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GazzaMataz
06-03-2004, 02:16 AM
I have often wondered what the advantages/disadvantages are between twin engined and single engined planes. I'm talking about the Me110, the P-38, the mosquito etc. I always thought that they would be that much faster, but I remember looking through an old RAF book as a kid and seeing that they were only marginally faster (that book is probably quite collectable now).

Where they better at climbing, faster at accelerating? I can imagine that they could carry a better bombload/armament but certainly not as manouverable...

Anyone?

Tickety boo...
Gazzamataz
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[This message was edited by GazzaMataz on Thu June 03 2004 at 01:40 AM.]

GazzaMataz
06-03-2004, 02:16 AM
I have often wondered what the advantages/disadvantages are between twin engined and single engined planes. I'm talking about the Me110, the P-38, the mosquito etc. I always thought that they would be that much faster, but I remember looking through an old RAF book as a kid and seeing that they were only marginally faster (that book is probably quite collectable now).

Where they better at climbing, faster at accelerating? I can imagine that they could carry a better bombload/armament but certainly not as manouverable...

Anyone?

Tickety boo...
Gazzamataz
http://www.gazzamataz.com

[This message was edited by GazzaMataz on Thu June 03 2004 at 01:40 AM.]

LEXX_Luthor
06-03-2004, 02:47 AM
Two engines can give more payload (guns, bombs, or fuel) so have greater firepower or range. But the range thing you won't notice on the corny internet dogfighter servers.

In the 1930s it was hoped the twin engines would compete with single engines, but they hoped the same with the bombers out running fighters. Not sure about this---if I recall in the biography of mathematician Abraham Robinson, there was talk about this, twin engines not providing the hoped flight performance advantages over single engines.


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Jieitai_Tsunami
06-03-2004, 02:52 AM
I think the disadvantages are weight and that is why I could shoot down P38s with the very light KI43 Japanese fighter.
I think most American planes are worked around powerful engines.

Does any one know if the P38 could climb better because of its power?

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LEXX_Luthor
06-03-2004, 02:56 AM
P~38 pilots who transitioned to P~51 hated the comparative slooow P~51 climb away from England...but they all prefered P~51 for other reasons. http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif

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"You will still have FB , you will lose nothing" ~WUAF_Badsight
"I had actually pre ordered CFS3 and I couldnt wait..." ~Bearcat99
"Gladiator and Falco, elegant weapons of a more civilized age" ~ElAurens
:
"Damn.....Where you did read about Spitfire made from a wood?
Close this book forever and don't open anymore!" ~Oleg_Maddox http://ubbxforums.ubi.com/images/smiley/16x16_smiley-surprised.gif

HamishUK
06-03-2004, 04:36 AM
Good question. Twins had many advantages over singles and also some disadvantages. Twins had the reliability issue if one engine was out the pilot could still make it home on the other. There was also the fact that it could lift heavier loads and travel further. Speed earlier in the war could be obtained using a twin (See the Mosquito, Blenheim and later the Marauder and Boston being very fast).

Twins however cost more to manufacture and were more complex in their requirements. It also took longer to build a twin than a single. They were also heavier on ground maintanence than singles.

This is still true today. The Jaguars I used to fly were twin jets and they were far heavier on down time than say a Hawk. Same as say for an F16. That is one reason why the F16 has been so successful in export is that it is a very cost effective multi-role aircraft. The single engine lowering procurement and life maintanence costs.

Personally if I was a pilot in WW2 I would prefer to fly a twin such as the Mossie or Lightning....safer when your over water too!

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tfu_iain1
06-03-2004, 05:56 AM
reason they were slower, well one of them, was the increased drag... those engines have a drag inducing profile... take mossie, unlike spit, it has three drag inducing faces, instead of 1 (engine and fuselage combined) the mossie has 3 (fuselage, and 2 engine nacelles). That is what the pfeil was trying to achieve (that pusher puller arado thing) which was twin engine power, with single engine aerodynamics. as the figues show, it worked quite well too, but had high maintenance and fuel requirements.

budvar62
06-03-2004, 06:44 AM
Hmm, but I thought the mossie was one of the fastest aircraft of the war, and could outrun spits and mustangs. Not an aeronautical engineer but presumably you have to balance increased drag against increased thrust, and fighter twins might well do pretty well on that front. What will always let them down is having two masses out from the axis of roll which is gonna kill their roll rate and therefore a big part of their manouevrability every time...

