The devices are deployed to slow planes after they land on airport runways, but the Federal Aviation Administration (FAA) was concerned about accidental inflight deployment that in the past has had fatal consequences. The Cairo-bound EgyptAir Boeing 767 crashed into the Atlantic Ocean some 30 minutes after leaving New York's John F. Kennedy International Airport on Sunday. On September 15 and October 19 the FAA advised US airlines, in two `notices of proposed rule-making', that they were considering issuing directives requiring inspections of thrust reverser devices and replacements of parts in certain Boeing 747s and 767s.

The first notice said that the FAA was considering requiring US airlines to take steps which would avoid "failure of the thrust reverser deactivation pins."

If these pins failed, therewas a risk of "deployment of the thrust reverser inflight and consequent reduced controllability of the airplane" according to the notice, which has been publicly available since September 15.If the FAA had gone on to issue this directive, US airlines operating Boeing 767s would have been required to replace certain components with "new, improved" versions, the notice said.

The second notice, on October 19, advised airlines that the FAA was planning to issue a directive requiring inspections "to detect damage and wear of the auxiliary track assembly of the thrust reverser, and corrective actions, if necessary."

Damage to the auxiliary track assembly could result in "a slider disengaging ...which could lead to separation of a portion of the thrust reverser from the airplane during flight, possible impact of separated portions on the airplane structure, and consequent possible rapid decompression of the airplane, reduced controllability of the airplane, or reduced structural integrity of the fuselage," theFAA notice said.

The FAA invited airlines to comment on the proposed directives by November 1 and December 3 respectively, and advised those reading the relevant "service information" to obtain it direct from Boeing. A Boeing spokesman already confirmed Monday that the EgyptAir Boeing 767 was built just after a Lauda airplane that crashed in Thailand in 1991. Lauda Air's 767 crashed in 1991, with 233 people on board, shortly after take-off from Bangkok, after one of its two engines accidentally hit reverse as the plane rose to 3,300 meters (10,000 feet).