Was deflection shooting easier in World War I?

[Romani]

Researching about the evolution of aerial gunnery and reflector gunsights, I've come across the striking finding that though effective ranges might have been longer in the 2nd World War, as a rough rule of thumb saying that it was possible of having decent chances of scoring a lethal hit at up to 200 meters, while in the 1st you had to start at 100 meters and closer to score a kill, deflection shooting was very much unheard of and the province of some experts with very good marksmanship.

Deflection shooting seems to have been beyond the grasp of the ordinary pilot, and most air services didn't bother to teach it in practice, so most kills were achieved by getting on the tail of the enemy.

By deflection shooting I mean firing at an angle at the target anywhere in its rear arc, from 3 to 9 positions, the only practical firing position for most pilots was firing from a few degrees on either side of the enemy 6. Given that each hour is 30 degrees of arc, I was surprised at finding how narrow the angle of fire actually was.

So my on-topic question is: for fixed forward machineguns (observer guns are another story), given the closer ranges in WWI, and the lower speeds of airplanes, was the lead neccesary to hit a target from any other position than its tail significantly smaller making prediction shooting (another name for deflecton) easier, and allowing the successful employ of tactics such as "slashing" attacks?

From gaming experience, I have found out that is quite difficult to get into the tail of a fighter more agile than yours, and staying there long enough in a pursuit curve to score hits (unless you are a very good shot, or get lucky, you need more than one burst). Examples of this are trying to follow a Camel
in a Albatros DVa, or a DrI in a SPAD.

But on the other hand, if you follow historical examples and common sense, and don't try to follow the target, but use your speed to attack in an oblique angle, cutting the line of flight of the target,what is usually called a "slashing" attack if I've it right, you get chances at a passing shot. Not as easy ny any means as shooting from the rear, but firing at close range to minimize the deflection modifier and a good marksman to compensate, and is possible to score successes this way, not likely in the first pass, but if you have the advantage in speed, you can get away, turn and repeat as neccesary. The pilot accounts I've read from both wars tend to bear this out. Aside from the surprise attack (valid for all kind of fighters) and the dive and zoom climb (valid for some), this must has been the tactic employed with fast but not very agile fighters, and only because the low speeds involved make prediction shooting a feasible proposition.

I am hamfisted and never have been able to test this theory myself in a WWI flight simulator, except against slow 2-seaters. But I've had it demonstrated to me by opponents, both human and computer, so I am fairly convinced that my tabletop experiences are not a simulation dice roll glitch based on faulty math, but that models quite approximately what happened in reality.

So can anybody more knowledgeable and/or math inclined prove that prediction shooting is workable at speeds of under 200 kph and gets exponientally difficult as speeds increase?

[TonyWilliams]

I am not a mathematician but it seems fairly obvious that the faster a plane travels, the further ahead of it you have to aim if you're attacking from an angle. To put it at its simplest, if you're attacking from the beam, in the time it takes your bullets to reach the target a plane travelling at 400 kmh will travel twice as far as one travelling at 200 kmh, so if you aim straight at the plane your bullets will miss by twice as much.

So deflection shooting should have been easier in WW1, although it was not really easy in either war. Only a few skilled shooters really mastered it, most of them probably having prior experience of shotgun shooting which is, of course, all about deflection shooting. In fact, shotgunning was used to teach people about deflection shooting in WW2 (in WW1 people got very little instruction of any sort on how to shoot).

