GLS approach

MachFly

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MachFly
I'm trying to find out what is a GLS approach and what equipment do you need to fly it?
Looking at the plates it looks like a standard RNAV with minimums lower than LVP, but can I fly it with a regular WAAS GPS?


Thanks
 
Well first you need someone to actually build one.
It will requires a VHF datalink receiver for the local augmentation (unlike WAAS that comes down on the GPS frequencies from a different satellite).
Obviously you're GPS receiver will need to understand how to process this data.
 
I saw those at IAH yeaterday, looked it up myself.
 
Well first you need someone to actually build one.
It will requires a VHF datalink receiver for the local augmentation (unlike WAAS that comes down on the GPS frequencies from a different satellite).
Obviously you're GPS receiver will need to understand how to process this data.

The Instrument Approach Procedures Inventory says that there are 11, Ron. Five of them are at Houston International.

Bob Gardner
 
OK...that wouldn't surprise me (multiple at the same airport). Once you put the Local Augmentation equipment and VHF datalink transmitter, you might as well get your money's worth out of it by using it on multiple runways (it's just "software" at that point).
 
OK...that wouldn't surprise me (multiple at the same airport). Once you put the Local Augmentation equipment and VHF datalink transmitter, you might as well get your money's worth out of it by using it on multiple runways (it's just "software" at that point).

As I recall a local augmentation site can serve runways up to 25 miles away.
 
So you receive a VHF signal from the ground with your nav radio like a standard ILS and then combine the location with the GPS signal increasing your accuracy?


The Instrument Approach Procedures Inventory says that there are 11, Ron. Five of them are at Houston International.

Bob Gardner

Another 4 at Newark.
 
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So you receive a VHF signal from the ground with your nav radio like a standard ILS and then combine the location with the GPS signal increasing your accuracy?

I believe it is much more complex than that. It has nothing to do with conventional ILS.
 
Sure sounds like a Continental project (ok, now United).
 
So you receive a VHF signal from the ground with your nav radio like a standard ILS and then combine the location with the GPS signal increasing your accuracy?

No. The LAAS is a signal that improves the GPS accuracy. You feed the datalink from the VHF receiver into the GPS and it synthesizes a "better than ILS" horizontal and vertical guidance.
 
Okay I think I got it now. Thanks for explaining.
 
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