[Top of Descent for Crossing Restriction [Aviation Rules of Thumb]] -- Flightsim Aviation Zone - Number 1 Flight Simulation and Aviation Resource! Information, Tools, Downloads, Databases, FAQ, Aviation Humour, Glossaries, Directory, FS2006, Multimedia, Screenshots, Free Flight Planner, Weather Reports | Aviation Databases - aircraft, airports, airlines, countries, timezones | Flight Simulator X
(x) close
  Sunday 28 May 2017 18:33 GMT  

Aviation Rules of Thumb

Top of Descent for Crossing Restriction

PREVIOUS Glide Ratio Calculation -- Index -- Top of Descent Distance Calculation NEXT

This formula is especially useful for turbo pilots wanting to stay out of icing and turbulance. It gives you a way to meet a crossing restriction and stay high as long as possible.

Take the difference in altitude and multiply by three. This will give you the distance from your crossing restriction to begin descent or Top of Descent.

Now multiply your ground speed time six. This will give you your rate of descent in feet per minute.

example: You are level at FL250. ATC tells you to cross ABC at 7000 ft. You are 70 NM from XYZ with a ground speed of 350 knots.

25000-7000 = 18000 (drop the zeros and use 18) x 3 = 54 nm

300 x 6 = 1800 or 1800 feet per minute descent

54 miles from ABC you must start down at 1800 fpm or greater to meet the restriction.

PREVIOUS Glide Ratio Calculation -- Index -- Top of Descent Distance Calculation NEXT

Aviation Rules of Thumb -- Flightsim Aviation Zone

Top of page
add to favorites @ E-mail this! Link to this!
Top of page
© 2002-2017 - Legal | Contact | Advertise | Sitemap
Visit our $pons0rs:
hosted by 123XS || also visit: Flightsim Search & Aviation Search || Link to us!