747 Classic

[carbheatcold]

I am hoping that someone will be able to answer the following question with regard to Body Gear Steering on the 747 Classic.

If the Body Gear Steering is left in the ARM position for T/O do you get a T/O config warning even if the gear is physically centered?

I know the warning will go off if the GEAR NOT CENTERED annunciator is lit and I also believe that the warning clears itself immediately when the Body Gear Steering sw is placed to DISARM as the gear is centered.

Many thanks in advance.

Carbheatcold

[18-Wheeler]

No, it's only the body gear position itself that activates the TO warning horn. The switch position isn't monitored.

[carbheatcold]

Thanks 18-Wheeler, it is as I suspected.

carbheatcold

[Flight Detent]

Good on ya!

18-Wheeler

Cheers

[18-Wheeler]

See FD, I pay attention!
(I just look like I'm asleep)

[PAXboy]

This question was specific to the Classic. Do the /300 + /400 have body gear steering too?

Also, when this is available (Classic) does the tiller operate both the nose and main gear, or are their separate controls for the body gear. I doubt it as it would be tricky to steer with two separate controls, so I suppose that you either 'link in' the body gear or not?

Thanks

[18-Wheeler]

The -300 is a Classic.
On the -400, bodygear on/off is automatic, so there's no switch to turn it on or off as such.
The tiller on all types only controls the nosewheel, but when the nosewheel goes past a certain point, the bodygear hydraulics are pressurised, (That's when the panel light comes on) then another few degrees of nosewheel angle actually turns the bdygear in the opposite direction to the nosewheel, all done automatically.

[PAXboy]

"-300 is a Classic" Oops Is the definition due to the -400 glass cockpit? IIRC these were referred to as a Video Nasty, by some?

The steering mechanism sounds really neat. Presumenly, the sideways drag on the wing gear units is not great, otherwise it would cause tyre wear?

Thanks for your information.

[Flight Detent]

Just to explain, in basic terms, a couple of things;

a/ all B747's, other than the -400 series, are known as CLASSICs,
ie, the SP, -100, -200 & -300 series.
b/ the amount of turn deflection of the body gear, in relation to the nose gear, is such that the wing gear struts/ bogies are not normally subject to much more than twisting forces, at taxiing speeds, and those forces are always kept in mind when rather sharp turns are required, at v/slow speeds, ie, always keep the aircraft moving forwards, to relieve the stresses.
Basic Captain stuff!!

Cheers