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Thanks! Looking forward to any illumination.
Thanks for the reply. And thanks for the reference, I'll get it. (I've got an expanded USN training video CD coming from Zeno's too, but if it's anything like the short version on Youtube, it's going to be too generic to be much help.)Sight used in early war period was the 3x telescopic fixed to the aircraft. Not used until near the end of the dive (there was a problem with the sight and windscreen fogging during rapid descents until special coatings became available). "Considered an aid to dive bombing not a panacea". Only in 1943 was a Reflector Sight fitted to the aircraft.
Thanks! Looking forward to any illumination.
To expand a bit: I'm a recently retired former attack guy (A-4/AV-8) who suddenly has plenty of time to catch up on my guilty pleasure of WWII historical reading. Thumbing through Shattered Sword, I saw several apparently widely accepted revisions to the familiar Midway narrative. But some of the specifics seem to me questionable, or at least not what I'd assumed, and some of it is in the most critical part of the battle.
For example, the description of the attack on Akagi has two claims I find hard to credit: 1) Best's section bombed in close formation; 2) we know who dropped the bomb that scored the fatal hit. On the first point, I've never even heard of anybody dive bombing in formation, and Best's after action says "The first section of the first division joined up immediately after pull-out from the dive." Which implies they'd separated. On the second point, the rationale from Shattered Sword was his backseater's quote "Nobody pushed his dive steeper or held it longer than Dick." In fact, in standard dive-bombing, a steep fast dive held to lower than planned altitude will always result in a long hit, and many duds.
However, it is possible for this to be a correct description. There are modern gunsights that rely on angle change to the target (e.g., ARBS), and with enough practice, and a relatively slow and low delivery, the human eyeball could probably come up with a comparable solution. In that case, there is no hard release altitude, you just have to pull out in time to avoid ground impact, and hope the bomb has time to arm. On that point, there are also contemporary reports of armorers spinning bomb fuze vanes prior to loading (to reduce bomb arming times). And while all this strikes me as ridiculously nonstandard and dangerous (especially loading partially armed bombs on carrier aircraft), there may have been various cowboy solutions to a procedures vacuum.
Anyway, I'm stuck with two incompatible interpretations, and I'd love any input on which was correct.
Genius! Just checked and Pensacola has an SBD-2 from the actual battle . . . and we just happen to have a reunion scheduled there for November. I think I can profitably shelve this burning curiosity for a few months, especially since I'll have the company of a couple dozen like-minded mud movers who ought to be interested in the early days of dive bombing. (I feel stupid, but that's not new.) Thanks a ton!The USN museum has many static exhibits and with your history of A-4 & AV-8 you may get a close up of the sight in the SBD-3 on display. I believe it was the training airplane recovered from Lake Michigan which was an actual combat veteran. It was supposed to be restored just as it was in combat.
My bold added to the above quote.There is a lengthy description with diagrams in Peter C Smith's book "Douglas SBD Dauntless" published by Crowood. Chapter Seven "The SBD Battle Scenario". It covers the whle operation from scouting to find the enemy through to withdrawal after the drop. Major points to answer most of your questions.:-
1. Typical cruise height to target - 14-16,000ft
2. Sub-sections stacked en echelon below one another giving all a clear view of target (weather permitting)
3. Visual contact with target 25-40 miles
4. Descent to 10-12,000ft assuming line astern of sections (or aircraft in sections), opening out to 500yd spacing to mitigate effects of AA, and aiming to cross the path of the target.
5. Optimum angle of attack was 70 degrees or just over (70-75 was the norm for SBD squadrons in the Pacific war)
6. Sight used in early war period was the 3x telescopic fixed to the aircraft. Not used until near the end of the dive (there was a problem with the sight and windscreen fogging during rapid descents until special coatings became available). "Considered an aid to dive bombing not a panacea". Only in 1943 was a Reflector Sight fitted to the aircraft.
7. Aircraft begins pull out at 2,900ft (3,000 ft slant range to target)
8. Bomb release at 2,500ft, Bombing Angle 6 degrees (slant range to target 2,650ft).
9. Pull out and escape at 1,500ft
10. Engine "kept revving over just enough to make sure of an instant response when called for".
Preferred direction of attack was downwind out of the sun. The pilot had to account for wind deflection and drift when aiming as well as target movement.
No speeds are mentioned in this chapter.
Just a couple of minor additions - from one of Eric Brown's Flight Test Reports.There is a lengthy description with diagrams in Peter C Smith's book "Douglas SBD Dauntless" published by Crowood. Chapter Seven "The SBD Battle Scenario". It covers the whle operation from scouting to find the enemy through to withdrawal after the drop. Major points to answer most of your questions.:-
1. Typical cruise height to target - 14-16,000ft
2. Sub-sections stacked en echelon below one another giving all a clear view of target (weather permitting)
3. Visual contact with target 25-40 miles
4. Descent to 10-12,000ft assuming line astern of sections (or aircraft in sections), opening out to 500yd spacing to mitigate effects of AA, and aiming to cross the path of the target.
