Looking at LHR ACA landings appear too high

[dfsaviation]

I have noticed when looking at Heathrow (LHR) approach that some flights appear to fly down the ILS but at 800 feet or so too high and somewhat north of 28R They then appear to land some way beyond the airport.

I have only noticed this for some Air Canada flights.

There must be some obvious reason for this - anyone have any clues?

I forget the flight number I just watched but it landed at about 11:10 GMT.

Great site btw

[dfsaviation]

Now everything landing at LHR seems to be landing at an altitude of 750 ft

[Mike]

Maybe an old thread can give you some answers.

http://forum.flightradar24.com/threads/196-Has-Schiphol-sunk

[dfsaviation]

Thanks - and of course over 19000 feet the QNH is taken as a standard reading by all aircraft.......

Though it doesn't explain what I saw the other day where an Air Canada flight '' failed '' to land at LHR but landed a few miles away. Maybe the GPS readings are out on some flights....

this is a fantastic site though....

[Anmer]

Maybe the GPS readings are out on some flights....[/B]
.

Older aircraft use INS rather than GPS and INS suffers from positional drift.