Bombers and Agility

[Darthtabby]

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.

 

[Shortround6]

A few factors to consider, using your example.

Could the He 111 out roll the Ju 88?
Once banked the He 111 might be able to out turn the Ju 88 as in do a turn of smaller radius, but if it takes longer to achieve the desired bank angle?
The He 111 might well have a smaller radius but is it going as fast? what is the actual degrees of turn per second? Ju 88 is doing a bigger circle but is covering the same arc quicker?
Can the He 111 sustain the turn? as in at what speed (Or G Loading) can it turn without losing more speed than the engines can make up for? This varies with Hight. To keep in the German family a 109E at 12,000ft could not quite maintain a 3 G turn at best turning speed (well below max speed)/rate of turn. If it turned any quicker (more Gs, tighter radius) it either lost altitude to maintain speed or slowed down. What could the bombers do?
Bombers out turning fighters only works in certain situations. British bombers out maneuvered night fighters just about long enough for the night fighter to lose both radar and/or visual contact. They might still be within a mile of each other. How much speed did the bomber lose doing this (often a dive was part of the corkscrew maneuver to help maintain speed).

For the Jets if the fighter tried to turn with the B-36 they sometimes stalled and lost thousands of feet of altitude which put them well out of firing range even if they could still see the B-36 in daylight. How long to get back into firing position?

There are a lot of things to consider in "maneuverability" or agility. Another is is the speed range as in the Famous Zero, very agile at low speeds, not so much at high speed.

 

[Greg Boeser]

Another consideration is the G limit of the aircraft in question. Fighters have relatively high G limits, stressed for 8-12 Gs.
Bombers had much lower G limits, usually less than 4.

 

[Shortround6]

Quite true.

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

However there is maneuverability and then there is maneuverability.

When I was a kid one of my friends fathers had flown Kingfishers off the Battleship Colorado in WW II.

He spoke once of being able to barrel roll the floatplane ( I don't know if that was approved or not

He also said the plane lost hundreds of feet of altitude while doing one roll.

So is the kingfisher maneuverable or not? It will do a barrel role and, if you have enough altitude, not crash.

Then there is the whole turn thing.

A 3 G turn requires a 70 degree bank and has over a 70% increase in stall speed. A He 111H was good for around 220-225mph at sea level in level flight, How long can it maintain a 3 G turn without either losing a lot of altitude or slowing down and stalling?

.

 

[nuuumannn]

The Short Stirling, being built out of the same material as Short Brothers and Harland at Belfast built the Titanic and her sisters from, where Stirlings were manufactured, was quite robust and was known to be quite manoeuvrable for such a big aircraft and could be thrown around with ease. Something to do with its short wingspan, so I believe.

I guess they had to be manoeuvrable as they suffered high losses in early sorties and individual aircraft were pulled out of service because of unreliabilities and defects at the manufacturer level... Not a great start.

 

[pbehn]

A Lancaster loaded with a Grand Slam and extra fuel to reach the Tirpitz was dangerously overloaded, after dropping the bomb and burning off all that fuel it was a joy to fly. With two less turrets and most radio equipment taken out and uprated engines it was comparatively light and powerful. The plane in those two different conditions cant be compared to each other, so its even harder to compare to others.

 

[spicmart]

The Lancaster was known for its agility (for a 4-engined bomber) which was much better than the Halifax'. It enabled the Lanc to perform the corkscrew manoever more effectively to evade nightfighter attacks. I'm curious how the B-24 and B-17 compared.

 

[Just Schmidt]

British bombers out maneuvered night fighters just about long enough for the night fighter to lose both radar and/or visual contact. They might still be within a mile of each other. How much speed did the bomber lose doing this (often a dive was part of the corkscrew maneuver to help maintain speed).

I think you are spot on. Add to this that the nightfighter had little incentive to try and follow the corckscrewing bomber. This was now alert to the attacker and had a potentially nasty sting in the tail, whereas there should be plenty of other unsuspecting bombers to go after in the bomber stream. at least in a 'typical' scenario. Well, not unsuspecting, but you know what I mean.

 

[Just Schmidt]

The Lancaster was known for its agility (for a 4-engined bomber) which was much better than the Halifax'. It enabled the Lanc to perform the corkscrew manoever more effectively to evade nightfighter attacks. I'm curious how the B-24 and B-17 compared.

