Post by Radialicious on Apr 2, 2008 23:21:16 GMT 12
Bruce, you are right about the carbs - don't go there! If it became obvious that the carbs were gonna give us enough headaches, I would probably look more towards re-preservation more than reactivation. However, I once worked on a project in Israel that took forgotten relics in the form of A-4N Skyhawks out of desert storage and back to airworthiness. To do that we needed solid Skyhawk knowledge as a team of engineers, and solid support from the Israelis who hosted us. The task at hand was daunting until we realised the support we had. In Blenheim we are oozing with experience and enthusiasm and there is still a lot of support within the community. When ZK-CPT was donated to the Marlborough Aero Club, most of the remaining spares followed. We still have them in storage.
I didn't have a great deal of time today to get deep into things so I crawled around the upper wings with a can of CRC. I opened up what I could and CRC'd what I couldn't. Graham Orphan came to check out the progress and we discussed what kind of publicity was suitable. As an attraction for Classic Fighters 09, she is a serious drawcard. She isn't a V-12 fighter or a tight aerobatics team but she is probably a one off anywhere in the world. I'd like to say that if all goes well, people will come to Omaka next year just to see and hear a Bristol Freighter do its thing. A perfect sequence would be to start her up, taxi to crowd centre, shut down, open the nose doors, set up a ramp and swallow a Ford Anglia, close up, start up, run up and taxi away.
We'll see though eh? The next couple of weeks will identify what she needs to come back to life. After I went loose with my can of CRC this morning I had to go to work. The cockpit in my B1900 is like a shoebox compared to ZK-CPT. Once the door closed, I twice flicked a switch, looked for life inside a turbine, pushed a lever forward, counted the degrees C, turned on a generator and Bob's your uncle. I love working between two PT-6's but there is absolutely no charm, appeal or personality to them. They are like an 18 year old that has got a text invite to a dance party. You flick a switch, they start without question, run as smooth as a clock, make heaps of grunt and run all day. I'm looking forward to the day when we have to learn the old way to coax a tired old man out of his sleep to do something he hasn't thought about doing for 20 years and has to be convinced that even because there is no apparent purpose to doing so, it is still a good idea.
Post by Dave Homewood on Apr 2, 2008 23:58:56 GMT 12
Al, at last year's Classic Fighters I was very impressed to see the engine runs of the Alison V12 and the radial from the Airspeed Oxford, and they were just sitting on mounts. Seeing unusual engines come to life on an airframe like the Freighter will be something else indeed.
I know there are no Freighters flying now but will this be the only one runnable? Or is that one in Canada still taxiable?
Post by Radialicious on Apr 3, 2008 19:55:32 GMT 12
Dave, I suspect that Canadian machine is still runnable (is that a word?). There are probably a number of B-170's around the world in similar condition to ours. They just need a bit of enthusiasm.
It was my day off today and I headed out to the airfield nice and early hoping to get the spark plugs out of the port engine and get some penetrating oil inside her lungs. My dependable Honda let me down severely this morning when the electronic ignition failed and I spent an hour and a half getting her to a garage. In the end I didn't make it to Omaka until late morning.
Now, for some reason, Mr and Mrs Bristol decided to make an igintion harness with round spark plug nuts instead of hex ones. These round nuts have 6 half round cut-outs around the circumference. I spent the entire afternoon on a lathe, mill and TIG welder making a cross between a crow's foot and peg spanner. It was a satisfying job and it worked really well but took a lot of time. In the end I only managed to get the plugs out of about five cylinders. I finish work at about 1.00pm tomorrow so I should have the rest out quick smart! I've got a recipe for a nice penetrating/lubricating oil that I will pump into all the cylinders. Hopefully that will get amongst the sleeves and free things up nicely. It was good to see a nice waxy grease in amongst the lower spark plugs that I pulled today.
So far, I haven't yet stumbled across anything that puts the brakes on this project. I'm very aware of the fact that there is another engine on the other wing that is awaiting the same treatment. It reminds me a lot of my early days in the RNZAF. Before a parade, we'd go hard out with parade gloss and spit polish our shoes to a ridiculous finish. It always seemed quite difficult to put the first shoe down and put the same effort into the second one. That is why I intend to start both engines as one event. The anticipation of the noise, smoke and smell will keep the enthusiasm up as the second engine gets the treatment.
So, tomorrows focus is to drown the cylinders with light penetrating oil and let her sit and think about it for a while. In the meantime I'll spend a bit of time in the cave that is the nacelle sussing and sorting out everything that lives behind the firewall. It is a fearsome place! If you can imagine the Hawker Hunter - a place where the designer swallowed all the switches and instruments and then vomited to give the cockpit its layout. That english designer was proud enough of his work to let everyone see it day to day. Imagine what you would find in an area not designed to be seen!