GazzaMataz
06-03-2004, 09:28 AM
Talking of Mosquitos I cannot inderstand why we still ain't got one... along with the Tempest... or the Typhoon... http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif

Tickety boo...
Gazzamataz
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Obi_Kwiet
06-03-2004, 09:54 AM
The P-38 did awesomely with the Zero's. The whole PT was one BnZ fest for the US early in the war.

SKIDRO_79FS
06-03-2004, 09:54 AM
LEXX, I have never met a P-38 pilot who "prefered" the P-51 (except for the fact it had proper heating,) in fact I know several who flew both and they will tell you that the P-51 was a great aircraft but the P-38 was "one of the great airplanes, one of the greatest fighters and one of the greatest weapons of all time." (Capt. Arthur Heiden, quoted in "Fork-Tailed Devil" by Martin Caidin)

You are right on the mark about their disappointment with the Mustang's inability to climb to altitude before reaching the "Continent", once the pilots discovered this,they realized why 8th. Fighter Command had given them such a hard-sell when the decision was made to transition over.

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VICTORY BY VALOR, GENTLEMEN TO THE END

tfu_iain1
06-03-2004, 10:03 AM
doesnt matter if your thrust has twice the force... that helps overcome the drag, increases accel and lift. a prop plane will never go faster than the engine can push the air to propel it forward... that is why there are physical limits to how fast prop planes can go. pfeil also got to accelerate air that had already been accelerated from front prop, tho not by much. this is why jets are so fast... the air comes out very very quickly. but a plane cannot go faster in level flight than the speed of the air pushed backwards by the propellers. thus the less drag the better.

Lateralus_17SS
06-03-2004, 10:12 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by SKIDRO_79FS:
LEXX, I have never met a P-38 pilot who "prefered" the P-51 (except for the fact it had proper heating,) in fact I know several who flew both and they will tell you that the P-51 was a great aircraft but the P-38 was "one of the great airplanes, one of the greatest fighters and one of the greatest weapons of all time." (Capt. Arthur Heiden, quoted in "Fork-Tailed Devil" by Martin Caidin)
<HR></BLOCKQUOTE>

Most WWII pilots will tell that their plane was the best; obviously they are speaking of several airplanes so most of them are still wrong.

Trying to define 'best airplane' is almost impossible anyway, seeing that it consists of weighing the pros and cons of each aircraft and deciding on an individual basis which ones are most important to you.

Hence why guys who were aces in the aircraft concluded that they had the best damn aircraft in the whole theatre.

FWdreamer
06-03-2004, 10:32 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Jieitai_Tsunami:
I think the disadvantages are weight and that is why I could shoot down P38s with the very light KI43 Japanese fighter.
I think most American planes are worked around powerful engines.

Does any one know if the P38 could climb better because of its power?
<HR></BLOCKQUOTE>S!
Sir not quite sure about its overall climb ratio, i think the zeros had it beat. I do know in the FB/AEP world we fly in that I can easily out zoom climb a zero for short amount of time in my p38. Have yet to try it against a ki84 though. I really guess the weight of the p38 is an advantage in that it helps my dive speed to get up their quick to get out of trouble and the powerful engines to keep that speed going in a climb.
Tsunami sir, post your comment also in the PF forum i bet guys like Skychimp will be able to answer your question for you if not found here. I always wanted to learn more about the IJA planes since flying them in cfs2.

Good Discussion going guys.

