"What was the maximum dive angle of US dive bombers" Topic

Specifically what were the maximum angles of attack of both the SBD Dauntless and the SB2C Helldiver? Also did this vary amongst the respective variants? Thanks and Salut y'all!

Bruce the Texas Grognard

Was it?

My father served in the South Pacific in MAG 2 and he told me that the Marines called the SB2C the "Son of a B***h 2nd Class.

80 degrees is about right. US dive bombers used a different air brake arrangement from German and Jaspanese dive bombers, allowing them to dive at much greater angles. This produced significantly greater accuracy.

the optimum way to dive bomb a target was to fly over it, roll inverted, so you can look up and see the target, then pull pointing the airplane right at the target nearly strait down so yes close to 80 degrees. Would have been a heck of a roller coaster and think of the poor tail gunner going through it all faced backwards.

Gents;

80 degrees is not right. The oft quoted 70 degree dive is a misnomer. A dive bombing attack was made VERTICAL (90 degrees). This reduced a three-dimensional problem [roll (stick), pitch (stick), yaw (rudder)] to a one dimensional problem [roll (stick)].

In USN practice, the approach was made with the target being viewed to the left side of the nose of the plane. The dive was initiated as the target disappeared from view under the wing. From the moment the dive was initiated the pilot was NOT to use RUDDER control at all. Doing so would impart ya w into the trajectory of the plane and thus the path of the bomb.

The pilot then pushed to vertical using the stick. The radioman gunner would have stowed the aft facing gun(s) and turned to face forward. Beginning at ten thousand feet he would call the altitude at each thousand feet through 4000 feet and then commence calling it out at every 100 feet. Ideally release would occur at 3,500 feet to 2,500 hundred feet. The dive being vertical, the pilot could hold the target in his sight as it moved by using the stick to roll about the vertical path to the target below him, so that his "position was such that the course the ship was steaming was in his "12 o'clock". As his path was straight down, the position of his nose was changed just by rolling. It was imperative that the rudder was used ONLY to keep the "ball" centered as the plane rolled. The possibility existed that the plane might actually push beyond the vertical, but if this was done he would no longer feel suspended in his seat belt-shoulder harness but would "feel" like he was being pulled out off the seat and he would just release a little stick pressure to go back to vertical.

About 10 seconds before the pilot intended to release, he would pull the stick back (NO rudder other than to hold the "ball" centered) so as to shallow the dive angle from vertical to 70 degrees. This period never lasted more than 10 seconds and it was done only to ensure that the bomb crutch would release to bomb such that it would clear the propeller arc on its path to the target.

The vast majority of misses were caused by the pilot applying rudder movement that moved the "ball" off center imparting "skid" into the path of the bomb. Most pilots were aware of when they did this and would know at that point that the bomb would be a miss – and say so at briefing and even to me when I interviewed so many for my Midway book.

The pullout from release began about three seconds after both bomb releases were triggered (electric via button, manual lever pulled) and from that point the pilot was fully engaged in getting the plane "straight and level" and on a path clear of enemy vessels, AA, and enemy fighters while heading to the rally point, attempting to reform the sections for a team defense. At the end of the pullout the radioman gunner was getting the guns back out and preparing to defend the plane and calling out dangers to the pilot.

Thus, the "70 degree" dive so oft quoted is an entire misnomer. All that is is the approximate angle of release. The British and Japanese release at a shallower angle of 50/55 degrees, while the Germans followed the American practice. Regardless, ALL dive bombers dived at a full NINETY degrees until pulling back for release.

As for the "roll inverted" approach, I can give you Dick Best's assessment of that – and I quote: "Anyone that says they did that is either lying or was an arrogant show off. That 'type' seldom got hits, and I would never have tolerated such a pilot in my squadron. Dive bombing is an art, not a circus performance, and success was measured only by HITS."

Hope this is of interest.

Mark E. Horan

This is from Mukund Murty's excellent 'Vengeance Tales':

A brief comparison between the dive-bombing techniques of the Stuka and the Vengeance :

Vengeance :
a) Approach target at approx. 12, 000'
b) Target goes past trailing edge of wing (usually port)
c) Select bombs to 'live,' bomb doors open
d) Wing over into dive
Alternately
b) Open bomb doors and fly over target
c) Observe target through window on floor
d) When target directly below half-roll into dive
e) Select dive brakes and dive at 70-90 degrees
f) Terminal velocity speed in dive approx. 320 mph
g) Release bombs at 4, 000 – 3, 500' agl
h) Retract dive brakes and initiate pull-out 3, 000' agl
f) Complete pull-out by 500' and exit or engage ground targets with guns

Stuka :
a) Approach target at approx. 13, 000'
b) Target goes past trailing edge of wing (usually port)
c) Close radiator flaps
d) Supercharger off
e) Wing over and half-roll into dive
Alternatively
e) Stick forward into dive
f) Set angle of dive 70-90 degrees(red lines showing various angles marked on canopy side panels)
g) Accelerate
h) Apply dive brakes
i) Release bomb 1, 600' agl
j) Retract dive brakes, open radiator shutter, supercharger on, initiate recovery
k) Recover around 700' agl and exit or engage target with guns

Readers will note the similarity of techniques, as also the following differences, in that the Stuka released its bomb from a lower height whilst executing recovery at a greater height (the latter advantage is arguable, as a higher aeroplane at low speed is possibly under a greater threat to ground fire).

What was the Vengeance like to fly ?

For excerpts, I quote from the book 'Vengeance!,' by Peter Smith which, I think, is the only reference book on the subject till date !

Report by RAF test pilots in the US (page 31)

"This aircraft is very easy to fly and land and gives the pilot a feeling of confidence. It has a fair performance but the take-off and initial rate of climb are sluggish. The controls, with the exception of the ailerons, are on the heavy side but the aircraft has no vices and the dive brakes are particularly good……and reduce the diving speed to a little over three hundred miles per hour. They do not cause changes in longitudinal trim and have no adverse effect on the flying controls…….having a large diameter radial engine the forward view is inferior to the comparable German type and this is more of a handicap during take-off and landing than in dive-bombing. Greater accuracy in dive-bombing would result were the flying controls improved. The ailerons are light and effective, but directional control, once the aircraft is committed to a dive and has gathered speed, requires adjustment of the rudder tab."

Northrop's Chief Test Pilot, Moye Stephens, 1941 (page 36)

"My initial impression was there was something inherently wrong with the ship. Included in its peculiarities was the British requirement of zero angle of incidence to facilitate dive-bombing. It was possible to dive straight down with a minimum degree of tuck-under; but, as a consequence, the ship's nose-high attitude in level flight effectively blocked out vision straight ahead. Among other novel first-flight impressions was an erroneous notion that the indicated airspeed had to be unbelievably modest."

Recommended RAF diving procedure (page 52) :

"At pull-out, if dive brakes are retracted at the start, more height is necessary for recovery but elevator control is lighter than if the dive brakes remain extended throughout the recovery. The extra speed gained by early retraction would be an added asset in getting away quickly.'

Canadian pilot, Bud 'Red' McInnes, 110 Sqn, 1943 (page 102)

" We knew, of course, that the aircraft had been constructed for a truly vertical dive. To my knowledge, it's the only aircraft that was, because, having no incidence, the aircraft did not creep, so, theoretically, a perfect dive would be possible."

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