Story ID: 
FAA Advises on Lower-altitude Speed Limits
By: Kerry Lynch
Caption: Max below 10,000 ft msl is 250 kias unless aircraft design dictates otherwise
Word Count: 312
The FAA is reminding operators of Part 25 transport-category aircraft that speeds greater than 250 knots indicated airspeed (kias) below 10,000 feet msl are prohibited unless the aircraft design dictates a higher minimum safe airspeed.
In a newly released Information for Operators (InFO 26010), the agency noted that Part 91.117(a) restricts the higher speed at altitudes lower than 10,000 feet except in cases that qualify under 91.117(d). If the minimum safe airspeed is more than 250 kias, then the aircraft can be operated at the minimum safe airspeed, the FAA explained.
The InFO comes with the introduction of some transport-category airplanes that require speeds in excess of 250 kias below 10,000 feet when operating with a “clean wing” configuration (when external equipment—landing gear, flaps, slats, and spoilers—is retracted to minimize drag). The introduction of these aircraft has caused confusion about how to comply with the speed limit regulations.
Aircraft in that configuration must still comply with the federal regulations unless they have higher minimum safe airspeeds. In those cases, the FAA said, operators should file “H” (heavy) on the flight plan to inform controllers that higher speeds may be necessary on departure. The FAA also provided an example of how such operators should notify air traffic control: “SoCal Departure, Call Sign 136 Heavy, minimum safe (climb) speed is 270 knots.” Controllers will acknowledge this.
However, the FAA warned that speed restrictions must be followed in cases of an obstacle departure procedure or standard instrument departure. “Since these restrictions may be published to meet procedure design criteria, terrain and obstacle clearance, or airspace containment, flight on these procedures at a higher airspeed may not be possible,” the FAA advised. “If an airspeed in excess of the published airspeed is required due to aircraft performance…the pilot should advise ATC and request a different departure procedure or alternative radar vectors for departure.”