powerandpassionWhat might have happened
[ATTACH=CONFIG]223454[/ATTACH]
I experienced a lightning strike on the trailing aerial while flying in an Anson T22. The trainee AEO using his TR1154/55 left the trailing aerial out when we flew close to a thunderstorm. There was a hell of a bang as though some fool had discharged a shotgun and some smoke from the AEO position. He sat there stupified with his radio u/s and the aerial winch shattered beside him. I was in the nav station a couple of seats behind. Of course the aerial had gone.
Attached is a photo of RAAF trailing aerial on Anson I frame, not sure if this is a direct copy of trailing aerial in use in RAF prewar.
These trailing aerials are a bakelite ‘fishing reel’ supported in a steel frame – I would guess that the original designers contemplated some form of insulation for a conductor line that would in greater probability impact with overhead powerlines rather than be involved in a lightning event. Perhaps the weakness of the design was that it did not then contemplate a lightning event. My understanding is that lightning strikes on aircraft were being grappled with in the 30’s and the science as yet not fully understood. There is a paper here
http://www.muzeumlotnictwa.pl/index.php/digitalizacja/katalog/1112
at the Kracow museum which deals with ‘why aircraft dropped out of the sky after lightning strikes’, trailing aerial strikes and eyewitness descriptions of strikes which would make loss of aircraft control self explanatory. I have a friend who was proximate to a car when struck by lightning who described ‘fireballs’ floating through the interior of the vehicle and a loud noise, which he realized later was him screaming !
My understanding is that lightning starts from the ground, thin leaders search upwards until a connection is made then the major discharge passes down the leader to the ground. The ‘hair standing on the head’ of the golfer in the open about to get struck by lightning is the invisible leader working its way up…
So it is likely that the leader made its way via the path of least resistance, the trailing aerial, to the bakelite winding reel, isolated from the warren truss steel tube airframe. The radio operator would have started to ‘feel funny’, as the leader searched for a pathway, dancing around his body, finally connecting to the radio set and table. The microphones would have started to crackle, a frown developing on the radio operators face…then the EXPLOSION, as the leader finally found a full pathway to the opposite potential in the cloud mass and the main discharge occurred…
Picture this : a miserable, dark winter with driving snow piloting an Anson I, freezing air blowing through every miserable crack in a flying seive, your hands underneath thick mittens are frozen and you can barely think, except to ruminate on what a dumb idea it is to be there, and how you can’t even open the thermos. Suddenly there is a blinding light and huge explosion : the wings have come off !? Before you can take control of your instant reptile panic a grotesque vision expands before you : fireballs dance towards you and the navigator/radio is frozen standing up with hellish flames shooting from the headphones around his head : calmly maintain height ? Drop 1000 feet while only 300 feet off the ground ?
powerandpassionDeaglan1, welcome.
It certainly looks like a fantastic object ! It would be a logical companion for the 1934 London – Melbourne air race, or the RAF making its way from the UK to India and Iraq in the 1920’s.
There are some folk on this forum with far more knowledge on clocks than me, but I understand that mechanical clocks were the norm even to WW2. I have an Air Ministry 6E/50 navigators ‘fob watch’ in my hand dated 1941, much the same as someone might have used on their waistcoat in 1890. Many of the RAF planes in the 20’s and 30’s had a rubber holder fixed to the instrument panel that allowed the navigator’s watch to be slipped in and out, which is probably how an intrepid traveller would handle the world time clock.
powerandpassion[QUOTE=powerandpassion;2089893]I am trying to work out the topography of 1930s British aircraft design rules and would appreciate if anyone could fill in any gaps.
Things that go bump in the night….
By the way if anyone wants to talk 1919 – 1939 metallurgy I would be pleased to uncork a bottle and settle in…
powerandpassionIts a great resource this forum. And its a big enuff hobby with room for all of us. Live and Let Live! Thoughts?[/QUOTE]
The forum is excellent. It has all the virtues and vices of anything with a heartbeat.
My main disturbing observation is how pasty we all look. When we finally see each other at shows or swaps we are disturbingly similar somatotypes : male endomorphs, hot chips in hand, bad skin, bad fashion. I figure it is a combination of late nights on the internet, more interest in matching a Mk V fuel pump to the right engine rather than the right shirt to the right pants and a yet to be diagnosed condition related to the shrinking of brain emotional restraint centres due to an exposure to radium gauges and phenylformaldehyde aircraft fittings.
