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Ian Burgess-Barber
13th Oct 2009, 15:54
Can anyone tell me if a "Nash Kelvinator Type H.S.P." prop as fitted to a RR Merlin XXV was something special. (I have never heard of this manufacturer before). Or, was it perhaps a Hamilton Standard made by a wartime sub-contractor?
Thanks

Brian Abraham
14th Oct 2009, 03:46
During the war they built Pratt and Whitney engines for Corsairs and Hellcats, and Hamilton Standard propellers, which I presume would have been fitted to a variety of types. One type they mentioned in adverts was the Corsair prop. They also built 219 Sikorsky helicopters. Be interested in the source of your info, as far as I am aware there was no Merlin XXV. Mark numbers up to XX used Roman numerals, and above XX Arabic numerals were used. Presuming a mark 25 is being referred to, they were used in the Mosquito VI and XIX and the de Havilland Hydromatic prop was a license built Hamilton Standard. Might assume Nash manufactured Hamilton Standard bits were interchangable with de Havilland manufactured license built Hamilton Standard bits.

Ian Burgess-Barber
14th Oct 2009, 09:32
Hello Brian and thank you so much for clarifying that for me .
You are right in that these Merlins were fitted to a Mosquito MK VI which crashed in 1948.
The A/C was built in1945 (airframe by Standard Motors Co. Ansty, Coventry and the Merlins by Ford Motor Co. Eccles Lancs).
I have had sight of the original Accidents Branch Investigators Report (Digital images from The National Archive at Kew) and "XXV" is how they typed it in that 1948 report. I have not had sight of the original AM Form 1180 (RAF Accident Card) but a recent e-mail from The Air Historical Branch (RAF) giving me the content of the relevant Accident Card uses the "XXV" designation also.
Was Nash Kelvinator a US company?
My thanks again to you, and the great resource that the 'Tech Log' is.
Ian BB

Brian Abraham
14th Oct 2009, 12:04
IBB, interesting story re the XXV, proves how official sources are not always correct. The Nash-Kelvinator was a joint effort of the Nash car company and Kelvinator of refrigerator fame. They had a number of production sites around the US. Do you have a ident on the Mossie in question?

Ian Burgess-Barber
14th Oct 2009, 14:05
Brian, Mosquito TE872 crashed just off the airfield, RAF Pershore, 14 Jan. 1948 after a feathering exercise in continuation training went tragically wrong. The pilot, Flying Officer G Burgess (my father), was killed. The passenger who was an RAF instrument repairer (on board in case the u/c needed to be lowered manually) was thrown clear of the wreck and survived.
Your comment that "official sources are not always correct" has real meaning for me as I research what really happened that day. The errors and omissions I am finding are sobering.
That is why I am being careful about establishing my facts, and your contribution has been most valuable to me
IanBB

enicalyth
15th Oct 2009, 12:50
Ian

As you surmised "hsp" means Hamilton Standard Propeller and there were many licensed manufacturers including de Havilland themselves. As for the Merlin, well Ford too was a large scale builder who did much to improve the breed.

Regarding nomenclature, a number of incorrect notations or spellings find their way into records such as MkXXV which then jars with the official history.

Hamilton Standard was then and still is regarded highly for the hydromatic propeller which uses high pressure oil to move a piston fore and aft, this motion being translated through cams into a change of prop blade angle with a governor controlling speed. But like all inventions and all training there is an outside chance that something quite unplanned goes wrong along the way. There is always an enquiry to try and ensure that it can't happen again but as pilots will tell you, sometimes there is no way out.

Graybeard
15th Oct 2009, 14:45
Kelvinator was named for Lord Kelvin, discoverer of absolute zero. Look it up on en.wikipedia.org and follow the links to Nash and Rambler.

Nash was best known among young people for its lay down seats. :)

GB

Ian Burgess-Barber
15th Oct 2009, 14:46
Enicalyth, thank you for your contribution, I am aware of the regard this prop is held in, but have learned from several sources (including a respected tech log contributor) that the weak link in the system was the feathering button: Quote
"A common problem with the hydromatic prop was that the button wouldn't pop out. The solenoid would hold the button in, and the propeller would feather, then with the pump running, continue to drive itself out of feather again. The solution was to guard against the button, watching the propeller, and popping the feather button out by hand once the prop had feathered".
Perhaps other readers out there have experienced this inconvenient trait. I wonder if any of the A/C Handling notes mentioned it, or would the cry have been the old Cop-Out "But everybody knows about that".
Ian BB

enicalyth
15th Oct 2009, 16:49
I have some Mosquito Pilot's Notes somewhere because my father, my flying instructor & Best Man and also my next door neighbour for ten years were all that generation. However Pilot's Notes expressed any criticism mildly though the veiled speech did not pass any of the pilots of the day by.

