View Full Version : Tailstrike protection warning
JammedStab
13th Jan 2012, 23:25
I was just reading about an old 747-100 that apparently has a warning system to prevent a tailstrike by alerting the pilots if the pitch on rotation is excessive. It is based on INS sensed pitch attitude.
I knew that some Airbuses have a warning system but was surprised that this existed back in the 70's.
Any other old aircraft like this have a similar warning?
On early B747-400's, there was an overration warning system. This used wheel bogey tilt angle "proximity" sensors.
A few of our early aircraft still have the wiring and sensors, but the system is pin programmed not to be active. Not sure why it was disabled.
Rgds
NSEU
Capt Claret
14th Jan 2012, 08:59
DH8-300 had warnings on the PFD for too high a pitch attitude. If memory serves the values were different for takeoff & landing.
thermostat
6th Feb 2012, 01:19
What's wrong with 3 degrees per second to 15 degrees. A total of 5 seconds.
Works for 99%.
Love_joy
6th Feb 2012, 23:02
The Dash 8 Q400 has a tail strike sensor on the critical part of the fuselage, triggering a master warning in the event it contacts. (approx 7º degrees pitch, but there are variables, ROD, oleo pressure etc).
Everything else I've flown just makes a horrible grinding noise if you go to far! Or so I'm told ;)
The cheapest protection is a aural PITCH warning at take-off. It's just a software upgrade and it easily pays for itself if you've ever had a tailstrike at takeoff.
When you have a mixed baby bus fleet, and if the new guy didn't get exposed to the 321 during line training/qualification, he could be quite surprised being PF on his first A321 takeoff if its a light load.It isn't always pretty.
bubbers44
7th Feb 2012, 00:30
An aural warning to tell you that you are over rotating. I once was that device. I was the FO that said Hey, dumb **** push the nose down, worked every time in the 80's. Now they want software for that?
Most modern wide bodies have tail strike warnings. Some Boeings (and the Concorde) do have extendable tail skids.
captjns
7th Feb 2012, 10:00
What's wrong with 3 degrees per second to 15 degrees. A total of 5 seconds.
Worked great for the -80 then the 707. Aircraft evolved, but certain sections of the "Boeing How To Do It" book had not kept up with the times. On the 737-900 on a hot day at 70+ tons, 3 degrees/per sec will get the skid.
Review each aircraft's FCTM. In it shows the strike angles for tail, engine pod and some cases the wing tip for takeoff and landing.
During takeoff, if you feel the aircraft is a bit doggier than planned when within a couple of degrees of a tail strike, than correct accordingly.