A USA-BASED Boeing expert testified yesterday that the cabin pressurisation control valve was probably set on manual during the Helios plane crash in August 2005 which killed 121 passengers and crew.
The control valve should be set on automatic on flights and it is the pilots’ responsibility for ensuring this is the case during a routine pre-flight check.
According to the state prosecution for the Helios trial which continued yesterday, that responsibility would also extend to the airline which would be at fault for hiring incompetent pilots.
According to the accident investigation report released in 2006, the outflow valve on flight ZU522 was in the manual position before takeoff, which did not allow the cabin to pressurise.
The lack of oxygen caused the pilots to pass out, but before they did, they had apparently failed to correctly troubleshoot a horn warning of cabin altitude.
James Murphy, technical analyst for Boeing testified via video-link yesterday amid objections by defence lawyer Polys Polyviou that the testimony was being controlled by Boeing.
Polyviou took issue over the strict standards set by American authorities on the nature of the questions which could be asked and also that the testimony took place in the presence of Boeing’s lawyers.
The court decided by a majority vote that the defence’s appeal was “vague” and proceeded with the trial after an hour’s delay.
Murphy explained in technical terms the reasons which led him to form the opinion that the pressurisation valve was set on manual.
The defence then proceeded to cross-examine the witness on the warning sound which should exist on the specific type of plane, Boeing 737, in regards to decompression and anomalies during take off.
Murphy responded that he was aware of the safety feature from reading an article but had not seen any instructions issued by the Federal Aviation Administration regarding the defence’s claims.
The defendants in the trial are Helios’ former chief pilot Ianko Stoimenov; Andreas Drakos, chairman of the board of Helios; Demetris Pantazis, chief executive officer; Giorgos Kikidis, operations manager for the airline; and Helios Airways as a legal entity.
They face charges of manslaughter and causing the death of 119 people through a reckless act.
All five defendants are on trial for “employing, and continuing to employ, unfit and inadequate pilots”.
They have all pleaded not guilty.
Cross-examination resumes today.