More importantly I cannot for the life of me recall a warbird history site, American I think, that links to just about every RAF wartime flight evaluation carried out. A particular idol of mine, D O Finlay, was one of the greatest test pilots at that establishment whose name I cannot remember either. Mental block all round.

By the time I was flying with HSPs pretty much all the vicissitudes had been ironed out but yes, I don't like the sound of those prop difficulties but then I would not want a prop lacking oil pressure, proper commanded speed and blade angle for whatever reason.

I'm sure someone will post the missing URL and it'll come to me anyway when I least expect it. I'll rummage through the loft and see what turns up, scan it and let you know.

Ian Burgess-Barber
15th Oct 2009, 17:24
Hello E, are you up early, or late in Oz?

Would that establishment be Boscombe Down or perhaps Farnborough?

Ian BB

Brian Abraham
15th Oct 2009, 23:55
Prop feathering buttons were also a problem on the Lancaster I've read. Same sort of problem as you describe, and also one gent who found upon pressing the button on a particular engine all four went into feather.
But everybody knows about that
A common problem. We had a local lad killed with his nav in a F-111. One of the contributing causes was suspected to be a quirk with the type that all the old heads knew about, for they had all experienced the problem, and it was one of those things that you only did once in your life and lesson well learnt - if you survived. At the time of this accident the aircraft had been in service for 20 years, but this particular gem of information was not passed down to the new boys. It is now.

Ian, if you want to delve into the prop and its operation you may find the following of interest.

de havilland | 1944 | 2380 | Flight Archive (http://www.flightglobal.com/pdfarchive/view/1944/1944%20-%202380.html)

HamStd (http://www.enginehistory.org/Propellers/HamStd/hamstd.htm)

deHavilland (http://www.enginehistory.org/Propellers/deHavilland/dehavilland.htm)

HydGov (http://www.enginehistory.org/Propellers/Governors/hydgov.htm)

You can find a online copy of the pilot notes here (FB 6 model)

Pilot's Notes - De Havilland Mosquito FB 6 (http://www.scribd.com/doc/4600762/Pilots-Notes-De-Havilland-Mosquito-FB-6)

cwatters
16th Oct 2009, 06:53
Hemmings Motor News: Nash-onal Pride (http://www.hemmings.com/hcc/stories/2006/06/01/hmn_feature9.html)

The firm would enjoy its greatest World War II success building the triple-bladed Hamilton Standard propellers, which were first designed and built in Britain. The variable-pitch units were highly efficient in terms of extending aircraft range, and by 1945, Nash-Kelvinator had churned out 158,134 of the propellers, along with 290,262 Hamilton Standard propeller governors. The total list of Nash's war production, however, boasted incredible variety, including more than 204,000 rocket motors, and more than 650,000 bomb fuses, plus innumerable small vehicle components for everything from Jeeps to Navy submarines.

http://cll.hemmings.com/story_image/46429-500-0.jpg

Ian Burgess-Barber
16th Oct 2009, 19:50
'Evening All,
I started this thread because, after a lifelong passion for aviation, I was startled to find a name on a prop that I had never heard of before, in an accident report about my father's fatal crash in 1948. It is remarkable that such (mundane maybe) historical facts become generally obscure so soon after the event.

cwatters: I am now humbled to find that Nash-Kelvinator made 158,134 of the things, and I write this in a study full of aviation books, magazines and manuals, piled around the walls, none of which ever mentioned this manufacturer. Thank you for including that glorious morale -boosting advert.

