A foam path is the now-discouraged[1] aviation safety practice of spreading a layer of fire suppression foam on an airport runway prior to an emergency landing. Originally, it was thought this would prevent fires, but the practice is no longer recommended.[1]
The U.S. FAA recommended foam paths for emergency landings beginning in 1966, but withdrew that recommendation in 1987, although it did not bar its use. In 2002, a circular recommended against using pre-foaming except in certain circumstances.[1] In particular, the FAA was concerned that pre-foaming would deplete firefighting foam supplies in the event they were needed to respond to a fire.[1] Also, foam on the runway may decrease the effectiveness of the landing airplane's brakes, possibly leading to it overshooting the runway. Starting in the early 2000's, the environmental risk of certain firefighting foams began to be recognized, providing another reason against the practice.[2]
Foam is still used in aviation firefighting, usually in conjunction with Purple-K dry chemical.
Examples
An example of this practice being used in an emergency is LOT Polish Airlines Flight 16. The aircraft experienced a hydraulic failure that prevented the pilots from extending the landing gear, prompting them to perform a belly landing.[3]
This technique was also used during the ditching of Pan Am Flight 6 in 1956 to "mark the […] ditching path and heading."[4]
References
- 1 2 3 4 "CertAlert No. 02-04: Aqueous Film Forming Foam (AFFF) Concentrations, Restrictions, and Other User Guidelines" (RTF), CertAlerts for Part 139 Airport Certification, Airport Safety and Operations Division, Federal Aviation Administration, 2002-07-11, retrieved 2023-12-10
- ↑ "How safe is firefighting foam?". FireRescue1. Retrieved 2022-03-25.
- ↑ "B763, Warsaw Poland, 2011 | SKYbrary Aviation Safety". skybrary.aero. Retrieved 2023-12-10.
- ↑ Accident investigation report: Pan American World Airways, Inc., Boeing 377, N 90943 in the Pacific Ocean, between Honolulu and San Francisco, October 16, 1956 (PDF), Civil Aeronautics Board, 1956-10-16, p. 5, retrieved 2023-12-10
External links
- Foam landing video[usurped] — Piedmont Airlines (now US Airways) 737 lands in a foam path in the 1980s