How to release bombs in Ju-88

[xpto]

Hi all.
I'm having trouble using the autopilot in Ju 88A. I trim the airplane, adjust the directional gyro and desired heading (autopilot), turn the autopilot on and adjust autopilot left/right while on bombsight, level bombing. Then the airplane start to drift to some side. Is this normal or a bug as I heared?
Again, what's the autopilot mode 22? Thank you.

[ATAG_MajorBorris]

Originally Posted by xpto

Hi all.
I'm having trouble using the autopilot in Ju 88A. I trim the airplane, adjust the directional gyro and desired heading (autopilot), turn the autopilot on and adjust autopilot left/right while on bombsight, level bombing. Then the airplane start to drift to some side. Is this normal or a bug as I heared?
Again, what's the autopilot mode 22? Thank you.

R22 is the radio nav I think.

So the auto is going left or right? Thats good, normaly it dives, just adjust the course setter untill you are straight and then in 1-3 degree increments get on course.

Check with us on coms(ATAG) if you have a chance and we will try it out

[Blackdog_kt]

The Ju88 gyrocompass is bugged: you can calibrate it, but it doesn't move when you turn.

Since the autopilot works by comparing the gyrocompass to your desired heading, the fact that the gyro is bugged means the autopilot gets false data.

Let's say for example that you are flying a heading of 90 degrees. You calibrate you gyrocompass, set the desired heading to 90 (actualy, 90+9=99, that's another issue in all gyrocompasses, the alignment between gyro and desired heading is a bit off, don't know if this is a bug or realistic limitation of the system) and engage the autopilot.

So your 88 is now flying straight. You take a look through the bombsight and realize you need to turn 2 degrees left to align your target.

You press the relevant keys and adjust your desired heading 2 degrees less than the heading the gyrocompass reads. The AP starts turning left.

And this is where the problems start. The gyro keeps showing 90 degrees (it's stuck), so the autopilot will never level off because it doesn't know it has reached the desired heading of 88 degrees.

At best, it will do a full 360 degree turn and come to settle on the same initial heading, but due to the slow response of the AP system (that's realistic) it will not: the more offset between gyrocompass and desired heading, the more the airplane banks. The more the airplane banks the slower it comes back to level. That's why even the 111 which has a working gyrocompass tends to S-turn a bit when changing headings via autopilot.

In the 88, it will do a complete circle and overshoot even the initial heading, resulting in the same problem repeating itself. So, it keeps going in circles forever.

This is a bug that has been reported a lot of times, so we're keeping our fingers crossed that it will be among the fixes included in the next patch.

[nadasero]

Originally Posted by xpto

Hi all.
I'm having trouble using the autopilot in Ju 88A. I trim the airplane, adjust the directional gyro and desired heading (autopilot), turn the autopilot on and adjust autopilot left/right while on bombsight, level bombing. Then the airplane start to drift to some side. Is this normal or a bug as I heared?
Again, what's the autopilot mode 22? Thank you.

Hi,

There is an autopilot mode 2. (I'm sure this is your question)

Mode 2 controls all three axis (including the trim). The artificial horizon is kept exactly centered, while the rudder keeps the intended course. This means you have no control over the elevator and the plane needs a specific speed to keep the altitude.

Because of the bug in the AP of the Ju88 you need the He111 to use this mode. The 111 needs about 300km/h for level flight. Mode 2 is ideal for level bombing with the bomb sight. The first step is to engage mode 2 and to use throttle until level flight is reached. Then you can change to the bomb position and enter the values. After this, the plane makes an very stable approach to the taget. You can change course with the AP and use the bombsight to drop the bombs.

[Blackdog_kt]

Let me get this straight:

Mode 1 (course autopilot): Only uses elevators to turn. Used to fly a selected heading by comparing the gyrocompass to the selected heading.

Mode 2 (R22): Controls all three axis and levels the artificial horizon, only turns using the rudder. It still needs a working gyrocompass.

Is this true?

Very interesting, since keeping the wings level will result in a smoother ride during the bomb run. If so, He111 here i come

[xpto]

Thank You.
Another question, the speed on bombsight should be ground speed or indicated air speed?

[robtek]

The difference of about 9° for the gyro compass is the deviation of the magnetic north to the geografic north.
The map is oriented to the geografic north, not the magnetic.
Additional is near the magnetic compass, good visible but not legible in the 109, the deviaton table for that plane, informing about the deviation between the indicated value and the real value for the magnetic compass.
Though the latter is not used ingame afaik.

[IvanK]

Map in game Magnetic variation is 10 degrees West

[xpto]

Originally Posted by robtek

The difference of about 9° for the gyro compass is the deviation of the magnetic north to the geografic north.
The map is oriented to the geografic north, not the magnetic.

I account for the magnetic declination when navigation planning (9° 16' W changing by 0° 7' E/year, for Calais in August 1940).
http://www.ngdc.noaa.gov/geomagmodel...alcDeclination

But the Ju 88 autopilot is probably bugged, it can't align the directional gyroscope with the autopilot heading (or it aligns but continue turning).

I tried the autopilot Mode 2 on the He-111 H2 and is really better than the course mode, for bombing. I level the plane until reach 300 kms/h to change the autopilot mode.

I'm having trouble when level bombing, introducing the TAS (true/ground air speed) on bombsight after have converted from IAS (indicated air speed) using the manual's table. If I stay at 1000m and use IAS, normally I get a shack. Above 1000m (usually above 2000m) and converting from IAS to TAS, the bombs will fall short for 100m, using a delay of 4/8m. Any thoughts on this distance error?

Edit: At 300km/h, 83m will be passed in 1s. I'll experiment using a pre-determined table height. I'll retire the target height also, when introducing height on the bombsight. The bombsight isn't a computer with radar and/or laser sensors

After align the airplane course with the target, I'll continue adjusting/correcting/aiming the bombsight to a point slighty before the target (for ripple delivery purpose), with automatic bombs delivery: is this the correct method of using the bombsight? Adjusting the bombsight after automation does it introduce some error?

[jimbop]

Adjusting the bombsight after automation should not introduce error. Many are having trouble with the automatic release - see this thread.