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View Full Version : Is there a DC7C Flight Engineer in the house ?


The AvgasDinosaur
6th Apr 2017, 15:58
Learned contributors,
I am hoping to contact a DC7C flight engineer or similarly turbo compound experienced flight engineer.
I am trying to write a novel and require some inside information.
Is there anyone willing to help or who can point me in the right direction.
Thanks for your time and trouble,
Be lucky
David
"The AvgasDinosaur"

megan
7th Apr 2017, 02:10
If you want to ask your questions here there may be some one with the requisite knowledge. And it will enlighten us all as well. Have a little info on the bookshelf, but no first hand knowledge.

treadigraph
7th Apr 2017, 06:42
Great shame 411A has gone to his maker, I'm sure he would have been able to help.

john_tullamarine
7th Apr 2017, 09:45
Indeed .. his counsel is sorely missed.

WHBM
7th Apr 2017, 11:59
411A :ok: always had it in for the DC7 due to it's Wright engines, and said the previous DC6B was a way better machine.

treadigraph
7th Apr 2017, 12:30
411A :ok: always had it in for the DC7 due to it's Wright engines, and said the previous DC6B was a way better machine.

Seem to recall Roger Bacon (Mike Ramsden!) on Wrights... it went something like this:

"The old Lockheed Constellation sat on the ramp. Passers by fled in panic as its four Wright Turbo Compounds burst into flames"

WHBM
7th Apr 2017, 13:36
Wright never really had the resources to sort out the Turbo-Compound, although airframers continued to buy it, just because it packed more power into the space than P&W managed. Of course, in the way of the 1940s-50s, each time they appeared to get to grips with something a higher power version was launched and problems continued.

But the issues by the time of the DC7C were nothing compared to those of the B29 in the Pacific in WW2, with earlier versions of the same engine. Read a fascinating detailed account by a subsequent US 1960s airline pilot of the issues he had experienced with the B29 Superfortress, where almost as many men were lost to B29 catastrophic engine failures as to enemy action. Apparently at Guam there was a forward maintenance base where they just junked failed/seized/blown Turbo-Compounds in a huge heap, getting to about 20 feet high, engines being added to the top by a large fork-lift.

I don't think Boeing ever used a Wright engine again after the wartime B29.

megan
7th Apr 2017, 15:26
The B-29 didn't use the turbo compound, but was turbo supercharged.

War time required the -29 and it's engine to be rushed into service before proper development could take place. The early engine had the exhaust on the front of the engine on the front bank of cylinders, so overheating from escaping exhaust gases impinged on the front cylinders resulting in overheating. It was found too, that particular attention had to be paid to maintenance of the cylinder cooling baffles. 100 hours was all they were getting out of an engine initially, but reached 400 hours at the end of the war, which was comparable with other combat engines, in airline service the TBO stretched into the thousands as the lessons were learnt. The -29 was closely cowled and take off was not to be attempted if the CHT was beyond a certain temp. The take off was begun with the cowl flaps fully open and it was the flight engineers job to progressively close the flaps as they accelerated down the runway. Such were the cooling demands.

Aircraft to use the turbo compound were the Neptune, Constellation, DC-7, Canadair Argus, Fairchild C-119, Martin Marlin.

A bit of bedtime reading Avgas.

http://aviatechno.net/files/wright_r3350_tc18ea/FLASH/index.html

Brit312
7th Apr 2017, 17:54
Megan, An interesting read and just to add a few points :-

1] The B-29 R3350 was a carburetor engine and so I was told this was a source of the engine fires on that particular installation. Once the engine became a fuel injector engine the engine fire problem was much reduced.

2] The Wright R3350 in all cases was a supercharged engine where the supercharger was directly driven from the crankshaft via a high or low gear. It was not a turbo supercharged engine.

The turbo term was used when turbo driven recovery turbines [ 3 off] were fitted to the engine . These recovery turbines were driven by the engines exhaust and each one recovered about 60 hp [ Total 180 hp per engine] . These turbines returned their recovered hp direct to the crankshaft , but had nothing to do with the supercharger

Brit312

tonytales
7th Apr 2017, 18:27
The B-29 was most definitely turbo-stumper charged. Fortunately the Constellations and DC-7 were not. The turbo-supercharger used a back pressure and thus put a load on the cylinder. The DA an EA series engine that were "Turbo-Compounds" used a blow-down turbine utilizing the exhaust gas velocity and imposed no back pressure on the cylinders.
The BA series of engines used on the B-29 an L-049/149 Constellations was a difficult engiNe to work. I never worked the b-29 but knew many vets who had. The power section cowling on both was poor. The fuel injection lines were an add-on. The engine leaked oil and made sludge. If you had a clean engine it probably had developed an injection line pinhole leak. Did I mention the engine mounting system? The attached to the engine by the rear cylinder heads, High-tension ignition added to the problems.
The BD and later series engines had little relation to the BA series. The final series, the EA were on later L-1049 , L-1649 and DC-7 including the C. Good engines but too late to save Wright's reputation.

megan
7th Apr 2017, 18:27
G'day Brit. You're correct re (1), the carburettor versions were prone to induction fires.