Chuck_Older
06-03-2004, 10:34 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Obi_Kwiet:
The P-38 did awesomely with the Zero's. The whole PT was one BnZ fest for the US early in the war.<HR></BLOCKQUOTE>

You're no good at trolling http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif

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Or can I hear the echoes from the days of '39?
~ Clash

SKIDRO_79FS
06-03-2004, 11:14 AM
Lateralus, I quoted Capt. Heiden a little out of context to emphasize my point, however, I think you also missed the fact that Heiden flew BOTH aircraft. He made an objective observation based upon his experiences and found the P-38 came out on top.

BTW Heiden was an instructor in the 40, 51 and 38 and retired after 40 years in aviation with 25,000 hours logged. His insight on this matter led to the creation of Caidin's book on the Lightning. he has also been a valuable source for numerous other books, magazine articles, websites and my own research for an upcoming project. He may not be a household name but his credentials speak volumes IMHO.

Yes, it's pretty much common knowledge that all combat aircraft have their relative merits and indeed nearly every aircraft flown during the war had it's day as "the best", but I was addressing the point made above that "they all prefered the P-51", which is not what I have found to be true among the many P-38 pilots I know and have spoken to or corresponded with. Of course there are exceptions, for instance Lt. Col. Mark Hubbard...

This brings us to your comment about aces thinking the aircraft they scored in being "the best" I suggest you take a look at the career of Lt. Col. Hubbard, the C.O. of the 20th. Fighter Group for a brief time. He became an ace in the P-38 after scoring four kills on an earlier tour in P-40s. He was quite verbal about his dis-like for the Lightning until the day he died in the mid-80's. Oh, and No, he didn't consider the P-40 the best either...

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VICTORY BY VALOR, GENTLEMEN TO THE END

horseback
06-03-2004, 11:33 AM
The P-38 was the only purpose-designed high performance fighter with a twin engine layout. It was able to compete with most enemy fighters it met, if properly flown. The others were designed for other purposes, and suffer in comparison for the fighter role.

The Mossie was designed as a two seat fast bomber/recon plane with a side role as a nightfighter; it was effective as a daylight fighter bomber in the absence of enemy fighters.

The Bf 110 was designed as a heavy 'destroyer' escort fighter, a role that just didn't work out against lighter, faster and more maneuverable single engine types. It was eventually effective primarily as a nightfighter and as a bomber destroyer before the long ranged escorts started showing up.

The Dornier 335 never made it to full operational use, but it might have been as successful as the Lightning, had it shown up in late '43 or earlier.

Nothing else is remotely comparable.

cheers

horseback

"Here's your new Mustangs, boys. You can learn to fly'em on the way to the target. Cheers!" -LTCOL Don Blakeslee, 4th FG CO, February 27th, 1944

VW-IceFire
06-03-2004, 01:05 PM
Yeah the P-38 was the only successful twin engined fighter to be around. Partially because of the range (a factor for both ETO and PTO) and because of its excellent design and the good stall characteristics.

Its downfall was problems with the european weather, complexity of manufacture and design (the counter rotating engins had to be built separately - they weren't interchangable), and it wasn't as agile as smaller, lighter, single engined opponents (Bf 109 in particular). In a strict BNZ sense the P-38 is quite good and very tough...so I think its combat record and ability is quite good but there are other factors that weighed it down and thats why the P-51 replaced it for the most part.

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Korolov
06-03-2004, 01:48 PM
If I remember correctly, the P-38 approached the USAAC's order for a high altitude interceptor with a twin engine design, since no single engine in production at the time had the power for the requirements of the USAAC. Lockheed put two engines in one airframe to achieve the desired performance, compared to other designs like the P-39 which chose to make the lightest airframe as possible (not counting production and combat ready models.)

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k5054
06-03-2004, 03:38 PM
"The P-38 was the only purpose-designed high performance fighter with a twin engine layout. It was able to compete with most enemy fighters it met, if properly flown. The others were designed for other purposes, and suffer in comparison for the fighter role."