5. Optimum angle of attack was 70 degrees or just over (70-75 was the norm for SBD squadrons in the Pacific war)
6. Sight used in early war period was the 3x telescopic fixed to the aircraft. Not used until near the end of the dive (there was a problem with the sight and windscreen fogging during rapid descents until special coatings became available). "Considered an aid to dive bombing not a panacea". Only in 1943 was a Reflector Sight fitted to the aircraft.
7. Aircraft begins pull out at 2,900ft (3,000 ft slant range to target)
8. Bomb release at 2,500ft, Bombing Angle 6 degrees (slant range to target 2,650ft).
9. Pull out and escape at 1,500ft
10. Engine "kept revving over just enough to make sure of an instant response when called for".
Preferred direction of attack was downwind out of the sun. The pilot had to account for wind deflection and drift when aiming as well as target movement.
No speeds are mentioned in this chapter.
I hope that this helps.
The telescopic sight was boresighted along the aircraft centerline. It had a non-adjustable crosshair reticle, and a slip/skip ball like a Turnn & Bank Indicator to give the pilot an indication of whether he was in coordinated flight. The later reflector sights were the same - so the pilots were using TLAR (That Looks About Right) computing. Dive Angles were at least 70 degrees - often more, so long bombs weren't very long.Thanks! Looking forward to any illumination.
To expand a bit: I'm a recently retired former attack guy (A-4/AV-8) who suddenly has plenty of time to catch up on my guilty pleasure of WWII historical reading. Thumbing through Shattered Sword, I saw several apparently widely accepted revisions to the familiar Midway narrative. But some of the specifics seem to me questionable, or at least not what I'd assumed, and some of it is in the most critical part of the battle.
For example, the description of the attack on Akagi has two claims I find hard to credit: 1) Best's section bombed in close formation; 2) we know who dropped the bomb that scored the fatal hit. On the first point, I've never even heard of anybody dive bombing in formation, and Best's after action says "The first section of the first division joined up immediately after pull-out from the dive." Which implies they'd separated. On the second point, the rationale from Shattered Sword was his backseater's quote "Nobody pushed his dive steeper or held it longer than Dick." In fact, in standard dive-bombing, a steep fast dive held to lower than planned altitude will always result in a long hit, and many duds.
However, it is possible for this to be a correct description. There are modern gunsights that rely on angle change to the target (e.g., ARBS), and with enough practice, and a relatively slow and low delivery, the human eyeball could probably come up with a comparable solution. In that case, there is no hard release altitude, you just have to pull out in time to avoid ground impact, and hope the bomb has time to arm. On that point, there are also contemporary reports of armorers spinning bomb fuze vanes prior to loading (to reduce bomb arming times). And while all this strikes me as ridiculously nonstandard and dangerous (especially loading partially armed bombs on carrier aircraft), there may have been various cowboy solutions to a procedures vacuum.
Anyway, I'm stuck with two incompatible interpretations, and I'd love any input on which was correct.
Thanks, that's about 90% of what I'm looking for. I'm still waiting on my training film, but it seems to me they have to have a set of criteria for bomb release height (to ensure proper arming, if nothing else). I got the SBD "Pilot's Handbook," and it has charts for terminal velocity dives that show a nose down AOA of about 4.8 degrees for a standard 70 degree 240 KIAS delivery, so a boresighted reticle would have about an 85 mil trajectory drop built in. That would seem to be in the ballpark.The telescopic sight was boresighted along the aircraft centerline. It had a non-adjustable crosshair reticle, and a slip/skip ball like a Turnn & Bank Indicator to give the pilot an indication of whether he was in coordinated flight. The later reflector sights were the same - so the pilots were using TLAR (That Looks About Right) computing. Dive Angles were at least 70 degrees - often more, so long bombs weren't very long.
Not a Jet Attack Guy, but it's always looked to me that you guys were bombing from somewhere around 45 degrees, and about twice as fast (or more) so a depressed sight is real important, and ARBS is Real Important. (There were World War 2 ARBS systems for SBDs and SB2Cs - precursors to the later DIve/Toss systems of the '60s. Don't know if they actually got used) - and a long bomb is going to be a lot longer.
