress. Give me a shout if you need the waterblaster to clean any more of the exterior and I will bring one out to give you a hand.
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Post by Dave Homewood on Apr 30, 2008 21:41:23 GMT 12
Photos please too Gav!
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Post by Radialicious on May 1, 2008 23:22:22 GMT 12
Thanks Gav, I'll be working in and out of Hokitika, Wanaka and CHCH this weekend so won't be able to get too much done. Thanks again for the offer of the waterblaster, I'll let you know. Pop out and see if anything grabs you. I've been doing night shifts this week so have only had a couple of short bursts on Big Bird. Yesterday I found a break in the rain to climb upstairs and dip the oil tank that I'd splashed a quick 10 gallons into. Thankfully the 10 gallons was still present in the tank and not on the ground. Today's activities were short lived but quite a lot was achieved. I was keen to see what was left in the fuel collector tank at the back of the port cave. There is a blanked service/drain cock which is lockwired closed in the base of each tank. After quite a while of funnelling 20 year old rancid fuel into a drum, I thought to myself, "Waidaminnut, this old stuff that is stinging my eyes and tastes like Chartreuse might still be useful". After closing the valve again I decided that there are a number of things that can be checked even with old, old, old AVGAS. Things like the two booster pumps that get fuel to the carburettor and into the crossfeed manifold, all the old hoses, the low pressure warning system, the filter bowl seals and the fuel pressure gauges would all react in one way or another to the 30 psi that the boost pumps provide. I thought I'd better wander down to the aeroclub and borrow a fire extinguisher. It makes me feel better if I have one on hand whenever I have the internal battery connected. A number of people saw me head back to Big Bird with this in hand and thought D-day was imminent. Shortly afterwards, a couple whose curiosity was uncontainable, turned up to see what was going on. They became quite useful as another set of eyes and ears. Because I was concentrating only on the port engine today, I had refitted the port fuel filter and bowl. I was pleased to have Kevin and Neville as onlookers. Shortly after turning on both booster pumps a moderate to quite large-ish gush of Chartruese was noted coming from the STBD engine. I double checked that I had turned on the correct pumps as I selected them off. Sure enough, I was correct. However, I had not checked that the fuel crossfeed was off.... Because it was on, and the filter and filter bowl to the STBD engine was in the boot of my car, there was nothing to prevent the AVGAS that I'd hoped would prove the port side, ended up gushing out of the STBD side! Shortly afterwards, with the crossfeed closed, all was found to be in order. It seemed a rather haphazard way to achieve the outcome but I learnt a lot about Big Birds innards and outtards. Plus it was nice to achieve such with AVGAS so old, stale, sour and worthless that has a street value comparable perhaps to that of Lion Brown. Its a day off tomorrow so more of the same on the STBD side. I was surfing earlier and stumbled on the following link. I hope it connects because it provides the (unexpected) link to Big Bird and her supersonic sisters. If there weren't trees in the distance, I'd swear the photo was taken from an aircraft carrier! Negative Ghostrider............ www.grantwebbphoto.com/assets/images/photo/325x325/aviation/17389_8.html
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Post by Freighter5910 on May 3, 2008 15:29:25 GMT 12
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Post by Radialicious on May 6, 2008 20:20:21 GMT 12
Hi Steve, thanks for the reply. I'm picking your Dad is Cliff. It will be nice to meet him - I read a lot of his writing when he was a correspondent with NZ Wings (I think) and NZCAA.
One of the things I really want to do once the engines are out of hibernation is to attack the wheels and brakes so she can be taxiied. I hope she will be mobile for Classic Fighters 2009. Before then, I hope we will be able to offer a number of public ground run events. Hopefully these will gather enough revenue to ensure Big Bird can be maintained in a runnable condition. I've yet to determine whether occasional ground runs will do her more harm than good versus being run and reinhibited. In saying that, it has become clear that her level of deep down preservation up until now hasn't been perfect.
Last year a couple of steam locomotives passed through Blenheim. As they are known to do, steam locomotives gather a massive amount of attention wherever they go. It seemed half the town turned up to witness a forgotten age. I can see a publicly announced ground run event will draw a lot of attention also. The Bristol Freighter almost became a background noise in Marlborough over the decades that they were operated by SAFE Air. Today, very few people would clearly remember their sound. Many or most would have never heard one. I want to change that! Down the track is plans for a reunion of Bristol drivers, both SAFE Air and RNZAF where the aircraft is theirs for a day to start, run and taxi to their hearts content.
Progress has slowed this week due to the fact that I have been severely distracted by a rather solid roster. On the weekend I managed to draw a couple of the engine indication and/or warning systems out of hibernation. I was sure my Dick Smith multimeter started trembling as I prepared to delve into some of the electricals. 'Light automotive and household use only. DO NOT USE IN THE BATH OR ON BRISTOL FREIGHTERS'
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Post by Brett on May 7, 2008 17:36:42 GMT 12
There is a Bristol car club in New Zealand. There might be a local member who would be interested in bringing their car along for publicity purposes if you want to get an article in the local papers prior to the big day.
The main contact is a guy in Auckland, but as he has registered his opposition to the civilianisation of Whenuapai he might be generally opposed to "fings wiv wings".
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Post by Freighter5910 on May 7, 2008 19:22:58 GMT 12
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