View Full Version : Largest Piston Airliner?

10th Feb 2010, 18:08
Hi all, try as I might I couldn't find this on google so...
what was the largest piston engine airliner - by largest I mean the most number of seats for fare paying passengers

what about today, which piston aircraft in regular service carries the most passengers? I can think of one but I want to see what you all have to say :)

I'm curious because I read maintenance costs are so much lower for pistons I'm suprised a niche isn't there for a simple plane as opposed to the ever more complicated regional jets appearing which must be hard to make a profit on

10th Feb 2010, 19:05
If we can count the military in there, how about the C124 Globemaster? 220 fully-equipped troops according to Wiki.

10th Feb 2010, 19:18
Perhaps the Bristol Brabazon?

Or would have been, had it not been for more efficient prop-jet and pure jet airliners of the early 1950s.

10th Feb 2010, 19:26
maintenance costs are so much lower for pistons

A remarkable statement. Justification?

As far as the original question goes, the Boeing Stratocruiser springs to mind.

10th Feb 2010, 19:27
The Lockheed Constitution might be a contender?

10th Feb 2010, 19:33
by largest I mean the most number of seats for fare paying passengers

I've read that 160 paid money to ride the Armagnac in high-density configuration.

http://img200.imageshack.us/img200/8950/arm3671597.jpg (http://img200.imageshack.us/i/arm3671597.jpg/)

10th Feb 2010, 19:35

I am amazed re your comment about Maintenance costs being cheaper for a Piston Aircraft.

Who told you that THE TOOTH FAIRY).

With due respect Piston Aircraft run on AVGAS (Petrol) as apposed to Jet Engines which run on Jet Fuel (Jet A1)

The costs of Avgas are somthing like 10 times the costs of Jet A1

I would go back to your source of information re Piston Aircraft and ask him to remove his head from his bottom

henry crun
10th Feb 2010, 19:49
The XC-99 would be a winner hands down, if you hadn't included "for fare paying passengers". :)

10th Feb 2010, 20:03
"I would go back to your source of information re Piston Aircraft and ask him to remove his head from his bottom..."

Well, that's a little strong, eh, even if it is correct? Stickflyer was just askin'.

I should think, having flown in my first piston-engine airliner, a Convair, in 1951, that passenger discomfort would be a HUGE turn-off, to say nothing of a piston engine's comparative lack of reliability.

Don't think anybody ever paid to ride a Constitution or a C-124. Got paid is more like it.

Nor did anybody ever pay to ride a Brabazon. The only one that ever carried [a few] non-paying VIP passengers was the Mk II, which was not piston-engined but powered by Bristol Proteus turboprops.

That Armagnac certainly beats the 1049 and 1649 Constellations and the Stratocruiser, which are the most capacious piston-engine civil transports I can think of...maybe Mr. Antonov designed something bigger?

10th Feb 2010, 20:08
learjet I'm going on what I've read about ownership costs for private flyers who own their own planes. They talk about the local mechanics knowing and having parts for common piston engines, while with a turbo prop you need specialist parts, or to have parts x-rayed every X hours, even adding a constant speed prop adds a heavy expense as does recractable undercarriage - the list goes on
OK the turboprops and jet regionals have a maintenance base and servicing but I bet it's not as cheap as with a piston engine
If you insist I'm wrong then I'm listening, isn't the twin otter a TP? Would be interested to compare it's MX costs and prove me wrong..
In the meantime I'm sticking to my guns with my PISTON engine thankyou!

Obviously I'm talking about the cheaper end of the market, the under 20 seaters here that might use such antiquated technology

I'm happy to bust a few myths along the way

10th Feb 2010, 21:55
If we can count the military in there, how about the C124 Globemaster? 220 fully-equipped troops according to Wiki.

C124 Globemaster was enormous.

I travelled in one from McGuire AFB, New Jersey to Europe in 1961. My log book shows McGuire to Harmon AFB, Newfoundland 4 hours 25m, Harmon to Lajes 7 hours 40m, Lajes to Wiesbaden 9 hours 10m.

Apart from size and the spaciousness of the cockpit the only thing that really impressed me was the Flight Engineer's station and the engine analyser that constantly monitored the health of the engines.

I shot some 8mm cine film of this trip and the screen-grab below gives some idea of how far it was from the top of the fuselage to the top of the wing, with a further drop to the gound below.


