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My A&P has this airplane. A prospective buyer came in wanting to test fly it. They went for a test flight, came back after a while. There were a few planes waiting to take off. The plane made a normal landing. Next thing, ATC directed all the holding airplanes to taxi back due to "aircraft down on runway". Turned out, the buyer retracted the gear instead of the flaps. I guess he's committed to buying that plane now.

P.S. Can't they make a safety switch so that gear can't be retracted on the ground?

Yes, some planes have a "squat switch" to prevent such an occurrence. Of course, it introduces a bit more complexity, cost, and another failure point in the system. Damned if you do, damned if you don't....

Ouch!!

What a bummer! That is one expensive mistake. I assume he is going to have to pay for it out of his pocket as I doubt he has any insurance.

A couple years ago, one of the owners of a Cardinal down at the airport took off with the towbar still attached and resting on the nose wheel pants. When he landed, it bounced up and the prop struck it. One of the other owners told me that insurance covered the teardown of the engine (which had only about 450 hours SMOH) and the new prop because it was an accident. That was a bit of a surprise to me.

On the 172RG I did my Commercial training in, the squat switch was located on the nose gear. It is a required part of the preflight. Just basically what amounts to a microswitch that's activated by the weight on the nose strut. Be certain it has no garbage in and around it that may serve to impede or make/break contact when you don't want it to.

Yep.

You can bet your last penny I looked at that one several times during the preflight.


Retracts are nice, indeed, but down and welded beats havin' to check for three in the green for this boy.

It's called a "squat" switch because it doesn't lock out the gear up circuit until the airplane "squats", or has weight on the landing gear sufficeint to actuate the switch.

This pilot apparently was a little too quick to raise the "flaps", and didn't look to see what his hands were actually touching! The wheels may have touched down, but the airplane was still flying ... otherwise nothing would have happened!

Like the man said: "You can't fix stupid". And THAT's why I would never own a retractable!

I'm not familiar with the Comanche, but it is probably like most retracts and has some method for prevention of gear retraction on the ground. I rode in one as a student, and it had a single small gear handle that was like most electric style retracts, so that would be my guess. I would suppose it has a microswitch somewhere on one of the mains.

Squat switches work by interrupting the signal, in the case of electric and electrohydraulic systems, to the electric motor. So if you put the handle up accidentally while on the ground, the motor doesn't activate, and the downlocks stay in place.

The problem comes when the switch is momentarily released (or engaged or "sensed", more on that later) while moving on the ground. If you take a turn a bit fast or go over a bump, the strut can extend a bit, and the squat switch may be displaced enough to allow the motor to operate...the downlocks are disengaged and up comes the gear.

Like Ed said, with Cessna single retracts, there is a squat switch on the nose (at least the 182 RG was that way, along with the 172). There are other microswitches for the up and down lights. The 310 wasn't dissimilar in operation. Debonairs also had a switch on the right main, but if I remember correctly, sitting on the ground, the switch was open instead of closed. It had the same result. Jim Hillibrand could confirm or refute that. The Aero Commander didn't have a squat switch since the gear was actuated totally by an engine driven hydraulic system, and the gear handle, a valve to direct hydraulic flow, had a manual guard to prevent unintentional retraction. The TBM has sensors built into the gear legs. The PC12, instead of microswitches, has proximity sensors (aka "prox switches") that never physically touch anything, but sense their proximity to metal tabs as the gear is moved about.

They are all differing systems to do the same thing...attempt to keep the gear down if the pilot screws up. Unfortunately, pilots will always find new and exciting ways to defeat any system. The best system for operating any part of an aircraft is in between the pilot's ears. Too bad that one's not foolproof either. All you can do is continue to train for the plane and be consistent with your procedures, whatever they may be.

Also this, if you've flown a retract or been with someone that does, is where the philosophy for not touching anything until off of the runway and coming to a full stop comes from. As long as that microswitch is functional, the gear shouldn't retract if you put the handle in the up position when at a full stop. Those microswitches do gum up at times with dirt and other crud, but they seem to keep going mostly.

Early Beech aircraft, specifically the Bonanzas, put the gear and flap handles, right and left, respectively, opposite to other manufacturers. The handles are dissimilar, but not so much that you might grab the wrong one. Newer planes attempt to stop this with differing methods. The PC12, for example, had a huge wheel-shaped gear handle and a smaller flap-shaped handle down on the pedestal.

It is accidents like this, along with aerodynamic improvements and COST, that encourage the manufacturers to shy away from retracts.

What is it - the flap switch is shaped like a flap by FAA mandate (no, it's not an accident the flap switch looks like that!) and the gear switch is shaped like a wheel.

Despite all this, activating the wrong system still happens. I'm not going to chastise anyone that's messed up the gear with the flaps. Hey - in the beginning - when we're learning to fly a comples, we're all very careful. As we gain time, it's human nature to EVENTUALLY miss something and make an error. And with the additional complexity of birds as we move along, the number of systems grows. For example, manifold pressure vs. rpm, pressurization, turbocharging systems, gear systems, flap systems, to say nothing of the increasing complexity of radio panels, nav systems, ad infinitum. Then, make it a multi.

Oh yeah.

You know, this thought has crossed my mind several times. Normally, complex aircraft move pretty fast, and you have so much less time to do stuff. Meaning, you have got to plan ahead and stay ahead of the airplane. Way ahead. Combine that with a single pilot IFR, and it's easy to see how the human factor can easily and completely get overwhelmed. Like I said, I'm not going to chastise anyone for something that happens - there but for the Grace of God go I. Proficiency and currency go a long way, but still, it only takes a distraction.

I'll tell ya something here. Yup. I'm guilty - not of a gear up, but of having a switch in the wrong position - like on my handheld radio input. On the way up to CWI, I was wondering why the number two rig had no ears.

Uh huh. Check it when I land, and yeah - there it was - in the "AUX" position. Radio electrically disconnected. In my own defense, I'll admit that I hadn't flown Mary Lou except once in about a month and a half. The last time I flew her - in late May - before she went in for annual, was when I brought her back from the avionics shop that installed the switch. I neglected to place the new step of "Radio antenna switch to Number Two" in the checklist I use every time i step in the bird. I flat out missed it. Still - no excuse - I should have been THOROUGHLY familiar with my bird. Believe me, I've kicked myself over this oversight. What a moron.

What I'm going to do this week is see if I can just bring it back to the shop, pull out the junk they installed, and just install another comm antenna and run some coax to the panel. I don't know whay they didn't do it like that in the first place. The arrangement now is so stupid - rf leaking into the marker beacon and modulating the lights as I talk. Plus it has no ears over ten miles out. Mary Lou will be lookin' more and more like a porcupine with all the antennas on her. But hey...at least it'll work.

We really fly some of the most simple airplanes around and when you come down to it, while there's a lot to do ustrairs and on the ground, it's in no way comparable to what some of our more complex bretheren have.



Anyway.... back to the original issue - take the extra half second to verify. Use a checklist - and I learned to keep it current.


"Uh.... say again please???"