Bombers and Agility

[Thumpalumpacus]

Or French...

I confess to mixing up who exactly is ugly and weird. To my eyes both the Russians and the French mastered that curious art in more than a few designs.

ETA: I'd think that ditching at sea in a Heyford must be quite, um, interesting.

 

[Shortround6]

Another perspective on the Big triplane.

Agile is certainly not the first word that springs to mind.

Except perhaps for the crew responsible for tying them down.

 

[pbehn]

Another perspective on the Big triplane.
View attachment 643512

Agile is certainly not the first word that springs to mind.

Except perhaps for the crew responsible for tying them down.

You must have a lot of duck, grouse and goose for dinner with a setup like that.

 

[Thumpalumpacus]

Another perspective on the Big triplane.
View attachment 643512

Agile is certainly not the first word that springs to mind.

Except perhaps for the crew responsible for tying them down.

There's a CoG joke in there somewhere.

 

[Ascent]

I quite like the look of the Heyford, but then I've always liked the look of those aircraft from the late prewar era.

 

[11bwmech]

Agility is not a term generally associated with large WWII bombers. Its one I tend to associate more with fast small to mid size bombers like the Douglas A-20. But it's my understanding that low wing loading is a reasonably good indicator of maneuverability, and some bombers like the He-111 and early models of the B-17 appear to have had relatively low wing loadings thanks to their very large wings. I've also occasionally come across references to British heavies using turns to escape German night fighters, and to high altitude bombers like the stripped down versions of the B-36 being able to evade interceptors due to the advantages that large wings offer in thin air.

I doubt the big bombers could roll all that well, but I do find myself wondering if I should be giving their turning capability more credit. It probably wasn't much use when flying in a combat box but I'm wondering if it might be tactically useful enough to matter in other circumstances.

I'm also wondering about the relative agility of big wings and small wings for bombers. A lot of the bombers that I've tended to think of as agile had relatively small wings. Admittedly some of them were relatively light bombers, but some were getting into medium bomber size. For a direct comparison, consider the Ju-88 and He-111: two bombers that could be had at very similar weights with very similar engine fits. The Ju-88 was considered a fast bomber and had heavy fighter variants, so I would generally presume that it was the more agile of the two. But the He-111 had roughly half again the wing area which makes me wonder if it might have actually been the more maneuverable of the two. I realize wing loading is not the only factor in agility, but its hard to ignore just how much lower the He-111's wing loading is.

Since you mentioned the B-36, which I worked on and flew in occasionally for over 5 years, I will repeat what I was told then: prior to air-to-air missiles but after the general use of jet fighters, the Peacemaker was presumed to be pretty safe at 40,000 ft. If the B-36 was flying at anything close to top speed, the only reasonable approach was from the rear. The big wing made it possible for the B-36 to turn so much tighter that the pursuer would be a mile or two away before completing its turn. Few fighters of that era (early to mid 50s) could reach that altitude with enough fuel to engage in a protracted dogfight. An F-89 pilot once said he could have gotten to a high-flying B-36, but he would have had to walk home.

 

[nuuumannn]

If memory serves, it was because the specification called for it to be able to carry torpedoes internally.

Yup, the original specification stated that, "It may be possible a limited number of this class of aircraft for torpedo dropping" and that the submission to the tender should stipulate whether two torpedoes carried side by side could be done. 18-inch torpedoes are stipulated. That part of the requirement was dropped before the Manchester prototype was built.

 

[Reluctant Poster]

The Liberator had very good manoeuvrability for its size.

The Fortress was reasonably manoeuvrable but according to the British the least so of the main five. The price to pay for getting top marks in formation flying and bomb aiming.

According to 8th AF studies the B-24 was a less accurate bomber than the B-17.

 

[Reluctant Poster]

The Lancaster/Manchester's was the only one that was not sectioned or constrained for whatever reason, which meant it could carry a variety of bomb types that pre-war designers didn't take into account when they first approached their bomber designs. The Halifax bomb bay for example was constrained by the complex door operating mechanisms, which protruded into the the bomb bay itself, the folding of the doors also providing obstruction, the upper-most entering the bomb bay to sit alongside its inner wall. A portion of the Halifaxes' and Stirling's bomb loads were carried in wing bays.



I remember the first time I heard of this type was the big Matchbox model, the aircraft might have been a ponderous thing, but it made a real impressive model!

When Rolls Royce was redesigning the Halifax cooling system to improve reliability and reduce drag they also redesigned the bomb bay doors through their Philips and Powis subsidiary (Miles). This allowed the bomb bay doors to be fully closed when carrying 4,000 and 8,000 lb bombs

 

[nuuumannn]

This allowed the bomb bay doors to be fully closed when carrying 4,000 and 8,000 lb bombs

That's not entirely accurate. The big 4,000 lb bomb couldn't be entirely enclosed within the bomb bay and the first Halifax to carry it, the B.II Series IA had to fly with the doors open against the bomb. A set of bulged doors was designed and trial fitted but never entered service.

