Hello,
In the event of a complete failure of the horizontal stabilizer (such as Alaska 261) what options do the crew have to maintain flight, or land the aircraft? Is there any way or procedure to keep the aircraft stable?
As always,
Thanks for your input!
Horizontal Stabilizer Failure
Moderators: lilfssister, North Shore, sky's the limit, sepia, Sulako, Right Seat Captain
Re: Horizontal Stabilizer Failure
YOU NEED TO ROLL IT!
-Denzel Washington, 2012
-Denzel Washington, 2012
Re: Horizontal Stabilizer Failure
Would a commercial aircraft maintain level flight while inverted? I was thinking perhaps trimming could help negate some of the effects of the jammed stabilizer, however I have never actually flown an aircraft so im not sure how effective that would be.
Re: Horizontal Stabilizer Failure
The questions has many "depends" in the answer. If it is simply a loss of elevator or stabilator control, but everything is there, and nothing is jammed, A later certificaion basis (mid '70's or later design plane) will include a procedure for landing without elevator control. This will be a combination of trim and power, but no elevator. providing this procedure satisfies the following certification requirement:
If the plane is certified to the earlier CAR 3 requirement, which predated Part 23, this requirement is not applicable in CAR 3, so the plane may not have a procedure published.
The CAR 3 1Cessna 172N, as an example, does have a procedure published for this. I've tried it, it's not easy. I would suggest that anyone who needed to do this plan to land on a pavement/concrete runway, certainly not grass, so that a poor landing will not result in the plane digging in, and flipping over - you'd rather slide, that roll into a ball.
A mentor of mine told me that he once had to land with no elevator control in a Lake Amphibian. The elevator pushrod had been in bilge water in winter cruise flight, and froze during the flight. He was able to land on the trim only, though Lakes have a different trim, it's not a tab, but rather a separate little elevator, hydraulically controlled. Still not easy to do!
If a part of the pitch control system is missing or jammed, that is not applicable.Sec. 23.145
Longitudinal control.
.......................
(e) It must be possible, by using the normal flight and power controls except the primary longitudinal control, to control the descent of the airplane to a zero rate of descent and to an attitude suitable for a controlled landing, without exceptional piloting skill, alertness, or strength, and without exceeding the operational and structural limitations of the airplane.
If the plane is certified to the earlier CAR 3 requirement, which predated Part 23, this requirement is not applicable in CAR 3, so the plane may not have a procedure published.
The CAR 3 1Cessna 172N, as an example, does have a procedure published for this. I've tried it, it's not easy. I would suggest that anyone who needed to do this plan to land on a pavement/concrete runway, certainly not grass, so that a poor landing will not result in the plane digging in, and flipping over - you'd rather slide, that roll into a ball.
A mentor of mine told me that he once had to land with no elevator control in a Lake Amphibian. The elevator pushrod had been in bilge water in winter cruise flight, and froze during the flight. He was able to land on the trim only, though Lakes have a different trim, it's not a tab, but rather a separate little elevator, hydraulically controlled. Still not easy to do!
Re: Horizontal Stabilizer Failure
The issue with Alaska 261 was that the stabilizer failed in the full-down position. Not much the crew could do about it.
United 232 landed (sort of...) with no elevator or rudder, just engine thrust.
...laura
United 232 landed (sort of...) with no elevator or rudder, just engine thrust.
...laura
