landing gear interface.

[Steve Franklin]

Hi there..

I have no idea about aviation so excuse me if this is a dumb question.

Why is that on planes the landing gear:

a) has such an unique interface relative to the other avionics. E.g Why the
long handle?
b) What is the purpose of the wheel at the end of the landing gear arm?


Cheers
Steve

[Allen]

"Steve Franklin" > wrote in message
...
> Hi there..
>
> I have no idea about aviation so excuse me if this is a dumb question.
>
> Why is that on planes the landing gear:
>
> a) has such an unique interface relative to the other avionics. E.g Why
> the long handle?
> b) What is the purpose of the wheel at the end of the landing gear arm?
>
>
> Cheers
> Steve

What kind of airplane are you looking at Steve? Some gear handles are only
an electric switch that activates a valve and on others the handle moves the
valve itself. The wheel on the end is a symbol of what the handle does.
Flap handles are usually a flat blade. Helps reduce the accidental gear
retraction accident :)

Allen

[Steve Franklin]

I have just been watching 'Executive Decision' on TV and the aircraft was a
Boeing 747. The handle for the landing gear seemed very long and it had a
wheel on the end that look a lot like a roller-blade wheel.

So you are saying the wheel has no function other than to provide an instant
identification to the pilot that it's the gear handle?

Cheers
Steve


"Allen" > wrote in message
t...
>
> "Steve Franklin" > wrote in message
> ...
>> Hi there..
>>
>> I have no idea about aviation so excuse me if this is a dumb question.
>>
>> Why is that on planes the landing gear:
>>
>> a) has such an unique interface relative to the other avionics. E.g Why
>> the long handle?
>> b) What is the purpose of the wheel at the end of the landing gear arm?
>>
>>
>> Cheers
>> Steve
>
> What kind of airplane are you looking at Steve? Some gear handles are
> only an electric switch that activates a valve and on others the handle
> moves the valve itself. The wheel on the end is a symbol of what the
> handle does. Flap handles are usually a flat blade. Helps reduce the
> accidental gear retraction accident :)
>
> Allen
>

[Steven P. McNicoll]

"Steve Franklin" > wrote in message
...
>
> I have no idea about aviation so excuse me if this is a dumb question.
>
> Why is that on planes the landing gear:
>
> a) has such an unique interface relative to the other avionics. E.g Why
> the long handle?
>

Landing gear is not avionics. The size of the gear "lever" depends on the
method of gear actuation. Aircraft with manual gear retraction and
extension need fairly long gear levers in order to obtain sufficient
mechanical advantage for the pilot. Aircraft with straight hydraulic
systems generally have longer gear levers than those with electric or
electrohydraulic systems because it takes more force to turn a valve than
actuate a switch.


>
> b) What is the purpose of the wheel at the end of the landing gear arm?
>

To readily identify it as the gear lever; move the "wheel" to move the
wheels.

[Kev]

Steve Franklin wrote:
> I have just been watching 'Executive Decision' on TV and the aircraft was a
> Boeing 747. The handle for the landing gear seemed very long and it had a
> wheel on the end that look a lot like a roller-blade wheel.
>
> So you are saying the wheel has no function other than to provide an instant
> identification to the pilot that it's the gear handle?

You're correct, it's so you can tell by feel and visual shape.

power = cylindrical
supercharger = cylindrical with triangular teeth
rpm = ridges like a section of a mechanical gear, flat ridges
mixture = like rpm, but thin sharp ridges
flags = flat with thin edge facing you
heat/alternate air = square facing you
gear = wheel

Kev

[Steve Franklin]

>
> power = cylindrical
> supercharger = cylindrical with triangular teeth
> rpm = ridges like a section of a mechanical gear, flat ridges
> mixture = like rpm, but thin sharp ridges
> flags = flat with thin edge facing you
> heat/alternate air = square facing you
> gear = wheel
>
> Kev
>


Thanks Kev...that makes so much more sense now....I can understand now. I
just couldn't understand why it wouldn't just be a button like so much
else..

But I can see now how important it would be if you say lost all power to the
cockpit instrumentation to be able to easily find the landing gear in the
dark if neccessary...

It all makes perfects sense...

Cheers
Steves

[George Patterson]

Steve Franklin wrote:

> But I can see now how important it would be if you say lost all power to the
> cockpit instrumentation to be able to easily find the landing gear in the
> dark if neccessary...

Actually, that's for all the time. In many cases you don't want to take your
eyes off of something else (like the runway) just to be sure you have the right
lever.

George Patterson
Give a person a fish and you feed him for a day; teach a person to
use the Internet and he won't bother you for weeks.