Description

On 23 August 2013, the Captain of a Boeing 757-200 (G-FCLK) being operated by an unrecorded airline with all passengers on board ready to depart from London Gatwick to Tenerife in normal daylight visibility decided that the discovery of hydraulic fluid leaking onto the brakes and producing smoke necessitated a precautionary rapid disembarkation of the passengers. His announcement to that effect was ineffective in communicating what was required and was interpreted by a significant number of the 220 passengers as an instruction to carry out an emergency evacuation during which 5 of them sustained minor injuries.

Investigation

An Investigation was carried out by the UK AAIB. The FDR did not contain relevant data and was not downloaded and although the CVR was successfully downloaded, the recording did not contain any relevant conversations or the Captain's PA announcement because both had taken place beyond the range of the flight deck area microphone and use of the PA system from the Cabin was not otherwise recorded.

The Investigation noted that the hydraulic fluid leak which had led to the decision to disembark all the passengers without delay had been from a main landing gear actuator which was an on-condition component and was subsequently found to be beyond economic repair due to multiple defects. The primary concern of the Investigation was the confusion amongst passengers as to what action was expected of them by the 'leave the aircraft' PA.

It was found that the aircraft was operating what was supposed to be a direct London Stansted to Tenerife flight which had been delayed when the aircraft which was originally intended to operate the flight became unserviceable before departure. The delay at Stansted was such that it was not possible for the crew available there to operate to Tenerife and back so they were instructed to fly the aircraft and its passengers to Gatwick where another crew would take over whilst the passengers remained on board.

It was the 49 year-old replacement Captain (who had 13,470 total flying hours including 9,250 on type), whose attention was drawn to a hydraulic leak and to smoke coming from the main landing gear which was still warm from the recent arrival at Gatwick whilst carrying out his pre-flight external check. He had then returned to the aircraft forward vestibule and made a PA which he later recalled as being “Ladies and Gentlemen, we need to clear the aircraft immediately; there is smoke on the left hand side”. He stated that when the passengers did not appear to react to this announcement, he had made a further announcement saying “Move, come this way!” The Cabin Crew were aware of the hydraulic leak but were not pre-warned that the Captain was going to make a disembarkation announcement of any sort and the SOP in place did not require this.

Shortly after the Captain had made his PA(s), he reported having been advised by one of the cabin crew by interphone that the door 3R emergency exit had been opened and the slide had deployed. When subsequently interviewed, the two passengers who had been seated together next to door 3R, the emergency exit immediately aft of the right wing, stated that their view forward was restricted by toilet compartments on both sides of the cabin immediately in front of their seat row. Their respective recollections of the PA were that it had not been preceded by any identification of who was making it and had been “smoke on the left side, get out, get out, get out” and “we have smoke on the left hand side, get out”. There was uncertainty about whether the announcement had been made by a member of the crew or not but the passenger nearest the exit advised that he had assessed the situation and contemplated how long it would take to disembark via the normal exit. As he examined the instructions on the emergency exit, he had heard another passenger telling him to “do it, do it”. He had then opened the exit and the slide had deployed. He had assisted some passengers onto the slide before going down it himself.

The member of Cabin Crew nearest to door 3R stated that "when the emergency exit was opened, he was not certain whether an evacuation had been commanded or not, but that on observing cabin crew members (from the off-going crew) helping passengers at the bottom of the slide, he continued to direct passengers to the emergency exit and down the slide, until it became apparent that cabin crew in the forward part of the aircraft were directing passengers to door 1L". The statements of other members of the cabin crew suggested that PA announcements had been made by the Cabin Manager, along the lines of "don’t panic, leave your bags, move to the forward door on the left hand side of the aircraft". It was not clear how many passengers had used door 3R to leave the aircraft with estimates ranging up to 100 but 20-30 being the most mentioned.

It was noted that the Operator had a formal SOP for 'Rapid Disembarkation' which specified use of steps or airbridge as directed and required that a specifically worded PA should first be made by the Flight Crew and that this should then be followed by another specifically worded and more detailed PA made by the Cabin Crew. This SOP was not followed. Whilst the Investigation was in progress, the Operator replaced this SOP with a new one for 'Controlled Disembarkation' which did not prescribe any form of words to be used for the Flight Crew-only announcement. In respect of the latter, it was considered that in the absence of this, flight crew obliged to make such an announcement "might bear this incident in mind" when deciding how to word it.

It was noted that:

• The opening of the exit could have been avoided had a member of cabin crew, aware of the intention to carry out a rapid disembarkation, been positioned at the exit.
• The Operations Manual required cabin crew to be in the vicinity of doors while on the ground and a reminder of this procedure had been issued to crew only ten days before the incident.
• This incident served as a further reminder of the benefits of having cabin crew close to doors while on the ground.
• It would not have taken much time to inform the cabin crew, by interphone, of the planned rapid disembarkation and instruct them to take positions by the exits. Such action would have prevented both an undesirable opening of an emergency exit and ensured that cabin crew were located appropriately so that they could deal with any escalation of the situation which might call for an emergency evacuation using slides to be carried out.
• The Operator advised that it does not plan to alter the modified procedures implemented during the Investigation which "bring airlines within their commercial group into line with each other".

The Final Report of the Investigation was published on 14 August 2014.

Related Articles

• Precautionary Rapid Disembarkation
• Hydraulic Fluid as a Fire Source
• Hydraulic Problems: Guidance for Flight Crews