Brian: Thank you for all your links - The official pilot's notes I see, do say re, feathering button, "if it does not spring out, it must be pulled out" - so, some warning there to stretch over to the right of the cockpit, feeling for the button though your service-issue flying glove whilst fighting the overspeeding prop with feet and left hand. Sadly, the ferry pilot's notes that I have in front of me do not contain this useful tip, (my dad was with No. 1 Ferry Unit at the time). Your Lancaster story is a wonder! I will run that past my own veteran Lancaster friends.
Check out The de Havilland Mosquito Page (http://www.mossie.org/Mosquito.html) for the hair -raising story of picking up a brand-new mossie from a maintenance unit in 1947 - loosing one engine, then both, (fuel contamination) and then pushing the feathering buttons and finding that they had not been connected! A very high speed crash followed with 2 SOB surviving.
Health & Safety was not a wartime priority and Cockpit Ergonomics were undreamed of in those times) but if you you read the records, the number of post-war crashes, (with mossies featuring in high numbers), is extraordinary.

My thanks to all for enlightening me, as you have, reference my question - Tech Log delivers again! Thanks also to the moderators for not pushing this down the screen to the Aviation History Thread before the Tech Log contributors worldwide could could bring their contributions to the party.
IanBB

Brian Abraham
17th Oct 2009, 02:09
Ian, forgive me, it was not a Lanc but a Halifax. On the Military thread "Gaining An R.A.F Pilots Brevet In WW11" page 20, post 397

During the day of an Operation we would take our aircraft up on an air test to give all the equipment on board a thorough workout. On one occasion I asked Bill, my Yorkshire Flight Engineer, to feather one of the engines so that I could practice some three engine flying. A rotating propellor, without power, causes enormous drag on the aircraft, so the blades of the propellor of the "dead" engine are turned electrically, so that the leading edge is presented to the airstream, This is called "feathering" as in rowing, when the blades of the oar are turned in similar fashion so that they do not cause drag in the water. We always carried out air tests at an altitude of 5,000ft. or more and it was just as well as when Bill pressed the button of the Port outer engine (The engines are numbered from 1 to 4 looking from the tail to the nose, so the Port outer was No.1). and "Bingo" ...all four engines promptly feathered themselves and, of course, stopped. Bill, the unflappable Yorkshireman , said "Bloody Quiet up here ", leaned forward and pressed the same button and all four engines unfeathered themselves. On the post mortem, later, it was found that a drop of solder from some electrical work above had neatly fused all four circuits together.

The same chap posts on page 54, post 1068. The account gives some feeling to the time in which your Father operated, and of the Mosquito.

A very poorly taught and little known factor in assymetrical engine flying is "Safety Speed " If, with your wheels down and full flap, you open up full power on the good side be it one or two engines and assuming a complete loss of power on the other then there is a speed at which you can no longer keep the aircraft straight. That, very simply put, is your Safety Speed and if you let the aircraft get below that speed you will start turning towards the lost engines, you will start losing height in the turn due to the added lift required and you will stall and lose control of the aircraft. It was, probably , the cause of most of the accidents at OTU's and HCU's during assymetrical flying because frankly, the Instructors themselves were not sufficiently trained to know this and therefore very little, if any, instruction was given until much later when Bomber Command Instructors School came into being and , very quickly, taught recognition of Safety Speed as being of vital importance to the people who were going to be Instructors. When I had my crash in a Mosquito , returning from a raid on a German Airfield in Holland on one engine I am now sure that it was because I let the speed drop too low and below the Safety speed and was unable to stop it from turning and crashing into the trees that saved our lives by lowering us more gently to the ground. I had never had the words "Safety Speed" given to me in any of the instruction that I had been given.

You will note in the pilot notes that the engine out procedures give one a feeling that the aircraft was to be treated with the GREATEST respect and CARE. The copy is of 1950 vintage though, and whether the notes in your Fathers day noted the same may be in question, particularly given the quote above by the Mosquito pilot about "safety speed". Perhaps the 1950 copy was a result of lessons learnt through such accidents as your Fathers.

