USAAC ground-attack/dive bomber (North American A-36 Apache)

[barney]

There's some period A-36 film. I can't figure out where this was taken, US or overseas. Anyway there is what appears to be practice bombing at the end - not much dive bombing, mostly level.


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

 

[davebender]

We need close up pictures from inside the A-36 cockpit. Perhaps that would allow us to determine what type bomb sight (if any) was standard equipment.

 

[gjs238]

My take from the article is that the USAAC didn't like dive-bombing.

Although Army doctrine held that dive-bombing was ineffective and dangerous, (because of the high dive and pull-out speeds)

 

[davebender]

Cockpit photograph of SBD dive bomber. Note the bomb site on top of the instrument panel.
Douglas SBD

A-36 cockpit pictures. Where is the bomb site?
File:North American A-36A cockpit USAF.jpg - Wikimedia Commons

http://daytonipms.com/Walks/A-36/CockpitStbdRear.jpg

http://daytonipms.com/Walks/A-36/CockpitPortRear.jpg

 

[tyrodtom]

No gunsight either, obiviously it, some instruments and several switches have been removed in those pictures.

 

[davebender]

The A-1C gunsight: a case study of technological innovation in the United States Air Force | Air Power History | Find Articles

Lt. Col. Leighton I. Davis was nearing the end of his second tour of duty at the U.S. Military Academy at West Point, New York, in April, 1943, when he received orders to command a fighter-bomber group composed of North American A-36s that was about to deploy overseas. He flew to Alabama in advance to meet his new boss and to look over the A-36--the ground attack version of the P-51 Mustang. "I was amazed to see that they still had ring and bead sights in the middle of the damn thing," exclaimed Leighton when he recalled the event in later years. (3) It was the same sight used in the P-12s that he had flown in 1936. Nothing new had been added to assist the pilot in his main mission: gunnery and dive bombing.

I can scarcely believe a dive bomber wouldn't have a proper bomb sight but that's what this article suggests.

 

[model299]

I can scarcely believe a dive bomber wouldn't have a proper bomb sight but that's what this article suggests.

Which suggests to me the AAC was never truly serious about the whole thing. At least not the people who were calling the shots.

 

[barney]

The A-1C gunsight: a case study of technological innovation in the United States Air Force | Air Power History | Find Articles

I can scarcely believe a dive bomber wouldn't have a proper bomb sight but that's what this article suggests.

If a bomb is released in a perfectly vertical dive at low altitude with the aircraft pointed at the target the only thing that might make you miss is high wind. So, for that sort of bomb run you wouldn't need much of a bomb sight – just something to look through to keep the plane pointed at the target. Now, come in at a 45 degree angle and it is a whole different problem.

 

[Siegfried]

Perhaps the A-36 bomb site wasn't as good as the Ju-87 bomb sight. Otherwise it's difficult to understand why it couldn't bomb accurately at similiar dive speeds.

The Ju 87 was a very steady platform not only for bombing but gunnery, it wasn't in the least bit 'twitchy' as an aircraft with a fighter herritage would be so it was easier to line up a bomb or a 30mm anti-tank gun. The FW 190 with 30mm AT gun was not such a success because of this.

The Ju 87, like Ju 88 had sophisticated automatic pullout devices to conduct the pullout when the pilot was incapacitated by G forces.

The Stuvi 5B computing dive bombing sight calculated a continious impact point. It worked at shallow angles (eg 20 degrees) in a Ju 88 or Me 410 but could also be fitted to a Ju 87 for steeper approaches. This sight eliminated the need for near vertical dives from about 1942 though they were still usefull and somewhat more accurate.

The final bomb sight of the war was the TSA-2D (Tief Schleuder Anlage) in which the pilot aimed at the target with his gun sight, pulled up when a buzzer sounded/light flashed and the computer tossed the bomb at the correct point of the pullup. It used an accelerometer and a choice of barometric or radio altimeter for altitude as part of the sensors for tracking the target during pullup and release. This sight was what would have (in fact was) fitted to Me 262 and planed for FW-190D13 ground attack variants. It was a very sophisticated sight.

If the USAAF wanted dive bombing sight and equipment it could have turned to the USN who were the experts in this field.

If the USAAF wanted a bridge destroyed it would send in a squadron or group of B-26's or A20 Havoc in formation at say 8000ft-10,000ft which would drop a string of bombs say 8 x 500lbs and that would do the job.