With respect to (2) you are correct depending on the particular aircraft, the B-29 had an engine driven supercharger plus two turbo chargers per engine.

Brit312
7th Apr 2017, 20:15
Thanks Tonytales and Megan for the corrections regarding the earliest B-29.
My limited experience is with R3350 BD engines, which had no turbo chargers just a straight supercharger. Tonytales I would agree with you they certainly used a lot of oil with engine top ups being by the gallon rather than the quarts and always be careful of hydraulic lock prior to starting

Spooky 2
10th Apr 2017, 09:35
Have some experience in the 1049H as a copilot and time in the DC6B as a FE if that will help. Unlike 411A my memory is not as keen as his was regarding specific details. Also, as I recall, his father was a Douglas engineer.

WHBM
10th Apr 2017, 17:17
This thread from a while ago had some contributions by those with some working knowledge of the Wright engine.

http://www.pprune.org/tech-log/362757-sound-wright-vs-pratt-whitney-super-constellation-vs-dc4.html

Shackeng
15th Jul 2017, 21:44
The B-29 didn't use the turbo compound, but was turbo supercharged.

War time required the -29 and it's engine to be rushed into service before proper development could take place. The early engine had the exhaust on the front of the engine on the front bank of cylinders, so overheating from escaping exhaust gases impinged on the front cylinders resulting in overheating. It was found too, that particular attention had to be paid to maintenance of the cylinder cooling baffles. 100 hours was all they were getting out of an engine initially, but reached 400 hours at the end of the war, which was comparable with other combat engines, in airline service the TBO stretched into the thousands as the lessons were learnt. The -29 was closely cowled and take off was not to be attempted if the CHT was beyond a certain temp. The take off was begun with the cowl flaps fully open and it was the flight engineers job to progressively close the flaps as they accelerated down the runway. Such were the cooling demands.

Aircraft to use the turbo compound were the Neptune, Constellation, DC-7, Canadair Argus, Fairchild C-119, Martin Marlin.

A bit of bedtime reading Avgas.

Wright R3350-TC18EA Service Manual (http://aviatechno.net/files/wright_r3350_tc18ea/FLASH/index.html)

This reminds me of the Bristol Centaurus as fitted to the Beverley. IIRC when it came into service the engine TBO was 200hours.

b1lanc
15th Jul 2017, 23:20
http://www.pprune.org/aviation-history-nostalgia/577182-ec-121-super-constellation-2.html

I had the manual that I referenced but auctioned it off in 2009. It was a very good read however. If you can find a copy you would enjoy.

One here if the link but I don't know how old the link is.
https://www.advancedpilot.com/store.html

CSP0103
16th Jul 2017, 01:12
Used the very engines you're interested in. Should still be lots of retired FE's over here to help you with your search.

ratpackgreenslug
16th Jul 2017, 09:38
Ref 411A:

Indeed .. his counsel is sorely missed.

So very true. His input was a special treasure, as indeed is the counsel of several members with thousands ( even 10's of thousands) of posts to their esteemed credit. Such erudite and garrulous contributions from prolifically sage like posters is a thing of serendipitous wonder. Always a joy to read. Do please keep posting.

esa-aardvark
17th Jul 2017, 16:37
Hello, my father was a crew chief on the B-29.
He once told me that if the turbo wastegate stuck,
then an engine overspeed was immediate. Then the propellor
would depart the aircraft, upwards, then the now unloaded
engine would overspeed a lot more, and also depart the aircraft.
Apparently happened so fast not possible to stop.
Regards, John

ORAC
17th Jul 2017, 19:44
The average airframe life in WWII was between 100-300 hours before being written off. It wasn't economic to use expensive material or components to build an engine which would last longer than the airframe it was attached to; those could be used more productively elsewhere.

Callous? In war with conscription lives and maintenance hours are cheaper than precious metals and production hours which can be spent on higher tech weapons and products.

Kewbick
23rd Jul 2017, 15:36
Quite the opposite. Air crews were precious. The training of qualified air crews took over a year from induction to front-line service.

Development of the Wright R-3350 engine started several years before WW.II . Although most of the problems of the engine have been discussed, I doubt access to "expensive materials" and "components" was the principal problem of the big Wright. Remember that during WW.II, the U.S. and Canada had nearly unfettered access to materials that Europe (ETO), did not.

Little known is the federal investigation into the poor workmanship, lack of oversight and corruption at the Wright plant during WW.II. By the end of WW.II most of the HR factory problems were resolved, and the R-3350 was upgraded to direct fuel injection, which solved many operational problems. Ultimately, the R-3350 achieved a TBO rating of 3,500 hours.