Forum: F-16 Procedures

What happens? As far as trailing edge flaps, landing gear config/warning light etc?

And yes gear is pinned down and safe!

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Aware as I saw the aftermath of it happening once. Mains retract, nose gear does not due to the angle, possibly because as soon as it started pilot shutdown engine, but hydraulics may not be able to overcome the angle of the nose strut. Interesting, what happens with WOW off mains and engine off? EPU fires and cannot be shut off because jet thinks its in the air and needs EPU with engine off. Turned out downlock failed and pilot bumped gear handle up while trying to turn off CMS system while entering EOR. Jet settled on ventrals, wingtanks, and nose gear. EPU burned itself out as no one could turn it off. A strange occurrence. JB

Of course if gear is pinned they will not retract! In this case he had not entered EOR yet.

Thanks JB, but the answer I’m looking for is during normal ground ops checks 3000 psi on A and B systems, gear pins in, and doing a trailing edge flap switch confidence check. When gear handle is up, you should get a Landing/TO config light but we are not? However the flaps need to move past the 25 degree mark for the light and that does not happen? I’m thinking something with the CADC?

VarkVet wrote:

Thanks JB, but the answer I’m looking for is during normal ground ops checks 3000 psi on A and B systems, gear pins in, and doing a trailing edge flap switch confidence check. When gear handle is up, you should get a Landing/TO config light but we are not? However the flaps need to move past the 25 degree mark for the light and that does not happen? I’m thinking something with the CADC?

Is your WOW C/B pulled? and also you got to have your AOA rotate down.
Are we talking about the same thing?

Posible bad Landing Gear Control Handle Assy or wiring. Aircraft is not sensing your handle is up.

sounds like a wiring or a relay issue

I believe AZANG had a incident where they put the handle up with aircraft on the ground and pins installed. Cant remember what they were trouble shooting for. But the mains partitially retracted and jet settled on centerline tank from what I remember. I believe pics and info is in the aircraft database.

For comparison, in the past year or two, the Jap F-2s had been having the same problems, with two or three incidents of landing gear retracting while the planes were static (twice, I think) or taxiing (once, I think) on the ground, and of control stick (actually its plastic handle portion, I think) breaking off at its bottom while the plane was in the air. 8(

For the gory details, check out my F-2 threads elsewhere in this site. 8D

Quote:

... they put the handle up with aircraft on the ground and pins installed. Cant remember what they were trouble shooting for. But the mains partitially retracted and jet settled on centerline tank ...

As mentioned previously by others, the gear can't move if the landing gear pins are installed.

If the jet is on the ground.. and the C/B's are not pulled and you put the gear handle up with Hyd power applied.. Nothing will happen. The WOW switches prevent this. Often times when jets are on alert status the pins are pulled and the gear handle is up. The jet will then start and when it takes off the WOW switches tell the jet that it can retract the gear.

Viperwiper wrote:

If the jet is on the ground.. and the C/B's are not pulled and you put the gear handle up with Hyd power applied.. Nothing will happen. The WOW switches prevent this. Often times when jets are on alert status the pins are pulled and the gear handle is up. The jet will then start and when it takes off the WOW switches tell the jet that it can retract the gear.

This is completely wrong. The left main gear WOW switch only prevents movement of the landing gear handle to up without depressing the downlock release button. It doesn't prevent the gear from trying to retract if the gear handle is up and electrical and hydraulic power are present. A jet should never be on alert status with the main gear pins pulled and the gear handle up. If the pilot doesn't catch the gear handle position error, the main gear will unlock for retraction during engine start and the aircraft will settle onto the fuselage or stores. The nose gear (if not pinned) will also attempt to retract but it won't be able to because the actuator doesn't have enough muscle to lift the nose so the nose gear can move aft for retraction.

This post reminds me of the funny story on how the gear handle got it's shape. In WWII, the gear and flaps handle were next to each other. B17 pilots wanting to put the flaps up, would pull the wrong handle and set the plane down on it's belly. Someone came up with the idea to put the tire shape on the end of the handle. Plus it was easier to find in an emergency.

SwampFox80 wrote:

I believe AZANG had a incident where they put the handle up with aircraft on the ground and pins installed. Cant remember what they were trouble shooting for. But the mains partitially retracted and jet settled on centerline tank from what I remember. I believe pics and info is in the aircraft database.

Actually the gear pins had been pulled out by the AZ technician on the ground. He was unaware of the procedure and him and the man in the aircraft were yelling instructions since they failed to bring headsets for the job.

Forum: F-16 Procedures

Gear handle up on ground?