Insight into the magnitude of forces involved in dogfights during WW2

[FLYBOYJ]

The early G-suit delivered about a 1.5 - 2 G improvement to tolerance, and so did the heightened footrest + tilted seat according to the chart I presented, that's the proof Adler.

I severely doubt that the Berger suit was as effective as modern G suits, infact I know it isn't.

They work the same way and applied the same pressure, how were that not as effective? I don't have any references in font of me (Bill might have a few) but I have seen testimony from P-51 drivers where they have stated that the G suit made the difference in air battles they were in.


The big difference is the g suit worked automatically, in the seat with stirrups you had to prepare for the g loading. In the height of battle that one or 2 seconds could mean everything....

 

[DerAdlerIstGelandet]

They work the same way and applied the same pressure, how were that not as effective? I don't have any references in font of me (Bill might have a few) but I have seen testimony from P-51 drivers where they have stated that the G suit made the difference in air battles they were in.


The big difference is the g suit worked automatically, in the seat with stirrups you had to prepare for the g loading. In the height of battle that one or 2 seconds could mean everything....

Agreed. I am still not convinced that it canceled out the G-Suit.

 

[drgondog]

Agreed. I am still not convinced that it canceled out the G-Suit.

There is no question that the G-suit was accepted as a 'diiference maker' by US fighter pilots in ETO.

A bigger question to me is why it was not universally adapted by RAF and LUftwaffe?

Joe - my data on the G-suit is strictly anecdotal both from personal comments and encounter reports. Physiologically speaking the simple act of applying pressure to abdomen and Upper thighs restricts flow of blood to lower body, which a reclined seat will facilitate - but not duplicate until some very advanced reclining state (I don't know the assymptotic approach migh be.)

I am sure the USAF studied it but I haven't put my fingers on any tables.

 

[DerAdlerIstGelandet]

There is no question that the G-suit was accepted as a 'diiference maker' by US fighter pilots in ETO.

A bigger question to me is why it was not universally adapted by RAF and LUftwaffe?

Agreed

I dont think it can be truthfully argued either.

 

[Soren]

I feel that the weight I used for the F4U-4 is too high, does anyone have some info on its cleanly loaded weight (Full internal fuel ammunition) ??

 

[drgondog]

I feel that the weight I used for the F4U-4 is too high, does anyone have some info on its cleanly loaded weight (Full internal fuel ammunition) ??

Vought F4U Corsair - USA

Soren - This source has the following for F4U-4

9,205 Empty
12,400 'normal load', no external stores, full internal fuel and ammo
14,670 'Max gross TO'

The web sites are all over the place but I think this set is close.

 

[Soren]

Roger that Bill, those figures look far more reasonable and right in the ballpark of what I suspected. I actually have the POH on my stationary but I'm currently out of town so I couldn't look it up.

Thanks mate!

The new figure:

F4U-4 Max G at 112 m/s (400 km/h): 5.88 G

Awesome a/c! Right up there alongside the FW190!

 

[renrich]

F4U4-empty-9205 lbs, combat-12420lbs, fighter, one extra tank-13530 lbs, bomber-two extra tanks(1000lb bomb)-14515 lbs, bomber-one extra tank(2000 lb bomb)-14412 lbs, rocket-one extra tank, 8 HVAR-14670 lbs

 

[Soren]

I used 5,600 kg (12,400 lbs).

 

[drgondog]

I used 5,600 kg (12,400 lbs).

Soren - all the loads you are presenting are based on G for Design Limit loads, aren't they?

Interesting but the most likely situation for experiencing a limit G load in any of those fighters is pulling out of a dive. Quite a few pilots would lose consciousness quickly near that level, particularly w/o G suit.

Having said that I suppose it is nice to think I still have wings and tail after I regain my senses?

Out of curiosity, what does the F4U Flight Manual say is the weight the Limit Load limit is tagged to? ie. for the 51 it was 8,000 for the 8G limit... which was neither empty nor normal mission profile (but closer to 51B w/o fuse tank than to P-51D).

 

[Soren]

No the G-loads I'm presenting are the max the a/c can pull at the specified speed, in this case 112 m/s (400 km/h). And 400 km/h was below the average speed at which dogfighting was taking place by 42 and onwards. In a pull out from a dive much higher G forces could be pulled, forces way exceeding the maximum load limit of the airframe.

I don't know the load limit for the F4U, but I'll look for it in the POH when I get home.

