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 Mph? Knots?
 Boeing 777-400 From United States of America, joined May 1999, 129 posts, RR: 2Posted Wed Aug 18 1999 17:28:00 UTC (15 years 7 months 2 weeks 5 days 17 hours ago) and read 4910 times:

 Hi I was wondering how many Miles per hour is 1 knot, and does the number change as the altitude increases? EX- would 550 knots at 5000 feet be the same amount of MPH as it would be at 35000 feet?
 DL 604 From , joined Dec 1969, posts, RR: Reply 1, posted Wed Aug 18 1999 17:30:55 UTC (15 years 7 months 2 weeks 5 days 17 hours ago) and read 4837 times:

 You took the words right out of my mouth! I was going to post that question, but it looks like ya beat me to it!   I was wondering myself, so help us both!    DL 604
 Panman From Trinidad and Tobago, joined Aug 1999, 790 posts, RR: 0 Reply 2, posted Wed Aug 18 1999 17:51:58 UTC (15 years 7 months 2 weeks 5 days 17 hours ago) and read 4845 times:

 As far as I am aware the ratio between mph and knots (nautical miles) remains the same. I believe 1 mile is something like 1.18 nautical miles (can't remember - doing this off the top of my head). Unlike Mach No which changes with density and altitude.
 Boeing727 From United States of America, joined May 1999, 957 posts, RR: 0 Reply 3, posted Wed Aug 18 1999 18:11:58 UTC (15 years 7 months 2 weeks 5 days 17 hours ago) and read 4835 times:

 I usually add about 15% to the value of knots when I tell my passengers how fast we are flying in mph; that is indicated air speed, of course. It is amlost the same ratio as meters to yards, which comes handy when I play golf in Europe. Regards, Boeing727
 Flyf15 From , joined Dec 1969, posts, RR: Reply 4, posted Wed Aug 18 1999 18:57:21 UTC (15 years 7 months 2 weeks 5 days 16 hours ago) and read 4833 times:

 From the dictionary: Knot: A unit of speed, one nautical mile per hour, approximately 1.85 kilometers (1.15 statute miles) per hour. A knot is, as I recall, a knot is one minute of latitude at the earth's surface.
 DL 604 From , joined Dec 1969, posts, RR: Reply 5, posted Wed Aug 18 1999 19:08:07 UTC (15 years 7 months 2 weeks 5 days 16 hours ago) and read 4830 times:

 So, if you are flying at 10,000 feet and climbing at 250 knots, how many miles per hour are you going? DL 604
 Purdue Cadet From , joined Dec 1969, posts, RR: Reply 6, posted Wed Aug 18 1999 19:24:36 UTC (15 years 7 months 2 weeks 5 days 15 hours ago) and read 4833 times:

 250 Knots would be about 288 mph. (250 kts) X (1.15 statute miles/ kt) = 287.5 statute miles per hour That math was done quickly in my head - I appologize if the multiplication is wrong.
 Buff From Australia, joined Mar 2007, 0 posts, RR: 1 Reply 7, posted Wed Aug 18 1999 19:58:08 UTC (15 years 7 months 2 weeks 5 days 15 hours ago) and read 4827 times:

 Flyf15 is correct, except for the relationship of a knot to latitude. "Knots" means nautical miles per hour, so is a unit of speed. A nautical mile is coincidentally equal to one minute of latitude, measured along a true north/south line, or in exact terms, 6080 feet. Good question - something that most flyers take for granted everybody else knows, but doesn't! Best Regards, Buff
 24291 From , joined Dec 1969, posts, RR: Reply 8, posted Wed Aug 18 1999 20:39:07 UTC (15 years 7 months 2 weeks 5 days 14 hours ago) and read 4822 times:

 I'll try and put this in other terms. One knot means 1 nautical mile per hour. A nautical mile is longer than a statute mile, hence 100 knots is faster than 100 mph. This ratio remains the same as others have said. I think your confusion lies with indicated airspeed (IAS) vs. ground speed. If you climb at a constant IAS of 250 kts. in calm wind for example, your ground speed will increase as you go higher. This is because as you climb, you pitot tube, which measures ram air pressure and delivers that information to your airspeed indicator, begins to move through less and less air. Its easy to maintain a constant IAS, however, because your airplane will move faster through the thinner air and keep the same volume of air entering the pitot. If you takeoff on a runway that is at 5,000 ft elevation, your airplane will move across the runway at a higher speed than when taking off from a runway at sea level (assuming standard atmospheric conditions), yet you IAS for rotation and takeoff (generally speaking) will always remain the same. So when you're on an airliner, your airplane may be cruising at 250 kts. IAS, but your pilot may announce a ground speed of something like 600 mph. It's actually hard to explain but I hope I did a good job.
 A330 From Belgium, joined May 1999, 649 posts, RR: 7 Reply 9, posted Thu Aug 19 1999 00:33:17 UTC (15 years 7 months 2 weeks 5 days 10 hours ago) and read 4811 times:

 Let me give you the CORRECT definition of a nautical mile: A NAUTICAL MILE AT ANY PLACE IS THE LENGTH OF AN ARC OF THE MERIDIAN SUBTENDING TO AN ANGLE OF 1' AT THE CENTRE OF CURVATURE OF THE PLACE. At the pole: 6107.8 FT At the equator: 6046.4 FT STANDARD: 6080 Ft or 10852 m for the mathematic freaks:formulae: ( 6077.1 - 30.7 x cos2*) in feet * is tèta 6077.1 is the mean value Tino
 Shiek!
 Buff From Australia, joined Mar 2007, 0 posts, RR: 1 Reply 10, posted Thu Aug 19 1999 03:16:14 UTC (15 years 7 months 2 weeks 5 days 8 hours ago) and read 4814 times:

 " STANDARD: 6080 Ft or 10852 m " Sure you don't mean 2393.7 m?! (I don't know the metric equivalent standard, but 6080 feet is correct in British measure. The differences in the Brit measure of course are due to the fact that the earth is not perfectly round.) Just to lighten this subject up even more, using the 1 minute of arc measure, wouldn't a nautical mile increase with altitude, ie distance from the centre of measurement?!! (I know it doesn't because the 6080' is a Standard Measure.) Best Regards, Buff
 Continental777 From United States of America, joined Oct 2000, 81 posts, RR: 0 Reply 11, posted Thu Aug 19 1999 03:22:55 UTC (15 years 7 months 2 weeks 5 days 7 hours ago) and read 4807 times:

 Boeing 777-400 did you copy the name from my discussion. no one is supposed to know about that. They just talked about I don't know if they will even go on with it. there is a 49/51 chance
 Buff From Australia, joined Mar 2007, 0 posts, RR: 1 Reply 12, posted Thu Aug 19 1999 03:23:03 UTC (15 years 7 months 2 weeks 5 days 7 hours ago) and read 4810 times:

 Can't read my own calculations! 6080 ft = 1854.4 metres Yikes. Best Regards, and apologies for the "make-up" post, Buff
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