 

[merlin]

A dive bomb run sets up the dive bomber in a relatively straight, predictable flight path that is a blessing to a light anti-aircraft battery or even AA machine guns regardless of the type of engine.

Surely, it is the low-level bombing that is the more dangerous as far as flak is concerned. That is - swinging the weapon left-to-right, seems physically easier than aiming lower and lower.
So tracking an aircraft across the horizon, is easier to maintain aim, than on one that is comes over at 10,000 ft then arcs over into a 70 degree dive.

 

[Milosh]

Which suggests to me the AAC was never truly serious about the whole thing. At least not the people who were calling the shots.

Maybe the USAAC changed over time, as it was an American demonstration that got Germany interested in dive bombing.

The FW 190 with 30mm AT gun was not such a success because of this.

I understood it was the mounting could not be strong enough as the gun moved all over the place when fired.

 

[Mustangtmg]

One would think that with a stunning airframe
as the P-51A one would not convert production
to the A-36 dive bomber variant but use the P-40
as a dive bomber instead thus leaving the
P-51 as a fighter.

There may have been technical reasons such as
the thicker wings of the P-51A allowing easier
mechanical integration of the split dive brakes or
placement of P-40 undercarriage. It may also
have been a way North American could
wangle a sale to the USAAF or North American
simply had the idea and Curtiss didn't.

Dive bombing seems to have been a US Navy speciality
and used by the Royal Navy on the Skua.

What is fascinating about the A-36 is its ability to
be both a full screaming dive bomber as well as
a very fast fighter aircraft. I don't think many
other aircraft were able to match this.

It's somewhat puzzling as to why the Luftwaffe didn't
copy this dive brake arrangement for its single seaters
or for the matter anyone else; though these type of
brakes were used on the Me 410 for instance.

By 1942 two new bomb sights were in service with the Luftwaffe.

1 The Lotfe 7C, this was a gyrostablised bombsight that had variable
speed drives that could be trimed in speed to track a target on the ground
to theraby establish true ground speed and therefore wind drift and
automatically calculate an offset.

More or less similar to the Norden.

2 The Stuvi 5B was a continuous computing shallow dive bombing sight.
It put a continuous impact point on to the target so that for instance
a Ju 88 without dive brakes and in a 20 degree dive could bomb accurately
in a shallow dive from say 8000ft to 5000ft.

The this bomb-sight was also used by Ju 87 Stuka; it was not suitable
for aircraft that didn't have good downward vision or alternatively
those that could go in a steep dive.

The British Mk XIV bomb-sight could also slide bomb.


s it seems dive bombing was no longer so important, except at sea, where the
small target the aircraft made reduced chance of a hit.


The allied moved to rockets. The Germans started to develop a computing
bombsight suitable for fighters that worked through the gunsight called
the TSA-2D. They also started to introduce rockets in the final months of
the war.

I'm curious to know if the US had or used any shallow dive or slide bombing sights.

It seems the doctrine was just to use a formation of Medium bombers such as
B-26 or B-25 to do a drop from medium altitude: say 8000-12000ft

I guess I've just never seen this before. I found this post through Google today, and I wondered if the many errors about the A-36A and P-51A have ever been pointed out and corrected?

Let me know.

I'm ready to help "fix" things.

Tom Griffith

 

[tomo pauk]

Tom, the member you've replied is very unlikely to post here again (unless he registered under a new name) since he is banned. But, at any rate, if you have some good information, data etc, not just about Mustangs of any flavor - don't hesitate to share

 

[MIflyer]

Fact was, the USAAF and USN fighters were pretty darn good ground attack aircraft with no more mods than adding some bomb racks; no other country could say that. The ultimate ground attack aircraft developed in WWII was the Vultee XA-41, which looked like the AD Skyraider's uglier cousin. It had an R-3350 engine and four 37MM cannon in the wings. But tests showed it was vulnerable to interception by fighters while the P-38, P-47, and P-51 could jettison their bombs and defend themselves if required.

By Korea that situation had changed to a degree. Jets capable of fighting the Mig-15 could not haul bombs very far, but the advent of the F-86F fighter bomber changed that somewhat. By Vietnam the incompatibility between supersonic jets and CAS was becoming undeniable and thus the A-7D and eventually the A-10 were developed.

