GPS Approach

[alex_kativhu]

What do you do when you request a gps approach whilst flying a plane without ILS capability (747-8) then the controller clears you to maintain a heading and perform an ILS landing?

Requested GPS approach again and was threatened with being reported

[tsukki]

I would set the LNAV to NAV1 (since NAV1 is tuned to the ILS) and descend manually, about -800 to -1200 fpm, while maintaining the glideslope

[mangoflies]

@alex_kativhu

without ILS capability (747-8)

That aircraft very much has ILS capabilities. It just doesn’t have APPR/autoland

[Ka77a51umAviation]

really? I thought it just gave you the runway heading automatically. I’m gonna try that

[tsukki]

if you’re using an aircraft with autoland capability, you can use APPR mode for an automatic descent, but since this is 747, which doesn’t have that capability, it only directs you to the runway heading using LNAV (but it doesn’t keep you on the centerline until short final)

[Ka77a51umAviation]

yeah i though u meant that it keeps you on the centerline, which would be cool since it does me lateral navigation

[alex_kativhu]

Thank you, could you kindly help with how you would execute that

[AndrewWu]

First, tune the ILS you want:

Then, just try to keep these markings centered using a combination of VS and heading:

Semantically, I’m not sure why the controller did that since you physically can’t make it a precision approach in the 748, but it wouldn’t be the weirdest thing I’ve seen ATC do. If it happens again, just follow the above steps to try to emulate the ILS.

[alex_kativhu]

Very helpful, thanks Andrew!