Pilot Question

[Jethers203 0]

Can the landing gear be put up while the plane is still on the ground? My professor said this happened with a 737 due to miss communication between the pilot and co-pilot.

I don't have my private pilot's license yet, but when I heard this I thought it was bull shit.

Can this same thing happen to a smaller plane as well? Just curious.

Clint D-24352

[diverdriver 5]

Yes.

[dkf1979 0]

I thought the landing gears where locked into position from the weight of the plane.

http://bodypilot.bounceme.net

[diverdriver 5]

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I thought the landing gears where locked into position from the weight of the plane.

No actually they aren't. They have an over center position that is supposed to keep them in position. But, take the hydraulic pressure off of the gear and it -can- collapse. The squat switch is supposed to prevent that from happening but it can fail also.

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[koz2000 1]

I've seen it happen,
Pilot landed, spoilers down, flaps up, gear up... DOH

At least he passengers were waiting and not on the plane

______________________________________________
- Does this small canopy make my balls look big? - J. Hayes -

[Jethers203 0]

Wow, thanks for the info. I have questioned some things my prof has said, but this one peaked my interest since I am working on getting my Pilots License. It seems there should be a safety thing that would prevent that from happening. Kind of like the safety thing on my truck that prevents me from turning the key when the engine is on.

Clint D-24352

[pilotdave 0]

I don't know the 737, but I think in any modern "high tech" aircraft, it would be nearly impossible.

I remember reading an "I learned about flying from that" article about a Cessna Cardinal pilot that bumped the gear handle by mistake on the ground and didnt notice. Nothing happens until weight comes off the wheels, so it was easy to miss. Problem was his takeoff wasn't too graceful, and after lifting off, he settled back down right away. The gear had only moved a little bit, but it was enough that it jammed when the weight came down.

To make a long story short, he had a back seat passenger open the panel in the floor and eventually got the gear to release and go down, and landed safely.

On a modern fly by wire aircraft, weight on wheels indication is very important because it gets fed as a parameter to the flight control computer (and weapons systems on military aircraft). The aircraft I've spent my whole career working on (all 9 or so months of it) uses 3 independent weight-on-wheels switches per landing gear. And the gear isn't physically capable of retracting when the aircraft is sitting on them.

Now a typical retractable might only use one wieght on wheels switch, but the probability of a failure and the pilot knocking the switch on the same flight would probably be very low. Landing gear handles on modern aircraft are designed so that 2 motions are requied... ie pull out and then up. That way there's much less chance it'll be moved by mistake.

So is it possible? Yeah, anything is possible. But probable? No. Has it happened? I'm sure!

Dave

[quade 3]

If you can imagine it, it probably has already happened.

If you've never imagined it in your wildest dreams -- it's going to happen soon.

quade -
The World's Most Boring Skydiver

[Lee03 0]

Yes, it can be done, and whoever does it will really feel stupid!

--------
To put your life in danger from time to time ... breeds a saneness in dealing with day-to-day trivialities.

--Nevil Shute, Slide Rule

[tombuch 0]

Quote

Wow, thanks for the info. I have questioned some things my prof has said, but this one peaked my interest since I am working on getting my Pilots License. It seems there should be a safety thing that would prevent that from happening. Kind of like the safety thing on my truck that prevents me from turning the key when the engine is on.

Clint D-24352

Airplanes are all pretty different. Older aircraft may be lacking in some obvious safety features.

On most modern airplanes that I am aware of there is a safety device called a squat switch. It basically detects weight on the gear and prevents the gear from retracting even if the switch is set for retraction. It's possible for that (or those) switches to fail.

There are also airspeed detectors that are designed to alert the pilot to a no gear condition at low airspeed and landing configuration. Some of those systems can prevent the retraction of gear on the ground. Most can also be disabled by the pilot. Again, those systems vary among different airplanes, and they too can fail.

In any case, safety devices can not be relied on, so it is technically possible for gear to be raised while the plane is on the ground. Also, a plane on takeoff roll will release pressure on the gear before reaching adequate rotation speed. If the gear switch is in the up position when this happens the landing gear could retract, and the plane would then slam and slide into the ground.

So, if you are worried about foolishly lifting the gear while parked on the ramp, relax. It's not likely to happen, but since it can happen, pilots are trained to avoid the trap.

Tom Buchanan
Commercial Pilot (IAMSEL,G)
Author JUMP! Skydiving Made Fun and Easy

Tom Buchanan
Instructor Emeritus
Comm Pilot MSEL,G
Author: JUMP! Skydiving Made Fun and Easy

[piisfish 135]

happened a few years ago on a Crossair plane, a Saab 340 or Saab 2000...
The pilot wanted to prove to the co-pilot it wouldn't work...

scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

[diverdriver 5]

Quote

So, if you are worried about foolishly lifting the gear while parked on the ramp, relax. It's not likely to happen, but since it can happen, pilots are trained to avoid the trap.