 

[pbehn]

I guess I've just never seen this before. I found this post through Google today, and I wondered if the many errors about the A-36A and P-51A have ever been pointed out and corrected?

Let me know.

I'm ready to help "fix" things.

Tom Griffith

The answer to the puzzle is in post #6

 

[drgondog]

This an old thread but misconceptions abound re: A-36.

The AAF was 'signing up' in late 1941 to a.) the need to better support their boss US Army with both fast bomb carrying fighters and light attack bombers, and b.) the concepts heavily pressured by Asst Secy War Harry Hopkins to consider studying Luftwaffe CAS doctrine and in particular, the successes of the Ju-87.

Additionally everyone in the AAC/AAF understood that observation aircraft like the O-47 were too slow to survive over a hostile battlefield. Accordingly the CAS cadre led primarily by Col Muir Fairchild developed plans for CAS/Recon that required fast fighter/recon and light bomber aircraft. Materiel Command under Echols was still churning out specs resulting in lumbering beasts like the Brewster XA-32 to replace A-24/-26 dive bomber types.

When FY41 funding emerged NAA was aware that there were funds for the 'Attack Fighter' that could be targeted to fit the Mustang into - gambled on a dive bomber version of the Mustang I with specs and preliminary design ready in December 1941. Between the emergence of the A-36 spec, Col Ira Eaker stopped by NAA and flew the XP-51 and was impressed enough that he urged Arnold to consider it as a fighter in lieu of the XP-46. Arnold visited NAA with Spaatz in late January 1942. There are no records detailing conversations with NAA but more engineering time was devoted to the A-36 including studies for fuel feed to external ferry tanks attached to bomb rack.

At this time Col Craig Asst COS & Dir Air War Plans and Col Fairchlld & Dir Miltary Requirements and Col Schlatter Dir CAS proposed the Mustang/A-36 (Fairchild on pont) to Materiel command with an authorization to release funding for 500 Attack version of Mustang. Echols fought bitterly to stop it, but War Plans had the political clout, supported by Spaatz to ram it down Echols throat.

Time passes, A-36 born and lessons learned from RAF's Conningham - CO Desert AF are aligned into AAF CAS doctrine - which will lead to future consideration for a battlefield CAS aircraft that an also win air supremacy over the battlefield - which will point future acceptance of the P-51A and thence to the P-51B devoted to CAS - not long range escort, which is how the P-51B headed to ETO as part of 9th AF - not 8th.

During training there were two fatal accidents related to the wing of the A-36. One was an attempted dive pull out with 2x1000 pound bombs in which the pilot overshot his target and while trying recover the target went 'negative G" and into the ground. The second was the result of opening the dive brakes AFTER entering the dive - despite warnings from NAA that the brakes should ONLY be opened in level flight. Training Command ordered the dive brakes wired shut, But, the 27th and 86th FBG ignored the order in combat and te A-36 was regarded as a 'very good to exceptional' dive bomber during combat ops in 1943/1944 when they finally ran out of airplanes - and converted to P-40 for short time, then P-47D for the duration.

While not as good an air fighter as the P-51B, post bombing run it was just as maneuverable as the Mustang I and P-51A - and a lot faster than 109 and 190 in its prime operating envelope under 6-7000 feet. Fully loaded with fuel and ammo, it was 300+heavier than the P-51A and 200 pounds heavier than the P-51 but slightly faster than the P-39Q and P-51A and much faster than the P-40N.

Additional note -just as the A-36 was arriving in the MTO the CAS doctrine in Plans Div shifted completely away from Dive Bombing to Fast Recon/Tactical Fighter bomber and both the P-51A and B were allocated by AAF to replace the P-39 and P-40 for all AAF Theatres as deliveries permitted. The A-36 was not a failure at all. It was just that for multi role operations the P-51A/B was superior in combination, any contemplated escort role, air superiority role and tactical recon role.

 

[MIflyer]

The A-36A used the gunsight to aim the bombs. See attached.

And the A-36A mainly did not do Close Air Support in direct support of troops in combat; that concept had not even been created yet. It attacked bridges, artillery emplacements, etc. Direct support of troops in combat was more or less first invented by the Air Commandos in Burma and at that point the RAF was very doubtful of the very idea that a forward observer could talk to aircraft directly to control their fire. One reason the P-51A got the job in Burma was that it was equipped with SCR-274-N HF radios capable of talking to the ground troops, while the RAF had gone to VHF for its fighters and the ground troops had no such equipment.

