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Confusing NTSB Report

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J.C.Airborne

Well-known member
Joined
Jan 13, 2006
Posts
92
I cant figure out how the accident occured. Supposedly the squat switch functioned. If it functioned then how did the gear raise?:

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DEN01LA124
On July 17, 2001, at 1005 mountain daylight time, a Beech 95-B55, N886N, registered to JDTS Leasing, LLC, and operated by Enterprise Airline Training Academy, was destroyed when the landing gear was retracted during landing roll at Centennial Airport, Englewood, Colorado. The flight instructor and the private pilot receiving instruction were not injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the instructional flight being conducted under Title 14 CFR Part 91. The flight originated at Englewood approximately 0830.

According to interviews conducted with the pilots and the accident report they submitted, the pilot receiving instruction was preparing for the multiengine practical test scheduled for the next day. After about an hour of practicing maneuvers, a simulated single engine ILS approach was made to runway 35R. They were then cleared to do a touch and go landing on runway 17L. The airplane touched down and slowed. The pilot receiving instruction raised the flaps and, instead of advancing the throttles to go around (which was the company's standard operating procedure), she raised the landing gear control switch instead, and the landing gear retracted. The airplane skidded to a halt and caught fire. Both occupants evacuated the airplane. The cabin area was gutted, and both wings sustained thermal damage.

The airplane was equipped with a squat switch that is designed to prevent inadvertent gear retraction when there is weight on the wheels. The switch later tested satisfactory.
 
The squat switch only works when the airplane has most of its weight on the wheels and the struts are almost fully compressed. If you're doing a touch and go then most of the weight is on the wings and the struts wouldn't "squat" (especially if it was a greaser). I know of a few other training accidents where the exact same thing has occured on Senecas with electric flaps. Gear instead of flaps on a touch and go... oops. Both squat switches tested fine afterwards.

Can't screw this up on an early Seneca or Seminole with manual flaps. :)

Flawed design... probably. It's still pilot error no matter what you try to blame it on.
 
Mmmmmm Burritos said:
The squat switch only works when the airplane has most of its weight on the wheels and the struts are almost fully compressed. If you're doing a touch and go then most of the weight is on the wings and the struts wouldn't "squat" (especially if it was a greaser). I know of a few other training accidents where the exact same thing has occured on Senecas with electric flaps. Gear instead of flaps on a touch and go... oops. Both squat switches tested fine afterwards.

Can't screw this up on an early Seneca or Seminole with manual flaps. :)

Flawed design... probably. It's still pilot error no matter what you try to blame it on.

But in order for the weight to be on the wings the aircraft would have to be on a takeoff roll creating some lift, if she took the gear in instead of advancing the throttle, where did the power come from to get the weight off the struts and allow the gear to be retracted?
 
J.C.Airborne said:
But in order for the weight to be on the wings the aircraft would have to be on a takeoff roll creating some lift, if she took the gear in instead of advancing the throttle, where did the power come from to get the weight off the struts and allow the gear to be retracted?

It was a touch and go, the aircraft was probably going to fast to activate the squat switches.
 
lift is a function of relative wind and angle of incidence, not power per se.

So, if they just landed from a touch and go and still had a decent amount of airspeed, then they still had some lift, albeit not as much as if they had rotated to a takeoff attitude.

Also could be something to do with a 'bump' in the pavement, like a crossing runway that could give you a little bit of an up and down, momentarily decreasing the weight on wheels at a bad time.
 
Last edited:
firstthird said:
So, if they just landed from a touch and go and still had a decent amount of airspeed, then they still had some life, albeit not as much as if they had rotated to a takeoff attitude.

Also could be something to do with a 'bump' in the pavement, like a crossing runway that could give you a little bit of an up and down, momentarily decreasing the weight on wheels at a bad time.

I agree. Most likely a combination of rough pavement and some lift due to the speed.

I have heard of a military pilot(must have been Air Force;)) who, trying to make a Sierra Hotel low transition takeoff, raised the gear handle before takeoff planning on the squat switches raising the gear immediately upon liftoff. Well, a few bumps in the pavement caused the gear to raise before rotation making the attempted takeoff a little more spectacular than planned as he skidded down the runway on his belly in a shower of sparks.
 
FL420 said:
I agree. Most likely a combination of rough pavement and some lift due to the speed.

I have heard of a military pilot(must have been Air Force;)) who, trying to make a Sierra Hotel low transition takeoff, raised the gear handle before takeoff planning on the squat switches raising the gear immediately upon liftoff. Well, a few bumps in the pavement caused the gear to raise before rotation making the attempted takeoff a little more spectacular than planned as he skidded down the runway on his belly in a shower of sparks.


There's a video of a Russian fighter doing this exact same thing. I have no idea where I saw it but I've seen it. Guy probably got shot.
 
I like manual flaps in the Senecas...you have to dump them to get any effective braking, so it was nice that all of ours had manual flaps. If you're co-ordinated enough, you can dump them in the flare and get the plane on the runway sooner. I used to do that a lot in our 182 with the horton stol kit as well.

Although I think I'm probably going to get some flak from some people on that procedure, it's one I have used in the past.

You have to co-ordinate your flap retraction with some increased pitch, but it worked out nicely for me.
 

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