10th Feb 2010, 22:20
stepwilk, the Centaurus powered Brabazon I was the only one ever to fly, the Brabazon II was never even completed, so it cannot have carried anyone, anywhere. Mores the pity

How many passengers did the Breguet Deux Ponts carry? I know the Armangac was bigger, but the Breguet had two decks decks so I just wondered?

10th Feb 2010, 22:31
Yes, you're absolutely right, my misteak...

10th Feb 2010, 22:37
Wiki says the Air France passenger Deux Ponts had seats for 48+59 standard (but up to 135 high-density)

Wiki gives from 84 to 108 seats for the Armagnac but potentially up to 160
Both types carried fare paying passengers (including to London)

The Centaurus powered Brabazon never got a C of A

10th Feb 2010, 22:38
The Deux Ponts could only carry 135 in high density layout.

10th Feb 2010, 22:52
...and at maximum payload operation it was more economical to run than the Stratocruiser. Using pence per seat-mile, 2.72 versus 3.66. It was also the only landplane prop-driven airliner to offer passenger accommodation on two full decks...?

http://img717.imageshack.us/img717/6250/lastscan5685879.jpg (http://img717.imageshack.us/i/lastscan5685879.jpg/)

10th Feb 2010, 23:03
A British runner-up was the Universal (civil Beverley)....max seats projected 132....G-AOEK actually flew civil flights in a Hunting-Clan/Blackburn operation in the the Gulf in 1955 but it appears only the tail boom had seats and the main purpose was hauling heavy freight to desert strips

11th Feb 2010, 08:01
OK the turboprops and jet regionals have a maintenance base and servicing but I bet it's not as cheap as with a piston engine
If you insist I'm wrong then I'm listening, isn't the twin otter a TP? Would be interested to compare it's MX costs and prove me wrong..
In the meantime I'm sticking to my guns with my PISTON engine thankyou!

You seem to be basing your facts on a simple 4-cylinder engine in a Cessna!

Maintenance costs on something like a 24 cylinder Wright Turbo Compound would have been very expensive. These engines used to shake themselves apart every few hundred hours!

11th Feb 2010, 10:11
Anyone know how many pax a Latecoere L631, six engine flyingboat could carry. They staged through Trincomalee carrying troops to Saigon in the early fifties.

Agaricus bisporus
11th Feb 2010, 11:02
Clearly if pistons were cheaper to run and maintain we'd all be using them now, so that idea is dead in the water. With the reliability problems of the Connies, for instance, (engine shutdowns a weekly event) and rebuilds of those fantastically complex engines a massive industry it is not hard to see why turbines gained the upper hand within a very few years of their introduction. The big pistons lasted a few hundred hours on the wing at most. Turbines now many tens of thousand. Bit of a no-brainer, really.

But the biggest pax piston operating now? Well, are there still any Connies left doing jollies or the odd charter - if not maybe a DC6 somewhere in S America? Precious few (largely due to operating costs...). Certainly no big pistons left on scheduled pax services - Air Kenya was the last I think, retiring their DC3s some 10 years ago.

11th Feb 2010, 11:59
"Maintenance costs on something like a 24 cylinder Wright Turbo Compound..."

The R-3350, which I've flown, had 18 cylinders. There would be no possible way to configure a multi-row (or for that matter single-row) radial with 24 cylinders.

11th Feb 2010, 12:32
I knew it had a helluva lot of cylinders but didn't bother checking the fine details.

The point I was trying to make is that they could not be compared with a 4-cylinder Lycoming.


11th Feb 2010, 12:33
This one is causing to cause all sorts of problems for definitions.

On 21st October 1929, the Dornier Do X 12-engined flying boat carried the greatest number to fly in one aircraft up to that time. 10 crew, 150 passengers and 9 stowaways. So, its either the winner or a good runner up to the Armagnac.........but it was a one-off not a scheduled service.

Likewise, if you include airships, the Graf Zeppelin (4 Diesels) carried 150 +45 crew on short flights but only 50 intercontinental. It would certainly win on length or volume criteria.

11th Feb 2010, 12:37
Off message , but did the Dornier DOX have the most piston engines with 12 . Only 100 or so passengers though.

Tyres O'Flaherty
11th Feb 2010, 13:18
Re Connie ''jollies'', not sure of the present status of it, but I think that's the plan for the Lufthansa Constellation.

