Squawk7777
16th Feb 2003, 04:53
I am trying to recall how the bomb-drop/pull-out dive configuration mechanism worked on the JU-87 Sturzkampfbomber or Stuka. I don't have access to my books right now :( . I wonder if some of you clever ppruners mind to re-explain it to me or recommend some links.
Thanks,
7 7 7 7
henry crun
16th Feb 2003, 06:09
Squawk, if I can remember correctly what I read a long time ago, the sight was connected to the autopilot, and the latter was connected to the elevator, dive brakes, and bomb release.
After setting the required release height, subsequent actions were all automatic including pull out and retrimming.
Also, if my memory is correct the JU88 in the dive bombing versions had a similar system.
Dive-Bomb Mechanism (http://homepage.tinet.ie/~nightingale/divebomb.html)
-Landing flaps at cruise positition
-Elevator trim at cruise position
-Rudder trim at cruise position
-Airscrew pitch set at cruise
-Contact altimeter switched on
-Contact altimeter set to release altitude
-Supercharger set at automatic
-Throttle pulled right back
-Cooler flaps opened
-Dive brakes opened
This last action made the aircraft nose over into the dive under the influence of the pull-out mechanism which was actuated by the opening of the dive brakes which also actuated the safety pilot control. The most difficult thing in divebombing training is avoiding overestimating the dive angle which invariably feels much steeper than it actually is. Every divebomber of WWII vintage featured some sort of synthetic aid to judge diving angle, and in the Ju-87 this consisted of a series of lines of inclination marked on the starboard front side screen of the cockpit.
These marks, when aligned with the horizon, gave dive angles of 30 degrees to 90 degrees. Now a dive angle of 90 degrees is a pretty palpitating experience for it always feels as if the aircraft is over the vertical and is bunting, and all this while terra firma is rushing closer with apparent suicidal rapidity. In fact, I have rarely seen a specialist divebomber put over 70 degrees in a dive, but the Ju-87 was a genuine 90 degree screamer! For some indefinable reason the Ju-87D felt right standing on its nose, and the acceleration to 335mph (540 km/h) was reached in about 4,500ft (1,370m), speed therafter creeping slowly up to the absolute permitted limit of 373mph (600 km/h) so that the feeling of being on a runaway roller-coaster experienced with most other divebombers was missing.
As speed built up, the nose of the Ju-87 was used as the aiming mark. The elevators were moderately light in the initial stages of the dive but they heavied up considerably as speed built up. Any alterations in azimuth to keep the aiming mark on the target could be made accurately by use of the ailerons. Thse also heavied up as speed increased but always remained very effective. Use of the elevator or rudder trimmers in a dive or pullout was strictly forbidden. During the dive it was necessary to watch the signal light on the contact altimeter, and when it came on, the knob on the control column was depressed to initiate the automatic pullout at 6g, a 1,475ft (450m) height margin being required to complete the maneuver. The automatic pullout mechanism had a high reputation for reliability, but in the event of failure the pullout could be effected with a full-blooded pull on the control column aided by judicious operation of the elevator trimmer to override the safety pilot control.
Once the aircraft had its nose safely pointed above the horizon from the pullout, the dive brakes were retracted, the airscrew pitch set to takeoff climb and the throttle opened to 1.15 atas of boost, although in consideration of enemy flak it was recommended that the full 1.35 atas be used. The radiator flaps were then opened.
Source: "Wings of the Luftwaffe" by Captain Eric Brown, CBE, DSC, AFC, Royal Navy (Shrewsbury, England: Airlife Publishing 1987)