The RAF became so alarmed in the late 1930s at the poor shooting of their pilots (as revealed by camera guns fitted for mock attacks on bombers) that they instituted the programme which resulted in the Gyro Gunsight, which probably doubled the chance of scoring a hit in deflection shooting.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion forum (http://forums.delphiforums.com/autogun/messages/)

[Machinbird]

Romani, Just the opinion of a used fighter jock who doesn't have all that much time in the Air to Air Gunnery pattern, but there were major differences between the aircraft and armament between WWI and WWII that make a big difference in the effectiveness of deflection shooting. In deflection shooting from the beam, there is a relatively short period of time that you have a viable firing solution. If you continue tracking too long, the g load builds to the stall or structural failure point. In WWI you almost had to hit the pilot or the fuel tank to make a kill since there were not that many critical systems in the WWI aircraft. This is a very small kill zone, even if you are firing closer due to the lower relative speeds. Furthermore cannon shells were essentially non-existent in air to air fighting in WWI, and the bullets fired were fired from at most two guns that were down-regulated by synchronizing gear. Net result was you were spraying fewer bullets per second in WWI, the target kill zone was smaller in WWI, and the ammunition was less effective in WWI although you could always shoot a golden BB. If the attacking aircraft does not make a kill in a beam attack, he can leave himself vulnerable as he pulls off target unless he is carrying scads of energy. Compare this with WWII where 6 and 8 gun fighters were common and some cannon shells were in use. WWII aircraft often had multiple fuel tanks, oil tanks, hydraulic tanks, glycol tanks distributed throughout the aircraft, not to mention hydraulic lines and electrical systems. The structure was less redundant. It was easier to get a single shot kill of a WWII aircraft than a WWI aircraft. Thus deflection shooting in WWII was more effective than in WWI.
Again, just my take on the situation.:darts:

[R Pope]

I have some pics of training apparatus where the gunner is seated in a section of an airplane fuselage mounted on a narrow guage railway car, and is shooting at a target on another rail line. Anyone experienced at hunting running game would have no problem figuring out the lead required in air combat, which is likely why Canadian farm boys did so well in the RFC.

[Barrett]

Deflection shooting was at least as much art as science. I don't think it was taught much at all in WW I, and even in WW II it was extremely limited. The world's only two air arms that trained at it were USN/USMC and the Finns. Everybody else used some variation of pursuit curve. Undoubtedly the major exception was H-J Marseille, who consistently hit maneuvering targets at high angle-off in an AF that was unable to train at the art.

In an attempt to answer Romani's question, hitting a deflection shot in WW I was PROPORTIONATELY easier than WW II but still it was beyond the ability of most pilots. Anything much over 100 yards/meters/daddy steps in TGW was long range whereas in War Deuce, most US units zeroed at 300 yds.

Though to an extent it's legend that Any Farmboy could become a good aerial gunner, many of the top aces of WW II grew up hunting: Joe Foss, Marion Carl, Dick Bong, etc. Others like Tommy McGuire were just naturally gifted and others like Dashing Dave McCampbell worked at it.

[Scott Powell]

i was under the impression that the Aldis helped with the abilty of judging range and lead needed. also, didnt the 'grid' sites employed on the DH2 attempt to help with lead distance?

[Vin]

If deflection shooting required more bullets than shooting from astern, that would put lewis gun armed aircraft at a distinct disadvantage.

[TomVrille]

[QUOTE=Romani]
Deflection shooting seems to have been beyond the grasp of the ordinary pilot, and most air services didn't bother to teach it in practice, so most kills were achieved by getting on the tail of the enemy.
QUOTE]

The reason that deflection shooting was seldom taught was because it had a much lower probability of success than an attack along the longitudinal axis of the target. As Machinbird has noted, most of the vulnerable components of a WW1 aircraft are clustered around the nose. If a vulnerability model were constructed for a typical WW1 aircraft, it would resemble a cylindrical volume centered on the fuselage axis and extending from the propeller boss to just behind the cockpit(s). The diameter of the vulnerability volume would be roughly the same as the maximum fuselage diameter.To get a "kill", the goal would be to pass the maximum number of bullets through this volume along the longest possible internal path lengths.