I think you missed one, the 262. Otherwise only P-38 and the Whirlwind were single-seat twins. IMHO none of the piston twins were better fighters in fact than the best singles. P-38 was competitive, but it is instructive to note that the 4 8th AF groups all got four times as many kills AS SOON AS they changed to P-51, same missions, same pilots. The P-38 was not competitive as a twin, it had nowhere to carry stuff on the CG, everything had to be external. It had no decent way to carry a second crewman (yes, I know about droopsnoot, no guns, and the M, only dwarfs allowed). Do335 would have had the same problems.
That's all not to say a good twin single-seater could not have been made, but it needed to go to a fifty foot or less span and two big engines. Whirlwind was small enough but didn't have the power, P-38 a little too big to get the speed needed to fight more agile singles. F5F and DH Hornet show the way, but neither saw action in WW2. Fw 187, given db engines might have been something. The problem is, unless it's really incontrovertibly better than the best single, it costs more to buy and run for no benefit.

SKIDRO_79FS
06-04-2004, 12:54 AM
The 20th. Fighter Group (one of the four 8th. Air
Force Groups initially equipped with Lockheed P-38s)
were combat operational from 28 December 1943 through
25 April 1945. They transitioned to the North American
P-51 on July 21, 1944.

Their total scores: 211 confirmed aerial victories, 81
Damaged, 11 Probables

Broken down, the scores were P-38: 89 confirmed-42
damaged-6 probables, the P-51: 122 confirmed - 39
Damaged-5 probables. That's hardly a "four-fold"
increase.

While the numbers do weigh in favor of the Mustang
there is much more that should be factored into the
equation here, allow me to elaborate:

During the seven months the Group flew the P-38 they
were often hard-pressed to reach the target area at
anywhere near full strength, due mainly to abortions
because of mechanical troubles. It should also be
taken into account that these pilots were not
necessarily well trained and were going up against
battle-hardened veterans all the while (at least until
late April 1944) also hamstrung by 8th. Fighter
Command's "escort only" doctrine and combating
frostbite due to insufficient cockpit heat.

On the other hand, the P-51 was in service with the
Group 60 days longer and debuted well after air
superiority over Europe had turned in favor of the
Allies. Also, by the closing months the Group were
also sending up so many aircraft that each of the
three squadrons was able to almost double normal
numbers (they were broken into "A" and "B" Groups and
often sent to two different targets simultaneously.)

Thus, considering these factors, the additional 33
victories scored by pilots in P-51s doesn't
necessarily indicate that aircraft was better, just
that there were more and the targets were not as
formidable as earlier in the war.

Facts are the P-38 was flown by the 20th. for a
shorter period of time against a numerically superior
and better trained adversary without the ability to
roam free looking for targets of opportunity. I would
also point out the amount of punishment a P-38 could
take (anyone remember the thread a little while back
with the collection of damaged Lightnings that came
home?) opposed to the much more fragile Mustang which
could be brought down by a single well placed round in
the radiator.

Also, the missions were not necessarily the same, I
again point to the 8 FC's doctrine, which changed from
escort to multi-role when Gen. Doolittle was placed in
command.

The decision to replace the P-38 with the P-51 was
purely economical, as stated above. It was, simply
put, twice as expensive to manufacture and maintain
and the learning curve for pilots was much higher.
This decision was made long before the P-38L was
developed and thus the best Lightning of the lot never
got the chance to prove itself against the Luftwaffe.

In regards to the agility of the Lightning I would
also direct you to read "The Long Reach: Deep Fighter
Escort Tactics", a collection of essays written by
various pilots from 8th. AF units. The Lightning's
ability to turn with Luftwaffe aircraft is well
documented there by the pilots that were flying it in
combat at that time, not 6 decades later. Considering
the book was intended for newly arrived replacement
pilots it was a sort of primer for them to learn long
range tactics from.

Oddly enough, confessed P-38 critic Lt. Col. Mark
Hubbard wrote "The P-38 will out turn any enemy
fighter in the air up to 25,000 feet," and then later
repeats "When the enemy attacks we continue on course
always in line abreast opened up formation so we
support each other." If a man who dis-liked the
aircraft states it could out turn anything then IMHO
it's pretty much a sure thing it was pretty agile in combat.

