Issue regarding Ju.88A’s autopilot during level bombing run

[I/JG54_chuishan]

Hello everyone~

I create this post for a little “trouble” that I have ran into these days when practicing level bombing technics using Ju.88A. It mainly deals with abnormal behavior of the autopilot.

When I engage the “Mode 22” of Ju.88, aircraft starts to descend normally, but it starts to swing back and forth at the same time. From the external view I can see clearly that aircraft is pitching up and down continuously with a relatively small angle but at a high frequency. The pitching continues when “Mode 22” makes aircraft stop descending and enter a level flight.

Though the pitching does not seem to influence flight condition, it has a VERY negative effect on the operation of bombsight. Landscape just wobbles up and down in the vision of the bombsight. Consequently, it becomes really tricky to have a good aim at the target. Even with bombsight automation engaged, the pitching goes on to affect my alterations because sight vision still wobbles around.

Since I have no idea how the autopilot works on real Ju.88s, I don’t know whether this abnormal behavior of the autopilot is a kind of special “feature” of the aircraft or it is simply a bug. I have tried altering the bomb load and fuel with no effect (actually the pitching went on after I dropped my payload over the target). I’m curious about whether there is someone else troubled with this issue. I will be really appreciated if anyone knows any solution to it.

Cheers~?

[Sokol1]

This issue exist since release, the way to minimize this is fly in the Ju 88 in the bombing speed ~320-330 km/h and trimmed "hands off" before engage "Mode 22", is convenient too add ~300 meters to planed bombing altitude for make up for loss when engaging autopilot "Mode 22".

 

Some types from "expert" in Ju 88 - I./KG40_BOPOH (Google Translator) 

 

Quote

AUTOPILOT -
To turn on the autopilot, turn to the desired course using the compass repeater (e.g. 342 °).
- When the course and the required position are achieved, balance the plane with trimmers.
- Combine the gyro reading with a magnetic compass repeater (342 °) and make sure that the set autopilot course is set within +/- 3 ° of the desired course (for example 344 °). 

Note:  the gyro-feed “takes” during the flight and must be periodically adjusted.

Turn the autopilot into Mode 1 (course). 
 

He will control the rudder and keep the plane on course. In this case, you can control elevators and ailerons. 

Ailerons can be used to help dampen vibrations. If the roll of the roll gauge moves away from the center, use the aileron trimmers to center it. 

Elevators can be used for leveling, pitching or diving.
To make turns with the autopilot turned on, change the course set for it using the "left-right course autopilot" knob.
- Turn on the autopilot in mode 2 (22) and it will completely take control of rudders, heights and ailerons. 

The autopilot will try to maintain a speed of 320-330 km/h, since it is necessary for horizontal bombing, and dives a little to gain this speed.

 

Edited September 14, 2019 by Sokol1

[Buzzsaw]

As has been mentioned by Sokol1, the aircraft should be trimmed and at 320-330 kmh before entering mode 22 to avoid these effects.

[I/JG54_chuishan]

8 hours ago, Sokol1 said:

This issue exist since release, the way to minimize this is fly in the Ju 88 in the bombing speed ~320-330 km/h and trimmed "hands off" before engage "Mode 22", is convenient too add ~300 meters to planed bombing altitude for make up for loss when engaging autopilot "Mode 22".

 

Some types from "expert" in Ju 88 - I./KG40_BOPOH (Google Translator) 

 

Thank you very much! ?

I suppose it is my speed doing the bomb run that causes the problem, for I always enter the bomb run with economic thrust and a speed about 300km/h.

5 hours ago, Buzzsaw said:

As has been mentioned by Sokol1, the aircraft should be trimmed and at 320-330 kmh before entering mode 22 to avoid these effects.

Thank you Buzzsaw? I can pin point the target with Ju.88 next time~