The longest path lengths are clearly associated with an attack along the target's longitudinal axis. For a representative burst of say 20 rounds, all 20 of these shots might pass through the vulnerability volume for an axial attack if the aiming was very good. For a beam attack, this number would decrease to from 2 to 8 shots, with 8 shots in volume at very short ranges, and 2 to 3 shots being more likely at typical WW1 engagement ranges. So, the kill probability is much better for either a head-on or tail attack. A tail attack is preferable because it retains the possibility of surprise, and subsequent very short firing range. It also minimizes the chance of counterfire by the target. All of these points were apparently recognized by Boelcke when formulating his Dicta! :pplane:

[TonyWilliams]

There was another reason for attacking from the rear rather than the front - the engine provided protection for the pilot, who was the main target (engines were much harder to damage).

Of course, the reverse would apply in the case of a pusher plane!

Tony Williams

[Romani]

Romani, Just the opinion of a used fighter jock who doesn't have all that much time in the Air to Air Gunnery pattern, but there were major differences between the aircraft and armament between WWI and WWII that make a big difference in the effectiveness of deflection shooting.


Well given that ignorance is bold, and a little knowledge even bolder, I will argue your claims :)

Of course, a lot more machineguns and cannons, but the basic math and historical record points out that was easier to hit an enemy fighter with a deflection shot with just 2 machineguns and iron sights in 1918 than with say, 6 cannon and/or machineguns and a reflector gunsight in 1943


In deflection shooting from the beam, there is a relatively short period of time that you have a viable firing solution.

If the target is flying perpendicular or you are attacking it from the target 4 or 8 quarter then that's impossible for any pilot save an expert for every age.

But even an attack made at mere 30 degree angle relative to the target (from the 5 or 8) was beyond the capabilties of the average pilot in WWII, regardless of the augmented weaponry.

It is known that the US air service in the interwar years studied Rene Fonck methods and tried to teach them, coming to the conclusion that they were beyond the grasp of the average pilot. Partly because they were only of application to people with excellent gunnery skills, but in view of these findings, I am wondering if they were also unappliable because fighter aircraft had evolved and gotten faster, rendering Fonck methods useless.


In WWI you almost had to hit the pilot or the fuel tank to make a kill since there were not that many critical systems in the WWI aircraft.

You forget the engine, and the radiator. And there are plenty of accounts of bullets ripping the fabric in control surfaces, breaking longerons, spars, struts, cutting bracing wires, and control cables. And those come from surviving airmen, so we never can guess what was the actual cause of most WWI kills. I do agree that hits to the pilot would be the leading cause, followed by engine hits, flamers, and assorted structural damage.

This is a very small kill zone, even if you are firing closer due to the lower relative speeds.

Yet there's a consistent theme of skilled pilots in WWI able to aim for the pilot. I cannot think of anything similar in WWII except on attacks on bombers.

and the bullets fired were fired from at most two guns that were down-regulated by synchronizing gear.

Yes, that has been covered in depth in this forum, and others. One surprising thing is how fast firing the Maxim/Vicker guns actually were, so they still pumped a lot of bullets, and when factoring in the Contantinesco gear and the variation in engine RPM, the firepower is not so much reduced.

Net result was you were spraying fewer bullets per second in WWI, the target kill zone was smaller in WWI, and the ammunition was less effective in WWI although you could always shoot a golden BB.
True, true (but ranges where much shorter), and it was not so much the ammunition but airplane construction, a bullet that doesn't hit a structural member will go through fabric leaving just a neat little hole, same can be said for plywood fuselages. Ammunition was effective enough, specially when incendiary and explosive bullets were introduced.

The lack of true explosive shells and the resilience of fabric covered airplanes are on the other hand compensated by the fact that the pilot had no armor to protect him (except, perhaps for a bullet resistant windscreen), and the fuel tanks were not self sealing, and to make matters worse, they were pressurized.

WWII aircraft often had multiple fuel tanks, oil tanks, hydraulic tanks, glycol tanks distributed throughout the aircraft, not to mention hydraulic lines and electrical systems.
I could add that airplanes armed with cannons had the additional risk of their explosive ammo being blown up.


It was easier to get a single shot kill of a WWII aircraft than a WWI aircraft.

