Dubai: Preliminary investigation results into the United Parcel Service (UPS) cargo plane crash suggest the pilots may have twice tried but failed to land during the hour prior to the crash.
The ill-fated Boeing 747-400 cargo plane bound for Cologne from Dubai took off at 7pm on Friday and crashed about an hour later in a military camp located between Emirates Road and Al Ain highway.
Sometime during the reported sequence of two "missed approaches" to the airport, the pilot declared an emergency, possibly due to smoke inside the cockpit.
Reports indicated that the pilots might have been forced to try to land at the government-owned facility after struggling with an onboard emergency that could have obscured their view of some instruments.
Neither UPS nor authorities commented on the precise sequence of events.
Hour's gap
After initially saying that the plane crashed on takeoff, a UPS spokeswoman on Saturday confirmed there was an hour's gap between the aircraft's takeoff and the crash. But she declined to elaborate.
The aircraft crashed initially into a parking lot inside the compound; became airborne again briefly; then crashed back down and came to rest, the person familiar with the matter said.
The crash site is approximately one kilometre long.
There were no ground casualties reported, a source said. The aircraft was carrying civilian cargo, the source added.
Some air safety websites on Friday claimed that the crew may have told air traffic controllers that smoke in the cockpit was severe enough to obscure some instruments.
Investigators from the US National Transportation Safety Board were despatched to participate in the probe, along with experts from Boeing and General Electric, which manufactured the aircraft's engines. If Friday's crash turns out to have involved smoke in the cockpit, it could revive a long-running debate over whether manufacturers and regulators are doing enough to protect pilots against such hazards.
Some safety experts believe onboard fire incidents affect at least 1,000 airliners annually around the world, though only a few turn out to be life-threatening
Protection
Nearly all passenger and cargo planes are equipped with emergency oxygen masks, smoke protection goggles and other safety systems intended to help pilots breathe and allow them to continue operating the aircraft in the unlikely event of smoke in the cockpit.
But for years some air-safety advocates along with manufacturers of advanced smoke hoods for pilots have argued that additional protection is necessary.
They said existing smoke protection devices are inadequate in dealing with heavy and continuous smoke in the cockpit.
JetBlue Airways and FedEx previously installed more-elaborate, smoke-hood systems on some aircraft, designed to create a smoke-free view of cockpit instruments even under the worst conditions. Other US and foreign airlines have considered such steps but in the end, decided against installing smoke hoods.
The US Federal Aviation Administration had installed such protective systems on its own fleet of aircraft.
