What is the best of these four Dive Bombers?

[oldcrowcv63]

This may not be a totally fair comparison but let's consider the relative numbers of dive bomber production over the runs of each aircraft relative to total aircraft production of fighters and bombers. This might give us an idea of the relative importance of dive bombing in each venue:

USAAF: combined A-36 + A-24 production (500+ 953)/140,000 ~ 1.04 %

USN: combined (SBD SB2C) Production ~ (5936+7140)/60,000 ~ 21.83 %

US combined Total 14,529/198,000 ~ 7.33 %

Japan combined Total (D3Y D4Y) 3,300 / 45,500 ~ 7.25 %

IJN Combined (D3Y D4Y) / 16,657 ~ 19.81 %

UK FAA Skua: (190/3,981) ~ 4.77 %

Luftwaffe Total JU-87 5009 / 74,000 ~ 6.77 %

These estimates may indicate the emphasis of dive bombing in the navies of Japan and the US but also the overall importance of dive bombing in a national priority scheme. In this the US, Japan and Germany are fairly close while the UK trails. The USAAF clearly had little relative interest in dive bombing as the normalized number of USAAF dive bombers is smaller than those of the UK considering ONLY the Skua as a representative example! I mean, in relative terms, there were fewer A-36's in the USAAF than there were Skuas in the FAA!

Very generally speaking, the USAAF was developing as a culture focused on strategic bombing and tended to regard anything not directly related to completing that mission successfully as something of a distraction. Battlefield Interdiction behind enemy lines was certainly an important mission but close air support at the front line tended to receive a greater emphasis in the USMC and USN. Of course the A-10, AC-47 and C-130 spectre gunships came out of the Vietnam experience and is now a more an integral part of the modern USAF if not necessarily seen as a prime career path. In this, I am speaking from conversations held with a relative who is retired USAF Col. Pilot with a career split between TACAIR and SAC.

What I think is an interesting question given the existence of the A-36 and its apparent quality is why none were employed by Kenney in MacArthur's Southwest Pacific Theater?

 

[renrich]

The Avenger was not used as a dive bomber.

 

[oldcrowcv63]

A question.
Was the Avenger used as a dive bomber?
John

yep and reputed to be a pretty good one. After Midway there wasn't much left of the USN's trained torpedo bombing corps. Only about one full carrier's torpedo squadron (VT) remained spread between a number of squadron fragments (including VT-5, VT-6 and VT-8 ) IIRC, the air groups of the Wasp and Ranger consisted of two scout-bombing squadrons and two fighter squadrons and no VT squadron. The USN also had a crap torpedo so it was not particularly useful. As I understand it, for those reasons, many TBF sortees were flown with 4 500 lb bombs instead of torpedos).

 

[oldcrowcv63]

The Avenger was not used as a dive bomber.

Ooops... Didn't see your post Rich. I was under the impression that the TBF was used as a dive bomber to attack the Chikuma at Santa Cruz. I'll check that.

 

[oldcrowcv63]

You'll love this! I have a video showing the TBF used as a Dive bomber: Check it out: It's VERY convincing!


View: https://www.youtube.com/watch?v=dXnnyLOF87w

I did find this reference which convinced me, no matter how good it may have been, it shouldn't be used as a dive bomber, at least its not a method I would have liked...

from: The Pacific War Online Encyclopedia: TBF Avenger, U.S. Carrier Torpedo Bomber

...it was discovered to be a surprisingly effective dive bomber if the landing gear were lowered to act as dive brakes.

without dive brakes (which I should have picked that up immediately), I wouldn't expect it to be much of a dive bomber and wouldn't have wanted to deploy my landing gear in combat under virtually any circumstances!

A number of sources (web pages) show attacks by about 8-12 bomb-toting TBFs on two IJN cruisers (Chikuma and Suzuya) at Santa Cruz with about 1 hit from all the ordnance released. Doesn't suggest a dive bombing attack let alone a successful or accurate one.

Late entry: Consulted Lundstrom who records these TBF attacks as by glide bombing....

 

[tomo pauk]

The dive bombing enabled by landing gear in lowered position was done by F4U. So why not for the Avenger, too, if it proved non problematic?

 

[Wildcat]

What I think is an interesting question given the existence of the A-36 and its apparent quality is why none were employed by Kenney in MacArthur's Southwest Pacific Theater?

I can't see Kenney employing the A-36, seeing as it was he who ordered the RAAF Vengeance wing out of New Guinea despite those units operating successfully with the type.

 

[buffnut453]

Agreed, both the USAAF and RAF were unenthusiastic about the dive bomber as a concept throughout the war. The Vengeance certainly proved its worth and yet it was removed from front-line operations and replaced by other types (eg one RAAF Vengeance unit, I think it was 25 Sqn, converted to Liberators - hardly similar roles).

