Sterile flight deck rule
In aviation, the sterile flight deck rule or sterile cockpit rule is a procedural requirement that during critical phases of flight, only activities required for the safe operation of the aircraft may be carried out by the flight crew, and all non-essential activities in the cockpit are forbidden. In the United States, the Federal Aviation Administration imposed the rule in 1981, after reviewing a series of accidents that were caused by flight crews who were distracted from their flying duties by engaging in non-essential conversations and activities during critical parts of the flight.
One such accident was Eastern Air Lines Flight 212, which crashed just short of the runway at Charlotte/Douglas International Airport in 1974 while conducting an instrument approach in dense fog. The National Transportation Safety Board concluded that a probable cause of the accident was lack of altitude awareness due to distraction from idle chatter among the flight crew during the approach phase of the flight. Another was the January 13, 1982 crash of Air Florida Flight 90. The NTSB determined that the probable cause of the crash included the flight crew's failure to enforce a sterile cockpit during the final preflight checklist procedure.
Historical background
In the early days of aviation, pilots had little chance to contemplate non-essential activities. Flying demanded constant attention, and the wind and engine noise in a slipstream-blasted open cockpit all but drowned out normal conversations. In the early years of instrument flying, the effort involved in "flying the beam" also forced pilots to concentrate on flying duties during instrument meteorological conditions.As aviation technology developed through the postwar period, increased comfort and sound reduction gradually created a more office-like environment in the cockpit, which is more conducive to distractions. Multi-person flight and cabin crews, autopilots, in-flight meals, newspaper service and other comforts further increased the availability and convenience of non–flight-related activities for crews during flight time. The introduction of the Cockpit Voice Recorder as an objective onboard observer played an important role in the assessment of the problem during accident investigation by the NTSB, and eventual implementation of the rules by the FAA.
Operating requirements
United States
According to the US Federal Aviation Regulations, the rule is legally applicable only to Part 121 and Part 135, and not to Part 91. It is specified in U.S. FAR 121.542/135.100, "Flight Crewmember Duties":Flight attendant and pilot communication
Research has shown that flight attendants, who must also observe the sterile flight deck rule, may be reluctant to call the flight deck while the rule is in effect, even during emergencies. For example:The FAA also noted that:
Japan Airlines took this a step further, describing in a flight attendant training manual several situations that would warrant flight-attendant-to-pilot communication during take-off and landing. Such situations included:
- Any outbreak of fire;
- The presence of smoke in the cabin;
- Any abnormality in the attitude of the aircraft during take-off and landing;
- The existence of any abnormal noise or vibration; and
- The observance of any fuel or other leakages.