Learjet 45

[FSDKT]

Somebody please explain to me what the IAS switch in the Learjet does before I park that plane permanently in the Tuscon graveyard.
Thanks

[Treker4747]

It wouldn't happen to be the IAS Hold switch for the Autopilot would it?

Which, you know, holds the selected IAS speed. (So long as the AUTOTHROTTLE is engaged. Made that mistake a few times...)

[FSDKT]

I set the speed with the SPD dial and then click on the IAS button once I'm airborne. My problem comes when I'm trying to land using the glide slope with ILS. Sometimes I oveshoot the glide slope, sometimes I underfly the blasted thing. Sometimes I can land too. So how does the autothrottle get engaged?
Thanks

[Treker4747]

>I set the speed with the SPD dial and then click on the IAS
>button once I'm airborne. My problem comes when I'm trying
>to land using the glide slope with ILS. Sometimes I
>oveshoot the glide slope, sometimes I underfly the blasted
>thing. Sometimes I can land too. So how does the
>autothrottle get engaged?
>Thanks


There should be a switch somewhere on the panel for the Learjet, near the autopilot, to engage/disengage the Autothrottle.

The Autothrottle will give the AP control over the throttle so it can adjust it as needed to control the plane's speed, etc.

If it's not engaged it dosen't matter what you set the Speed Control to, the plane won't be able to adjust the throttle to change the speed. If you're trying to make an ILS approach, probably not a bad idea to have it engaged with your approach speed set in the AP.

Just make sure you switch of the AT once you're on the ground so that you can pull back the thrust into the reversers. If the AT is still on when you try and do this, it won't happen.

Made that mistake a few times too.

I'm fairly sure the AT is tied to a keystroke, but I use a switch from my GoFlight GF-T8 so all I have to do is reach up and flip off a couple switched to disengage the AP and AT so I can control the airplane on my own on the ground.