CABINsafety
Despite a briefing and illustrated safety cards, passengers on an Embraer 195 were unsure of what to do while using an overwing exit. © Daniel Guerra/Airliners.net
BY LINDA WERFELMAN
he U.K. Air Accidents Investigation Man. Five of the 95 people in the air- concerned about the possibility of fire, Branch (AAIB) has recommended plane received minor injuries during declared an emergency and diverted to design reviews and modifica- the evacuation. Ronaldsway. The fumes and smoke in- tions of emergency exits on public About 10 minutes after takeoff on a tensified during the surveillance radar Ttransport aircraft following an emer- scheduled passenger flight from Man- approach, and the captain “considered gency landing in which passengers in chester, England, to Belfast, Northern that he would probably conduct an an Embraer 195 became confused about Ireland, the no. 1 air cycle machine evacuation on landing,” the report said. how to use an overwing exit. (ACM) failed, sending fumes onto the He did not notify the cabin crew or The AAIB issued the safety recom- flight deck. The cabin crew reported air traffic control because “he thought mendations as a result of its investiga- an unusual odor and a haze in parts of that to tell them anything at this late tion of the Aug. 1, 2008, incident that the cabin. stage of the flight might cause confu- prompted the emergency landing at The pilots donned oxygen masks sion should he decide not to order an Ronaldsway Airport on the Isle of and, because the commander was evacuation,” the report said. where’s the Exit?
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After completing the approach and land- At the left overwing exit, passengers became ing on Runway 26, the commander turned the confused about how to move from the wing to airplane into the wind and stopped at a runway the ground. intersection, telling the cabin crew first to “A 61-cm-wide [2-ft-wide] walkway was stand by and, seconds later, to evacuate (Figure demarcated at the wing root in black paint, with 1, p. 48). arrows pointing towards the trailing edge,” the Cabin crewmembers responded by open- report said. “This was not noticed by some pas- ing their assigned doors. Passengers opened sengers; one passenger thought that the mark- the left overwing exit door; the right over- ings denoted an engineers’ walkway rather than wing exit door could not be opened because an escape route. The overriding comment from the forward upper part of the door trim was passengers who evacuated onto the wing was jammed beneath the ceiling edge panel (Fig- that it was not obvious to them that they were ure 2, p. 49). meant to climb off the wing via the trailing edge.” The escape slides inflated automatically, but Two male passengers who used the overwing the slide at Door 1 Left had not fully inflated exit jumped from the rear of the wing to the when the first passenger arrived at that exit, ground — a “considerable drop” of about 1.7 m and, as a result, the senior cabin crewmember (5.6 ft), the report said — helped other passen- (SCCM) initially directed passengers away from gers to the ground. They told investigators that, Passengers did not that exit. After the slide inflated, the SCCM without their help, some passengers might have realize that the arrows “had to push himself past the flow of passengers” been seriously injured trying to climb down off on the wing denoted to cross the aisle to Door 1 Right and open it, the wing. an evacuation route. the report said. A review of each passenger’s seat position Passengers said later that the slides and his or her choice of exit showed that none were “very steep,” and they were “sur- of the passengers used Door 1 Right.1 The prised by the speed at which they slid report speculated that this was probably partly down them,” the report said. “The slides a result of the “staggered layout” of that exit and also ended without any round-out at the Door 1 Left exit, which would have been the the bottom, causing passengers to slide first exit that passengers reached as they moved straight onto the ground at speed. This, forward from their seats. and attempts by passengers to slow them- The report also noted that a cabin crew- selves on the slides, were the principal member was positioned next to Door 1 Left to causes of injury reported.” assist passengers there, while Door 1 Right was The report said that when the cabin unattended. “Passengers would have therefore crew became aware of the problems, they had to find and use [Door 1 Right] at their own “tried to reduce injuries by instructing initiative,” the report said. passengers to sit down as they got onto The cabin crew estimated that all passen- the slide and by controlling the flow of gers were evacuated within one minute. At that
U.K. Air Accidents Investigation Branch Investigation Accidents Air U.K. passengers down the slides.” time, two cabin crewmembers checked that no
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passengers remained in the airplane and evacu- wing” — were on the seatbacks in front of these ated through Door 2 Left. passengers, and each passenger had a safety card that contained a diagram depicting passengers Passenger Briefings “climbing off the trailing edge of the wing onto The investigation found that before departure, the ground,” the report said. cabin crewmembers had briefed the passen- After the incident, the operator modified the gers seated next to the overwing exits on their safety briefing for passengers seated next to the operation. Similar instructions — including overwing exits “to make them aware that the “the depiction of an arrow apparently guiding arrows on the wing indicate direction of evacua- passengers towards the trailing edge of the tion (i.e., aft over trailing edge of the wing),” the report said.