My hunch is that the B-17 should be far more forgiving of drastic manouvers than at least the B-24. But this is largely academical as, unlike the night bombers, over Europe these usually flew in tight formations where a corckscrew could pose a danger to other aircraft, and any solo-manouver was not going to do any good for the formation. Of course a night bomber ran the risk of ramming another, but to a far lesser degree.

 

[FLYBOYJ]

Some thoughts -

The purpose of the heavy bomber during WW2 was to lob as many bombs on a target as possible. The fact that you had a large 4 engine bomber with good maneuverability for it's size (like the Lancaster) was a design plus, but in the bigger picture, you're not going to accurately drop bombs if you're jinking all over the place. (Unless you're in a Lancaster bombing dams) Additionally you have a crew inside that bomber that is going to be flung around like rag dolls if they are not expecting continual adverse maneuverers, thus making it harder if not impossible for them to do their jobs. The Luftwaffe tried with disastrous results to take a heavy bomber and make it a dive bomber (He 177).

I know that there were times heavy bombers had to take evasive action to avoid fighters but lets face it, that was more out of situational necessity rather than normal operations.

From what I've been told by at least 2 or 3 B-24 drivers, the B-24 was actually not that bad to fly (with it's thick Davis Airfoil) until you lost an engine, then even trimmed became a brick.

Smaller medium bombers are naturally going to be more maneuverable because of size and wing loading unless otherwise dictated by design. The He 111 had a lower wing loading than say the B-25 or A-20 but the B-25 and A-20 had about 600 more HP bolted to the airframe. Look at things like wing loading and power to weight ratios (if available) to get a better picture of this.

My 2 cents - invest wisely!

 

[pbehn]

Some thoughts -

The purpose of the heavy bomber during WW2 was to lob as many bombs on a target as possible. The fact that you had a large 4 engine bomber with good maneuverability for it's size (like the Lancaster) was a design plus, but in the bigger picture, you're not going to accurately drop bombs if you're jinking all over the place. (Unless you're in a Lancaster bombing dams) Additionally you have a crew inside that bomber that is going to be flung around like rag dolls if they are not expecting continual adverse maneuverers, thus making it harder if not impossible for them to do their jobs. The Luftwaffe tried with disastrous results to take a heavy bomber and make it a dive bomber (He 177).
in daylight
I know that there were times heavy bombers had to take evasive action to avoid fighters but lets face it, that was more out of situational necessity rather than normal operations.

One of the leaders of 617 squadron encouraged pilots and crews to practice aerobatics. He had been blown upside down on a raid, he thought that being upside down for the first time while on a raid was a bad idea. He also encouraged crews to practice violent evasive maneuvers in daylight so the whole crew knew what to expect and what to do as far as opening fire and stopping firing went.

 

[FLYBOYJ]

One of the leaders of 617 squadron encouraged pilots and crews to practice aerobatics. He had been blown upside down on a raid, he thought that being upside down for the first time while on a raid was a bad idea. He also encouraged crews to practice violent evasive maneuvers in daylight so the whole crew knew what to expect and what to do as far as opening fire and stopping firing went.

I'm assuming we're talking Lancasters - were "aerobatic" maneuvers even permitted by the manufacturer?

Again, situational necessity rather than normal operations.

 

[pbehn]

I'm assuming we're talking Lancasters - were "aerobatic" maneuvers even permitted by the manufacturer?

Again, situational necessity rather than normal operations.

Yes they were in Lancasters. Probably not but if you are told to fly at 60ft in the dark towards a flak tower and other stuff you are unlikely to care about such instructions. I remember some test pilot doing a barrel roll in a Boeing 707, Boeing were horrified although the pilot explained that he maintained just 1 G. While Boeing agreed, it just isnt what potential passengers want to see so he never did it again.

The main objective to the practicing was for all the crew to know what would happen. What could get thrown about that you needed and so had to be secured, What you could hit your head arms and ribs on etc. What you could hold on to so you reached for it without thinking. As far as I remember the favourite was a rapid climb with engines partially shut down then engines on full power for a dive and turn to left or right starting the "corkscrew".

Some crews never spotted an enemy fighter, but it was a possibility as soon as you crossed the coast, its best for all if they train for it.

