Dive bombing

[Ray]

Please pardon my ignorance, I've studied more on WW2 over the years, and am still on a sharp learning curve for WW1. Was there any defined, or organized attempt at refining dive bombing during the war. Most dive bombing referrences are to developments in techniques and equipment during the 20's and 30's. But on the fighter and level bomber side you see direct referrence to WW1.

From what I've read some pilots and even squadrons would try different methods when they went up, and then relay somethings by word of mouth. But so far I haven't seen any "major record keeping" so to speak of, done for dive bombing.

Ray

[Barrett]

The RAF conducted experiments in dive angle/speed/release height with a variety of small bombs, though I don't recall specifics. Some of Peter Smith's books likely address the topic as well as others. I used to be acquainted with an American SE-5 pilot who tried bombing bridges in 1918. He concluded that the optimum approach was slightly angled along the length of the span, which is exactly the procedure used well into the jet age, before PGMs. Of course, during The Vietnam Thing, the Demo libwimps like LBJ and Robt. Strange McNamara often prohibited that approach, because "overs" and "unders" could put ordnance on the end of bridges where "civilians" likely manned the flak guns.

[Ray]

Thanks for the info Barrett. I think I'm now hooked on a new area, aka WW1. I've been reading some on Navy/dive bombing and for the first time kept thinking hey, no referrences to WW1, so started looking harder in that direction. Thanks for the help and another addiction folks!

Ray

[Barrett]

A bit of follow-up, Ray. It's been claimed that the USN/USMC "invented" dive bombing which of course is absurd. But the marines may rightly claim to have perfected the technique in the US armed forces, and the navy took it even farther in the late '20s with advent of our first big-deck carriers, Lexington and Saratoga.

[Ray]

Everything I've been reading reference the Navy or Marines. Even european countries credit the Marines in Nicaragua.

I just stumbled across a brief bit on the RFC testing at Orfordness Bombing Range. Very brief actually because thats all they said. I assumed this was the trials with the SE5 you were talking about.

[Lufbery]

Barrett, of course, really know his stuff.

I found some additional material on this site. The site's author, Emmanuel Gustin, is, I believe, the same fellow who worked with Tony Williams (a fellow forumite) on his book on aircraft armaments. Mr. Gustin lists his sources at the end of the article, so if you can rum them down, they may help.

Here's the quote:

The Origins of Dive Bombing

The concept of dive bombing was certainly not unique to the German Luftwaffe. The theoretical basis for it is simple enough, that it would come to different minds in different places and at different times. It would probably be unjustified to look for the "inventor" of dive bombing.

In normal (horizontal) bombing the released bomb has a horizontal, forward speed vector given to it by the movement of the aircraft. To this a vertical acceleration is added, caused by the pull of gravity, which causes to bomb to fall. The combination of the two results in a parabolic curve, which is distorted by the drag of the bomb and the wind. The basic idea of dive bombing is to make the speed vector of the aircraft coincide with the direction of gravity -- vertical -- so that the trajectory of the bomb becomes a straight line instead of a complicated curve. This greatly reduces the problems of bomb aiming. Because the bomb is usually released from lower altitude and at higher speeds, the effects of the wind are also minimised.

...

The technique was first used during Word War I. The first officially acknowledged dive bombing attack seems to have been made by Lieutenant Harry Brown of the RFC (Royal Flying Corps) who sank a munitions barge in 1917. After the end of the war the RAF (Royal Air Force) conducted research and experiments, but finally decided that the method was too dangerous and halted its development. Instead, the British chose to concentrate their efforts on the creation of a strategic bombardment force. The FAA (Fleet Air Arm) kept the idea alive, but the development on its aircraft was seriously hampered by the RAF control over all aircraft, including shipboard aircraft.

The development of dive bombing continued in the USA. The USMC (US Marine Corps) practised dive bombing, although seldom at angles of more than 45 degrees, during operations in Haiti in 1919. A more refined form of the technique, influenced strongly by aviators who had flown in Europe during W.W.I, was used by them during the US intervention in Nicaragua in 1927. During these years, the USMC pilots also included spectacular dive bombing demonstrations in their air show routines. The USN (US Navy) adopted dive bombing as doctrine, not to provide ground units with tactical air support (as had been the goal of the USMC) but as an effective method to hit enemy ships -- relatively small, moving targets. The aircraft used during these years were developments of the Curtiss Hawk family of fighter biplanes, the F6C and BF2C. The name of `Helldiver' was attached to these aircraft, although this would not become officially the name of an American aircraft until the Curtiss SB2C was introduced, during W.W.II.

Regards,

[Alan]

I would just call into question the confidence the average line pilot would have in his crate being able to pull off a high speed dive.

With wing shedding being something of a problem for Nieuports and wing struts being an Albitrii problem, it would seem that only a limited number of aircraft types would be able to withstand the stress of a dive with additional drag from a bomb.

Which brings up two more issues- I've only seen British aeroplanes carrying small bombs on their scouts. And, IIRC, they didn't dive bomb with them either. Could their reticence be doctrine-based or the fact that they knew other aircraft types had stress problems.

Or, were the aircraft of the day even designed for it? Which, I guess if it were a doctrine-based ignorance they probably weren't designed for it...

Barrett, you mentioned an SE-5 pilot and his thoughts on it but did that include high angles of attack?

[wulffo]

I believe to have read something about Udet being so impressed by the Curtis, that he pushed Goering to purchase two one of which he flew himself. This supposedly was the bait to get Udet involved with the Luftwaffe again. Also, this seems to have started the German development of a dive bombing concept. Obviously years after the US adaption of the concept.

[TonyWilliams]

Originally Posted by Alan

Or, were the aircraft of the day even designed for it? Which, I guess if it were a doctrine-based ignorance they probably weren't designed for it...

Well, you can hardly expect aircraft to have been designed for a purpose which had only just been thought of and whose viability was being tried out with whatever equipment they had to hand.

Clearly, the first purpose-designed dive-bombers wouldn't have been designed before the technique had been proven to be worthwhile with existing planes.

I agree that the first systematic testing and application of dive-bombing seems to have carried out by the British during WW1, regardless of how unsuitable their available planes or bombs might have been.

Tony Williams: Military gun and ammunition website and discussion
forum

[Barrett]

Some technical observations:

It's probably true that DIVE bombing was rare in WW I, depending on one's definition. A 45-degree dive is functionally closer to glide bombing, but for bombs carried beneath the fuselage that's about all that could safely be done. If you get much steeper you run the risk of putting your ordnance thru the prop arc.

Genuine dive bombing is sorta acknowledged to begin at 60 degrees, but the USN went to 70 and the Luftwaffe to 80-plus. Note that the US and German dive bombers all had a bomb displacing gear ("trapeze") to loft the bomb clear of the prop. Such gadgets just didn't exist in TGW.

I've done just enough dive bombing to know that from the pilot's seat, 70 degrees appears vertical. For those who wanted a true 90-degree dive, it was necessary to "bunt" the nose past the pure vertical to get a true zero-lift vector. It makes for optimum accuracy, but the pullout is a doozy when gravity's elephant steps on your head...