 

[Readie]

You'll love this! I have a video showing the TBF used as a Dive bomber: Check it out: It's VERY convincing!


View: https://www.youtube.com/watch?v=dXnnyLOF87w

I did find this reference which convinced me, no matter how good it may have been, it shouldn't be used as a dive bomber, at least its not a method I would have liked...

from: The Pacific War Online Encyclopedia: TBF Avenger, U.S. Carrier Torpedo Bomber

...it was discovered to be a surprisingly effective dive bomber if the landing gear were lowered to act as dive brakes.

without dive brakes (which I should have picked that up immediately), I wouldn't expect it to be much of a dive bomber and wouldn't have wanted to deploy my landing gear in combat under virtually any circumstances!

A number of sources (web pages) show attacks by about 8-12 bomb-toting TBFs on two IJN cruisers (Chikuma and Suzuya) at Santa Cruz with about 1 hit from all the ordnance released. Doesn't suggest a dive bombing attack let alone a successful or accurate one.

Late entry: Consulted Lundstrom who records these TBF attacks as by glide bombing....

Still a bit confused guys...was the Avenger used operationally as a 'dive bomber'?

The articles I have read seem to indicate it could have been but, don't say if it was in action so's to speak.
I see that none other than G W Bush was an Avenger pilot in WW2.
John

 

[davebender]

Once the bombs were gone a Ju-87 could probably out-turn a Spitfire. That doesn't make the Ju-87 a great fighter aircraft.

Dive bombers are relatively easy to kill if proper tactics are employed. Trying to out turn a dive bomber @ 150 mph is simply throwning away your fighter aircraft advantages of speed, acceleration and climb.

 

[tomo pauk]

Isn't that what I've said?

 

[oldcrowcv63]

Still a bit confused guys...was the Avenger used operationally as a 'dive bomber'?

The articles I have read seem to indicate it could have been but, don't say if it was in action so's to speak.
I see that none other than G W Bush was an Avenger pilot in WW2.
John

As far as I can gather, Renrich was correct, the TBF was not employed as a dive bomber (at least typically). My statement that it was, is suspect, since I have only been able to find a couple of references to its potential use as a dive bomber but no instances of its actual use. I thought the best possibility might be chichi jima, but haven't found any verification of that. The use of the landing gear as a dive break is mentioned on a number of sites and I can assure you that Grumman iron works would be capable of producing landing gear assemblies with that kind of strength, so perhaps it was occasionally used in that manner.

Would I want to do it? Personnally, I don't like the idea. Let the F4U studs adopt that tactic. Evidently the F4U Main gear doors (purpose designed?) acting as ersatz dive breaks:

http://forums.ubi.com/archive/index.php/t-186248.html

with F4U dive methodology described in this forum in a lengthy post reproduced from FAA test pilot Capt Eric Brown's Wings of the Navy.

Scrivner's TBF/TBM Avenger in action Series pub states that a weapon delivery on a moving vessel was to attack in a 30-45 degree dive to a release point at 500 ft or less altitude. An intervalometer was used to release the bombs (presumably a stick of 4 x 500 pounders) in a string 60-75 feet apart.

 

[FLYBOYJ]

Once the bombs were gone a Ju-87 could probably out-turn a Spitfire. That doesn't make the Ju-87 a great fighter aircraft.

At speed - I doubt it...

Dive bombers are relatively easy to kill if proper tactics are employed.

The same could be said for any bomb laden single engine aircraft

 

[oldcrowcv63]

I can't see Kenney employing the A-36, seeing as it was he who ordered the RAAF Vengeance wing out of New Guinea despite those units operating successfully with the type.

This really is a bit of a mystery. Why would Kenney be so dead set against a proven antishipping technology/technique in a theater that ahould have provided a target rich environment?

 

[T Bolt]

This really is a bit of a mystery. Why would Kenney be so dead set against a proven antishipping technology/technique in a theater that ahould have provided a target rich environment?

A commending general's unreasonable hatred for a particular aircraft is nothing new here.. Doolittle hated the B-24 so much that he had all of them removed from the 8th Air Force, most going to the 15th in Italy.

 

[oldcrowcv63]

This is doubly interesting because both Kenney and Doolittle were reputed to be among the most technically savvy generals! What did they know about these aircraft (B-24 / A-35) or the dive bombing technique that turned them off to them/it? Do you have a reference for Doolittle's antipathy to the Liberator? I'd like to read more on that. B-24 and PB4Y has always been a favorite of mine, but don't know much about them other than some very favorable operational accounts

 

[oldcrowcv63]

Raid on Chichi Jima, Possibly an excerpt or interview releated to or from Bradley's Flyboys:

A Strike on Chichi Jima in Sea Forum

The pilot(s) talk of dives without further elaboration.