Don will appreciate the effort that went into designing the Strikemaster undercarriage extension/retraction system and the resulting effort required to maintain it. This principle is graphically demonstrated inside the nacelle of a B-170.
The Bristol rule of thumb formula is - difficulty of maintenance equals the cube of ten times the effort required to design something that, whilst it works, and works well, is fifteen times as complex as what is reasonably required for such a component, system or structure and twenty to twenty five times as complex as how the Americans would do it.
Al, your updates really do make fascinating reading, and it's wonderful that they are written by someone who is obviously so at one with these engines and their systems. Your passion for these engines and the aircraft really do come through in your writing.
I hope that everything runs smoothly for this project, as the B170 really was one of the workhorses of NZ aviation, alongside other notable types like the C-47/DC-3 and Fletcher/Cresco family.
A 'live' B-170 would certainly be worth seeing/hearing once again.
Hi Al and all you other B170 lovers in NZ. Just want to wish you guys the best of luck getting CPT runable. My name is Paul Hawkins one of the founders of Hawkair Aviation in Terrace BC Canada. l spent one month getting the last airworthy B170, C-GYQS up and running in 2004. We then took her on the last ever B170 flight to the Wetaskiwin museum in Alberta. She will never fly again but would fire up with a little gas and some TLC. A couple things l would like to mention. lf the oil tank was not totaly drained oil will have leaked down into the engine sump and will get blown out of the crank case breather on start up. it is interesting to watch together with a huge smoke show but will create an oil slick all the way back to the tail. There is a check valve drain next to the scavange filter at the base of the sump. Also before flicking the primer pump switch make sure it is not siezed. The pump tends to dry out and will blow it's fuse. There is only one primer pump for both engines situated just behind the stb engine fire wall. l am sure you have plenty of ex Safeair enginners on your door step that would love to get into some nice black Bristol oil again but if want any other info give me a call.
Post by Radialicious on Apr 5, 2008 23:40:27 GMT 12
Gidday again. Thanks for the letter Paul. That info is good to know. I have followed with interest the work that Hawkair has done and I must say there is a strong appeal as a commercial pilot, to that kind of operation and its machinery. I haven't yet ruled out pursuing a job overseas flying piston engine heavies before they really start to disappear. Thanks guys for the feedback and appreciation of this project. I can't help but help but use 3 of Sir Ed Hillary's famous words to describe why I am doing this - "because it's there".
I have had a fascination for engines ever since Dad bought me a 3.5 horse Briggs and Stratton at a garage sale when I was about 10 years old. That poor engine got pulled to bits, reassembled, started, pulled to bits etc etc many many times as I grew up in Dad's workshop. Dad was an RNZAF machinist who setup and ran the RNZAF Museum workshops for the first seven years in No.7 hangar at Wigram. ZK-CLT passed through there before she flew north on her way to Canada. It is hard to say how many classes I bunked off school to watch her being prepared for her big adventure. That is where I got to enjoy being on board during a ground run. After I too joined the RNZAF, I tracked down a derelict Armstrong Siddley Cheetah Mk10 ex Airspeed Oxford. It was found on Peter Colemans property outside of Omaka and took me a good couple of years to get her back to running condition. I still own that Cheetah and will one day point some fuel and oil back her way and get her running too.
I spent a few hours yesterday getting the spark plugs out of the port engine and introducing some light penetrating oil into the upper cylinders. The engine whilst free to turn could best be described as 'reluctant'. I guess when you add up 14 pistons, 14 sleeves, gears and cranks, 12 conrods, 2 master rods and bearings, two mags, accessory gearbox, vacuum pump, compressor, generator, oil pump, fuel pump, and supercharger drive train all turning via a .44 to 1 reduction gear, it is hardly surprising! After almost 20 years of inattention, I guess we are lucky these engines turn at all. I poured about four litres of light oil into the upper cylinders yesterday and almost immediately the big Herc went into relax mode. With all that goodness in her lungs, I carefully pulled the prop thru several turns. Some of the oil promptly found its way into the exhausts. I suspect there will be a fearsome smoke-up when we go to start the old girl. I've seen the shorts of C-GYQS starting on Youtube. Very encouraging stuff! After several turns of the prop I went up top and filled all the upper facing cylinders with oil and cowled her back up. I want this oil to seep, drip, plop and splash around much of the internals whilst I work aft of the firewall.