We are OK. In fact we are wonderful. Should really concentrate on letting each other know when we are in town so we can share a beer. I am in Melbourne, Australia. Anytime, PM, happy to catch up. Grow the passion.
Ed
powerandpassionThe Calling
Power&Passion
Are you a vicar ? My local vicar is so ‘wooden’ you can’t tell the difference between him and a plank.
Great comment – by the way ! I do like a bit of religous fire and brimstone with my supper.
I would be a vicar except I am too into sex, alcohol, lying (“just going to the auction to look”) and youtube videos of rhubarbs to probably make it into a collar. All these vices do not, however, preclude me from politics, which is a different field of theology, or battle of ideas. Toronto mayor Rob Ford has established the high water mark for political behaviour, and I doubt that there is anything anyone can conjure to beat him, unless Boris Johnson decides to up the vaudeville. So there is a place where I can lay my talents.
In theology there is ample provision for war, blood and guts : just read the old Testament. I have to admit that part of the pleasure of warbirds is the fact that they expressly are tools of war. No thought of fuel economy and plenty of head scratching over how to fit a 57mm cannon into a Mosquito. That is, how to deliver a piece of metal as thick as your wrist at 500 metres per second into the hide of someone with different ideas.
(1 Corinthians 13:11) When I was a child, I spoke like a child, I thought like a child, I reasoned like a child. When I became a man, I gave up childish ways. So to me warbirds are about the battle of ideas. I look at a Messerschmit and I see bodies being turned to soap. I look at a Kawa saki Hien and I see folk chopped with swords for sport. I like a piece of metal that introduced some counter arguments into these paradigms.
I do worry about turning ploughshears to swords, but then the naivete post WW1 delivered the world into the abyss of WW2. “Why are you so into warbirds and war?” the missus says. I guess the answer is that so my kids don’t have to be in one, if they actually know what a war is and what tools of war do. It does help that warbirds look good too, in a plug ugly A-10 Warthog way, or liquid cooled V 12 front end way. Then the sound of a prop tip breaking the sound barrier. What’s not to like? Amen.
powerandpassionPR Blue
Does anyone happen to know an accurate colour match for what is often colloquially termed ‘de Havilland Blue’? The engines on display at the Stag Lane and latterly Leavesden showrooms (and now scattered between Salisbury Hall, RRHT Derby and RRHT Bristol) were all painted in this French blue-like hue and I’ve saw Vintech restoring some engines in the same colour when I visited a few years ago.
Any help gratefully received.
Lee Howard
This may be photo reconaissance blue (azure blue RAAF). A Sid Cotton (sidcot flying suit) innovation immediately pre war was an all over eggshell blue that he observed made his aircraft very difficult to spot. This scheme was adopted for PR Spitfires under Cottons direction and I understand later to PR Mosquitos.
powerandpassionOil Cooler Dreaming
The brass fins of the oil cooler have spacing rings between them made of aluminium. Inside the brass fin itself is a matching aluminium ring, so the brass plate is sandwiched between aluminium. I am looking at machining these aluminium rings up. The cross section of the spacing ring is figure 8 shaped. Why do this ? Why machine in an extra groove in the guts ? Why not just a simple piece of tube cut to length ?
Then it hits me : Hot oil would pump through the assembly under pressure, the aluminium spacer ring, with its higher heat conductivity, would heat and swell before the brass fin. In fact the figure 8 section would heat and swell fastest at the thinnest section, effectively forcing the ‘beads’ at the top and bottom of the figure 8 to seal the brass fin against leakage. How bloody clever ! How elegant ! How simple ! These days a plumber squirts silicone gel around a seal and charges you a quid a second for this masterclass, but in those days there was no silicone, in engines or breasts ! A self sealing metal to metal contact made by folk who knew their materials and made them perform. I am slowly falling in love with my VP oil cooler, and learning to take no design feature for granted.
Another lesson is patience. There is no fully annealed B12 type brass sheet I can easily get on the market, I will have to take half hard and anneal it myself. The model railway folk are good here, the gents who make one eighth scale working steam locomotives out of brass sheet – true craftsmen.
The man doing destructive tests on solder is in hospital, so I have to wait.