 

[FLYBOYJ]

Yes they were in Lancasters. Probably not but if you are told to fly at 60ft in the dark towards a flak tower and other stuff you are unlikely to care about such instructions. I remember some test pilot doing a barrel roll in a Boeing 707, Boeing were horrified although the pilot explained that he maintained just 1 G. While Boeing agreed, it just isnt what potential passengers want to see so he never did it again.

That was Tex Johnson and although he successfully completed the maneuver during an event over Seattle, he did exceed design limitations (although he did not hurt the aircraft structurally)

The main objective to the practicing was for all the crew to know what would happen. What could get thrown about that you needed and so had to be secured, What you could hit your head arms and ribs on etc. What you could hold on to so you reached for it without thinking. As far as I remember the favourite was a rapid climb with engines partially shut down then engines on full power for a dive and turn to left or right starting the "corkscrew".

Agree on the training during adverse maneuvers, it's still done today (it was done when I was in a P-3 squadron). Full aerobatic maneuvers (abrupt changes along the aircraft axis, I believe more than 45 degrees bank angle and more than 30 degrees up or down pitch) on most if not all larger 4 engine aircraft is prohibited.

Some crews never spotted an enemy fighter, but it was a possibility as soon as you crossed the coast, its best for all if they train for it.

Absolutely

 

[Greyman]

The Lancaster was known for its agility (for a 4-engined bomber) which was much better than the Halifax'. It enabled the Lanc to perform the corkscrew manoever more effectively to evade nightfighter attacks. I'm curious how the B-24 and B-17 compared.

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.

 

[pbehn]

I have often read that the Stirling was "surprisingly manoeuvrable for its size" I dont know whether this was because of its large tail, its narrow wing span or the fact that even compared to other British heavies it was fffing enormous. Image from wiki.

 

[Greg Boeser]

Holy !

 

[FLYBOYJ]

The Sterling was indeed a monster in size! I did notice that some marks employed a "Second Pilot" or co-pilot, which as history dictates, brings a margin of operational safety. As stated examine wing loading and power to weight ratios for an idea of maneuverability.

I have a soft spot for the Halifax. Always liked the looks of the aircraft.

 

[Darthtabby]

Smaller medium bombers are naturally going to be more maneuverable because of size and wing loading unless otherwise dictated by design. The He 111 had a lower wing loading than say the B-25 or A-20 but the B-25 and A-20 had about 600 more HP bolted to the airframe. Look at things like wing loading and power to weight ratios (if available) to get a better picture of this.

I have actually been crunching a lot of numbers for wing and power loadings lately. It's what prompted me to make this thread.

There are a couple cases of bombers with similar engine fits and weights where one had 50%+ more wing area. The aforementioned He-111 and Ju-88 (I was thinking of the H-6 and A-4) is one. The B-23 and early B-25 is another. In both cases it's the aircraft with the smaller wing area (the Ju-88 and B-25) that I would have presumed is more agile. Makes me wonder if my assumptions are wrong, or if maybe wing loading is a far less useful indicator of maneuverability in bombers then it is for fighters. G Greyman 's comment about the British finding the B-17 less maneuverable then the B-24 would seem to suggest wing loading isn't as good an indicator for bombers.

I am noticing that the B-17 and B-23 seem to have substantially higher service ceilings then their B-24 and B-25 counterparts. The opposite seems to be the case with the He-111H-6 and Ju-88A-4, but perhaps the 211Js on the Junkers performed better at altitude then the 211Fs on the Heinkel.

For the Jets if the fighter tried to turn with the B-36 they sometimes stalled and lost thousands of feet of altitude which put them well out of firing range even if they could still see the B-36 in daylight. How long to get back into firing position?

Was this sort of thing ever an issue for aircraft trying to attack the B-29 in WWII, or did the B-29 not fly high enough for that?

 

[Greyman]

... the British finding the B-17 less maneuverable then the B-24 would seem to suggest wing loading isn't as good an indicator for bombers.

A lot more goes into manoeuvrability than just plain turning. In this particular case changing direction rapidly is at a premium. The Lancaster could go into a dive faster, gain speed in a dive faster, pull out of the dive faster, and was faster to change from a climb to a dive again (at the top of a corkscrew, say).

The weakest point regarding the Lancaster's manoeuvrability seems to be the rolling (both lag and stiffness), though the Fortress was also less than stellar due to stiff (but responsive) ailerons.

The US aircraft had an advantage over the earlier Merlin heavies due to their engines withstanding negative Gs.