B732, London Gatwick UK, 1993
B732, London Gatwick UK, 1993
On 20 October 1993, a Boeing 737-200 being operated by Air Malta on a scheduled passenger flight from Malta to London Gatwick landed at destination on the taxiway parallel to the runway for which landing clearance had been given in good visibility at night after a Surveillance Radar Approach (SRA) terminating at 2 miles from touchdown had been conducted in VMC. There was no damage to the aircraft or injury to the occupants and the aircraft taxied to the allocated gate after the landing.
On 20 October 1993, a Boeing 737-200 being operated by Air Malta on a scheduled passenger flight from Malta to London Gatwick landed at destination on the taxiway parallel to the runway for which landing clearance had been given in good visibility at night after a Surveillance Radar Approach (SRA) terminating at 2 miles from touchdown had been conducted in Visual Meteorological Conditions (VMC). There was no damage to the aircraft or injury to the occupants and the aircraft taxied to the allocated gate after the landing.
An Investigation was carried out by the UK AAIB. It was established that the First Officer was PF for the approach to destination and that whilst both flight crew had operated to Gatwick at night before on a number of occasions, they had not landed on Runway 26R/08L before. It was noted that as the two parallel runways at Gatwick are only 200 metres apart, they cannot be used simultaneously and that Runway 26R/08L, which usually functions as one of two parallel taxiways to the north of the main runway 26L/08R and is only used as a runway to facilitate maintenance occupation of the main runway in quiet periods, usually at night.
It was found that they had been aware before their departure from Malta through sight of Notice To Airmen information that a runway change at their intended destination was planned to take effect about 15 minutes before their expected arrival time. However, when they approached Gatwick they were early and, as a consequence, were initially told to expect runway 26L. When this was later changed to a surveillance radar approach to Runway 26R, the flight crew did not re-brief themselves on the approach or runway lighting which would prevail.
It was established that at about 4 miles from touchdown, the flight crew had:
“discussed and resolved their doubts concerning the identification of the runway so that thereafter they were both convinced that they were landing on the correct one”.
The Investigation noted that a very similar incident had occurred at Gatwick five years previously when as BAC One Eleven had landed on Taxiway 2 in the belief that it was Runway 08L. Some of the Safety Recommendations made after that event had not been implemented by the UK CAA on the grounds that they were “not necessary” and as a consequence, the un-implemented content was repeated in the recommendations made as a result of the latest investigation since the non implementation was considered to have (again) played a direct role in a very similar occurrence.
Causal Factors as follows were identified by the Investigation (reproduced verbatim):
- Runway 26R was clearly visible throughout the approach but the pilots looked for and selected a pattern of lights to the right of it because they assumed erroneously that 26R was in fact 26L and they knew that the designated runway had to be to the right of this.
- The flight crew had not briefed themselves on the lighting they were expecting to see on Runway 26R once the change of runway had been confirmed.
- The crew’s misinterpretation of the visual cues was facilitated by:
(a) The similarity between the night time view of Runways 26L and 26R with associated taxiways to the right which are marked with green centerline lighting.
(b) The use of Runway 26R sometimes as a runway with edge lighting and sometimes as a taxiway with centreline lighting.
(c) The green centreline lights of Taxiway 2 were set at a brilliance of 30% until the aircraft was about 2 miles from touchdown when they were reset to 10%. Whilst the lights were at the brighter intensity, the chance of mistaking Taxiway 2 for the runway was considerably increased and the mistake was possible at an earlier stage in the approach.
The Final Report of the Investigation was published on 12 May 1994 and may be seen in full at SKYbrary bookshelf: AAIB UK Aircraft Accident Report 3/94
Three Safety Recommendations were made as a result of the Investigation, one whilst it was in progress and two more at publication of the Final Report from where all are reproduced verbatim below:
- (The CAA ensure that) the lighting of runways and taxiways at London Gatwick Airport should be re-examined with particular reference to the elimination of any possible confusion for pilots identifying Runway 26R/08L and Taxiway 2A. Recommended modifications include
(a)Rendering the green centreline lighting of Taxiway 2 invisible to pilots on approach to Runway 26R/08L.
(b) The removal of the white strobe lights sited either side of Runway 26L/08R, which were originally installed to assist in the identification of this runway when 26R/08L was commissioned, leaving the strobe lights at the thresholds of 26R/08L in order to facilitate its positive identification. (93-66 made on 19 November 1993)
- The CAA should revise the content of the Gatwick Automatic Terminal Information Service (ATIS) broadcast in the light of the guidelines contained in ICAO Document 9426 (ATS Planning Document). Any advice concerning runway lighting and other identifying features when Runway 26R/08L is in use should be at the beginning of the broadcast rather than the end. (93-67)
- A further review of the lighting at Gatwick Airport should consider in particular:
(a) The modification of the green centreline lighting of Taxiway 2 to make it uni-directional and switchable for the direction in use.
(b) The development of systematic procedures to manage the choice of lighting selection.
(c) Shielding, where possible, of all extraneous lighting so as to cause minimum confusion to approaching aircraft. (94-6)