The toolmakers all want a lot of money for a multistage press tool that presses and blanks out the brass shells and openings. I will have to either press out then waterjet openings or waterjet blanks with openings then press out, hoping that the distortion in the sheet does not put holes out of alignment.
There are lots of spacing rings, distance pieces to machine out, that will keep things busy until after Christmas.
I put my head under a DC-3 bonnet and there was a brass oil cooler, and when I think about it I have a seen a brass oil cooler on a P40 too. So brass oil coolers travelled through to mid thirties designs and across design schools of thought. The choice of brass must have been far more purposeful than just the fact that brass was a familiar material from radiator work. The more that I think about it the late 20’s -30’s oil cooler was really a heat modulator rather than oil cooler. In other words it was designed to allow oil to HEAT up first ( by being an inefficient heat transfer device) then to allow it to lose SOME heat at altitude. Old Jock was a fitter friend of a friend who described heating up oil outside of the aircraft in the scramble days then pouring it in just before readiness, so engines could be started from ‘cold’ and roar away from base within minutes. So you really didn’t want a highly efficient oil cooler in the first ten minutes, you wanted a good heat modulator. Ahh yes ! The Hawker Hart-Hind-Demon had a coolant radiator that the pilot raised or lowered into the airstream depending on conditions. Raise out of the airstream at start to allow the engine to heat up then lower as things settled in. So the VP Oil ‘cooler’ design was consistent with this engineering approach, except the pilot did not have to raise or lower it into the airstream, because the designers knew their materials.
Self intelligent metal to metal joints, heat modulating materials eighty years ago. Grandpa had some tricks !
powerandpassionCoolant gauge
Good morning everyone,
I work as QA Manager for Marilake Aero systems in Ferndown, Dorset, we repair avionics equipment and instruments for many types of aircraft.Recently we received a Mk VIIIH oil temperature gauge (stores ref 6A/494) removed from the last flying Battle of Britain aircraft (R4118), we would sincerely like to return the unit serviceable so that the aircraft can remain airworthy, but the capillary tube between the gauge and the temp bulb is leaking and we dont have any repair documentation that shows us how to dismantle the temp bulb.
does anyone have anything we can use to help us service the unit and keep this classic aircraft flying please (we only have the test section from Air Pub 1275)?
AP1275 1939 lists 6a/494 as coolant gauge, Mk VIIIH, ethyl ether filled.
RAAF Schedule of aircraft instruments 1946 lists Mk VIIIH with 10 ft capillary also used on Spitfire, 15ft capillary on Battle and 30 ft capillary on Mosquito so NOS spares might be around. Just roll up the excess capillary.
Oil temp gauge is fitted with mercury injected at high pressure. I am not an instrument tech, but I figure that most folk have avoided rebuilding these gauges because NOS was around, and the method of manufacture is fussy to recreate.
‘Instruments’ Category X Licence by RW Sloley, Pitman 1935 gives some clues for coolant gauge :
capillary tube has 1mm bore, ethyl ether boiling point is 34.6 degrees C, so I guess that ethyl ether was cooled to < 34 degrees when bulb was filled.
‘Aircraft Instruments’ by J Riley, Engineering Dept Smith & Sons, NAG Press (did my wife have a printing press?) 1939 gives some more :
the capillary is soldered to the gauge and the bulb, flared sleeves being fitted to prevent damage to the tube.
So the bulb cannot be dismantled without melting the solder at the top, which would no doubt volatize the ethyl ether. I wonder how they filled the bulb with ethyl ether then soldered the capillary in to begin with ?
Maybe it’s like the mystery of fried ice cream, which a chef showed me the secret of making after I had washed ten thousand dishes in my kitchen hand days….
Perhaps the bulb was filled with <34 degrees liquid ether in a coolroom then placed in a holder with the bulb base immersed in ice/dry ice. Then the top of the bulb could be soldered with a hope of preventing volatized ether escaping into your face or depressurizing a pressure based system.
I would be interested to talk to somebody who could successfully resolder new capillary to old gauges & recharge with ether or mercury under pressure all the old gauges that have work or age hardened capillaries or tin snips applied to the capillary to assist in removal.
powerandpassionGordon folding wings
Here are two more photographs of the Reigate Grammar School ‘Fairey Gordon’ which date from 1947. They are taken from the school magazine, ‘The Old Reigatian’, to which wiesso refers in his last post. Whilst their resolution leaves something to be desired, they are important in that, probably, they are the last taken of this aeroplane. Anyhow, from what they do illustrate can anyone else add to the debate as to whether the aeroplane was a Fairey Gordon or some other type?
