Definition
A unit of speed equal to one statute mile (5,280 feet) traveled in one hour. In aviation, MPH was the standard speed unit on older airspeed indicators and in older publications, but most modern aircraft and aeronautical materials use knots (nautical miles per hour) instead.
Plain English
How many miles you cover in one hour. If something is going 100 mph, it travels 100 miles in an hour.
Context Anchor
Seen in aircraft handbooks, cockpit speed markings, and FAA training text when a speed is given in miles per hour instead of knots.
Derivation
Mile comes from the Latin 'mille passuum' meaning 'a thousand paces' — originally a Roman measure of distance. Combined with 'per hour' it simply describes distance covered in a set time.
Why Pilots Care
Older FAA handbooks and some performance charts list speeds in MPH rather than knots, so pilots must convert accurately to avoid using the wrong target speed.
Intuition Check
Do not assume MPH and knots are the same. MPH uses land miles; knots use nautical miles, so the numbers are not equal.
Example Sentence 1
The older trainer's airspeed indicator was marked in MPH, so the pilot mentally converted the pattern speed from knots before flying it.
Example Sentence 2
The pilot converted the published 100-knot cruise speed to 115 MPH before checking the older performance table.