Today I lifted ALL the cowls of the port engine. Again I apologise for not yet having photos. With all the cowls, doors, hatches and wing leading edges open she looks nothing short of a Dr Seuss machine! The B-170 is a perfect example of an airframe designed around the QECU concept. The Quick Engine Change Unit is basically an engine nestled into a nacelle that carries most of the components and accessories needed for its operation. Quick-disconnect fittings make the connection of fuel, oil and electrical systems a quick step by step process. In my experience, the C-130 has the best QEC design that I have seen. The controls are rigged to a point on the spar and the controls at the engine end are rigged to datums on the QEC. Four bolts hold the QECU to the wing and ridiculously simple couplings connect the previously rigged systems to each other. The A-4 Skyhawk was cleverly designed and for some airframe related tasks, the QECU nature of the engine and airframe meant that it was often easier to take the tail off and slide the engine out than struggle for space and access. The B-170 leading edges inboard and outboard of the the engine hinge upwards and the side cowls are almost a metre square and give amazing access and light into the nacelle. This helped me peer into the cave where the rest of the engine and her systems could be surveyed. I am still looking for the proverbial spanner in the works that says "na man, cowl her up, forget it, too hard". Today I found more that said "yeah man, keep it up!". The main fuel filter bowl, whilst it still had fuel in it, was spotless. No water or dirt even though it is literally the lowest point in the fuel system. I must admit that this old fuel gave a freshly skinned knuckle a real tickle up for a long time after I stopped tinkering. Access to the magnetos isn't too bad and I soon had the distributor cover off the left mag to inspect the interior. It was also clean and dry. I'll need to get a strong light source into it and confirm the condition of the points cam and lubricator before I reassemble it for good. Again an example of another push in the right direction. The other mag is next and then a quite detailed visit to Carburettor Street. It is a fearsome looking piece of kit. The biggest hose that feeds into it is about 1.5 inches across and in fact isn't the fuel line! It is an oil pressure feed to operate the boost and mixture servos and the anti-ice system in the throat and butterfly. There is suddenly a need to get back into the books to put a name to the face of all the other plumbing, wiring and electrickery that exists in the cave. I considered today that I would disconnect the generators and run everything off external power and/or flight batteries. The output of the gennies is such that there is a risk of damage to the old cables and regulators that look after such high amperage current. These cables make their way from the cave, into the wing, into the cockpit and out again. It was soon clear that this disconnection had already been done, at least on the port engine. With the view to one day taxiing this machine I briefly looked into the pneumatics. Pneumatics are great when they work 'coz air is cheap and readily available. However, when it leaks, it is bloody hard to detect. More importantly, the tanks or receivers that store it can be a headache if their internal condition isn't flash. I think they are charged to 400 psi and there is a risk that 400 pounds would be quite destructive and/or hazardous if one 'went off'. The brakes are run off compressed air and are required for steering if we wish to taxi her. Hopefully the tanks will be safe to pressurise. I have thought that maybe a tweak of the regulators might get us away with use of a lower system pressure that will still provide effective braking. Yet another can of worms that is too tempting not to open....
I am out of town for a couple of days with work but for some reason have monday arvo, tuesday, wednesday, thursday and friday morning off. Three-ish days should let me chop out the port engine and make a start on the starboard.
My fingernails are black, several knuckles have the tops missing, my work clothes are a fire hazard and all manner of s**t needs to be washed out of my hair each night. I'm sure my copilots go to work dreading yet another Bristol war story each day. I do suspect that they will be amongst the front of the audience when we finally flick the switches and kick her in the guts. This Bristol project is gaining more and more interest in the community. There is as yet no date given to the big moment for the reason that I want to be sure that we give these old engines the best possible chance of waking up predictably and without too many surprises and/or disappoinments. There is talk of a TV crew being there at the time and I'd prefer the country to think they had been shutdown only the night before. I will be disappointed if however, Blenheim doesn't lose an hour or two of daylight as the smoke clears.....
Post by Radialicious on Apr 6, 2008 0:22:36 GMT 12
TOO RIGHT CRAIG!!!
A friend here at Omaka is on the prowl for a P&W R-4360 to add to the list of interesting aeroengines that run during the lunchbreak at Classic Fighters airshows. He was a bank deposit away from securing a runner complete with B-36 propeller. It was sold from under him but he is still looking. He didn't have to look far for a volunteer to help get it running.
