Airbus will go into the full-scale evacuation test of the A380 in 11 days' time confident of demonstrating that it can show the safe egress of 750 passengers, but prepared to repeat the exercise a week later if the figure is significantly lower.
The manufacturer has also confirmed that European and US regulators could refuse to accept the raw numerical result if they are unhappy with any aspects of what they observe physically happening during the test.
As announced, the demonstration will take place in Hamburg on Sunday 26 March using 853 volunteer ‘passengers’ drawn from Airbus staff and local gym members, plus a Lufthansa cabin crew. They have to be safely evacuated in 90s.
Airbus says some 16 observers from the US Federal Aviation Administration and the European Aviation Safety Agency will watch the work using a battery of 40 infrared cameras inside and outside the aircraft.
It is planned that they will make their ruling on the initial approved load for type-certification within a few days – possibly even the following day – after which Airbus will decide whether it needs to repeat the test, which requires some 1,100 volunteers each time.
Answering questions at a briefing in Toulouse, A380 safety director Francis Guimera said: “If it is below 650 we will definitely have to do it again. But we are really confident of it being above 750.”
One concern is that a technical fault or injury to a participant could negate the test. Guimera says: “There are two or three things that could be an issue – either we have one slide that does not inflate or deflates during the test, in which case we have to stop for safety reasons. Or if we have an untimely safety event for the evacuees in which case again we have to stop.”
He also explains that, even if a particular number of people are evacuated, that might not be the final certified figure if the regulators are dissatisfied about how the evacuation proceeded.
“What we cannot suffer is that inside the cabin we have some congestion in some doors which fortuitiously for us is solved by the cabin crew but [the regulators] say ‘you are lucky to achieve that figure,” he says.
Apart from that degree of discretion, the details of the test – which is vastly more ambitious than anything previously attempted by an airframer - have been agreed.
Key points are:
- Half the 16 exits will be unavailable. Although Airbus will be told 48hr before the test which doors to disable, the cabin crew will not know.
- The test will take place in the dark with only minimal safety lighting outside.
- The crew and volunteers must be ‘naïve’ – in that they must not have taken part in any similar exercise within the last six months.
- They must comprise of: a minimum 40% females; 35% over 50 years; and 15% female and over 50 years.
- For safety reasons, the upper deck slides in operation will be pre-deployed, the regulators having agreed that this gives no advantage because of the time taken for the doors to open. The occupants enter the aircraft through a tunnel and cannot see which slides are in place.
- Regulators will dump soft obstacles such as baggage into the aisles and elsewhere before the test.
The evacuation concept for the twin-deck aircraft is that each deck is considered separate, but the regulations apply to the aircraft as a whole. For the initial test, there will be 538 passengers and 11 cabin crew on the main deck, and 315 passengers with seven cabin crew on the upper deck – plus two pilots.
One unknown is whether passengers will attempt to use the staircase between the two to pass from one to the other.
Another aspect being studied for the first time is the interaction between the evacuees from the two decks once they reach the ground.
“One issue is what happens to the people on the ground and how they mix. It is the first time [the regulators] look at that. It is not a concern for us but it is one particular thing to be taken into consideration. We may have some people who will totally refuse to obey the cabin attendants,” says Guimera.
Airbus has run computer simulations of the exercise in co-operation with Cranfield University in the UK, but Guimera says: “When you simulate something, the reality is totally different.”
KIERAN DALY / TOULOUSE
Source: Flight International