With respect to reliability of official accounts and designations of equipment, I found it interesting that the only place I've seen the Mosquito Mk. VI referred to as a "6" (Arabic rather than Roman) is the official pilot notes. World is full of surprises - and you learn something new every day.

enicalyth
19th Oct 2009, 09:32
Dear Ian,

Not A&AEE, I was happily there for a while. I have had a scuff around some of my father’s papers and also keepsakes given to me after friends died such as their Notes and odd manuals. One thing at the back of my mind is how well and how frequently Notes were updated. Amending them was a chore. A carton of booklets and a wodge of amendments was dumped on your desk. You quickly learned to do the most recent ones first otherwise you spent ages cutting out and gumming in strips, scoring out and inking in only to open an envelope of amendments and find a complete printed page or pages that superseded your labour! In ideal circumstances Unit Notes would be assiduously kept and updated but the risk that privately held copies such as those in my hands would be incomplete was real. [There is a company that prints “repro” Notes to a high standard but these comments are just as valid and the same holds for records at DoRIS]. Ferry units would have to be particularly “hot” given the nature and variety of aircraft. It is no mean testimony to your father that he flew Mosquitoes and did so in a ferry unit, his skills would have had to be rated well above average on both counts. During wartime when shadow factories were there to ensure continuity of supply aircraft would be constructed to drawings and schedules that differed slightly and were fitted with propellers from multiple source even when the maker itself held a licence. That a de Havilland aircraft was built in a non-DH factory, with non-RR engines and a non-DH HSP Hydromatic is not something I would read too much significance into. Two aircraft side-by-side with consecutive numbers might be subtly different. As I said before it is not always granted to us to have the time and height to put wrongs to right.

Best Rgds

The “E”

Ian Burgess-Barber
19th Oct 2009, 17:18
G'Day to my Antipodean Advisors
Brian (Victoria?) & The "E" NSW

And to think that all of this came out of me not recognizing a name on a prop.

Brian, I knew that Lancaster crews felt sorry for the Halifax guys because they couldn't fly as high, but now we add duff soldering to their woes as well!
I note your comments about about treating the mossie with CARE, Do I remember hearing, that to fly them in combat, one needed a minimum 1000 hrs time before converting to the type. This minimum seems to have been dropped once hostilities ended.

The "E", Thanks for your notes on notes. I seem to remember all that cutting and pasting amendments with my 'Pooley's Flight Guide' back in the pre-computerised days. Thank you for your perception of my dad's skills. I had the privilege of speaking recently with a gent (86 yrs. young), who gained his wings with my father on Course 12 at No. 5 B.F.T.S. in Florida, May 1943. He, unprompted, told me that my dad's flying was held in high regard by his peers. My father's log shows that he flew 17 types in his 1170 hours TT. The mossie was his 13th type as 1st Pilot, (what price superstition) and he had 54 hours P1 on-type at the time of the crash. It is most gratifying to hear (especially from a flyer with A.&AEE experience) words of praise for a pilot serving with a Ferry Unit. So often it seems, the Ferry guys (and gals, pace ATA) are perceived to be at the bottom of the hierarchy of aviotomy (along with the Instructors). Taking nothing away from the heroic combat flyers of course, but surely both ferry work and instruction are full of challenges, and are certainly more demanding than peacetime (A to B and back) flying. I wonder when humankind will outgrow something as primitive as a "pecking order" and develop a more level respect for the diverse contributions of all. Must stop now as I seem to be on the verge of waxing philosophical - and I haven't touched a drop this evening - yet.
Thanks again gents for your input.
Ian BB

Ian Burgess-Barber
11th Nov 2009, 20:31
'Evening All

Have now read a report of the inquest of the above accident (verdict was "Misadventure").
The passenger, aircraftman xxxxxx is quoted as saying "The pilot shouted over the intercom - 'It's stuck, I shall try to crash land' A few seconds later the aircraft tilted to port and then came the crash." Wing- Commander xxxxxx said that the probable cause of the accident was the failure of the port engine to exert thrust after the unfeathering action .... an experienced Flying Officer should have taken certain action to avoid the accident. The Pilots remark "it's stuck" probably implied that the air screw was stuck in fine pitch.

Do our technically qualified correspondents think that "it's stuck" refers to the prop or, maybe to the feathering button, or is it really not possible to judge at this remove?

The inquest added a rider that there was no evidence to show any negligence on the part of those servicing the machine.
The CO said that a pipe fracture could have been involved.
The accident report said that the CSU was examined and found to have no fault.
The RAF accident card says "engine oversped.......presumably due to faulty procedure by pilot."
In all the evidence there is much use of "probably" and "presumably" and clever semantics and legal hair-splitting -and the words "pilot error" are absolutely never to be seen - but relentlessly implied.
Will I ever know?