 

[drgondog]

No the G-loads I'm presenting are the max the a/c can pull at the specified speed, in this case 112 m/s (400 km/h). And 400 km/h was below the average speed at which dogfighting was taking place by 42 and onwards. In a pull out from a dive much higher G forces could be pulled, forces way exceeding the maximum load limit of the airframe.

I don't know the load limit for the F4U, but I'll look for it in the POH when I get home.

I got that Soren.

I think what I meant was, that very few fighters were going to go very far in the horizontal at 400mph. They might enter at that speed but wouldn't have the power to sustain it. On the other hand it's easy to find 400mph and 6 G's recovering from a dive. You might find it in a rolling pull out (and be delighted you kept your tail)

Gene/Crump did an excellent job showing the G limits in sustained turns for all the important birds which you noted also. From recall I seem to remember 3-3.5 G's for both the 51 and the Fw 190 in the 280mph range as 'peak' for some sustained period. I think the curves were representative for the energy available to sustain such high G turns.

Again, I dealing only from my faulty and ancient memory. I could look those up but I'm too lazy right now.

 

[Soren]

Yes Crumpp did an excellent analysis.

The P-51D was able to sustain a max of ~3 G, the FW190A8 slightly more, the Dora-9 much more. The FW190 is esp. superior in sustained turn rates at slow to medium speeds. His charts also demonstrated how close the 109 Spit are in terms of turn performance.

 

[Soren]

I got that Soren.

I think what I meant was, that very few fighters were going to go very far in the horizontal at 400mph. They might enter at that speed but wouldn't have the power to sustain it. On the other hand it's easy to find 400mph and 6 G's recovering from a dive. You might find it in a rolling pull out (and be delighted you kept your tail)
.

Roger that Bill, that is why timing is so important in real dogfights. A P-51 might be straight behind a FW190 and chasing it, and then the FW190 suddenly knives hard left pulling 6 G, the P-51 is completely unable to follow this maneuver as not only does the 190 start off first but it also enters the bank angle much faster. The P-51 will overshoot. It's the same if you close on an enemy fast and he suddenly turns into you, forcing a lead you can't possibly pull at that speed.

The best thing to do in both situations is climb, esp. when you're up against a more agile fighter such as the 190.

 

[drgondog]

Roger that Bill, that is why timing is so important in real dogfights. A P-51 might be straight behind a FW190 and chasing it, and then the FW190 suddenly knives hard left pulling 6 G, the P-51 is completely unable to follow this maneuver as not only does the 190 start off first but it also enters the bank angle much faster. The P-51 will overshoot. It's the same if you close on an enemy fast and he suddenly turns into you, forcing a lead you can't possibly pull at that speed.

The best thing to do in both situations is climb, esp. when you're up against a more agile fighter such as the 190.

A good manuever, except the Fw 190 stalled badly trying to pull a turn so tight he was pulling 6 g's.. or he misjugdged the distance and pulled into his turn too soon, and as he stalled out pulling the high g's the pesky 51 pilot nailed him in recovery (just kidding Soren)

More likely the 51 pilot pulls into a high scissor and cuts the circle or keeps on going, but shouln't waste his energy trying to stay in a turn like that when he has so much more energy? At least I hope I wouldn't. Might be like a F-4 trying to stay horizontal with a Mig 17..

And, if the Fw 190A is at 25,000 feet trying this he is having less fun than he wants today - pilot skill being similar. He is having more fun with a Dora but still at an energy disadvantage with an aircraft equal or nearly equal..

All in fun

Bill

 

[renrich]

To me, I believe that many of us on this forum tend to use the term "dogfight" incorrectly in the context of WW2. If, for instance, you look at flight tests done by USN of A6Ms versus Navy fighters, they say "DO NOT DOGFIGHT WITH A ZERO," which, to me, means getting into a slow, turning fight in the horizontal. All this discussion about pulling Gs at 300 or 400 mph in WW2 means to me that the ACM in that particular fight was not "dogfighting" If you read Bob Johnsons's book, few, if any kills he had were "dogfights" I know these are modern terms but in Shaw's book on ACM (it is packed so I can't remember the name of the book) he uses the terms "angles or energy fights" It would be interesting to know how many encounters in WW2 in the ETO were angles(dogfights) or energy fights. There may be another category which I believe was the by far dominant category, find oneself on an unsuspecting enemies six with a no deflection shot and shoot him down (maybe that is called a sniper fight). My point is (if there is one) that we may put too much emphasis on "dogfighting" qualities when not that much of that category was done.

