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“And like no other sculpture in the history of art, the dead engine and dead airframe come to life at the touch of a human hand, and join their life with the pilot's own.”

345. Job Half Done

Looking at yesterday’s list, there are relatively few we can actually tick off, and we are going to have to come back again in a couple of weeks. to finish the job off.

But we’ve done the best we can, and we’ve each brought home a selection of jobs that can be progressed better at home.

 

Here, at least, is the repair to the rear fuselage fabric which has gone very well indeed.

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The tailskid, though it’s invisible, is just awaiting some more bolts of the right length to be ticked off.

I’ve repositioned the pulsometer a little lower to see if it will stay full all the time, and I’ve brought back the inlet piping for modification when I’ve got access to a proper torch to undo the silver solder, and Theo’s got the tacho drive gearbox to make a slightly more secure mounting for it.

And the two big jobs are going okay. last night I cleaned the petrol tank, and swilled it out half a dozen times then left it full of water overnight, and today Jean-Michel Munn resoldered as many of the the leaking rivet heads as he could find. He air tested it and found a couple more, but it’s looking under control, and when he’s got it airtight they are all set up to etch and paint with two-pack epoxy which should look a lot smarter than the previous paint which was applied in something of a hurry.

But the job which kept me awake last night – the broken piston rings – seems to have come to a satisfactory conclusion. It was generally agreed by Phil and the manufacturers of the rings that the most likely cause was too small a gap between the ends of the ring. Getting it just right is a complex dance; different manufacturers (the le Rhone was built by at least four different factories) recommended different amounts, and it’s complicated by the fact that it’s a ‘choked’ bore; the diameter is 4 thou (thousandths of an inch) smaller at the top than the bottom, to allow for the fact that in flight the top is hotter than the bottom and will expand more. You measure the gap by inserting the ring on its own into the bore and measuring the gap between the two ends – and it’s anyone’s guess whether this should be at the bottom or top or somewhere in between!

But the consensus – based on the fact that it was the topmost rings that failed in every case – was that the gap had been a bit too small, and the gap was closing right up at the top of the bore, causing the ring to bind and overheat. thankfully no other damage had occurred, so a replacement set has been ordered and will be fitted in a week or so.

We were only there for three days, but our sense of gratitude to the guys in Engineering at Shuttleworth can’t be overstated. They have a completely unique facility and breadth of experience in this very specialist field, and would be quite within their rights to guard it jealously and not let anyone in. Instead of which, they move other precious artefacts around to give us space in the wonderful warm hangar, welcome us in with cups of tea, lend us their tools, and freely give their time to advise us about the problems we face.

To all of you, but particularly Jean-Michel, Phil, Andy, Rory and Gareth, a huge, huge thank you.

One other excitement – Theo brought up the half propeller which we’re going to shoot holes in. He’s wrapped the fabric round and applied the first coats of dope, and my job now is to apply more dope to the fabric band and varnish to the rest before we see how much damage a 0.303 bullet actually does!

No photo yet – I want to preserve the surprise…

And finally, you may remember the YouTube channel called the Great War Team, who have been assembling one of the most consistently entertaining and knowledgeable accounts of WWI week by week. They came to Stow Maries and did a special episode on 1264, and i suggested that they might like to do another special on the Coastal Motor Boats that were developed from an idea originating from three junior officers including Grandad’s younger brother, Bill. Bill helped to develop them and served on them throughout the war with very great distinction – it is generally believed that he deserved a VC for his part in the Kronstadt raid, but they’d already awarded two and so he must missed out.

Anyway, their researchers took the material I provided and expanded it enormously, resulting in an excellent brief summary of their use in WWI.

 

 

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344. Down and Dirty

Our maintenance week started with a fairly simple list of jobs, and this week at Shuttleworth to get them done.

  1. Repair damage to the rear fuselage fabric.
  2. Repair the slackening of the tailskid in its pivot bracket.
  3. Colour code the struts by painting narrow strips of contrasting colours on the tops of the struts, the sockets in the upper wings, and the box they live in in the trailer to ensure they don’t get muddled.
  4. Reposition the pulsometer to try and make it work at all times.
  5. Seal the minor leaks in the petrol tank
  6. Do a routine check on the engine by pulling all the cylinders
  7. Remount the tacho cable gearbox more securely.
  8. Repair the damaged wheel trim.
  9. Complete the wiring of the solar panel charger to the trailer winch battery.
  10. Dope a fabric bandage onto the freshly-made dummy propeller, ready to have holes shot in it.
  11. Clean the flies off the back of the propeller.

