The Sterile Cockpit Rule: What is It and Who Has to Use It?

Pilot and co-pilot checking instruments in cockpit of plane
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The Sterile Cockpit Rule is a federal aviation regulation that was enacted in 1981 after a series of accidents occurred when pilots became distracted during critical phases of flight. What we know to be the "sterile cockpit rule" is described in the excerpt below from the Federal Aviation Regulations, 14 CFR 121.542 - FLIGHT CREWMEMBER DUTIES(Part 121 of the federal aviation regulations has to do with the operating requirements for domestic, flag and supplemental operations).

 

This regulation is the same as the one found in 14 CFR 135.100 - Flight Crewmember Duties (Part 135 of the FARs regulates the operating requirements for commuter and on-demand operations and rules governing persons on board such aircraft.) 

Both Part 121 and Part 135 operators must adhere to the sterile cockpit rule, which limits non-pertinent conversation during "critical phases of flight" - taxi, takeoff, landing, and operations below 10,000 feet mean sea level.

 

14 CFR 121.542 - FLIGHT CREWMEMBER DUTIES 

(a) No certificate holder shall require, nor may any flight crewmember perform, any duties during a critical phase of flight except those duties required for the safe operation of the aircraft. Duties such as company required calls made for such non safety related purposes as ordering galley supplies and confirming passenger connections, announcements made to passengers promoting the air carrier or pointing out sights of interest, and filling out company payroll and related records are not required for the safe operation of the aircraft.

(b) No flight crewmember may engage in, nor may any pilot in command permit, any activity during a critical phase of flight which could distract any flight crewmember from the performance of his or her duties or which could interfere in any way with the proper conduct of those duties. Activities such as eating meals, engaging in nonessential conversations within the cockpit and nonessential communications between the cabin and cockpit crews, and reading publications not related to the proper conduct of the flight are not required for the safe operation of the aircraft.

(c) For the purposes of this section, critical phases of flight includes all ground operations involving taxi, takeoff and landing, and all other flight operations conducted below 10,000 feet, except cruise flight.

NOTE: Taxi is defined as ‘‘movement of an airplane under its own power on the surface of an airport.’’

[Doc. No. 20661, 46 FR 5502, Jan. 19, 1981]

According to one report done by the ASRS, which analyzed a series of accidents in which the pilots did not adhere to the sterile cockpit rule, those non-compliance events lead to incidents and errors such as: 

  • Altitude deviations
  • Course deviations
  • Runway transgressions
  • General distractions with no specific adverse consequences

According to the ASRS report, many of the pilot narratives that were analyzed following these events included statements from pilots admitting that complying with the sterile cockpit rule may have prevented the incident or accident. 

While pilots operating under Part 91 of the FARs (general aviation, for example) aren't required to follow the sterile cockpit rule, it's a pretty common practice. Most pilots observe rule (and should observe the rule) regardless of the type of operation.