Welcome Guest. Sign in or Signup

3 Answers

How fast would an aircraft have to fly to keep the sun on the horizon?

Asked by: 9656 views General Aviation

They say that no question is stupid, so here it goes. How fast would an aircraft have to fly to keep the sun on the horizon, say on a route across the SW USA, East to West? I have flown at sundown many times from Pit to LA and just wondered if you could possibly keep up with the sun?

Ace Any FAA Written Test!
Actual FAA Questions / Free Lifetime Updates
The best explanations in the business
Fast, efficient study.
Pass Your Checkride With Confidence!
FAA Practical Test prep that reflects actual checkrides.
Any checkride: Airplane, Helicopter, Glider, etc.
Written and maintained by actual pilot examiners and master CFIs.
The World's Most Trusted eLogbook
Be Organized, Current, Professional, and Safe.
Highly customizable - for student pilots through pros.
Free Transition Service for users of other eLogs.
Our sincere thanks to pilots such as yourself who support AskACFI while helping themselves by using the awesome PC, Mac, iPhone/iPad, and Android aviation apps of our sponsors.

3 Answers



  1. tresclements@msn.com on Jul 26, 2010

    This is a pretty straight forward question that I have pondered in the past. The math is pretty simple for an approximate answer. All you need to know is the circumference of the earth where you plan to fly.

    According to a quick google search the circumference of the earth is ~24,859.82 miles so I am going to assume that since you will be north of the equator this would be about the same at altitude. You can spend more time dialing this number in if you want.

    All you have to do is divide the circumference or miles around the earth by the number of hours in a day. So 24 859.82miles / 24 hr= 1 035.82583 miles/hr

    +5 Votes Thumb up 5 Votes Thumb down 0 Votes



  2. Paul on Jul 26, 2010

    1035 assumes the flight is on the equator. If it was further north or south the circumference is obviously less.

    At mid latitudes during the summer it would be about 730 miles per hour or about .95 mach (faster than a Citation X!) You might have to get up quite north to have a Citation X keep north.

    +4 Votes Thumb up 4 Votes Thumb down 0 Votes



  3. EML on Feb 21, 2015

    At altitude (let’s say 35000 feet) you would have to fly @ approx 1690 mph to keep up with the sun

    -3 Votes Thumb up 0 Votes Thumb down 3 Votes


The following terms have been auto-detected the question above and any answers or discussion provided. Click on a term to see its definition from the Dauntless Aviation JargonBuster Glossary.

Answer Question

Our sincere thanks to all who contribute constructively to this forum in answering flight training questions. If you are a flight instructor or represent a flight school / FBO offering flight instruction, you are welcome to include links to your site and related contact information as it pertains to offering local flight instruction in a specific geographic area. Additionally, direct links to FAA and related official government sources of information are welcome. However we thank you for your understanding that links to other sites or text that may be construed as explicit or implicit advertising of other business, sites, or goods/services are not permitted even if such links nominally are relevant to the question asked.