[ATTACH=CONFIG]222565[/ATTACH][ATTACH=CONFIG]222566[/ATTACH]
Pg 74 of the Gordon AP details wing folding procedure :
http://www.muzeumlotnictwa.pl/index.php/digitalizacja/katalog/1160
powerandpassionHawker biplane info
Hi Paul,
I have a copy of the order you mentioned already, it’s Wirraway Order No. 57 of 29 August 1941. Sadly my copy does not include any drawings.
The order references drawing 08-73901, would love to get my hands on that one!
Regards,
Derek
Derek,
Do you have any information on Hawker biplanes : Hart, Audax, Hind, Demon, Hartbees (SA) – you seem to have a lot of APs and Wirraway stuff – CC gear detail ? Can you PM to exchange info ? We have Belgian beer in Australia but I wonder what Wirraway information is doing in Belgium !
powerandpassionI will ask
According to the legend / accepted wisdom, the beer was in modified wing tanks. Do you know if this is correct, or were more practical methods found?
TIA
Given that it is now nearly 70 years after the event I do not think that any secrecy statutes will now apply on this critical armament question !
I will ask him but as I think about it now he also took one or two passengers to and fro, implying that there was no navigator on what would have been a humdrum, repeat flight at a time when most twenty something pilots really wanted to be demobbed and somewhere else, so standards were slipping. Most of these passengers were soldiers with not enough leave time to catch a train to get back to the UK, so would cadge a ride back. Subject to fitting a keg through the access door I am sure there were many willing helpers to push a keg into the navigators seat ex UK.
It was an FB, so I figure the armourers would have put it in the bomb bay if they were doing it in a bulk, organised fashion, again I will ask.
A history of HM Customs I have read details the problems with handling contraband via postwar airforce flights to the continent, watches, stockings, gold etc. I am sure the stuff would be put anywhere, including in jettison tanks.
In the Pacific, there was a RAAF scandal centred around Clive ‘Killer’ Caldwell and planes filled with grog to be sold to US troops. Once things wound down and servicemen considered an uncertain future on ‘civvy’ street I am sure there was a tendency to think of ‘superannuation schemes’ to assist the transition. Contraband would fit wherever the human imagination might see that it would fit.
powerandpassionYes
Hi
basically as per thread title,
curiosity mainly
the two stage merlin was slightly heavier
so was the undercarriage the same ?
tyres / pressures ?
U/C legs ?likewise the initial bombload was 2000lb on the first mossies then some mod’d to 4000lb,
did the mod’d mossies have the same u/c ?or did they all just sit lower on the ground when loaded.
I googled it & booked it, but I cant find anything about it, only info about the bombay mods.
cheers
Jerry
I don’t really know but I think the short answer is yes.
Based on the following :
Basic physics : Force = Mass X Acceleration, F= M X A
Therefore a standard Mosquito of a standard weight will transfer different forces to its undercarriage depending on the speed of landing, therefore the designer must allow for high speed landings that will stress the undercarriage to a certain level. So the undercarriage would be designed to cope with high speed emergency landings. This design factor could be adapted to the carrying of heavier loads, on condition that landings were more gentle. In practical terms very few aircraft would return with loads, and would land gingerly in any case.
In reflecting on the original Mosquito design, an unarmed reconaissance aircraft, later provided with machine guns, bombs and cannon of various calibre, let alone larger engines, there would appear to be a large design safety factor initially provided in the undercarriage, which allowed armourers to push the envelope with munitions. I have yet to see the steel components of the U/C different across Mosquitos. Only the wheels seemed to have changed, from single drum spoked wheels to dual drum wheels with greater braking capacity, consistent with stopping higher mass loads.
In respect of the U/C design, it was based on rubber buffers, in which APs allow a certain factor of compression to indicate whether they were sound or not. Since Malaya was occupied by the Japanese, cutting off supplies of rubber to the UK, and South American supplies were delayed in arriving through the US, a great deal of effort went into recycling rubber for military applications. Recycled crumb rubber was incorporated into new mouldings to an extent which has not been equalled to this day, with consequent affects on elastomer performance. Thus a practical response to heavier munitions loads was to ensure the purest rubber went into the most demanding applications, a simple way to extend the performance of the existing U/C design. Today, as you do in performance vehicles, you might use polyurethane instead of rubber for the same affect.