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VICTORY BY VALOR, GENTLEMEN TO THE END

k5054
06-04-2004, 03:40 AM
Tell us about the other three groups, and about the losses. Fact is, the p-38 did a lot worse than the other two on same day same mission basis, and that's how I judge it. I discount all stories from pilots about what out-turns what, not because they are wrong, but because the term out-turn is so meaningless on its own. Tell us Zemke's view, having been group commander with all three types.

I was using the term agility in a wider sense than turn rate, the P-38 had about 22 times the roll inertia of a FW190 with around 1.5 times the aileron power. Hence the delay in roll of 1/4-1/2 seconds compared to any single, powered ailerons or not. That is a lack of agility, P-38s config was a worst case for roll inertia, except for the 109Z/P-82 layout. That p-38 could compete with singles is an achievement, but to make it out as better than the best singles is just plain wrong. When it went up against the Varsity, the LW pre-spring '44, it didn't do too well, for whatever reason. The 8th didn't give it a second chance.

HamishUK
06-04-2004, 03:47 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by horseback:
The Mossie was designed as a two seat fast bomber/recon plane with a side role as a nightfighter; it was effective as a daylight fighter bomber in the absence of enemy fighters.
<HR></BLOCKQUOTE>

You are correct in that the Mossie was at first intended as a fast bomber / recon. However by the time the MkVI appeared the Mossie was one of the most highly effective daylight fighter/bombers that the allieds had.

"She could fly long range bombing missions, outrun any German fighter she needed too and still dogfight effectively with a FW or a 109 on the return journey home. As a plane the Mosquito excelled in both roles and I would fly no other had it been my choice" A quote from Wing Com Nigel 'Smudger' Smith who flew the Mosquito on 84 missions deep into Reich territory.

The Mossie was so well respected as a true multi-role aircraft that even the Germans were developing their own 'Moskito' (which fortunately failed to see service due to poor quality wood glue being used and the numerous accidents that followed).

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horseback
06-04-2004, 08:08 AM
Skidro-

Good answer. I would, however, point out that the 8th AF's problems with the Lightning were not paralleled in the Med, where groups that had been "bottle-fed" throughout their training in the type by Lockheed's engineering and test pilot staffs, fought the German and Italian units in the Med from the early days of Torch (when, because of range and performance, they often were deployed where they were outnumbered) to a standstill. These groups managed to consistantly inflict greater losses than they took against a veteran opponent from almost day one--nearly unique among rookie American combat units in this regard.

The fact is that the Lightning pilot needed a much longer gestation period before he could properly exploit the aircraft's strengths, compared to the Thunderbolt or Mustang. Groups that had the early buildup on the type with heavy support from Lockheed instead of the standard AAF fighter pilot training did very well in both the Pacific and the Med.

Had the 78th FG (also an early P-38 group Stateside) been allowed to keep their Lightnings instead of having to surrender them to the 1st and 78th groups for Torch, the P-38's reputation in the 8th AF might well have been much better. As it was, pilots from that group made a pretty good transition to the relatively simpler Thunderbolt, providing many of the early USAAF aces.

cheers

horseback

"Here's your new Mustangs, boys. You can learn to fly'em on the way to the target. Cheers!" -LTCOL Don Blakeslee, 4th FG CO, February 27th, 1944

lrrp22
06-04-2004, 09:20 AM
Horseback,

Don't forget the initial two Mustang groups. The 354th and 357th scored at an astonishing rate for green units (veteran groups too, for that matter).

Despite the P-51B's early teething problems, they out-scored their Lightening cohort groups at a 4 to 1 rate.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by horseback:
These groups managed to consistantly inflict greater losses than they took against a veteran opponent from almost day one--nearly unique among rookie American combat units in this regard.
<HR></BLOCKQUOTE>

Biloxi72
06-04-2004, 09:42 AM
S!
I am a die hard p38 fan and feel while the 38 did good in the ETO it really did its best work while in the Pacific and Med theaters. Where its long range, great load outs, heavy armour and firepower were just the right counter to the Japanese threat till the Hellcat and Corsair could make their present felt.

