PA31 Landing Gear Unsafe Horn - 3 Green down & Locked

[Flying Timer]

Anyone ever experienced a "Horn" signal from the LG Unsafe adviser after a smooth landing?. Also getting intermittent LG Unsafe signal on the Gear down check after engine start? Any idea what might be the cause...?

[wollypilot]

microswitch on throttle lever? i think it is on the left one on the hoe.
cheers. wp.

[Ranger]

It wasn't on a HO, but on the 402 I had the same thing and it was the actual horn had come off its mount and was hanging on by the wires and the way that horn works is when it touches a ground it would go off as well as the gear unsafe light would come on. On the landing roll the plane would be bouncing enough for the horn to sway on the wires and touch a ground giving the false indications....

[Cat Driver]

Might this question be better put to the maintenance facility that is responsible for the airplane, rather than here?

Cat

[Mach .28]

Firstly...Yes Cat us maintenance guys do check out this forum too.

Secondly. Had this problem before on a PA31-310. Traced the problem to the L/H gear rigging.

We started off by having the horn once in a while on startup when doing a gear check. Then developed into a problem with the L/H green light taking a while to come on in the air

The problem is that Piper unlike Cessna will not give you proper dimensions on how far the actuator should extend with the landing gear down.

The plane would indicate green on jacks but during test flights would take a bit to get the green to come on. We finally just kicked the tire when it was on jacks and it JUST broke the microswitch. Re-rigged the gear out a hair and it was all good.

Have the maintenance guys check the wires carefully for any shorts as well.

Hope this helps any further questions just PM me.

[max diff.]

On the ground do you get the horn when you apply a slight upward movement on the gear handle? I'm not talking 'force' but just slight pressure.

[ZBB118.10]

This has happened to me several times...when the gear lever returns to its centre position the micro switch on it quite often sticks...try pushing the gear lever in very gently (in a forward sense) and this normally solves the problem. Has happened to me on the run up several times - scared the crap outta me first time around!!!!!!!

[scabber]

has nothing to do with the gear handle... if the gear handle hasnt snapped back into place... then you need new hyrd pumps.

its the microswitch in the throttle quad. sticking. pull the power pack CB I think, and have a mechanic change the switch out.

[flyinhigh]

If the handle does not come to neutral it is not necessarily the pumps, we had this problem and changed the pumps and it turns out that it was a switch in the nose compartment that operate the inner doors giving us grief.

[aero-singidunum]

The old HO that i worked on had same problems, we end up replacing switches and some wires and never had problem after that

[Wasn't Me]

The problem is not limited to the HO. Most aircraft have cabling the sends the safe/not safe signals. the cableing get worn and does brake once in a while.

[Airtids]

Here's an interesting one we had: Gear unsafe light kept coming on when we were in cruise, gear up and safely stowed. Snag it, maintenance would put it on jacks, re-rig, and swing it, and then release it. Next flight, same thing. This went on for 2 weeks until maintenance discovered the CRACKED AIRFRAME !!
Every time we would fly it, the stress would cause the frame to shift, gear would come out of adjustment, and nose gear would come off the up-lock switch. On the ground, under no stress, the system could be rigged and swung no problem. You should've heard the language coming out of the engineer everytime we'd bring it back in- make a trucker blush!

[Benwa]

This went on for 2 weeks until maintenance discovered the CRACKED AIRFRAME !!

Having witnessed a few of Flying Timer's not so soft landings, I'd say it's plausible ! Just Kidding.