Some all up weights show that a 4,000lb bomb was well within design capabilities given other items were stripped out :
PR Mk XVI : 25,917 lb (unarmed)
B Mk XVI : 25,917 lb (no guns or cannon, 4,000lb bomb)
F Mk II : 19,670 lb (4 X 20mm cannon, 4 X .303 brownings)
AP 970 ‘Design Requirements for Aeroplanes’ stipulated the design factors for aircraft accepted by the Air Ministry.
Chap Sect 9 (i) ” The U/C shock absorption capacity is to be such that the resultant ground reaction shall not exceed three times the weight of the aeroplane fully loaded when the aeroplane lands with the specified vertical velocity, thrust line horizontal”
Therefore there was a 300% factor of safety in the design, which armourers could use to inform different load configurations. No need to change the U/C. The plane would fail to take off before the U/C would fail in practical terms.
My father carried beer kegs from the UK and documents back from Nuremburg immediately post war in Mosquitos with no reported ill affects on the undercarriage, so beer kegs OK too.
powerandpassionRealpolitik
Real politics I’m afraid mike J. Although by the end of the war what influence Churchill still had is debatable and I think he knew that there was very little the West could do to stop the Soviets doing what they wanted in the east.
Realpolitik is a cool logic. It is an adjective that often shields the conscience of the timid and the cruelty of the assertive.
My father is 97, former Polish pilot in the RAF. On his way to join the RAF in 1942 he was exposed to what might be called acute experiences of the human condition, courtesy of Hitler and Stalin. In all the times that he has spoken of these experiences he has been phlegmatic in his description. When you deal with an assertive murderer, you expect murder.
The only time I have seen him upset, to this day, is in describing the decision of the UK government to deny Polish servicemen the right to march in the Victory Parade. I understand this was a decision of the Atlee government. I wonder if this would have occurred if Churchill were still Prime Minister. Irrespective of the tensions arising from the resetting of Europe’s fault lines, Churchill had both the instinct and the credibility to force the issue with Stalin : it was just a parade. It was not Britain’s finest hour.
Much has changed since then. It would cause no offence to anyone to allow Polish ex servicemen, while they are still alive, a belated acknowledgement of their fundamental part in the Battle of Britain, when the realpolitik of Ambassador Joseph Kennedy of the United Sates deemed it prudent to advise the United States government to abandon Britain to the Nazis. Thankfully Atlee was not the President.
I wonder what can be done in Great Britain today in the form of a formal invitation from the government to Polish ex servicemen to participate in a commemorative event linked to VE Day. No doubt some remaining servicemen will say ‘too little, too late’ and most would not be able to physically attend. Some may find the gesture helpful in dissipating a spirit of what, to a young serviceman, after all the effort, could only be felt as a betrayal. It does nobody any good to leave it unresolved.
The use of the Polish Air Force symbol at a football match in the United Kingdom has a far deeper meaning and connection in Polish spirit than the everyday of a football match might imply. The powers that be understood this in the war and allowed it on the fuselage of Polish squadrons as they allowed Commonwealth airmen a shoulder patch that connected each to their own country and story.
I guess the lesson for today is always listen to the earnest reasoning of realpolitik : never trust it.
powerandpassionTrainer panel
Can anyone help identify this instrument panel ?.
I believe it to be off of a Hawker biplane. It has the cut out for the bomb release lever on the top left hand side. Looks similar to Hart/Hector, but it is not an exact match for any that I have seen.
Cheer’s.
Bob T.
Trainer panel, back cockpit ? Does look very Hartish, but carve out for CC gear pump on RHS missing.
Does have all the instrument cut outs consistent with something like a back panel.
Would love to get a paper template to compare against front panel and make some deductions.
powerandpassionHeaven on a stick
& a Griffon…(Red Baron P51)
When I was five I dreamt of working in a jelly bean factory.
When I was 25 I dreamt of being lassoed by Wonder Woman, toyed with by Cat Woman.
Now that I look like Homer Simpson I dream of a warehouse of V12s…
Thanks for sharing ! How much for the lot ? Something doesn’t look right about the Griffon. Maybe we’ll just put some thicker oil in it….
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