LOWI LOCR26

[Wennerholm 44]

   Hi! Do not take into account that LOWI may be too small for the PMDG B744. When I am at final at ORBX LOWI LOCR26, I get alarm from the GPWS.

My B744 licence is in landing configuration.

[skelsey 765]

In places where the terrain is challenging such as Innsbruck, it it entirely possible to get spurious GPWS warnings as a function of terrain closure rate etc. Especially if you fly somewhere the aeroplane wasn't designed for!

Are you on the correct track and complying with all the published minimum altitudes?

[Wennerholm 44]

The B744 catch "GS" but not the LOC. I use Navigraph charts and follow them as close as possible. I guess I do something wrong during the approach or maybe the ORBX elevation level is incorrect.

[skelsey 765]

I'm not sure how the aircraft is tracking the glideslope as there isn't one - it's a localiser only approach! This suggests to me that you are following some form of VNAV generated pseudo glideslope. Can you provide some more information about how you are flying the approach, which modes you are using etc? 

26 minutes ago, Wenholt said:

I guess I do something wrong during the approach or maybe the ORBX elevation level is incorrect.

Not necessarily. As I said before, in the real aircraft in certain areas of difficult terrain it is possible to do everything absolutely correctly and still get GPWS warnings because it is simply not possible to programme a system capable of dealing with every possible combination of terrain and approach. If you fly the aircraft on a procedure not designed for it you may equally exceed the system capability - hence your statement to ignore the fact that the 747 is too large for Innsbruck is very difficult to reconcile. There's obviously nothing stopping you from flying it in in the sim, but if you try and make the aeroplane do something unrealistic you shouldn't be surprised if you subsequently experience anomalies or unrealistic responses from the aircraft.

[Wennerholm 44]

I will fly ESSA-LOWI this evening (UTC+1) and then I report to you. Thank´s for your help!

[DaveCT2003 1,820]

GPWS warnings aren't only about terrain, they can also be triggered by the aircraft attitude/speed.  Flying a slower approach will help some, but it's normal to get spurious GPWS warnings in places like the area surrounding LOWI.

 

 

[Wennerholm 44]

Yes. I only get GPWS alarm at LOWI. Maybe I perform a to steep approach.

[Jovabra 18]

In the real world there are a lot of stations excluded for (false) warnings due to abnormal terrain/ground surfaces. On a regulare basis the EGPWS computer need some update during maintenance or a turn-around check. What about the excludings of LOWI i don't no. See the instruction movie from Honeywell.

Regards,

Jo va Bra

[Wennerholm 44]

Hi! Jo det var bra! I just learn something new. Thank´s!