Damn I need to get saving :ok:

11th Feb 2010, 17:44
Glad to have asked this question! A lot of interesting aircraft I never knew
existed and great pictures, I bet they sounded great too

I looked for Soviet behemoths but it seems they quickly pressed on with turboprops after the war eg the IL-18's and took a while to consider really large passenger planes. The DC3-like IL-14 was the largest I found

Re: the piston engine. Apologies yes I was thinking of 4 cylinder Lycomings in today's small passenger planes being cheaper than perhaps a turbo prop in the same plane, not the large radial engines that powered those beasts! I should have made it clearer I was thinking about very small passenger piston aircraft

One piston still flying today is the AN-2 which I think has 10 seats and theres a large Cessna or two. And some bush planes
But I'm not sure which of them carries the most pax... ?

11th Feb 2010, 18:32
The De Havilland Canada DHC-3 Otter is still in daily operation, and carries 10 or 11 passengers.

11th Feb 2010, 18:35
With the reliability problems of the Connies, for instance, (engine shutdowns a weekly event)
It wasn't the Connie itself that was unreliable, but the Wright Turbo-Compound engine it used. This was never got right. Douglas made the unwise step of moving on from the DC-6 (Pratt & Whitney engines) to the DC-7 (Wright Turbo Compounds) and got all the problems of the engine too. The jets came along shortly afterwards, the older DC-6s carried on in secondary tasks all through the 1960s and beyond but the DC-7s mostly went to the breakers straight away. Some hadn't had 5 years service.

But even this was nothing compared to the initial usage of the Wright engine in WW2. The B29 was renowned for engine failures in the Pacific, it seems to have accounted for almost as many losses as enemy action. It is quite unbelievable that the atomc bomb was put onto such an unreliable aircraft, although I did read once that the Enola Gay engines had been hand-built by engineers rather than taken from the normal assembly line. Another account described a scene at Guam in 1945 where USAF maintenance had accumulated a huge mountain of unserviceable Wright engines off B29s, hundreds of them, which was about 30 feet high, they must have been using a crane to pile them up like that. I wonder what became of them (cruel cynics would say they were shipped back to the US and sold to Lockheed for the Connie :) ).

11th Feb 2010, 19:29
But even this was nothing compared to the initial usage of the Wright engine in WW2. The B29 was renowned for engine failures in the Pacific, it seems to have accounted for almost as many losses as enemy action.

Quite correct, my father flew B-29s and he told me that at max combat takeoff weight the loss of just one engine on takeoff would result in a crash, nearly all of which were fatal to all crew members. I'm trying to recall exactly how long after takeoff it was until the B-29 could be in a position to return for a safe landing after the loss of a engine. I think, and am willing to be corrected, that it was around three minutes and that required dumping the bomb load. He said basically that all takeoffs were 'ground effect' takeoffs before they knew what 'ground effect' was.

My father considered the B-29 horribly under powered. The B-50 was much better.

11th Feb 2010, 22:32
Bregeut Deux Ponts

Another type I remember, known to us schoolkids, alas, as the "Duck's Pants". There was a deep night Air France freighter which in the mid-1960s made a climbing turn out of Heathrow over a relative's house in Chertsey at about 02.00, maybe at 1,000 feet if they were lucky, and was renowned for waking up the whole town.

But more remembered was one of the Air France pax/freighter combi conversions which did the afternoon flight a few days a week from Paris to Bristol and back, up to about 1968. I was once allowed to accompany next door's au pair (who, as I was an immature 15 year old, I quite fancied), returning to Paris, to Bristol Lulsgate to "show the way", we took a local bus which put us off at Lulsgate Bottom, and walked up the remaining half mile to the airport, me manfully struggling with her suitcase, with the Deux Ponts silhouetted on the skyline against the evening winter sunset. It was the only one I ever actually saw (that Chertsey one was only heard). They seemed to have got about half a dozen pax that day, who would have been lost in such a large aircraft, goodness knows why it was used on the route.

Agaricus bisporus
12th Feb 2010, 12:56
Some alarming "facts" from Wikipedia. The article also says that the B29 had an impressive power to weight ratio which hardly seems in line with the Confederate Air Force's experience. Changing the top cylinders every two - three missions! Man, that was one problem aeroplane!