 

[Soren]

A good manuever, except the Fw 190 stalled badly trying to pull a turn so tight he was pulling 6 g's.. or he misjugdged the distance and pulled into his turn too soon, and as he stalled out pulling the high g's the pesky 51 pilot nailed him in recovery (just kidding Soren)

More likely the 51 pilot pulls into a high scissor and cuts the circle or keeps on going, but shouln't waste his energy trying to stay in a turn like that when he has so much more energy? At least I hope I wouldn't. Might be like a F-4 trying to stay horizontal with a Mig 17..

And, if the Fw 190A is at 25,000 feet trying this he is having less fun than he wants today - pilot skill being similar. He is having more fun with a Dora but still at an energy disadvantage with an aircraft equal or nearly equal..

All in fun

Bill

The FW190 stalled no more badly in a turn than the P-51 (The Laminar airfoils means sharp and unpredictable stalls in high G turns), infact there'd be more warning in the FW190 if the ailerons are correctly adjusted. If you read the reports made by the RAE AFDU whilst flying the FW190G3 Jabo it notes the very mild stalling characteristics of the a/c and the ample amount of warning given. (Post war USAAF tests note the same with a underpowered Dora)

The problem with the FW190 is that its got so light controls that if you're not used to it you can easily pull too much and cause the a/c to stall, while an experienced pilot would know exactly how much to pull before stalling. FW190 pilots all note they easily felt the buffeting when pulling high G turns and knew when not to pull any tighter.

At low to medium alt the P-51 is better off not trying to dogfight a FW190 as the FW190 turns tighter and has a better sustained turn rate, so climbing would be the best choice. At 25,000 ft I agree completely that a FW190A would be allot better off doing Split S's and head for the deck instead of hanging around in Mustang territory, whilst a Dora-9 could stay and fight with its better performance. (You'd have to go bloody high for the P-51 to gain a power advantage over the Dora-9)

 

[drgondog]

The FW190 stalled no more badly in a turn than the P-51 (The Laminar airfoils means sharp and unpredictable stalls in high G turns), infact there'd be more warning in the FW190 if the ailerons are correctly adjusted. If you read the reports made by the RAE AFDU whilst flying the FW190G3 Jabo it notes the very mild stalling characteristics of the a/c and the ample amount of warning given. (Post war USAAF tests note the same with a underpowered Dora)

The problem with the FW190 is that its got so light controls that if you're not used to it you can easily pull too much and cause the a/c to stall, while an experienced pilot would know exactly how much to pull before stalling. FW190 pilots all note they easily felt the buffeting when pulling high G turns and knew when not to pull any tighter.

At low to medium alt the P-51 is better off not trying to dogfight a FW190 as the FW190 turns tighter and has a better sustained turn rate, so climbing would be the best choice. At 25,000 ft I agree completely that a FW190A would be allot better off doing Split S's and head for the deck instead of hanging around in Mustang territory, whilst a Dora-9 could stay and fight with its better performance. (You'd have to go bloody high for the P-51 to gain a power advantage over the Dora-9)

Soren - My only point in pulling your leg is that BOTH would pretty much stall out in a 4G turn at any altitude at 400mph, much worse as the G's (attempted) increased.

F-16s with inclined seats, great T/W ratio (>1) and G suits can pull more sustained G's than the pilot.

By comparison the 51 and 190 had minimal power(and Thrust) to weight ratios and could only achieve even 3-3 1/2 Gs for limited time before stalling out. Even then the air speed would be bleeding away at an alarming rate

As to the other judgements, the airplane was not as much a factor as the pilots and tactical advantage... all the airplanes we are talking about had areas of superiority and inferiority in pure flight test scenarios in comparison.

Regards,

Bill

 

[Glider]

Soren,
Can I ask where you get the information that the Laminar airfoils in a P51 would means sharp and unpredictable stalls in high G turns.

The Pilots notes disagree pointing out that its stall is mild and there is little tendancy to drop into a spin.

 

[renrich]

Hmmmmm, I know we all have problems with Eric Browns 's extreme bias toward certain AC but in "Duels in the Sky" he is an unabashed fan of the FW190, saying when it first appeared it was the most advanced fighter in the world. He says the A4 appearing a year later maintained that status for a while. However, "stalling speed in clean configuration was 127 mph. The stall came suddenly and virtually without warning, the port wing dropping so violently that the Ac almost inverted itself. This proved to be the fighters Achilles heel, for if it was pulled into a "g" stall in a tight turn, it would flick into the opposite bank and, unless the pilot had his wits about him, into an incipient spin." Interestingly, the USN flight test comparing the A4 to Navy AC reported the same characteristics-stall with little warning, aileron reversal in tight turns to left, turning to right tends to drop nose and dive.