EVEN FOR a government report, this one that collects complaints from commercial airline pilots and flight attendants has a very bureaucratic title: "ASRS Database Report Set, Passenger Electronic Devices." But look inside and see why you should heed those pretakeoff instructions to turn off your personal electronic devices.Flight navigation disrupted. Instrument readings corrupted. Cockpit radio communications confused. All because some people didn\u2019t turn off their mobile phones.The reports, issued periodically by the NASA Aviation Safety Reporting System, cover safety concerns voluntarily reported by workers?from problem passengers to flight crew fatigue. It\u2019s part of a program started in 1975 to collect field reports to improve aviation safety; more than 300,000 incidents have been filed. NASA publishes selected entries, ensures the anonymity of the filers, and warns readers not to draw conclusions from, say, the 50 complaints included in an October 2003 report about passengers using devices at unauthorized times.Suffice to say, however, that commercial airline pilots and flight attendants won\u2019t hesitate to return a Boeing 737 to the terminal and have police remove a cell phone user. This selection from the NASA report concerning a flight to Grand Rapids, Mich., shows why: "DC-9 flight crew experienced an involuntary turn by the autopilot during cruise. Autopilot reacted normally after the captain asked passengers to turn off any personal electronic devices. Crew later learned that a cell phone in an overhead bin was heard during the time of the autopilot problem."