The smell of jet fuel is fairly common in the passenger cabin when your plane is preparing to taxi. Far less so is the aroma of dirty socks, rancid cheese, or a wet dog—the typical unpleasant notice that engine oil vapors have seeped in, too.
These smells are usually found in jet engine “bleed air,” which is outside air that’s been shunted from the engines into an air conditioning system and then to the cabin. In various systems—cabin pressurization, water-tank storage pressure, even heating to dissipate wing ice—this air is highly useful to the plane’s operation.
Yet, when engine seals deteriorate, the bleed air can mix with fumes from high-temperature synthetic engine oil. At high-enough concentrations, flight crews and passengers can grow ill, forcing pilots to divert to the closest airport. The latest publicly known incident was Aug. 2, when a Florida-bound JetBlue Airways Corp. flight diverted to Oklahoma City, where several people were treated for breathing difficulties. In October 2016, a British Airways Airbus A380 bound for London from California diverted to Vancouver after all 25 crew members became ill. Cabin fumes were suspected in that case.
Given the potential for catastrophe, these “toxic fume events” have spurred airline labor organizations to lobby for passage of a U.S. Senate measure called the Cabin Air Safety Act. The legislation, from Senator Richard Blumenthal, a Connecticut Democrat, would require the Federal Aviation Administration to devise a standard form for incident reports from pilots, flight attendants, and maintenance technicians. The agency would then publish a quarterly tally, require annual training so flight crews could identify fume events, and make airlines install carbon monoxide sensors fleetwide.
Blumenthal’s proposal was offered in June as an amendment to legislation reauthorizing the FAA, and co-sponsored by two other Democratic senators. A similar measure on fumes is pending in the House, proposed…