True story. Two guys (part owners) of an Aerotstar (small piston twin 6 seat) are at their plane. One is a mechanic and the other the pilot. The pilot outside the plane yells forward to the mechanic and calls for him to retract the flaps after ground isnpection. The mechanic then selects power on, hydraulic pressure comes up and he graps the landing gear handle. The nose gear retracts and crushes the gear doors.

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[usedtajump 1]

So far, in 30 years in aviation, I've personally seen two Kingair 200s, a Saberliner 60 and a Hawker 700 gears retract sitting on the ramp.

The older I get the less I care who I piss off.

[sducoach 0]

Quade,

Can I steal that quote?

Blues,

J.E.

James 4:8

[goose491 0]

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Can the landing gear be put up while the plane is still on the ground? My professor said this happened with a 737 due to miss communication between the pilot and co-pilot.

It happened... on an episode of the Simpsons.

Crazy-Clown airlines.

My Karma ran over my Dogma!!!

[FrogNog 1]

Quote

It seems there should be a safety thing that would prevent that from happening.

Safeties are devices and devices can fail. This is why in skydiving, aviation, and firearms anything that is a backup device should only actually be used as a backup. (i.e. Flipping the gear switch while saying "I know there is a safety on this plane to prevent this" is contraindicated.)

-=-=-=-=-
Pull.

[quade 3]

Feel free.

quade -
The World's Most Boring Skydiver

[Praetorian 1]

You'll love this, 2 USAF F-16 pilots desided to race, as they were in identical aircraft and it was a pretty stright line from the runway to their designated endpoint only reducing drag would make a differience, one of the pilots set his gear to the retract position so that the instant he lifted off the gear would close... at some point it the take off roll a head wind gusted, little lift off, lot of belly flop.

Good Judgment comes from experience...a lot of experience comes from bad
judgment.

[kallend 1,621]

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I thought the landing gears where locked into position from the weight of the plane.

No actually they aren't. They have an over center position that is supposed to keep them in position. But, take the hydraulic pressure off of the gear and it -can- collapse. The squat switch is supposed to prevent that from happening but it can fail also.

My Mooney don't have no new fangled "hydraulics" in its LG.

...

The only sure way to survive a canopy collision is not to have one.

[redshift 0]

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Can the landing gear be put up while the plane is still on the ground?

Even better: supposedly, some test pilot back in the X-15 days forgot to put his landing gear down, bellied it in, and then decided to lie and say that he thought he'd put it down. So to support his story, he flipped the gear-down switch... whereupon the plane climbed up on its gear like some huge insect getting to its feet. Nice hydraulics, if true.

[rickjump1 0]

We physically put gear pins in aircraft that are being towed, having other than routine maintenance performed, or left on the ramp for extended time. This prevents the gear from retracting as long as the pins are installed. Pins must be removed during preflight or you will not be able to retract the gear in flight.

Do your part for global warming: ban beans and hold all popcorn farts.

[sundevil777 93]

During my former life as part of the 777 flight deck design group, the crew operations guys said that (on the old prop airliners) raising the LG was an accepted method of stopping a plane if the end of the runway had dangerous obstacles. Their brakes weren't very good, and it was considered an effective way of putting an anchor out on a poorly executed aborted takeoff.

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[michaelmullins 77]

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Can the landing gear be put up while the plane is still on the ground? My professor said this happened with a 737 due to miss communication between the pilot and co-pilot.




Everyone that has answered this question "can the landing gear be put up while the plane is still on the ground" in the affirmative is absolutely wrong.

There is no aircraft that the landing gear can be "put up" while it is on the ground. You can lower the aircraft but you can't make the wheels come up.

Mike Mullins

• Quote

[Jethers203 0]

Mr. Mullins,

I will go with what you said over everybody else. If anyone knows it would be you. Thanks for the reply.

Also, could you tell Joel that everyone from Skydive El Paso says hi. It was fun to jump with him when he was here.

Clint D-24352

[diverdriver 5]

Quote

Everyone that has answered this question "can the landing gear be put up while the plane is still on the ground" in the affirmative is absolutely wrong.

There is no aircraft that the landing gear can be "put up" while it is on the ground. You can lower the aircraft but you can't make the wheels come up.

Mike Mullins

Damnit Yoda, you aren't supposed to make us young jedi look so naive! LOL....oh man I'm crying here.

ROFLMAO.

signed....Luke.

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125