The crash of a Boeing aircraft near Athens last August that killed all 121 passengers and crew will go down in aviation history as a case study of what can go wrong, according to an interim report to be released by the Investigation Commission for Accidents and Flight Security (EDAAP) in early April. Apparently neither of the two malfunctions that appeared simultaneously during the flight could have caused the aircraft to crash if there had not also been dozens of other omissions related to flight security. Sources have revealed to Kathimerini that the report will attribute a long series of mistakes on the part of all those in Cyprus involved in flight security. The report will attribute blame to both state and airline authorities for the unprecedented lack of any evaluation of the flight security system by the Cypriot Civil Aviation Authority. As for Helios Airways, the findings point to criminal negligence on the ground and in the air, both on the part of company officials and ground staff involved in the particular flight. Mistakes on the ground The Helios aircraft crashed because of errors made on the ground which were then not dealt with in the air. During takeoff, just a few minutes after 9 a.m., instruments almost simultaneously gave two warnings regarding air pressure and cooling systems. Clarifications were sought from technicians on the ground. The warnings (both an alarm and a light) came when the aircraft rose above 10,000 feet. Technicians on the ground in Larnaca had left the cabin air pressure switch in the manual position, instead of switching it over to auto, as they were supposed to do. The aircraft cabin was already losing pressure and, as it turned out, the flight crew had not carried out the appropriate checks before takeoff in accordance with the pre-takeoff checklist. The pressure switch had not been checked and so remained in the manual position; the warning alarm caused confusion since the same alarm also sounds for a quite different malfunction - the position of the flaps and the wheels while on the ground. As the aircraft rose to its cruising altitude of 34,000 feet and the problem remained unsolved, the gradual decompression began to affect passengers and crew; the latter, however, did not realize what was wrong. The air pressure level in the cabin was shown to be the same as it had been at 8,500 feet, when the second malfunction (overheating) in the communication cooling system (found under the pilot's seat) occurred. The German pilot got up to deal with the second malfunction. He may have attempted to reset the system or activate a backup system. Meanwhile, the airplane had become a gas chamber. Passengers and crew would at first have fallen into an altered state and then lost consciousness, while the pilot collapsed in the cockpit. From then on the plane was on automatic pilot. All the passengers would have suffered irreversible brain damage due to lack of oxygen, according to the coroners' report. Even if the heroic cabin steward Andreas Prodromou, who sent out a Mayday message, had been able to land the plane as he apparently was trying to do, the rest of those on board still breathing would have been in a vegetative state. Prodromou stayed conscious by using portable oxygen bottles, perhaps because he had been able to put an oxygen mask on when the plane fell to 14,000 feet. The problems had begun on the ground. During the groundchecks carried out just a few hours before the flight took off, Helios's ground engineers had switched the air pressure valve to manual in order to create artificial compression conditions, but then forgot to switch it back to auto. Then the flight crew on board neglected to check it, either by scanning or by reading out and naming the items on the pre-flight checklist. Nor did they switch it back during the flight, since they probably attributed the warning indication to a breakdown in the warning system or some other cause. The crash showed a failure of the checking systems. The Flight Authority, a branch of the Cypriot Transport Ministry, was compromised and the airline found accountable but protected by a network of entangled interests and silence. The Cypriot Civil Aviation Authority did not carry out the required checks and had not adopted the International Civil Aviation Organization (ICAO) instructions, nor did it take into serious consideration the written recommendations submitted by its two British advisers. Although blatant omissions had been noted, and the Cypriot Civil Aviation Authority should have been under the supervision of the European Aviation Safety Agency and the Joint Aviation Authority, both these bodies failed to act. The airline itself was characterized by a complete absence of air safety culture. Its chief concern was low-cost staff (with a six-month turnover) and hiring pilots on the cheap who were out of work and without many prospects. Boeing weaknesses The accident has revealed the weaknesses in the functioning of the Boeing 737-300, of which about 4,000 are in use around the world. The investigating committee has already made four recommendations to the manufacturer. According the ICAO, security recommendations must be issued before the accident report and sent to the manufacturer, if the head of the investigation believes they are urgent. According to sources, the head of the committee, Akrivos Tsolakis, sent the four recommendations to Boeing via the US Aircraft Accident Investigation Committee. All four concern the cabin air pressure system; hundreds of incidents involving this system have been reported around the world. Two of the recommendations have already been adopted and Boeing has informed all airlines flying B737-300s. One of these recommendations concerns the fact that the same warning sign appears for both the cabin pressure and the flaps - two different functions. The manufacturer is required to separate the two warning systems. The second recommendation adopted concerns an omission in the technical manual used by technicians on the ground with regard to setting the pressure switch to manual. The manual instructs technicians to switch back to the «original position» and not to «auto,» which would be clearer. The EDAAP report will be sent to the Air Accident Investigation Committee in Cyprus, since Helios was based there, and to the US National Transportation Safety Board, since Boeing is based in the US. According to the law, EDAAP must make note of their comments within 60 days so as to reach its final conclusions. After the report is completed, the due process of law may proceed in Athens and Nicosia and the investigation will enter another phase, this time in the civil courts.