Evidence does not bear this out, WWI airplanes could be shot down by a single bullet to the unprotected pilot, as it happened to many aces.

I would make the case that it was easier to make a kill against a WWII aircraft if having a proper sight and good armament.

I will grant that hits on the glycol circuit seem to have been a bigger hazzard in WWII than in the first one, we don't hear much about fighters being disabled by shots to the radiator. I have been pondering this for a long time and I believe that later fighters with bigger engines recquiring a larger cooling system were more likely to this type of damage (larger radiator surface, longer pipes) and more quickly disabled by it (bigger engine, more waste heat, overheats and seizes much faster), than WWI airplanes with their simple, small car size radiators with thin pipes.

[/I] Thus deflection shooting in WWII was more effective than in WWI.
Again, just my take on the situation.:darts:[/QUOTE]

You are basing your argument in hit probability and lethality, but the problem is about leading the target, and this was patently hard to achieve in WWII.

It seems that the lower speed of Great War airplanes reduces the amount of lead recquired, making this kind of shot possible. It might also be the case that these lower speeds means the target remains for a longer time in the sights, making up for the low punch of twin rifle caliber MGs. The short effective range compensates for the rest.

Anyway, the question is mostly theoretical, as only an ace pilot could pull it off.

Interesting responses, thank you all!
:spandau:

[Simba]

The Royal Flying Corps taught air-air shooting at its Gunnery School at Hythe from mid-1917 onwards - including deflection shooting. Another school was set up at Loch Doon in Scotland.

Accurate deflection shooting is an art mastered by few; they're best described as 'natural shots'. Ordinary mortals had to wait for the reflector gunsights of the 'thirties and gyro sights of the 'forties before they could begin to contribute a greater share to 'the bag'.

One successful shooting method discovered in WW1 and rediscovered in WW2 was the use of a gun fired from below and behind by an attacker 'flying formation' with the target, which reduced the deflection element to zero and provided an ideal ballistic path with little bullet-drop at the ranges used. The RFC's Albert Ball scored many of his victories by such means, pulling his overwing Lewis back against its mounting guide and firing from close range at an angle of about 30 degrees. In WW2, Japanese and Luftwaffe twin-engined nightfighters employed single or twin cannon mounted behind the pilot to shoot the wings off Allied heavy bombers; the oblique angle (usually 60 degrees or greater) led to the Luftwaffe's nicknaming the system 'Schrage Musik' ('Slanting', i.e. 'Jazz' Music).

[Machinbird]

Of course, a lot more machineguns and cannons, but the basic math and historical record points out that was easier to hit an enemy fighter with a deflection shot with just 2 machineguns and iron sights in 1918 than with say, 6 cannon and/or machineguns and a reflector gunsight in 1943
Hi Romani. I am impressed that someone disagreed strongly enough to write a rebuttal. Thanks for taking the time.
I don't doubt that it was relatively easy to hit an enemy fighter in WWI (assuming you weren't hit first) but I really doubt many pilots could achieve the concentration of fire required to bring down an aircraft consistently(ie with a high probability of kill) from any place other than the deep six o'clock. Remember we aren't counting golden BB type kills (Luck=low probability of kill), although good/bad luck was a real factor in combat, especially if you did it day after day.
I blame the inability to concentrate fire primarily on the limited training provided WWI pilots.


