Tag Archives: tail stall

Tail Stall Detection and Recovery

My FIRC this time around has a section on tail stalls, and being the information is somewhat rare, I thought it appropriate to cover here. Bare in mind, this is generic information for airplanes under 12,500 lbs, the actual flight manual or pilots operating handbook, if updated is always the best source.

Tailplane Stall Detection:

Tailplane stalls most often, but not always occur when flaps are being extended, or power is being added. One should also note, that if wings are picking up ice, the tail is likely to do so as well, in fact perhaps 2-3X as much as the wing… and sadly, its not visible to the pilot. In any case, if the potential exists for tail icing, one should be hand flying, rather than relying on the autopilot. Yoke forces are key.

Symptoms include

  • Lightening loads.
  • Difficulty trimming.
  • Pilot-induced (pitch) oscillations.
  • Buffets in yoke, not airframe. (The yoke pulls forward, sometimes smashing to the stop and can’t be pulled back; forces of more than 100 lbs. can occur.)
  • Very sudden pitch-down, which can be unrecoverable on approach.

Do note, that stall warning systems can also end up iced over, and as such may not function.

Tailplane Stall Recovery

  • If you just added flaps, and symptons of a tail stall occur, retract the flaps.
  • If the yoke slams forward, it may be necessary to apply significant force to pull it back. In either case, as contrasted with a wing stall, the recovery action is the reverse, ie pull back.

In General

  • pull back
  • reduce power
  • reduce flaps

Being tail stall recovery is the reverse of everything one is taught, its imperative to that one detects the yoke forces, rather than the airframe going mushy.

Additional Resources:

Actual Tail Stall Event
http://aircrafticing.grc.nasa.gov/courses/inflight_icing/related/3_2_3f_RI.html

Useful videos and data from Nasa
http://aircrafticing.grc.nasa.gov/resources/related.html

AC No: 23.143-1 “Ice Contaminated Tailplane Stall”

Aircraft Accidents where tail stall occurred

http://www.flightsafety.org/fsd/fsd_jun-sep97.pdf

10mar64 DC4 Slick Airways,.Boston-“Loss of balancing forces on stabalizer, due ice accretion,causing aircraft to pitch nose down too low to effect recovery…

15jan’77 Viscount,Skyline sweden,”ice on leading edge of Stabalizer causing flow seperation and Stabalizer…

06Apr58 Viscount,Capital airlines,Michigan,Undetected ice accretion on stabalizer,in conjunction with specific speed and configuration,caused loss of pitch control…