One TBM suffered significant damage due to a collision with another Avenger damaged and ultimately destroyed by AAA. This one evidently made it back but ditched near its carrier! Check out the fusalage aft of the turret. It's been damaged too and the aircraft folded up on water impact. Pilot (only one aboard) survived.

Grumman Iron works indeed:

 

[oldcrowcv63]

Air Power Development Centre

"Lieutenant General George Kenney, grounded its three squadrons of Vultee Vengeance dive-bombers in No 10 Operational Group on this day. The Vengeance units formed half the operational strength of 10 Group, a new mobile force formed by the RAAF to keep up with its American allies as they advanced north-west through New Guinea. Kenney, however, considered the US-built Vengeance to be a failed and inefficient type, and was unwilling to have them taking up space on overcrowded airfields in the forward area. The Vengeances had only taken part in operations for a few weeks when he ordered them out of New Guinea."

This sounds like he just wanted longer-ranged, higher-payload B-24s and didn't have ramp space for both types. But there must have been more to it. The fact that these aircraft weren't even USAAF owned and only in operation for a brief time smacks of some sort of attendent political issue.

 

[Wildcat]

Air Power Development Centre

"Lieutenant General George Kenney, grounded its three squadrons of Vultee Vengeance dive-bombers in No 10 Operational Group on this day. The Vengeance units formed half the operational strength of 10 Group, a new mobile force formed by the RAAF to keep up with its American allies as they advanced north-west through New Guinea. Kenney, however, considered the US-built Vengeance to be a failed and inefficient type, and was unwilling to have them taking up space on overcrowded airfields in the forward area. The Vengeances had only taken part in operations for a few weeks when he ordered them out of New Guinea."

This sounds like he just wanted longer-ranged, higher-payload B-24s and didn't have ramp space for both types. But there must have been more to it. The fact that these aircraft weren't even USAAF owned and only in operation for a brief time smacks of some sort of attendent political issue.

How Kenney came to the conclusion that the Vengeance was ineffective is a mystery to me, and I dare say to the RAAF leaders of 77 Wing also. To say that the news came as a shock to them would be an understatment. No.24 squadron had been flying dive bombing missions over both New Britain and New Guinea for a full 6 months prior to this, losing not a single aircraft to enemy fighters and possibly 3 to AA fire (all force landed on return to base with engine problems). As for accurately putting bombs on difficult targets hiden in mountainous jungles, the Vengeance had no equal in New Guinea, certainly more suited to the role than the P-38 which is often quoted as being the aircraft the Vengeances were making room for on the "overcrowded" airfields.

 

[R Leonard]

I think we need to be a little clearer on terminology. In the WWII timeframe the USN identified four different air attack profiles

1. dive bombing​

2. glide bombing​

3. horizontal bombing at level flight​

4. low-level bombing at minimum altitudes​

Dive bombing was defined as occurring at angles of attack ranging from 90° down to 60°. If you were to look at the major "real" dive bombers from the war years (SBD, D3A, Ju87, SB2C and so on) you would quick note that they all have common features, among which was that they carried their primary ordnance center-lined and they all employed bomb displacement gear to swing said ordnance when released clear of the propeller arc. Bomb displacement gear was developed in the late 1920s when it was determined that a steep angle dive and release could present some unpleasant results if the ordnance were to come in contact with a spinning propeller. This unhappy fact was in conflict with the greater accuracy, not to mention certain foiling of defensive fire solutions, one could achieve with near vertical angles of attack and a center-line carrying of the ordnance. Thus the displacement gear would swing the bomb clear in an arc and producing a known trajectory pattern for which one could account in one's sighting picture. The other handy piece of equipment was a dive brake of some kind, not so much to slow the aircraft, but to provide stabilization during the ordnance delivery. This was found in various forms on the major dive bomber players; its absence was a noticeable performance limiter in others such as the SB2U.

Such WW2 dive bombing attacks as defined by and executed by the USN (90° down to 60°) fell easily in the realm of the SBD and the SB2C, both of which were equipped with said bomb displacement gear and dive brakes. A dive bombing attack, correctly executed, especially when in the 75° plus angles of attack range was very difficult to defend against from either directed AA fire or even from a CAP. (The SB2U, again, was a whole different ballgame in spite of the presence of displacement gear but without a dive brake.)

Glide bombing was defined as occurring at angles of attack ranging from 55° down to 30°. Glide bombing by attack, as opposed to fighter, aircraft was where one could expect to find torpedo-bombers as no displacement gear is required. The TBF, then, was not a "dive bomber" nor was it used for dive bombing attacks as defined by the USN. There are two issues here, the construction of the aircraft and doctrine, the second being somewhat driven by the first.