Thanks, I'll stick to turbines.

an engine that would overheat regularly at combat weights, particularly during climbs after takeoff. Unseated valves released fuel-air mixtures during engine combustion that acted as a blowtorch against the valve stems. When these burned through the engines disintegrated and caught fire. A fire that was not immediately contained in the forward part of the engine by fire extinguishers became impossible to put out. An accessory housing manufactured of magnesium (http://en.wikipedia.org/wiki/Magnesium) alloy (http://en.wikipedia.org/wiki/Alloy) in the back of the engine would often catch fire and produce heat so intense it burned through the firewall to the main wing spar in no more than 90 seconds, resulting in catastrophic failure of the wing.
This problem would not be fully cured until the aircraft was re-engined with the more powerful Pratt & Whitney R-4360 "Wasp Major" (http://en.wikipedia.org/wiki/Pratt_%26_Whitney_Wasp_Major) in the B-29D (http://en.wikipedia.org/wiki/B-29_Superfortress_variants#B-29D)/B-50 (http://en.wikipedia.org/wiki/B-50_Superfortress) program, which arrived too late for World War II (http://en.wikipedia.org/wiki/World_War_II). Interim measures included cuffs placed on propeller blades to divert a greater flow of cooling air into the intakes, which had baffles installed to direct a stream of air onto the exhaust valves. Oil flow to the valves was also increased, asbestos (http://en.wikipedia.org/wiki/Asbestos) baffles installed around rubber push rod (http://en.wikipedia.org/wiki/Push_rod) fittings to prevent oil loss, thorough pre-flight inspections made to detect unseated valves, and frequent replacement of the uppermost five cylinders (every 25 hours of engine time) and the entire engines (every 75 hours).[3] (http://en.wikipedia.org/wiki/B-29_Superfortress#cite_note-2)
Pilots, including the present-day pilots of the Commemorative Air Force (http://en.wikipedia.org/wiki/Commemorative_Air_Force)ís Fifi, the last-remaining flying B-29, describe flight after takeoff as being an urgent struggle for airspeed (generally, flight after takeoff should consist of striving for altitude). Radial engines (http://en.wikipedia.org/wiki/Radial_engine) need airflow to keep them cool, and failure to get up to speed as soon as possible could result in an engine failure and risk of fire.

12th Feb 2010, 14:33
Re the Deux Ponts, it featured in many a publication in the 1950s concerning London Airport, as it then was, due to the fact that Air France used it as a back up aircraft for their Paris schedules (back up both in terms of replacement aircraft and extra capacity).

I remember them in the 1950s when they seemed huge compared to everything else in front of Queens Buildings and later, in the 1960s, I'd regularly see one on the way to school as they flew an early morning freight flight into Manchester.

The last Air France one I saw was at Toussus le Noble, unfortunately in bits as it was scrapped in early 1979 and was still lying around at the time of the Paris show that year. I drove right up to it, parked next to the ex Senegal Govt Constellation, also awaiting scrapping and was able to climb aboard what was left of the cockpit.

Here's a photo taken the same month with the outer fin of the Connie showing at the rear. F-BASX - Air France Breguet 763 Deux Ponts Aircraft - Toussus-Le-Noble Photo @ Airplane-Pictures.net (http://www.airplane-pictures.net/image2247.html) By the time I was there the Deux Ponts' the nose had been cut of and the cockpit section was lying at an angle on the ground.

Of course the official name was the Breguet Provence, the military version being the Sahara and Air France called them the Universel when used as freighters - and weren't those upward opening lower fuselage doors impressive?

I seem to recall 1950s publications talking of a large percentage of wood being used in the fuselage construction but don't remember seeing too much wood lying around at Toussus. Anyone like to comment?

12th Feb 2010, 18:29
I see above the B-29 was finally re-engined with the P&W R-4360, same engine that went into the Boeing Stratocruiser. This had issues of it's own, among them a propensity of the props to shed blades in the cruise, especially mid-ocean (possibly an issue of how much power they had to handle).

The R-4360 was a 28-cylinder (7-cyl x 4 rows). On a 4-engined aircraft that's 224 sparking plugs, what chance all would be working 100% in the mag check ? It also suffered from having 4 rows of cylinders, the back row were just too shielded by those in front and would overheat. The Big Ends on the crankshaft must have been a fitter's delight as well !

12th Feb 2010, 20:27
Breguet Deux-Ponts got a mention in the press when it visited London in June 1954 as this press cutting shows:


12th Feb 2010, 21:40
I seem to recall 1950s publications talking of a large percentage of wood being used in the fuselage construction but don't remember seeing too much wood lying around at Toussus. Anyone like to comment?

