Foam path
Encyclopedia
A foam path is the 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 now discouraged.
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. 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. Also, foam on the runway may decrease the effectiveness of the landing airplane's brake
s, possibly leading to it overshooting the runway.
Foam is still used in aviation firefighting, usually in conjunction with Purple-K
dry chemical.
Airport
An airport is a location where aircraft such as fixed-wing aircraft, helicopters, and blimps take off and land. Aircraft may be stored or maintained at an airport...
runway
Runway
According to ICAO a runway is a "defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft." Runways may be a man-made surface or a natural surface .- Orientation and dimensions :Runways are named by a number between 01 and 36, which is generally one tenth...
prior to an emergency landing
Emergency landing
An emergency landing is a landing made by an aircraft in response to a crisis which either interferes with the operation of the aircraft or involves sudden medical emergencies necessitating diversion to the nearest airport.-Types of emergency landings:...
. Originally, it was thought this would prevent fires, but the practice is now discouraged.
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. 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. Also, foam on the runway may decrease the effectiveness of the landing airplane's brake
Brake
A brake is a mechanical device which inhibits motion. Its opposite component is a clutch. The rest of this article is dedicated to various types of vehicular brakes....
s, possibly leading to it overshooting the runway.
Foam is still used in aviation firefighting, usually in conjunction with Purple-K
Purple-K
Purple-K is a dry-chemical fire suppression agent used in some dry powder fire extinguishers. It is the most effective dry chemical in fighting class B fires, and can be used against some energized electrical equipment fires...
dry chemical.
External links
- Runway foaming requirements - BoeingBoeingThe Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...
recommendations to airplane operators (PDF) - CertAlert No. 02-04 - FAA circular from 2002 recommending against runway foaming (rtf)
- Foam landing video - Piedmont AirlinesPiedmont Airlines (1948-1989)Piedmont Airlines was a major airline in the United States which operated from 1948 until its operations were merged into USAir in 1989. Its headquarters were located at One Piedmont Plaza in Winston-Salem, North Carolina, a building which is now part of Wake Forest University.As of April 1989,...
(now US AirwaysUS AirwaysUS Airways, Inc. is a major airline based in the U.S. city of Tempe, Arizona. The airline is an operating unit of US Airways Group and is the sixth largest airline by traffic and eighth largest by market value in the country....
) 737Boeing 737The Boeing 737 is a short- to medium-range, twin-engine narrow-body jet airliner. Originally developed as a shorter, lower-cost twin-engine airliner derived from Boeing's 707 and 727, the 737 has developed into a family of nine passenger models with a capacity of 85 to 215 passengers...
lands in a foam path in the 1980s