Plane creeping left on ground with brake on and right engine at 84% RPM

[gulredrel]

Hello,

 

could you please check the following.

 

Steps to reproduce:

- cold start at airfield --> front wheel always seems tilted to the left

- check parking brake set

- connect ground power and ground air supply

- RIO startup initiate (maybe not needed here)

- start right engine

- disconnect ground power and ground air supply

- throttle up right engine to around 84% RPM (needed to start left engine via crossbleed)

 

--> Plane starts creeping/rolling to the left.

 

I think I red that there is a bug with the tilted front wheel on startups. But shouldn't the brakes hold the plane anyway, since there are no wheel chocks?

 

trk-File and screenshots

 

https://www.dropbox.com/s/ewuu3cl7l70gyuq/F-14_right_engine_creeping.trk?dl=1

 

 

 

 

Thanks

Jens

[IronMike]

Ok, I see now. It is prolly the throttle up that makes it creep (means it does not creep fwd in a normal startup procedure). I need to verify if the break would hold (as Naquaii mentioned in the other thread cross bleed starts on ground were not a thing, only for air starts). It could be that at 84% it would move past the parking break, so not sure if this is really a bug.

 

What is a bug is the tilted front wheel however, which is on the list, alas lower on priority atm.

 

I'll investigate this further. Thanks!

Edited January 27, 2020 by IronMike

[gulredrel]

Thanks for checking.

Maybe this is correct and one needs wheel chocks for ground crossbleed starts.

I think they would have them on the ramp for safety reasons anyway.

[IronMike]

Thanks for checking.

Maybe this is correct and one needs wheel chocks for ground crossbleed starts.

I think they would have them on the ramp for safety reasons anyway.

 

 

 

 

I forwarded the question to our SMEs. It is also likely that you exceed a max rpm with park brake set, or that simply the increased rpm from the right engine together with the tilted wheel allow for this movement, not sure.

 

 

 

EDIT: I checked with our maintenance SMEs and cross bleed engine starts were a thing on the boat, rarely on land though. I initially said they weren't, that was wrong. My apologies.

Edited January 28, 2020 by IronMike