 

[Kevin J]

The A-36A used the gunsight to aim the bombs. See attached.

And the A-36A mainly did not do Close Air Support in direct support of troops in combat; that concept had not even been created yet. It attacked bridges, artillery emplacements, etc. Direct support of troops in combat was more or less first invented by the Air Commandos in Burma and at that point the RAF was very doubtful of the very idea that a forward observer could talk to aircraft directly to control their fire. One reason the P-51A got the job in Burma was that it was equipped with SCR-274-N HF radios capable of talking to the ground troops, while the RAF had gone to VHF for its fighters and the ground troops had no such equipment. View attachment 566538

I thought the cab rank idea was invented by the 8th Army in North Africa.

 

[pbehn]

You gotta have sympathy with the guys at N.A. "Hey that's a great slippery fighter you got there, can you put some breaks on it so it can fly straight downwards"?

 

[ColFord]

A large number of the exercises held by the Squadrons of RAF Army Co-operation Command with the Home Forces units of the British Army in 1942-3 were to test different forms of co-operation with the Army, including various methods of close air support. It was a standard part of the training for the Army Co-operation Command pilots as they went through the School of Army Co-operation at Old Sarum for the airborne control and direction of Army artillery. This included use of 'synthetic' trainers - a large scale sand table where using an intercom system to mimic use of R/T the pilots would practice direction of Army artillery, with the fall of shot being displayed on the table by someone under the table expelling cigarette smoke up at the appropriate point, to full on direction of Army artillery units of various types on ranges located on Salisbury Plains.

The RAF ACC Mustangs were initially fitted with HF which was used for both air to air and air to ground communication, the set used being compatible with Army R/T frequencies and equipment. However, the exercises and trials revealed that the HF sets were too easily prone to interference, and changes were made to providing VHF sets, with Army units provided with compatible VHF sets. These were put into command tanks in armoured units, communications vans attached to artillery units and also placed with Army HQ units with the Air Liaison Officers attached to the HQs. By the time of D-Day they had contact cars with Army reconnaissance units, which included RAF pilots with recent operational experience acting as controllers and with multiple radio sets to give them maximum connectivity with RAF and Army units. By late 1944, the RAF Tac/R Mustangs were running dual radio set-ups, VHF for longer range air to air and air to ground, plus UHF for air to air tactical communication.

RAF ACC officers conducted visits to the MTO to observe the tactics and procedures used there by the Desert Air Force and 8th Army and brought details including policy documentation back to the UK. Exercise Spartan in early 1943 gave a large scale work out for those proposed tactics and procedures. This included in part practice of tactics to be used in providing close air support to Army units in both attack/advance and defensive/retreat scenarios.

A large part of the training for the RAF ACC pilots was in providing tactical reconnaissance, artillery reconnaissance, direction of close air support, and was also expanded in early 1944 to specialist training in naval gunfire direction in preparation for D-Day. In recent times there have been a couple of interesting books published on RAF Army Co-operation in WW2, based off access to original documentation held in the UK Archives, with documentaton from both the RAF side and British Army side of the discussion and development of the tactics and policies that would guide provision of air support to the Army in the field from the time of the conclusion of the Battle of France, through until the invasion of occupied Europe. (Look up "Army Co-operation Command and Tactical Air Power Development in Britain 1940-1943 : the role of Army Co-operation Command in Army Air SUpport" by Matthew Powell - there is online his Phd thesis and and number of papers delivered to RAF Air Power History conferences and similar available on line)

I should also mention, that in addition to senior RAF officers (most with recent operational experience) from the UK going to the MTO, some also went to the India-Burma front in late 1942 to mid-1943 to see what was being developed there, and a number of senior RAF officers from the MTO and India-Burma also made trips to the UK to see what was developing there and to pass on their recent operational experience details to the UK based units. A number of senior RAF officers from the UK were also posted to the operational and planning staffs in the MTO where they took an active part in the final campaigns against the Germans in North Africa, and then particularly the invasions of Sicily and Italy. They then brought that experience and "lessons learnt" back with them to the UK to perform similar roles for Operation Neptune/Overlord.