going up & down

[davidb]

Hi there!

At first: great job! Great aircraft.. really impressed.

But: I downloaded your beautiful KC-135R and this problem is keeping me from sleep!

When I climb to FL240-250 or above and level off (on autopilot), the nose just keeps on going up and down. I tried reducing weight/fuel (to 1%) but that seems to help just a bit. Decending to FL220 solves the problem.

Am I doing something wrong? Hope you can help.

Regards,

David

[piedmont700]

What airspeed are you holding at? You should be running by Mach numbers at that altitude, not indicated... I could see you flying right above stall speed and that happening, but I'm not sure

[aerofoto - HJG Admin]

I haven't taken any of the 135's "high" .... but .... I do recall reading there's a known performance issue flying them above FL275.

These aircraft apparently start a "fugoid-like" motion (going up and down) which then increases in momentum the higher one climbs.

This's a known problem .... which is being looked at only as we can afford time to do so.

Incidentally (in case anyone's wondering) this has nothing whatsover to do with our new B707/720 panels or their supporting gauge sets.

This issue has been known about since prior to released of the new panels.

As I said .... it is being looked at

Mark C
AKL/NZ

[lck135]

Is there any fix to this? I get the same exact problem and it takes the fun out of flying the KC-135 for me with the constant up and down pitching. Thanks.

[aerofoto - HJG Admin]

Unfortunately this is a known issue with the KC135 FDE .... reported both here and on other forums.

I understand this only occurs above FL275 .... and only in AP controlled flight.

The problem will be addressed .... but .... only when someone's got time to look at it.

Most of us right now are head down/bum up at the moment with private matters.

Please refere to a PM which I've just sent you

Mark C
AKL/NZ