Kindjordan From United States of America, joined Nov 2004, 59 posts, RR: 0 Posted (10 years 4 months 4 weeks 1 day 17 hours ago) and read 3841 times:
Hey guys.....today i was on jetblue 118 from MSY>JFK....about 20 minutes from our initial descent from 330, I was watching the moving map on tv's...and i saw the ground speed was indicating 691mph ground speed. I thought this was alittle high and was wondering if anyone here could confirm this. I thought maybee the gps was off a little as they sometimes are....any input would be apreicated-J
Starlionblue From Greenland, joined Feb 2004, 17303 posts, RR: 67
Reply 3, posted (10 years 4 months 4 weeks 1 day 17 hours ago) and read 3809 times:
Well I could explain. Do you know anything about wormholes?
Seriously, ground speed is the speed of the plane relative to the ground. Airspeed is the speed of the aircraft relative to the air around it. So if the air is moving in the same direction as the plane (wind, jetstream, etc...) relative to the ground the ground speed can be quite high despite airspeed remaining well within acceptable limits. This phenomenon is of course referred to as "tailwind".
691mph=1112km/h. This is in the high range but not unusual. Jetstreams can move at several hundred mph.
[Edited 2004-12-27 03:56:44]
"There are no stupid questions, but there are a lot of inquisitive idiots."
Aaron747 From Japan, joined Aug 2003, 8533 posts, RR: 26
Reply 6, posted (10 years 4 months 4 weeks 1 day 2 hours ago) and read 3406 times:
cool story jordan. when I was returning to SJC from NRT on AA128 last March, we rode the jet stream for about two hours just southwest of alaska. the flight progress screen was showing our groundspeed to be over 780 mph.
now, it's important to keep in mind that groundspeed is irrelevant as far as the aircraft is concerned. airplanes only know airspeed.
If you need someone to blame / throw a rock in the air / you'll hit someone guilty