Evacuation Routes Previous Incident The report noted the previous AAIB investi- gation of an April 1, 2002, incident in which passengers in a Fokker F28 experienced similar problems using overwing exits during an emergency evacuation after the cabin filled with Door 1 Right slide Door 1 Left slide smoke while the airplane was taxiing for takeoff from Manchester International Airport.2 The final AAIB report on the 2002 incident said that passengers using the left overwing exit “congregated on the wing looking for a way down” and that some passengers eventu- ally “slid or jumped from the wing tip and leading edge (a drop of some 7 to 8 ft), instead of sliding off the wing trailing edge down the extended flaps.” Left overwing exit Right overwing exit As a result of its investigation of the Fok- ker incident, the AAIB recommended that the U.K. Civil Aviation Authority (CAA) and the European Joint Aviation Authorities (JAA) Unknown whether right or left rear slide used review “the design, contrast and conspicu- ity of wing surface markings associated with Unoccupied seats (One of these seats emergency exits on public transport aircraft was occupied by with the aim of ensuring that the route to a passenger, but it is unknown which be taken from wing to ground is marked seat or which exit the occupant used.) unambiguously.” The report said that the CAA accepted the recommendation, but there was no response from the JAA. Door 2 Left slide Door 2 Right slide As a result of the more recent Embraer inci- dent, the AAIB re-issued the safety recommen- dation, directing it this time to the European
Source: U.K. Air Accidents Investigation Branch Aviation Safety Agency (EASA), which now has responsibility for aircraft certification through- Figure 1 out Europe.
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The AAIB’s subsequent evaluation of dance with the minimum equipment Overwing Emergency Exit the SB’s effectiveness found that a 2-mm list. It had been damaged four days clearance was insufficient to prevent before the incident in another event
Ceiling jamming of the door trim behind the that involved smoke in the cabin. edge panel ceiling edge panel “if the door was lifted Examination of both ACMs during the initial stages of opening or revealed that Stage 2 turbine blade if it was opened energetically, such as failures had occurred in each unit, Door trim might be the case in an actual emergen- causing the turbine blade tips to come cy,” the report said. “It was concluded in contact with the ACM casings; this that [although] the SB reduced the prob- produced fine metallic particles, which ability of a jam, the potential for a jam were released into the cabin air system, had not been eliminated.” “creating the reported symptoms of The report traced the problem to smoke and fumes inside the aircraft,” the EASA’s certification of the Embraer the report said. 195 — “largely on the basis of its simi- The report quoted the airplane larity to the Embraer 190.” manufacturer as saying that this Source: U.K. Air Accidents Investigation Branch However, the report added, “during incident was “the only known case of Figure 2 Embraer 195 development, the ceiling the failure of an ACM Stage 2 turbine edge panel manufacturer introduced during single-pack operation on the “It is apparent from this incident changes to the configuration and Embraer 190/195 fleet.” that the issue of ambiguous overwing dimensions of the cutouts around the In addition, the manufacturer said escape route markings … still exists,” overwing exit aperture, reducing the that modifications and maintenance the AAIB said. “It is therefore appropri- clearance between the ceiling panel and had “significantly improved” the ate that this matter is re-examined.” the door trim. These changes were not reliability of the Embraer 190/195 air notified to the aircraft manufacturer.” conditioning packs. As a result, the Door Jam Current aircraft certification re- AAIB said no further safety recommen- A post-incident examination of the quirements do not discuss the potential dations were needed. right overwing emergency exit door for jamming, “except that there must This article is based on AAIB Serious Incident found insufficient clearance between be provisions ‘to minimize the prob- Report EW/C2008/08/01, included in the AAIB the top edge of the door trim and the ability of jamming of emergency exits Bulletin published in June 2010 and available ceiling edge panel. “Over most of its resulting from fuselage deformation in online at