Post by Radialicious on Apr 8, 2008 21:38:35 GMT 12
We had a good day today on the port engine. First up was a proper huck-out of the forward section of the cave. There is now very little evidence of the haybale behind the firewall. As per Paul's suggestion I began to drain the sump. There is a spring loaded fitting that couples with an adaptor and hose and makes draining the sump a quick, clean and easy operation. I don't have that adaptor. What a mess... Next time I delve into our support equipment parts book, I'll see if it is worth making one or just bodging up something to suit. It took a bit of huffing and puffing to get the spinner off the prop this arvo. It is secured to its backplate by a number of screws that were surprisingly easy to remove. The spinner however was not so keen. Inside, forward of the prop hub is a diapragm that locates on the pitch change dome. It was stuck solid! I had to get a piece of aluminium rod about 2 feet long to act as a drift and carefully work the diapragm off. Luckily the portion of the dome that it locates against is only 3/4 inch or so long. It was soon clear that the spinner was ready to come off so I repositioned my stepladder under the prop. The spinner on a Bristol could probably be used as a playhut for a number of children. It is a big bit of kit. I was concerned for the continued integrity of my foo-foo valve as I lifted the spinner clear of the dome. It was effing heavy and from the second to last rung of a stepladder, I felt seriously precarious or sericarious. Not a good place to be! Somehow I managed to lift this thing (diameter of over two feet) up and over my head to rest on my back between my shoulders. If you imagine that biblical bloke with the earth on his back - Atlas?, you know what it looked like as I made my way back to the ground. The Bristol spinner is very soft and certainly not heat treated. It is also a brilliant haven for hay. Again an incredible amount of rubbish came out of it. Smoko was next on the list and my old friend Bill Ashley was working on a syndicate Citabria rebuild at Stuart and Wayne Tantrums hangar. During the coffee stop I imformed Bill of my project. Bill was once the Chief Pilot of SAFE Air and was unaware of what I was up to. He was very very keen to see what I was up to and offered lots of useful advice. It will be the likes of him or his mate Owen Hughes that will share the cockpit with me when we go to crank this thing up. Bill has 10 000hrs on Bristols and has many many war stories.
His most famous was an overnight in CHCH when he got on the jars with a Colonel who had flown a Deep Freeze Globemaster in from the States. For some reason, these two decided to try on each others uniforms for shits and giggles. They decided to stay in uniform while they finished off their night. The next morning Bill awoke in the Colonels uniform and thought that he'd better return it and get his own one back prior to reporting for his shift. Sadly the Globemaster and its crew had gone. Bill had to report and fly his shift in the uniform of a highly decorated US officer much to the delight of his colleagues. Along with the rebuild of the Citabria, Bill is ASL's exam agent for PPL students and also refuels part time at Woodbourne. Like many of his time, he is a true gentleman and I look forward to putting life back into his old office.
The other significant development today was the spraying of oil into ALL the cylinders and a bit of exercise for the internals. The old radial loosened up significantly after I did this. There isn't a great deal left to do on this side. I need to now work out what is the easiest, safest and most reliable way of getting fuel to the engines. There are also a number of components that need to be checked for function. I'm keen to check these in a workshop so that I can say with some assurance that they'll work in front of an audience. The list so far includes fuel booster and priming pumps, booster coil and the anti-surge valve. This contraption protects the matrix of the oil coolers from excessive pressure after start with cold thick oil. It effectively bypasses the oil cooler until the oil thins out with heat and its pressure drops away. Many other machines use a temperature sensing bulb and all is simple. This thing is full of pistons, poppets, springs, seals and all manner of Britishisms.
Tomorrows task(s) - refit the spinner. Got a HIAB booked to help with the lifting of that. Soapy cleanup of the engine and prop. Re-drench the cylinders. Huck out the sump. Somehow. Try and find the carb in amongst all the hoses, pipes, linkages, elbows, ducts and darkness. Hopefully by the time I go back to work on Friday, I can get the port monster squared away and look forward to her sister.
Post by Dave Homewood on Apr 8, 2008 23:49:38 GMT 12
Al, have you approached the local press to publicise this restoration yet? I was just thinking that maybe if you did and mentioned that the engine requires certain specialist tools, there amy be ex-mechs around town who have those tools in their home workshops, saved when the aircraft were retired. You know what mechanics are like, most collect old tools... Just an idea, it might save you doing some toolmaking.
Attention Radialicious. I was passed your message regarding ZK-CPT and found this most interesting. I am from England and act as the Information Service Co-ordinator for Air-Britain. I am also in the very final stages of writing a comprehensive history of the Bristol Freighter. If fact it is to be sent to the publishers very shortly. I would very much like to include some details of your plans for this aircraft and am asking if you would be so kind as to let me know the details of what you propose to do with her. I already have very detailed histories of every Freighter built and would very much like to add a footnote to explain that you plan to get 'CPT running again in the book. You can contact me directly (if allowed by this forum) on email@example.com This is very good news indeed, and I wish you every success with the project. Derek.