Unusual vibration (XBox One)

[Performance nut]

Finally got Panther engines (experimental) and test flew my first real supersonic jet. Things were going good up until 550m/sec+. After that, small corrections would create an oscillation that the SAS had one heck of a time compensating for (Jeb had his hands full to say the least). I was able to smooth it out by geeeeeeeeeeeeently straightening the plane out (roll or pitch adjustments) but it was temporary before they came back.

This doesn't seem to be having an adverse effect, just makes it look like my plane is having a seizure. What helped minimize it was assigning pitch/roll/yaw to specific control surfaces only (ie: control surface A can only do pitch controls but no yaw or roll) but it didn't negate it. I know the Panther engines vector so I was wondering if all the various controls weren't working well together and needed to be tuned (ie: turn off gimbal control on the Panthers or at least minimize it). The plane design is extremely stable because I managed to get the Cg to stay in the same place when fuel is being consumed (it moves a small amount but towards the nose of the plane).

 

[Pecan]

51 minutes ago, Performance nut said:

Finally got Panther engines (experimental) and test flew my first real supersonic jet. Things were going good up until 550m/sec+. After that, small corrections would create an oscillation that the SAS had one heck of a time compensating for (Jeb had his hands full to say the least). I was able to smooth it out by geeeeeeeeeeeeently straightening the plane out (roll or pitch adjustments) but it was temporary before they came back.

This doesn't seem to be having an adverse effect, just makes it look like my plane is having a seizure. What helped minimize it was assigning pitch/roll/yaw to specific control surfaces only (ie: control surface A can only do pitch controls but no yaw or roll) but it didn't negate it. I know the Panther engines vector so I was wondering if all the various controls weren't working well together and needed to be tuned (ie: turn off gimbal control on the Panthers or at least minimize it). The plane design is extremely stable because I managed to get the Cg to stay in the same place when fuel is being consumed (it moves a small amount but towards the nose of the plane).

 

Try to fly using trim (alt-WASDQE) instead of SAS.  Remember that SAS 'heading hold' keeps you going in a straight line, which a constant altitude *around* the world isn't.
Apart from that, you don't tell us what altitude you were at, so we don't know what the sound barrier would have been (varies with atmospheric pressure).  Mach effects are a thing!

Mainly though; trim - it's just a much gentler way to fly an atmospheric vehicle.

[Performance nut]

1 minute ago, Pecan said:

Try to fly using trim (alt-WASDQE) instead of SAS.  Remember that SAS 'heading hold' keeps you going in a straight line, which a constant altitude *around* the world isn't.
Apart from that, you don't tell us what altitude you were at, so we don't know what the sound barrier would have been (varies with atmospheric pressure).  Mach effects are a thing!

Mainly though; trim - it's just a much gentler way to fly an atmospheric vehicle.

Unfortunately this is for the Xbox One, so there is not way to trim that I'm aware of. Altitude varied, 4-5km is about where I was staying a majority of the time.

Thanks for the input

 

[Pecan]

3 minutes ago, Performance nut said:

Unfortunately this is for the Xbox One, so there is not way to trim that I'm aware of. Altitude varied, 4-5km is about where I was staying a majority of the time.

Thanks for the input

 

Doh!  You've even got it in your title.  I can't find the console keybindings guide but you should have some sort of <moderator> button.  On Windows it's alt and, of course, keyboard uses WASDQE for pitch/yaw/roll.  Point is, you should be able to set and adjust trim (eg; slight pitch-up is typical) using <moderator>+<attitude control>.  for atmospheric work it makes things an awful lot easier (just like in real life).  Every few minutes you might have to adjust it slightly, as fuel burns, altitude and velocity change but the rest of the time your 'planes can fly 'hands-off'.

[Red Iron Crown]

Trim controls for XBox are detailed here:

 

[Performance nut]

1 hour ago, Red Iron Crown said:

Trim controls for XBox are detailed here:

 

Thanks for the link... though I'm confused about the method:
Trim Pitch Down: LB/RT + Hold LS Down So does this mean I hit either left bumper OR right trigger plus hold left stick down? Or is it left bumper plus right trigger plus hold left stick down? (wow this is going to get confusing).

[Red Iron Crown]

@Performance nut I don't have an XBox to test on, you should give it a try and report back.