If the target is flying perpendicular or you are attacking it from the target 4 or 8 quarter then that's impossible for any pilot save an expert for every age. Hate to disagree, but you can be blown out of the sky from any angle. It is mostly a matter of marksmanship and concentration of fire. Probabilities play heavily in any air to air shooting and the better pilots know how to put the odds in their favor. But in the end, the lethality of a bullet comes down to fractions of an inch. You hit major structure and deflect the bullet slightly one way or another. You either hit or just miss some critical element in the aircraft. The more bullets you can put on a tight path toward the target, the greater the probability that you will achieve the desired effect. The shorter your firing opportunity, the harder it is to get sufficient bullets on target. The steadier you fly, the more closely your bullets are grouped. Yes one bullet can make a kill, but there is a reason aircraft used machine guns for air to air.
It is known that the US air service in the interwar years studied Rene Fonck methods and tried to teach them, coming to the conclusion that they were beyond the grasp of the average pilot. Partly because they were only of application to people with excellent gunnery skills, but in view of these findings, I am wondering if they were also unappliable because fighter aircraft had evolved and gotten faster, rendering Fonck methods useless. Deflection shooting is applicable to gun equipped jet aircraft, so I see no reason it should lose its effectiveness in WWII.
I think the big thing is training. It is hard to generate proper training opportunities for air to air deflection shooting. I personally think some of the air combat simulator programs can teach deflection shooting more effectively than anything other than live combat.

In WWI you almost had to hit the pilot or the fuel tank to make a kill since there were not that many critical systems in the WWI aircraft.
You forget the engine, and the radiator. And there are plenty of accounts of bullets ripping the fabric in control surfaces, breaking longerons, spars, struts, cutting bracing wires, and control cables. And those come from surviving airmen, so we never can guess what was the actual cause of most WWI kills. I do agree that hits to the pilot would be the leading cause, followed by engine hits, flamers, and assorted structural damage.
Didn't forget the engine and cooling system. It is just that with WWI calibre ammo, you just didn't tend to get prompt kills with hits on these items. There was a lot of redundant structure in WWI aircraft and the probability of kill from damage to structure was relatively low (but spectacular when it occurred.) Think how many bullets hit nothing but fabric or perhaps a rib before exiting out the other side. There are multitudes of stories of pilots returning with broken flying wires and damage to significant structure. Seems to me that if that was an effective way to shoot down aircraft, you wouldn't be reading so many stories with this type damage as a common element.:D


Yet there's a consistent theme of skilled pilots in WWI able to aim for the pilot. I cannot think of anything similar in WWII except on attacks on bombers. Even from deep in the six o'clock, you had better aim for the pilot in WWI. Nothing else produced such a prompt kill, except perhaps fire.




The lack of true explosive shells and the resilience of fabric covered airplanes are on the other hand compensated by the fact that the pilot had no armor to protect him (except, perhaps for a bullet resistant windscreen), and the fuel tanks were not self sealing, and to make matters worse, they were pressurized. I believe you are making my point for me here. The pilot and the fuel tank were the desired targets to get a prompt kill.

It was easier to get a single shot kill of a WWII aircraft than a WWI aircraft.
I would make the case that it was easier to make a kill against a WWII aircraft if having a proper sight and good armament.
You are almost reinforcing my point. I just think it was easier to shoot a WWII aircraft down with a single shot.

You are basing your argument in hit probability and lethality, but the problem is about leading the target, and this was patently hard to achieve in WWII. Leading the target is only part of the problem. The problem is getting enough bullets in the target to get a high probability of kill. At least from my perspective.;)

[Greybeard]

I don't think deflection shooting was easier in WWI, first, because lighter scouts were prone to higher dispersion in wind and turbulences, second, because their pilots have no aid to perform it (i.e.: gyroscopic gunsight).

Of course, I'm neglecting all about weapons type and its effectiveness, considering sheer ballistic question.

GB

[Romani]

I don't think deflection shooting was easier in WWI, first, because lighter scouts were prone to higher dispersion in wind and turbulences,
GB

Is that really the case? I think vibration and buffeting gets much worse with speed. Even in a good road,a car bumps and shakes a lot more at 140 km/h h than at 70. Even if flying is a much smoother ride,

I saw the exposition they have in the Science Museum of London dedicated to the Spitfire. They had screens that showed gun camera footage taken from both german and british fighters. Nothing special about that.. seen plenty of those in wartime docummentaries. But the catch is that these were wartime training movies to teach gunnery. They superimposed a computer generated graph over the screen that plotted the movement of a hapless Spiftire caught in the sights of a Messerschmitt (German film and cameras were better so the surviving footage is clearer than British one)

