It passed Athens International Airport and subsequently entered the holding pattern for the Kea VOR, where it remained. The 737 automatically followed its pre-programmed course, levelling at F元40 and overflying the Kea VOR, southeast of Athens, at 10:21 – 74min after take-off. Investigators state that lack of cabin crew procedures to address the loss of pressurisation, and continuation of the climb despite the deployment of masks, contributed to the accident. But these ended as the 737 climbed through 28,900ft – after which there was no response to radio calls, the crew having succumbed to hypoxia as the aircraft failed to pressurise. Over the following eight minutes, several communications between the captain and the operations centre took place regarding the original problems relayed to the operations centre. But the inquiry report says that the flight crew failed to identify cabin-altitude warnings and did not notice indications that mask deployment had occurred. Passenger oxygen masks deployed in the cabin as the aircraft climbed through 18,200ft. The investigators also list “ineffectiveness of measures” taken by Boeing in response to previous pressurisation incidents on the aircraft type.īut the report also points to a creeping, underlying failure of safety oversight by regulatory authorities.Īs the Helios 737 was climbing through 16,000ft (4,850m) – having been cleared to flight level 340 (34,000ft) – the captain contacted the company’s operations centre to report a take-off configuration warning and a problem with the equipment cooling system.
It cites “inadequate application” of crew resource management principles. But the aircraft failed to pressurise as it climbed to cruise altitude, incapacitating the crew and leading to the 737’s crashing as the engines ran out of fuel.Īside from the immediate contributory factors the final report identifies four latent causes of the accident, including deficiencies in the operator’s organisation, safety culture and quality management.
Helios flight ZU522 departed the Cypriot city of Larnaca for Prague on 14 August last year with 115 passengers and six crew members. The final report into the accident, released today, shows that the crew did not realise that the pressurisation selector was in the ‘manual’ position while carrying out pre-flight procedures or while reading checklists – it says the switch could have been left in the ‘manual’ position, rather than returned to the ‘automatic’ position, during non-scheduled maintenance. Investigators have concluded that an incorrectly-set cabin pressurisation switch, and the failure to recognise warnings of oxygen depletion, led to the fatal loss of a Helios Airways Boeing 737-300 aircraft in Greece last year. Decade of Airline Excellence Awards 2020.Airline Business special: CEOs to watch in 2021.FlightGlobal Guide to Business Aviation Training and Safety 2021.
Helios flight 522 update#