Monday started fine – I’d driven across to Biggleswade, the wings were off and the fuselage in the nice warm engineering hangar by lunchtime – and with Theo and Chill arriving late morning, we had the engine out by the close of play.

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Theo and Chill getting up close and personal with the engine…

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… and shortly afterwards, out she came.

So far, so good.

Tuesday started in a great mood, therefore, and when Ninja David took the first few cylinders off, everything looked immaculate.

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Spotless piston…

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… and spotless cylinder.

And while he was on with that, we managed to extract the petrol tank.

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The tank came free finally.

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You can see some evidence of leakage here – probably from about half a dozen rivet heads, which is what we were expecting.

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The condition of the tank elsewhere was generally reasonable.

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The brass oil tank looks immaculate, thank goodness. The petrol tank is bad enough to remove, but this would be a nightmare!

However, as David worked his way round the engine, he came across some broken piston rings.

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Here’s one in situ…

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… and we’ve ended up with five or six that need replacing.

There are one or two areas of external rust on the tank that are causing some concern, and we’ve taken the decision to have Shuttleworth etch and paint the tank with two-pack epoxy, which Andy assures us is the only paint system that is impervious to castor oil!

Otherwise, we are making good progress with the rest of the jobs.

But the two issues above cannot be resolved this week, so we’ll have done as much as we can by tomorrow night and go home early, and fix another date to reassemble.

The broken rings are a considerable disappointment and a relief; we aren’t yet sure why they broke, but at least the pistons and liners are in good condition.

Investigation into the cause is continuing; we need to be sure we’ve cracked the problem (and not the rings) before we run the engine again.

343. Digitised

I’m a member of the Experimental Aircraft Association (EAA) in the USA, and I’ve discovered that they are offering a year’s licence for a student version of Solidworks, the industry standard 3D CAD program.

I’ve always been fascinated by 3D CAD, and so for the past couple of months I’ve been starting to rebuild the Scout digitally, using our original drawings.

It’s a long – indeed a very long – learning process, but I’m slowly getting there and I thought you might be interested to see some of the results.

Here’s the tailplane and elevator, for example, with every part individually modelled.XD775Test2.jpg

And an example of the sort of drawings I’ll have at the end.

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It’s very, very time consuming, but I do find it rewarding, and I’m aiming to reproduce the entire aircraft. Eventually!

 

342. Fake News

The search for truth never ends.

We are of course interested to see if 1264 matches up to the original performance figures. But what are the original figures? Here are the figures from various sources, including the numbers from the US quoted below, which we only came across last night.

Performance figures, Bristol Scout Type C with 80hp le Rhône engine

 

Source Date Max speed, sea level, mph Time to 1,000ft, min Time to 10,000ft, min
Book of Bristol Aircraft 1948 95   21.3
Bristol Aircraft, by C Barnes 1964 93 60sec  
Windsock Datafile, J M Bruce 1994 92.7 55sec 21.3
The British Technical Department AP 1916 89 (@6,500ft)   21.3
US Division of Military Aeronautics Technical Order no. 1. 1918 88.3   23.45

The 1948 Book of Bristol Aircraft quotes 95mph for types 1, 2 and 3, increasing to 104mph for the Type 4 and 110mph for the Type 5. How these type numbers relate to the normal Types A to D isn’t clear – and doesn’t identify which engine is fitted in each case.

US Division of Military Aeronautics Technical Order no. 1 uses data obtained from serial number B763 which was sent across to the US for evaluation as a possible trainer, and was a slightly tired Type D.

So how does 1264 compare?

Well, the fastest I’ve managed to achieve is around 75kt, or 86mph. This is not very scientific, since I’m only reading the ASI and guessing what is straight and level, but it won’t be too far off. The engine is continuing to bed in and may deliver more power during the year. It would be interesting to try with some more accurate instrumentation at some point, and in colder weather, which will make a significant difference.

The maximum rate of climb I’ve achieved is around 800fpm, but climb performance in any light aircraft is affected to a very large extent by turbulence, temperature, humidity and so on. I suspect on a cold day we could get considerably more, though possibly not as much as 1,000fpm. It will be interesting to see if we can get more data during 2018.

All told, they are still slightly disappointing, though probably as good as one can expect in the circumstances.