"It was a marveleous aircraft! It was the best aircraft I flew in the war by far. I never flew the P-51, its been one of my life regrets, but I flew just about everything else there was. I liked the P-38s rate of climb, its speed, the way it handled, and its firepower directly out the nose. The P-38 would turn with almost anything, in fact it would out turn the P-47, out climb it, and out maneuver it. The P-38 was one of the great aircraft of WWII."...Charles MacDonald, P-38 Ace

horseback
06-04-2004, 10:12 AM
Irrp,

I don't forget them. They were trained for single-engine fighters, just like the kids in the 20th and 77th FGs, and they had veteran combat leaders like Don Blakeslee & Jim Howard around to show them the way. Oddly, the P-38 groups didn't get a seasoned pro assigned to help shepherd them through the transition to combat the way the Mustang groups did.

Training and leadership are more important than the aircraft type, and most authorities agree that the P-38 groups brought into the 8th AF in late '43 were poorly served in this regard. Throw in the delicacy of the Allison engine/turbosupercharger combo compared to the Packard Merlin or Pratt & Whitney R-2800 in that theater, and you have serious problems.

The economics of the situation led to the deletion of the Lightning from the 8th AF inventory; the P-38 cost more, it required more maintenance, it took longer to build, and it took longer to train pilots to use it properly.

Mustang and Thunderbolt units were simply able to reach their full potential sooner, and while the full potential of the Lightning was close to the Mustang's, Doolittle didn't have the luxery of the time needed to wring the problems out and get them fixed. He wanted Mustangs and he got them.

The fact that the Pony was the cheapest to produce of the three is strictly incidental.

cheers

horseback

"Here's your new Mustangs, boys. You can learn to fly'em on the way to the target. Cheers!" -LTCOL Don Blakeslee, 4th FG CO, February 27th, 1944

k5054
06-04-2004, 11:40 AM
"Training and leadership are more important than the aircraft type, and most authorities agree that the P-38 groups brought into the 8th AF in late '43 were poorly served in this regard."

Not your fault, but some of the authorities you say agree in fact have been suspected of unfair criticism of some of those group commanders to hide the defects of the P-38 as delivered and operated. The fact that 4 groups all had similar experiences and kill ratios tends to point away from personnel as the cause. All those guys started off believing in the P-38 and were disillusioned by real experience. Some of them, as you point out, still believe in the P-38, it didn't fail because of them.
The p-38 had the worst kill rate and the worst loss rate of the three 8th AF fighters, and the worst serviceability rate too. That's why Dolittle wanted to get rid of it, and he made the right decision. The price didn't come into it, the Air Corps didn't make him pay for them.

Doug_Thompson
06-04-2004, 12:11 PM
Twin-engined planes were less maneuverable and much more expensive. I don't know the correct aeronautical term, but when you have two sources of power, it's harder to roll than when you have one source that provides a type of "axis" to spin upon.

Interestingly, this manueverability issue is one of the reasons Dornier developed the twin-engine "Arrow" ("Pfiel" in German, I think) with its "push me, pull you configuration of one "puller" engine in front and one "pusher" engine in back.

The plane could have been built years earlier but the unconventional idea didn't get much support. When they finally did try it, there were some real positives. First and foremost, it was one fast son-of-a-gun. It combined the clean design similar to a single-engined plane with the power of two engines. It flew well over 400 mph and, on war emergency power, set something of a record at 479 mph.

Second, maneuverability was very good for a two-engined plane, for the reasons described. Third, torque from the engines offset each other. Fourth, the plane was found to be relatively easy to fly when one or the other of the engines was damaged. A regular two-engined plane had real yaw problems when one engine failed. It was perfectly possible, for instance, to use the power of two engines to take off and climb, then turn one engine off for cruising.

There were some big drawbacks. Rear visability was very bad. They also had to invent an ejector seat for a pilot to have any chance of survival if he had to bail out.

