Expert: D. Norkus - 5/21/2005

Question
Hi,

I believe that in the US, the FAA requires that aircraft flying up to a certain height have to keep all their landing and navigation lights on. Can you tell me what that height is?
Thx

Answer
Mark

Nav lights must be on at any time from sunset until sunrise regardless of altitude.

The landing lights in airline FAR Part 121 operations are usually turned off when passing through 10,000ft MSL. For aircraft operating under Part 91, it is not specified but at the pilots discretion:

Title 14: Aeronautics and Space
PART 91—GENERAL OPERATING AND FLIGHT RULES
Subpart C— Equipment, Instrument, and Certificate Requirements

§ 91.209   Aircraft lights

No person may:

(a) During the period from sunset to sunrise (or, in Alaska, during the period a prominent unlighted object cannot be seen from a distance of 3 statute miles or the sun is more than 6 degrees below the horizon)—

(1) Operate an aircraft unless it has lighted position lights;

(2) Park or move an aircraft in, or in dangerous proximity to, a night flight operations area of an airport unless the aircraft—

(i) Is clearly illuminated;

(ii) Has lighted position lights; or

(iii) is in an area that is marked by obstruction lights;

(3) Anchor an aircraft unless the aircraft—

(i) Has lighted anchor lights; or

(ii) Is in an area where anchor lights are not required on vessels; or

(b) Operate an aircraft that is equipped with an anticollision light system, unless it has lighted anticollision lights. However, the anticollision lights need not be lighted when the pilot-in-command determines that, because of operating conditions, it would be in the interest of safety to turn the lights off.

Hope that helps
Dottie