As I understand it, if the tactical situation allowed (As in not having to shoot Zeros off your tail), the Radio Operator/Gunner would rotate his seat forward and call off altitudes in the dive -Thanks, that's about 90% of what I'm looking for. I'm still waiting on my training film, but it seems to me they have to have a set of criteria for bomb release height (to ensure proper arming, if nothing else). I got the SBD "Pilot's Handbook," and it has charts for terminal velocity dives that show a nose down AOA of about 4.8 degrees for a standard 70 degree 240 KIAS delivery, so a boresighted reticle would have about an 85 mil trajectory drop built in. That would seem to be in the ballpark.
We had data for lots of deliveries, from laydown to 60 degree dives. We generally did laydown for napalm and some special weapons, 10 deg/450K popups, and 30 deg/ 450-500K for practice. But real world was practically always 45 deg/500K with a 5000'+ release. And yes, the slant range is such that a long (or short) bomb will be grossly off target. Obviously a steeper dive removes a lot of the error sensitivity (in the extreme: a 90 degree dive has zero error due to release height), and a lower airspeed allows for much shorter slant range, and correcting on the fly for wind or a moving target is more of a TLAR problem than a ballistics one. So I can see how that might be a reasonable approach, with some constraints.
We had a set of bombing manuals: a classified tactics manual, and an unclassified ballistics manual (with trajectory drop, slant range, time of fall, and error sensitivities for every piece of ordnance and every plausible release). I wouldn't expect quite the level of detail in 1942, but it seems to me they had to have something that covered at least the limits of the basic bombs (esp 500# and 1000#), fuzes, and standard deliveries. The Pilot's Handbook reads like a very short NATOPS manual, and I just assumed there was something similar out there for tactical training, but so far haven't been able to find anything.
Yes, the Pilot's Handbook has good pictures of the rear instrument panel and controls (interestingly, the stick is removable, and in one picture it's in the "stowed position" on the side of the cockpit). I read somewhere that a Zero couldn't chase an SBD in the actual dive (I thought it was in Dusty Kleiss's book, but if so, I can't find it again). If that's right, I'd expect the usual SOP was to face forward.As I understand it, if the tactical situation allowed (As in not having to shoot Zeros off your tail), the Radio Operator/Gunner would rotate his seat forward and call off altitudes in the dive -
Not unlike the WSO/NFO in the F-4. According to the manuals in my collection, the Gunner's cockpit had its own instruments (Airspeed, Altimeter, Compass and Clock), and a stick, rudder and throttle (But not mixure and prop).
"There were World War 2 ARBS systems for SBDs and SB2Cs - precursors to the later DIve/Toss systems of the '60s. Don't know if they actually got used."The telescopic sight was boresighted along the aircraft centerline. It had a non-adjustable crosshair reticle, and a slip/skip ball like a Turnn & Bank Indicator to give the pilot an indication of whether he was in coordinated flight. The later reflector sights were the same - so the pilots were using TLAR (That Looks About Right) computing. Dive Angles were at least 70 degrees - often more, so long bombs weren't very long.
Not a Jet Attack Guy, but it's always looked to me that you guys were bombing from somewhere around 45 degrees, and about twice as fast (or more) so a depressed sight is real important, and ARBS is Real Important. (There were World War 2 ARBS systems for SBDs and SB2Cs - precursors to the later DIve/Toss systems of the '60s. Don't know if they actually got used) - and a long bomb is going to be a lot longer.
Thus, the first and third bombs were misses, with the third landing very close aboard indeed. It was the second bomb, landing at the aft edge of the middle elevator, which doomed Akagi. This weapon was almost unquestionably aimed by Best himself. He was a noted dive-bomber pilot and had a reputation for both boldness and consummate skill. In the words of his backseater, Aviation Chief Radioman James F. Murray, "Nobody pushed his dive steeper or held it longer than Dick."44 Given the "V" formation Best's element dived in, it is almost inconceivable that the trajectories of the bombs could have crossed in midair. Furthermore, from what we know about how the bombs landed in relation to the ship and each other, that is, in a rough "V" pattern themselves, it is likewise almost a certainty that the center plane in the "V" dropped the bomb that hit dead center on Akagi. That plane was piloted by Lieutenant Best.
This also corresponds with Best's after action report. In that case it is impossible to determine which bomb was whose (and it certainly is possible for the guy who dropped the bomb on the left to impact on the center, or right--and the lead's bomb can land second, or third, though that's slightly less likely).
I hope your copy is in better shape than mine is.Your conclusion doesn't follow. We know that Best was in the middle, according to Parshall and Tully, who site Mark Horan. From the first paperback edition of Shattered Sword:
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You appear to believe that with a loose formation of diving aircraft, the bomb impacts must mirror their location in the formation. That isn't true.Your conclusion doesn't follow. We know that Best was in the middle, according to Parshall and Tully, who site Mark Horan. From the first paperback edition of Shattered Sword:
You appear to believe that with a loose formation of diving aircraft, the bomb impacts must mirror their location in the formation. That isn't true.