BinaryFalcon
06-04-2004, 01:18 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Doug_Thompson:
Twin-engined planes were less maneuverable and much more expensive. I don't know the correct aeronautical term, but when you have two sources of power, it's harder to roll than when you have one source that provides a type of "axis" to spin upon.
<HR></BLOCKQUOTE>

This isn't exactly true. There will likely be more weight on either side to overcome (assuming a conventional twin layout), but with large enough control surfaces you can create and sustain roll rates just as well as single engined craft. Further, if you have counter rotating props (such as in the P38), the aircraft won't have a roll bias or preference like a single engine aircraft will. Basically most single engine planes (unless they're special and have counterotating props on one hub) will roll in one direction more quickly and easily than in the other. Twins will do equally well either way.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>
Interestingly, this manueverability issue is one of the reasons Dornier developed the twin-engine "Arrow" ("Pfiel" in German, I think) with its "push me, pull you configuration of one "puller" engine in front and one "pusher" engine in back.
<HR></BLOCKQUOTE>

While I won't discount that as a possibility, I doubt it was one of the main considerations when choosing that format, if it was considered at all (which seems unlikely to me). Mainly, I believe the design decision was based on the factors you list below.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>
First and foremost, it was one fast son-of-a-gun. It combined the clean design similar to a single-engined plane with the power of two engines.
<HR></BLOCKQUOTE>

Frontal cross section is a very important thing, and that, probably more than anything else, is why they went for an inline twin rather than the conventional side by side design. Less frontal surface area (generally) gives you less drag and greater speed and lower fuel flows for a given amount of power. Definitely desireable in any aircraft, fighter or not.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>
Second, maneuverability was very good for a two-engined plane, for the reasons described.
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Again, I don't really think that was much of a consideration, as it's not going to make a whole lot of difference either way.

Even if it did, you'd be trading roll speed for pitch speed, as you'd now have two large masses at the front and back of the fuselage instead of halfway out on the wings.

Minor consideration, if at all.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Third, torque from the engines offset each other.
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Again, not so much of a factor, as any twin can be set up this way, and most during the war were. From a practical standpoint, it's the best way to go, especially if handling qualities are important to what you intend to do.

However, with that said, you can probably do it cheaper with an inline twin than you can with a conventional, because you should be able to use just one type of engine to create counter rotating props instead of having to keep right and left hand engines (and parts) in stock. The act of turning the engine around and mounting it "backwards" automatically makes the prop turn in a direction opposite the one in the front.

Definitely a maintenance bonus (at least in theory).
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Fourth, the plane was found to be relatively easy to fly when one or the other of the engines was damaged. A regular two-engined plane had real yaw problems when one engine failed.

<HR></BLOCKQUOTE>This is true. It's also why (trivia time) that if you get your multi-engine rating on an inline twin (such as a Skymaster), you are not authorized to fly a conventional twin. Inline twins with an engine out handle pretty much like any single, except for the performance loss. Conventional twins with an engine out can range anywhere from moderately annoying to impossible to fly, depending on the conditions.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>It was perfectly possible, for instance, to use the power of two engines to take off and climb, then turn one engine off for cruising.<HR></BLOCKQUOTE>

Eh, I'll give this one a definite maybe. It may have been possible at times, but overall, you wouldn't want to do it. Losing an engine in a twin removes half of your power, but can take up to 80% of your performance. It's not a 1:1 ratio. Lots of piston twins can't keep on going if they lose an engine, and there's a good chance that even the best of them will be coming down once an engine is gone. It just may take a while. But again, that will depend a lot on the aircraft in question and the conditions. In any case, you certainly won't be able to maintain altitude nearly as well, and your service ceiling will be considerably lower.

It's nice having some flyable twins in FB, but I've found the single engine performance modeling to be extremely tame, overall.

Doug_Thompson
06-04-2004, 03:25 PM
Turns out there's a Do 335 thread, which I replied to at length before reading this.

Obviously, as a layman, I'll defer to a pilot.