The European Aviation Safety Agency has approved the Airbus A320 series for Category IIIb precision approaches using microwave landing system guidance, the manufacturer says.
MLS was seen as a successor to instrument landing systems before the emergence of satellite-based navigation, but satellite guidance has yet to fulfil accuracy and integrity requirements for Cat III. MLS or ILS at Cat IIIb standards reduces decision height to less than 50ft (15m), or even zero, with a 50-200m runway visual range requirement.
British Airways is to use MLS on A320s and A321s at London Heathrow airport to reduce disruption to operations in poor visibility. The accuracy of ILS can be severely compromised by multi-path signal reflection as aircraft taxi around the airport, thus restricting aircraft surface movement, whereas MLS is immune to such interference.
Thales is the manufacturer of the BA on-board multi-mode receiver that provides MLS and ILS capability - and the MLS ground stations at each runway.
Source: Flight International
