When the landing gear wont deploy

[wildone63]

When a pilot is faced with having to land a plane without landing gear,as per the recent incident in Poland involving a Boeing 767,would it ever be feasible to put the plane down on the grass alongside the runway?
I would think there would be some advantages to this:
Possible slightly smoother landing than on tarmac,and less damage to plane,
defintley less friction than aluminium fuselage scraping along tarmac at 150mph,so much less risk of sparks and fire breaking out.
No damage to runway allowing airport to be re-opened sooner.
Any thoughts?

[mattdaniels]

No way IMO. Runway is a much better option. Engines will dig in to the grass. They don't like ingesting anything but air. Risk of ripping the wings off or worse flipping the whole aircraft.

[davepoth]

mattdaniels said:

No way IMO. Runway is a much better option. Engines will dig in to the grass. They don't like ingesting anything but air. Risk of ripping the wings off or worse flipping the whole aircraft.

For underslung engines, this is exactly right. I think for low winged planes with high mounted engines (727 or learjet for example) the grass is preferable though.

[Eric Mc]

Also. running along the grass beside a runway will mean you will eventually meet a taxiway intersection which means a change of surface.
Finally, grass is very poor at retardation - especially if it's wet.

[paintman]

Would have thought that with the runway you have a smooth surface that you will slide along without the chance of something digging in & causing large bits of the aircraft to break off/break up.

[mrmr96]

paintman said:

Would have thought that with the runway you have a smooth surface that you will slide along without the chance of something digging in & causing large bits of the aircraft to break off/break up.

^ yup. That.

[Cupramax]

Think they also sprayed the runway with some sort of anti spark lube hence with the Poland one there was next to no sparking and less chance of a fire.

[mattdaniels]

Yep all airports definitely do have tankers of "anti spark lube" on standby for any emergency.

[Simpo Two]

Presuming you come in with a high angle of attack for minimum landing speed, such that the tail touches first, how do you avoid the nose going 'wallop' from about 50 feet (for want of a better phrase)? Or do you keep it more level and take the higher speed?

[Ginetta G15 Girl]

High Alpha does not necessarily mean nose high or tail strike.

[Ginetta G15 Girl]

mattdaniels said:

Yep all airports definitely do have tankers of "anti spark lube" on standby for any emergency.

Erm.

No, they don't.

[Torquey]

I'd also have thought more friction from the Tarmac means the plane will stop sooner than on grass.

Good thought though. I did think hard about it after watching that Poland video.

[Chuck328]

Ginetta G15 Girl said:

High Alpha does not necessarily mean nose high or tail strike.

Can you elaborate please? AoA = Angle at which the airflow meets the chord line (from memory)? Ergo, at slower speeds, that would mean fairly high nose attitude?

[deviant]

Ginetta G15 Girl said:

mattdaniels said:

Yep all airports definitely do have tankers of "anti spark lube" on standby for any emergency.

Erm.

No, they don't.

[The Big G]

Chuck328 said:

Ginetta G15 Girl said:

High Alpha does not necessarily mean nose high or tail strike.

Can you elaborate please? AoA = Angle at which the airflow meets the chord line (from memory)? Ergo, at slower speeds, that would mean fairly high nose attitude?

Flaps and Slats might help a bit. They change the mean chord of a wing and therefor the AOA. ie by bending down the bit at the back the angle of attack will increase even if the aircraft pitch doesn't.

[hidetheelephants]

Ginetta G15 Girl said:

mattdaniels said:

Yep all airports definitely do have tankers of "anti spark lube" on standby for any emergency.

Erm.

No, they don't.

They do, they just call it foam; have you never watched any of the rubbish 'Airport; death and bad acting' disaster films?

[ninja-lewis]

Call International Rescue!

[mattdaniels]

deviant said:

[Simpo Two]

Let's hope the system that caused the u/c to fail doesn't also work the flaps and slats.

Still don't see how you can get the fuselage horizontal at minimum flying speed though - and the tail will hit the ground sooner as there's no u/c.

One for Mr Sullenberger!

[Eric Mc]

Simpo Two said:

Let's hope the system that caused the u/c to fail doesn't also work the flaps and slats.

Still don't see how you can get the fuselage horizontal at minimum flying speed though - and the tail will hit the ground sooner as there's no u/c.

One for Mr Sullenberger!

Kudicious use of flap and ground effect?

Didn't the BA 777 pilot use that technique to "balloon" the aircraft over the perimeter road at Heathrow?