There's a good article on the Breguet in Aeroplane Monthly (July 1992) by John Stroud and he describes it as an all-metal aircraft.
"The unpressurised fuselage, of duralumin with stressed metal skin..."

13th Feb 2010, 09:08
That would tie in with my recollection of the wreck and the photos I took at Toussus.

13th Feb 2010, 18:29
Well since one flew over my house today and the sound had me scurrying out to see what it was - Largest piston airplane regularly carrying passengers today - the Trislander (17). Good old England :)

13th Feb 2010, 19:45
I can remember that around 1950(ish) there were some fairly big flying boats at Hythe, near Southampton, new in those days, I think, not sure if they had four or six engines? Can't find anything on Google so maybe it never entered passenger service.:confused:

13th Feb 2010, 20:29
Could you be thinking of the Short Shetland? There was one civil prototype of this boat. It was bigger than a Sunderland (of which you would have also seen the civil version, the Solent, Sandringham etc) but smaller than the Princess, but had four piston engines.


13th Feb 2010, 21:11

The flying boats in question were SARO Princesses and they were still in existence in 1965. Three were built but I think only one (G-ALUN) was completed and flown. I don't think it ever entered service.

13th Feb 2010, 22:19
"I can remember that around 1950(ish) there were some fairly big flying boats at Hythe, near Southampton, new in those days, I think, not sure if they had four or six engines? Can't find anything on Google so maybe it never entered passenger service."

Parabellum - as Kitwe says, the Saunders Roe Princes were laid up around the period you mention, but also at that time Aquila Airways were still in operation (ceased 1958);

Aquila Airways: Facts, Discussion Forum, and Encyclopedia Article (http://www.absoluteastronomy.com/topics/Aquila_Airways)

I can remember my Dad taking me to Southampton to see one of the big Cunard liners (QE or possibly QM) and an Aquila Sunderland (/) was taxiing - and he told me we had missed a trip to Kenya in something similar when he first went there in '54 (I believe it was by about 2 yrs)

PZU - Out of Africa (Retired)

14th Feb 2010, 02:25
The big problem with many old piston engines is that the octane rating they were designed for is no longer available.

So the engines on historic a/c like the B-29 are now operated on much less than the original horsepower:uhoh:

The Canadian forces operated the piston Argus for many years after turbines had taken over. They had to get a refinery to make up a $pecial batch to keep it flying. The CAF doesn't have that kind of money.

crackling jet
14th Feb 2010, 15:46
WHBM, The breguet du ponts was operated into Bristol in the sixties not so much for the passenger traffic but the transfer of freight heading for BAC Filton, a lot of Concorde parts arrived that way. I remember seeing as a kid when i was living on the road beside the airport, God it was an ugly beast, probably the original BUFF.

14th Feb 2010, 17:00
I routinely buy race gas for my track car--modified Porsche 911--for $8 US a gallon, and as I remember, it's 104 octane. I know that's not 115/130, but certainly Fifi doesn't have to burn 100LL...

15th Feb 2010, 00:34
Thanks kitwe, pzu and harmonious dragmaster, yes it comes back to me now, the Princesses!

14th Mar 2010, 17:05
Despite it's wingspan of 188ft. and length of 142 ft. it carried only 46 passengers.

14th Mar 2010, 18:25
As far as I can see, nobody has mentioned Howard Hughes' Hk1, or 'Spruce Goose'. It was designed to carry up to 750 men, had 8 engines of 3000 hp each, and contrary to popular belief, it did fly, albeit only for about a mile at rooftop height.

14th Mar 2010, 19:04
It's hardly "contrary to popular belief," since I think anybody with a pulse is aware that the Hughes Hercules (I hate the demeaning term "Spruce Goose") got off the water. But the real question is whether it actually flew or simply flew in ground effect.

The latter involves a perfectly legitimate category of vehicle, for the Soviets made a variety of WIG craft designed to cruise fast over large bodies of water, but people continue to argue whether the Hercules was an airplane or a WIG craft.

14th Mar 2010, 19:09
stepwilk :

I don't think the term 'Spruce Goose' was meant to be demeaning and I certainly didn't mean it that way.

The topic came up in conversation recently around the dinner table at a social gathering of about 10 people, mostly in aviation and all pretty bright, two of them US Americans, and only 2 of us thought it ever flew, the others were convinced it never got off the ground (or water). You may move in more enlightened circles than I do!

