KDTWflyer From United States of America, joined Jun 2004, 828 posts, RR: 1 Posted (9 months 3 weeks 12 hours ago) and read 2965 times:
I got this Gulfstream IV landing in PTK yesterday and noticed the horizontal stabilizer dancing around like crazy (almost like that inflight flutter footage from NASA but less extreme) during the rollout phase on 9R. My only guess is that it is from the reverse thrust jet blast hitting the horizontal stabilizer however I have not seen it before as much as this. Check it out...
GoBoeing From United States of America, joined Jun 2000, 2683 posts, RR: 14
Reply 1, posted (9 months 3 weeks 12 hours ago) and read 2955 times:
Yep, lots of bouncing around back there.
I don't have any time in Gulfstreams but when I was on the ERJ, if you put in a good amount of reverse thrust the yoke would shake a lot from the tail buffeting around. On the ERJ, and I'd imagine every other t-tail out there most likely, idle was not enough to do this. Only when the engines were spooled up would it buffet to that extent.
oly720man From United Kingdom, joined May 2004, 6688 posts, RR: 11
Reply 3, posted (9 months 2 weeks 6 days 19 hours ago) and read 2650 times:
The reverse thrust doesn't hit the tailplane directly, it's pointing forwards and up ahead of the tailplane.
But, as the reverse jet spreads and slows down into a very turbulent mess it will move backwards due to the forwards motion of the aircraft. So it's a very disturbed area of flow that causes the vibration of the tailplane, rather than direct impact.
wingscrubber From UK - England, joined Sep 2001, 845 posts, RR: 0
Reply 6, posted (9 months 2 weeks 4 days 21 hours ago) and read 2301 times:
Some nice thrust reverser CFD visualisation here, scroll down to page 15-