Aeronautical engineers and pilots have said contaminated fuel was not responsible for the crash of Dana Air flight J9 0992 that killed all153 person passengers on board on June 3, 2012.
The pilot of the aircraft reported the failure of the two engines before it crashed into Iju area of Lagos where it crushed three houses and killed 10 people on ground.
Following the crash, there were media reports that the preliminary report from aviation experts from the United States, who are working with the Accident Investigation Bureau (AIB) had suggested that impure fuel could have caused the two engines and the throttles of the crashed plane to fail midair.
However, a pilot who is also an engineer told THISDAY last Sunday that although contaminated fuel could damage and eventually kill the engine of an aircraft but for the fuel to wreck such damage it must have been so contaminated that it could not be dispensed with a browser- the machine that feeds fuel to the aircraft.
And the pilot will receive enough signs from the aircraft and gauges to know at the time of taking off that the fuel in the aircraft was highly contaminated.
"There is equipment in modern aircraft that signify to the pilot when an engine begins to receive contaminated fuel and these signs will appear in the numerous gauges in the aircraft," the pilot said.
According to him, fuel filters would begin to clog and fail to transmit fuel to the engine and the pilot would receive fuel filter warning and if this situation continues a fuel bypass in the aircraft will pass the filters and begin to feed the engine directly.
"And the pilot will get the sign from the gauges that fuel filters are clogging. When it clogs too much because it has residues, a fuel bypass will open and deliver fuel directly to the engine. It will give lasting signs to the pilot. Then the fuel pressure gauge will give its own signs when the fuel fails to flow to the engine the way it should and the gauge will begin to drop."
He said that a pilot would relate the sign from the pressure gauge to that of the filter gauge and another significant sign is that the engine output would begin to drop.
"There is no way a pilot can fly without noticing all these and it takes time for these things to happen. There will be fuel filter warning; fuel pump warning and engine output warning. These are sequences of warning, which the pilot would begin to notice at take-off and should land the plane at the nearest airport. As a pilot you are trained to understand each of these signs and each of the two engines will experience these changes differently."
Besides, THISDAY learnt that such contaminated fuel that could kill two engines of an aircraft could not be served by modern browser, used by oil marketers to feed aircraft because it has its in-built filtration system.
"If bad fuel caused this it means the fuel is so contaminated that it can be felt and you cannot get such fuel certified. The Jet A1 must be a mixture of diesel and conveyed in drums because any of the modern browsers or refuelling equipment cannot move it to the aircraft with the modern filtration as it is today," another pilot told THISDAY.
Last December, the Nigeria Civil Aviation Authority (NCAA) dismissed the allegation that some fuel marketers sell DPK (kerosene) as Jet A1 (aviation fuel), noting that it had in place stringent measures, which fuel marketers comply with to supply the product.
The Director -General of NCAA, Dr Harold Demuren, had said: "I want to put your mind at rest that aviation is safe and secured. But let me say this; I can assure the public that there is no danger in all our flight operations and we will keep it that way. We have stringent measures put in place before aviation fuel can get into the aircraft; and we don't start from the airport. It starts from the refineries because it is a procedural thing. Nobody can import any fuel here without the Directorate of Petroleum Resources (DPR). There are lots of certifications and processes."