(I'm currently looking for a photograph that illustrates this that I've seen, but can't for the life of me remember where I saw it)

 

[Reluctant Poster]

That's not entirely accurate. The big 4,000 lb bomb couldn't be entirely enclosed within the bomb bay and the first Halifax to carry it, the B.II Series IA had to fly with the doors open against the bomb. A set of bulged doors was designed and trial fitted but never entered service.

(I'm currently looking for a photograph that illustrates this that I've seen, but can't for the life of me remember where I saw it)

Yes the doors were partly open. There is a picture in "Rolls-Royce and the Halifax. It was lsited as aspecila fitment and as far as I know was not used on operations.

 

[Greg Boeser]

According to 8th AF studies the B-24 was a less accurate bomber than the B-17.

Makes sense. At higher altitudes the B-24 was less stable that the B-17. Formations were therefore looser, resulting in a more dispersed bombing pattern.

 

[nuuumannn]

It was lsited as aspecila fitment and as far as I know was not used on operations.

There was a bulged bomb bay door system designed and fifty sets were ordered but a Halifax underwent trials with it at Boscombe Down and it was found not to offer any beneficial performance increases, which at the time the Halifax was undergoing evaluation for drag reduction, which was affecting performance, and so the decision was made not to adopt the bulged doors and instead fly with the doors against the bombs, as per the picture (found it!). The B.II Series IA was the ultimate Merlin engined Halifax bomber variant that underwent production and was the basis of the Hercules engined Mk.III that incorporated the drag reduction measures.

The Halifax bomb doors were complex, there were eight individual door coverings to the bomb bay, four on each side, for comparison the Lancaster/Manchester had two, one on each side.

 

[K5083]

Alex Henshaw, production test pilot at Castle Bromwich, used to loop and roll Lancasters on test. The Vulcan prototype was rolled at Farnborough in 1952 IIRC. Not much use operationally though.

 

[GregP]

Well, THIS is pretty ugly:

and I'm guessing not all that maneuverable. Curtiss Duck, built to try to get around the Wright patent on lateral control by wing warping or other device.

This has to rank with the non-maneuverable ugly bombers. Amiot 1043M.

Not too sure this one qualifies as an aircraft. The AD Scout.

Any actual proof it ever flew? Looks like the pilot needed some serious rock-climbing skills just to get aboard. Considering where the propeller is, he'd also need some serious rock-climbing skills in high winds to abandon aircraft if the engine was still running without becoming sausage. Who knows? It MIGHT have been maneuverable. but I'd rather make friends with a porcupine than attempt to fly it. You might have time to eat lunch in the event of a nose over before the nose actually hit the ground.

 

[mikemike]

Quite true.

The Ju-88 would have had a higher G limit to handle the dive bombing role.

The Ju 88 A-4 was stressed for 10 G. With later variants, due to higher weights, this degraded to about 7 G, roughly the same as a F-15.

 

[BiffF15]

The Ju 88 A-4 was stressed for 10 G. With later variants, due to higher weights, this degraded to about 7 G, roughly the same as a F-15.

The F15 has a 9 G limit. Initially the F15A/B had a 7G limit but that was later increased to 9 with the addition of the OWS (Overload Warning System) fleet wide (F15A-D).

I've known of several instances where more than 11 were pulled and the plane landed safely.

Cheers,
Biff

 

[Shortround6]

Are we comparing service limits or ultimate strength limits?

If the JU 88 was built to American standards of WW II then it was either 10 G's service limit and 15 Gs ultimate or 6.6 G's service limit and 10 G's ultimate.
The later is higher than American twin engine bombers (B-25s running light were rated at 3.67 G's service. )
American fighters were usually designed (later versions slipped a little sometimes) for 8 G's service and 12 G's ultimate.

Other air forces used different safety margins.

Lets make sure we are comparing apples to apples.

 

[nuuumannn]

This has to rank with the non-maneuverable ugly bombers. Amiot 1043M.

Yup, the French built some spectacularly underperforming mansions for bombers, with poor performance except for range and altitude. French bombers in the late 30s were reaching heights that other manufacturers could only dream of, at the expense of performance and payload of course. They also didn't have many of them at any given time.

 

[Thumpalumpacus]

Alex Henshaw, production test pilot at Castle Bromwich, used to loop and roll Lancasters on test. The Vulcan prototype was rolled at Farnborough in 1952 IIRC. Not much use operationally though.

The Boeing 707 was barrel-rolled in a test-flight as well. Again, not much use in ops.