If you look at the TBF/TBM you can see that the ordnance is carried internally in a closed bomb bay. The airplane did not have displacement gear and so, with the combined factors of internal storage and simple drop mechanism, glide bombing the best the type could do. Quite frankly, a discussion centered on lowering ones landing gear to reduce diving speed, and thus facilitate a dive bombing profile, is so much nonsense . . . no displacement gear equals no dive bombing.

The TBF/TBM could most certainly execute a glide bombing attack and, especially as worthy targets for torpedoes went away, quite often did. Glide bomb, however, remained a very dangerous way of doing business. Although one keeps one's speed up, it requires a straight in approach on a target which, if shooting back, is straight into the optimal angle of defensive fires. This is similar to the torpedo attack profile which was not known for happy outcomes. Note the results with VMSB-241 at Midway, in the aforementioned SB2U (the non-dive bombing dive bomber) . . . losses not as bad as VT-8 (det), VT-8, VT-6 or VT-3, but certainly bad enough, and mostly due to over-exposure. The only advantage over the torpedo approach was speed, the more the better.

Horizontal level bombing is usually, and correctly, thought of as being in the province of the multi-engine bomber - more often than not carried out at some altitude above the expected effective AA fire. What is often forgotten is that the TBF/TBMs were equipped with Norden bomb sights (after all, the Norden bomb sight was developed for the USN long before the USAAF ever got their hands on one). But what should be remembered is that the USN was well aware that level bombing of moving ships was pretty much an exercise in futility. Level bombing by TBF/TBMs was pretty much limited to shore targets and usually from those higher altitudes. At the end of the war it was not unusual to see flights of TBMs unloading their ordnance on stationary targets such as the ferry docks at Hakodate on Hokkaido while the dive bombers and fighter-bombers went after the ferries themselves. Interestingly, in the last month of combat operation by the fast carriers of TF-38, not a single torpedo was dropped. TBMs were exclusively bomb haulers, almost exclusively in the level bombing profile, and SUBCAP depth bomb carriers.

Low level bombing was originally the preferred method for fighters, back to the days of F4Fs carrying itty-bitty bombs. Some early fighter squadrons, VF-42 and VF-3 come to mind, dispensed with the idea entirely and removed the bomb racks from under the wings of their aircraft. No racks, no low level bombing. All that said, the advent of the rocket for low level attacks reopened the field to just about anyone who wanted to play. All the active carrier aircraft by the end of the war, F6F, F4U, FM-2, TBM, TBF, SB2C carried and dispensed rockets with great abandon at maritime and land targets. One F6F driver even was able to down a Japanese airplane with a rocket. Napalm was another interesting capability brought increased usage of low level bombing in support of ground forces.

And then there were the variations on a theme. Fighters such as the F6F and F4U, by the end of the war were known for their bomb hauling ability. It is oft bandied about that these fighters, when not performing more glamorous fighter type shooting up the bad guys' airplanes duties or even those pesky, and much more common, low level attacks, executed dive bombing attacks. Well, yes . . . and no. A more correct description was a very steep glide bombing profile or, perhaps, a not so steep dive bombing attack. The truth to the matter was these attacks were usually conducted at attack angle ranging from about 40° up to around 65°, on rare occasion up as high as 70°. Note that this profile neatly straddles the high end of the glide profile, the 5° demarcation between glide and dive profile and into the low end of the dive profile. While still facing the potential problem of traveling through some prime defensive fire terrain, the speeds at which such attacks could be executed paid off more for the attacker then the angle of approach did for the defender . . . not to mention that Japanese AA fire had its, ummm, problems, which only got worse as time went on. Bombs on these types were usually carried somewhat off center and attached to underside pylons. This method provided a separation factor which allowed them to enter the attack profile nether area somewhere between the glide bombing and dive bombing profiles. It was certainly not, popular tales to the contrary, a common practice to lower landing gear in the F4U, nor the F6F for that matter, when delivering any bomb attack. It should be remembered that speed was the name of the game, more speed meant less time under fire. The inconvenient fact arguing against such an odd practice was that there were limits to the speeds at which one should or could lower one's landing gear, specifically pointed out the respective pilot's manuals. In neither of the manuals is there any discussion of lowering landing gear in a dive profile; in fact, for example, the F4U manual warns against EXCEEDING 375 kts in a dive when carrying ordnance. The gunsight in these fighters could be used to arrive at the correct release point for the weight of bomb carried at the speed the airplane was travelling; there was no need to slow down, nor any desire to do so. Generally, attacks by these fighter attacks would be generally classed as low-level and glide bombing attacks were one to adhere to the doctrinal definitions . . . if a true dive-bombing attack profile was called for, there were dedicated aircraft for that purpose and fighters were better used for AA suppression.

A big part of the problem in discussing dive bombing and USN aircraft is correct use of the terminology. Dive bombing has a very specific meaning and does not mean simply some degrees off the horizontal. By the USN's own definitions, the TBF/TBM was a glide bomber, not a dive bomber.

Rich