When one of my family is flying I follow progress of the flight by the airlines site and another system like RLM.
Invariably the data on the sites differ.
Right now I am following NWA49 out of Paris.. Each site has a different dep. time.
NWA says it will land at 4:19 and RLM says 4:51
Do they have different definitions?
Anyone know how this stuff works???

fairhope,

This is a guess, but maybe the two sites are defining departure differently.

NWA may be tracking pushback time, and RLM wheels up time.

Could you provide the urls?

http://nwa.com - enter "49"


http://www.rlmsoftware.com/ Select Northwest--enter "49"

ttt

Fairhope,

Sorry for the lengthy delay. I've no idea why the difference. Perhaps you should contact RLM directly.

It is a mystery how some of these sites have different info. I was tracking a flight Chicago to New Orleans yesterday and American Airlines website had (correctly) that the flight was delayed and eventually cancelled, and Expedia flight tracker had it taking off and landing in New Orleans. I usually go with the airline site.

So, who's right in the end?

I saw this thread on that morning, and sure enough, NW's ETA is 32 minutes earlier than the other flight trackers out there. No idea why. I usually use the one on cheaptickets.com, but it was down that morning.

Generally, the difference is only a few minutes...

gc hit the nail on the head. Airlines consider push back as their starting time. Flight Tracker goes by wheels off the ground.

Curious

But we're talking about estimated arrival time, not departure. Big difference.