341. Shuttleworth Engineering Wweekend

If you haven’t been before, this is a really great event to put in your diary. It’s the ultimate chance to get up close an personal with some truly amazing machinery, and talk to the people who actually look after it and make sure it runs.

It’s usually on the last Friday and Saturday of the year, and what’s in the workshop depends on what’s being worked on at the time.

We were invited this weekend, and found ourselves in some very distinguished company. the 1909 Bleriot XI, the oldest flying aircraft in the world was up at the far end, together with the Avro504K, the Bristol M1C Monoplane, and the Mark V Spitfire.

It was great to see a section of the shop dedicated to the Bristol Scout,

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and as usual the four of us spent two days on our feet without interruption, talking to people who loved to hear the story or who knew it and wanted to keep in touch.

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Fred, a young man who asked some very intelligent questions.

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The Air Cadets were introduced to 1264, but the Spitfire nearby was an even greater draw!

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This is Hannah Harper, a young volunteer with the Shuttleworth Collection

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At the end of the first day, we were all allowed to sit in the cockpit of the Spitfire

Both Theo and I found ourselves immediately at home the Spitfire cockpit.

Altogether, a simply wonderful weekend, as usual.

 

 

 

340. HMS Queen Elizabeth

There has been discussion on FaceBook about the practicability of operating the Bristol Scout from the deck of our newest, largest warship, HMS Queen Elizabeth.

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In fact, this was the suggestion made by Air Chief Marshal Sir Michael Alcock at the BMFA Awards evening, and you would think there would be a good deal of nautical mileage in PR terms on both sides.

In fact, the most sensible thing would be to arrange for the existing Royal Navy Historic Flight (Swordfishes, Sea Furies and the Sea Vixen) to be paraded on the flight deck together with the associate aircraft (Westland Wasp, Westland Wessex, Gazelle etc. as well as the Bristol Scout). All the above aircraft were operated from ships, and it would make a truly excellent PR opportunity.

How would we get them there? Well, the most problematic would be the Sea Fury and sea Vixen, and they’d have to be dismantled, road hauled to Portsmouth, and craned on board. theoretically the rotary wing machines would be flown aboard, and the Scout could be trailered.

Could we operate 1264 from the deck?

Well, take off would be very straightforward indeed. Probably best done in calm conditions with light winds, and HMS QE stationary. wind direction would be almost irrelevant, since we could get off with a reasonable margin of safety taking off across the flight deck which is 73m wide, and there would be sufficient variety of launching points to avoid the turbulence from the islands and the ski jump.

Landing could present one or two more problems, but none would be insuperable. The first issue is the lack of directional stability. landing on grass, we rely on getting the tailskid down as soon as possible after the mainwheels so that the drag will slow her down and keep her straight. Hard surfaces are anathema to us, and even adding a temporary tailwheel would be little help since the skid isn’t steerable. No, John Bulmer’s suggestion of a block attached to the skid designed to provide drag on the QE’s surface would be perfect. She stops in around 30m so once again there’s plenty of room in any direction.

We’d prefer to replicate the arrangements made for Commander Dunning on his first successful ship landing aboard HMS Furious in 1917 and have rope handles attached at a number of points with crew standing by to hold her fast as she lands, but that should be sufficient.

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And what are the historical connections? Well, the Bristol Scout was the first wheeled aircraft to take off from a moving ship. It would be huge fun to replicate that, even if it meant putting to sea to do so. And 1264 was at Gallipoli at the same time as an earlier HMS Queen Elizabeth. HMS Queen Elizabeth had left by the time Grandad got there, but it’s another tentative link at least.

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339. Back Home

Today, Thursday, Chill and I met up at the Shuttleworth Collection to get 1264 put back together and on display in no. 1 hangar with all her WWI contemporaries.

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All went smoothly, and I was able to get a couple of bits done on the trailer while I was there.

Meanwhile there was great excitement in the blister hangar as the Collection’s Spitfire was being weighed; one of the last stages before being allowed back in the air again, after a restoration that’s lasted more than a decade. Can’t wait!

On my way home, I drove past the remains of the Airlander, which has been parked outside the famous Cardington sheds for a couple of years during development.

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2-20170605_090049.jpgApparently she was flown on Saturday, but broke loose from the mooring mast shortly afterwards, triggering an automatic deflation system which prevented it from floating away across the countryside.

But, gosh, she does look a mess…

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