Well, I feel now a lot better at my unability in flight sims to keep a steady course trying to keep the target aircraft on the sights, the Spitfire wobbled up and down in the sights and the German tracers and bullets were flying everywhere. Again nothing new for anybody that has studied gun camera footage. The plotted graph was interesting, it showed that the target moved up and down the sights plotting a graph like a russian mountain or a sinus function. And that from the dozens of rounds fired by the german in those 5 seconds, only 4 or 5 cannon shells hit the mark, as it was seen by the impact flashes, and spread all over. And that at a close range, I would say from the aparent size of the Spitfire, less than 200 meters.

It's true that due to inertia, a heavier, denser airplane will not wobble in the air as much as a flimsy wood and fabric biplane. That's basic physics, but so is increased vibration and turbulence with higher speeds.

No, I think we are missing the mark, I believe what really matters is the stability of the airplane as a gun platform and this depends on mass distribution and response of control surfaces. I suspect a SPAD XIII might have been a steadier gun platform than a handful of an airplane such as one of the late Messerschmitts, or conversely, a Huricane more stable than a twitchy Camel.

[Pips]

That last point of yours Romani is very important.

Most high scoring Scout pilots preferred to fly the Se.5 because of 1) it's speed and 2) it was a far more stable gun platform than the Camel. For the same reasons the French preferred the Spad (VII or XIII) over various Nieuport models. Rickenbacker said he like flying the N.28 for it's manoeuverability, but preferred to fight in the Spad XIII due to it's strength and stability as a gun platform.

The same was felt between the Hurricane and the Spitfire. The Hurricane was rock solid, the Spitfire danced all over the place. This is well illustrated by Stanford Tuck's in his bio 'Fly For Your Life'.

[TonyWilliams]

I suspect a SPAD XIII might have been a steadier gun platform than a handful of an airplane such as one of the late Messerschmitts, or conversely, a Huricane more stable than a twitchy Camel.
There are two issues here: one is the longitudinal stability of the aircraft, the other is how sensitive it is to buffeting in turbulence.

The first issue depends on the design of the plane rather than the era - planes from either war could be stable, or unstable (modern fighter jets are completely unstable, being kept pointing forwards only by their computerised flight control system).

The second issue concerns size and weight, and especially wing loading. The lightweight WW1 fighters, with their very low wing loading by WW2 standards, would be much more vulnerable to buffeting.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion forum (http://forums.delphiforums.com/autogun/messages/)

[TonyWilliams]

It was easier to get a single shot kill of a WWII aircraft than a WWI aircraft.

I doubt that very much. I have read test reports in WW2 of the results of shooting MGs at aircraft on the ground. Aircraft structures were very much stronger than in WW1, and there was lots of hardware, armour etc in them. In one test, firing at the back of a Blenheim bomber (hardly the toughest WW2 plane) with .303 and 7.92mm armour-piercing bullets, most of the bullets never even reached the armour - they were absorbed or deflected by the structure. Incendiary bullets only stood a 1 in 10 chance of igniting the tanks. I have similar tests on a Bf 109 and it is amazing what they could soak up.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion forum (http://forums.delphiforums.com/autogun/messages/)

[Greybeard]

Again, we're confusing the core question with global environment during the two world wars, this latter adding useless elements to the question.

Deflection shooting is what we're talking of. To perform it an average pilot requires to shoot leading his target trajectory with highest allowable accuracy. This needs a stable gun-platform to point effectively where intended. Well, as mentioned by Tony Williams, WWI scouts, with their higher surface to weight ratio, were absolutely less stable (try mentally to compare a flight of yours in an airliner with same on a ULM just to have an idea).

In addition, some later WWII fighters got aiming devices which increased significantly above mentioned "allowable accuracy". This should solve any further doubt.