On September 25, 1978, a Pacific Southwest Airlines Boeing 727 was on a visual approach to San Diego's Lindbergh Field, when it collided with a Cessna 172. The cockpit voice recorder recovered from the wreckage of PSA Flight 182 revealed that there had been substantial nonessential conversation on the flight deck among the three crewmembers and a deadheading PSA captain during critical moments preceding the accident. Although there were a number of factors responsible for this loss of 144 lives (including seven on the ground), the National Transportation Safety Board concluded that distractions caused by extraneous cockpit conversation probably were a contributing factor.
From this tragedy was born what is known in the airline industry as the "sterile cockpit rule." Federal Aviation Regulations Part 121.542, which applies to air carrier operations, makes it illegal for flight crewmembers to engage in nonessential conversation during critical phases of flight (which include taxi, takeoff, landing, and all other flight operations conducted below 10,000 feet, except cruise flight).
This regulation initially met with resistance, but most airline pilots now concede that the sterile cockpit does contribute to safety. Consequently, there are many who believe that a quiet cockpit during certain terminal operations could also benefit general aviation. No, they are not suggesting that the FAA create another regulation. (Lacking a cockpit voice recorder, there would be no way to detect noncompliance.) Rather, it is suggested that general aviation pilots voluntarily apply a similar concept during high- workload operations.
Some years ago, for example, a pilot was executing a VOR/DME approach to a northern California airport at night in a non-radar environment. The reported weather included a 500-foot overcast and a visibility of 2 miles. The airplane impacted a hill that was a mile to the left of the final approach course.
An analysis of the communications recorded by ATC revealed the sound of passengers laughing and joking in the background as the pilot of the Piper Cherokee Six reported passing the final approach fix. Was this accident caused by a cockpit contaminated with noise pollution? We will never know.
Nor can we know or even guess at the number of general aviation accidents that might have been the result of pilots' being distracted by extraneous and nonessential cockpit conversation. But it is reasonable to conclude that there have been some — and perhaps many.
For example, pilots are taught that distraction is a primary cause of accidents resulting from an inadvertent stall/spin. This is why FAA designated examiners are encouraged to be creative about distracting applicants while they maneuver at minimum controllable airspeed during flight tests. Many of these examiners have discovered that intrusive conversation is all that is necessary to distract the pilot and precipitate an inadvertent event.
Might not similar distractions cause pilots to miss important transmissions from air traffic control? How many gear-up accidents can be attributed to similar distractions?
A pilot can prevent being distracted by passengers during critical phases of flight simply by briefing them before departure. All he has to do is to say something like, "Look, Joe [or Jane], I'm going to be busy talking with air traffic controllers during the first few minutes of flight, and it is important that I don't miss any of their calls. So I'd appreciate it if you would contain your enthusiasm until after we've cleared the local area (unless you notice something about which I need to know)."
Such a briefing should be conducted tactfully so as not to alarm a nervous passenger. Consider keeping him occupied with "traffic-watch." Make him feel important by asking him to silently point out nearby aircraft. The idea is to keep the passenger busy so that he does not interrupt departure and arrival duties.
The sterile cockpit is particularly desirable during instrument and tower-controlled departures, low visibility, special-VFR and night departures, and all similar arrivals. It obviously is not as important when departing an uncontrolled airport on a severely clear day.
The idea is to take command of and control the cockpit environment during all critical phases of flight. Some pilots go so far as to advise their right-seat passengers that the intercom will be turned off until the departure workload has been reduced. After all, it is important for a pilot to monitor and digest all communications, not just those directed at him. Conversations to and from other aircraft help a pilot to remain aware of other traffic and better understand the conditions in which he is operating.
Consider, too, that the majority of accidents occur during the "11 critical minutes of flight." These consist of the 3 minutes that begin with initial power application and the 8 minutes ending with the landing roll.
One pilot I know claims with a grin that he takes advantage of the sterile-cockpit concept as an excuse to silence a loquacious mate — for the entire flight.
Related Articles
