March 25: British Airways (BA) became the first commercial airline to introduce the onboard Microwave Landing System (MLS), which increases the safe landing rate during periods of low visibility at Heathrow by more than 20%.
On average, there are ten foggy days each year at Heathrow, resulting in air traffic control having to reduce the number of aircraft landings, leading to delays, diversions and cancellations. Periods of intense rain can also lead to restrictions on the normal landing rate.
This new system has been installed on 29 of the airline’s Airbus A320s and A321s with the remaining 12 to be completed by the end of 2009.
In foggy conditions pilots normally use Instrument Landing Systems (ILS) to guide the aircraft on to the runway. However ILS is susceptible to interference from other aircraft crossing in front of the runway transmitters, so air traffic control has to increase the space between the landing aircraft to protect the ILS signals. MLS equipped aircraft can make their landing approaches without the need for additional air traffic spacing.
The Airbus A320 family of aircraft are the first commercial aircraft to be certificated by the European Aviation Safety Agency (EASA) to operate the new system, which has been developed for British Airways by aerospace group Thales.