14th Mar 2010, 19:59
My "Spruce Goose" phobia is purely a personal thing, didn't mean it as a put-down. I'm almost alone in feeling the same way about "Connie" for Constellation. Ever since flying the thing, I haven't been able to call it anything by a Constellation.

That's interesting that your friends weren't aware the Hercules got off the water. I think the two photos of it that most people have seen are Hughes in the left seat, turning toward the camera and wearing a fedora. and the three-quarters front view of it "flying."

Noah Zark.
16th Mar 2010, 01:18
Perhaps the Bristol Brabazon?

The Brab. was only kitted out with about 100 seats, in very roomy configuration.

16th Mar 2010, 02:32
From wiki...

When completed, it was capable of carrying 750 fully-equipped troopsI wonder if that should be altered to "...it was capable of carrying 750 very scared fully-equipped troops".
The idea was to ferry those troops, or equipment, by air (to escape the U-Boats) across the Atlantic to reach the combat zone.
I have a wartime Popular Science article which apart from enthusiastically describing the enormous dimensions of the "soon to fly" behemoth mentions an estimated cruising speed of 145 mph. That's not much faster than the Gigant?

http://img11.imageshack.us/img11/3519/bigbastard.jpg (http://img11.imageshack.us/i/bigbastard.jpg/)

So, I have this mental picture of an enormous aircraft lumbering along close to the water heavily loaded with many many poor souls heading off to war without any defensive armament. Sounds bad.

http://img717.imageshack.us/img717/9144/me323b26kd9.jpg (http://img717.imageshack.us/i/me323b26kd9.jpg/)

16th Mar 2010, 03:56
No one has brought up the XC-99, the passenger/cargo version of the B-36. It was supposed to carry 400 troops but spent most of its time hauling cargo.

henry crun
16th Mar 2010, 04:43
MarkerInbound: I suggest you read post #8.

24th Mar 2010, 19:00
Gosh, the Canadair Argus. My last sighting of this somewhat strange hybrid aircraft (airframe similar to Britannia 312 with Wright R3350 turbo-compounds) was at St.Ives, Cornwall in September 1972. Walking around the town I was surprised to hear the unmistakeable muffled roar of the big Wright's at climb power, then over the rooftops flew the Argus, on departure from St.Mawgan, no higher than around 1500ft in a very shallow climb.

Re the B29, although these were equipped with supercharged Wrights, they weren't the turbo-compounds as fitted to Super Connies and DC7's. As far as I'm aware, these weren't introduced until the early 1950's, initially on the Lockheed Neptune. Even the early Super Connies had non-compounded Wrights (the basic L1049).

Yes, the Wright turbos were renowed for their unreliability, usually involving failure of the PRT itself (power recovery turbine). So why did Canadair choose this powerplant for the Argus, with its role of extended overwater reconaissance? I remember reading an account by a retired TWA skipper failures were dramatically reduced if the supercharger was not "changed gear" to its second stage at higher altitude. So maybe this procedure was adopted by crews in preference to a higher cruise altitude with the chance of a PRT failure.

diesel addict
25th Mar 2010, 17:46
IIRC the Argus (Arguses, Argii ??) were fitted with piston engines as they had a much better sfc in the low-level low-speed cruise, which, of course, is where they passed most of their time.....

26th Mar 2010, 00:29
One poster touched on the diesels used in the Graf Zeppelin. These, surely are the way to go for aircraft which aren't economic with turboprops. Look at the advantages:

No spark plugs
Burn Jet A1
Best specific fuel consumption of any engine turning a propeller (correct me if I'm wrong)Junkers had them on the JU86 and the Blohm & Voss BV138 patrol flying boat used them too, and that was in the days of mechanical injection. Fit them with a modern common rail system and a FADEC, and there's potential for you. Eurocopter are looking at putting a diesel in their Colibri helicopter as well.

1st Apr 2010, 11:48
...as for pax seating, not sure. Maybe the Shakey Jake?

4th Apr 2010, 02:47
There's a fairly complete history of R-3350 development and service in wikipedia (http://en.wikipedia.org/wiki/Wright_R-3350).

One additional factor working against the early R-3350s was the exhaust system design. The front row of cylinders had exhaust ports facing forward into a manifold upstream of the cylinders. This manifold preheated the cooling air for the cylinder heads - hardly a stroke of genius. :ouch:

The P&W R-2800, by contrast, had all exhaust ports facing aft to avoid this preheating.