Ill-fated Ethiopian aircraft crashed at speed of 926km/hr
Wednesday March 11 2020
On March 10, 2019, at 08:38, Ethiopian Airlines flight 302, Boeing 737-8 Max, took off from Addis Ababa’s Bole International Airport bound for Nairobi’s Jomo Kenyatta International Airport (JKIA).
On board were 157 passengers including its two pilots, Captain Yared Getachew, 29, and First Officer Ahmednur Mohammed Omar, 29.
It also had five cabin crew, one in-flight security officer and 149 regular passengers.
READY FOR TAKE-OFF
At 08:36:12 the airplane lined up on the runway and a minute later, the flight’s first officer, Mr Omar, reported to the control tower that they were ready for take-off.
At 08:37:36, the air traffic control (ATC) issued take off clearance to ET-302. The pilots were then advised to contact radar.
The take-off was normal, with the engines performing at the right speeds.
ERROR IN SENSOR
Shortly after lift-off, the left angle of attack, a sensor that helps to avoid an aerodynamic stall, became erroneous.
The plane’s airspeed and altitude values from the left air data system began deviating from the corresponding right side values. The left and right recorded values began deviating.
At 08:39:30, the radar controller identified ET-302 and instructed it to climb 34,000 feet.
At 8:39:51, the first faulty sensor activated, putting the aircraft on a nose-down for 9 seconds.
The pilot flying it pulled to pitch up the airplane.
At 8:40:22, the second automatic nose-down trim activated, pushing the plane again on a nose diving position. This saw the planes ground proximity warning system sound “Don’t sink” for three seconds and “Pull up” also displayed on its flight display for another three seconds.
At 08:40:43, the third nose-down activated sensor pushing the plane nose downwards. Seven seconds later, Captain Getachew told First Officer Omar, “Advise we would like to maintain one-four-thousand. We have flight control problem.”
Mr Omar complied and the request was approved by air traffic control.
Following the approval of the ATC, the new target altitude of 14,000 feet was set but Captain Getachew was unable to maintain the flight path and requested to return back to Bole Airport.
At 08:43:21, the nose-down trim activated was about 5 seconds. This now saw the plane pitch 40 degrees angle. At this point the plane’s descent rate increased from 100 feet per minute to more than 5,000 feet per minute.
At 08:43:36 the enhanced ground proximity warning system (EGPWS) sounded “Terrain... Terrain... Pull Up... Pull up...”
At 08: 44, the aircraft hit the ground.
All 157 people on board died.
These details are part of a 130-page interim report released by the Ethiopian Aircraft Accident Investigation Bureau on Tuesday on the one-year anniversary of the ill-fated flight’s crash.
For the first time, the report gives an inside look at what could have happened to Flight 302, leading to disaster.
The report shows that the aircraft plummeted to the ground at great speeds of 500 feet per second, with its nose down 40 degrees.
“At the end of the flight, computed airspeed values reached 926 kilometre per hour, pitch values were greater than 40 degrees nose down and descent rate values were greater than 33,000 feet per minute,” the report said.
“The aircraft impacted the terrain creating a crater approximately 10 meters deep, with a hole of about 28 meters width and 40 meters length. The damages to the aircraft are consistent with a high energy impact.”
In their findings, the Ethiopian investigators have singled out faulty systems on a Boeing 737 Max as the leading cause of the crash, concentrating on the technical elements of the flight. They have so far identified no issues with the airline or pilots’ handling of the jet during its six-minute flight.
The investigators have singled out inaccurate sensor readings which activated the MCAS (Manoeuvring Characteristics Augmentation System) anti-stall system that pushed the plane down, a record four times, as the two pilots struggled to steady the jet.
“Shortly after lift-off, the left and right recorded angle of attack (AOA) values deviated. The left AOA value were erroneous and reached 74.5 degrees while the right AOA reached a maximum value of 15.3 degrees. The difference between the left and the right AOA values was 59 degrees and remained as such until near the end of the recording,” the report said.
As part of safety recommendations, the investigators, in the interim report, advise Boeing to have the design of MCAS changed to consider the use of data from both AOA and/or other independent systems for redundancy.
The plane maker has not provided any reaction to the report, instead posting a short statement on its website extending its sympathies to the Ethiopian and Lion Air crash victims.
“We mourn those whose lives were lost on Ethiopian Airlines Flight 302 and Lion Air Flight 610 and offer our deepest sympathies to their families and friends,” Boeing said.
The US Federal Aviation Administration, which has since grounded all 737 Max aircraft across the world, has instead taken a cautious approach to the interim report, noting that it will consult other reports, before making its final decision over the crash.
“We believe it’s important to have the full final report to evaluate it against other independent reports so that we might fully understand all of the factors – both mechanical and human – that played a role in this tragic loss of life,” the US aviation agency said.
So far Boeing has given Ksh10 billion ($100,000) to 346 families of the Ethiopian and Indonesian Lion air that went down in 2018 “to provide assistance to communities and families affected by the crash”.
Out of this, half will go towards the Boeing Financial Assistance Fund which provides around Ksh14.5 million ($145,000) per family.
The Ethiopian crash came with serious ramifications in the aviation sector, which saw the grounding of all Boeing 737 Max aircraft, its bestselling jet.
The plane maker is now working to return the jetliner to service by June this year, even though this still does not seem feasible.
The grounding of the planes has cost Boeing more than $700 billion, having lost more than 87 orders, and another $100 billion in revenues as the fleet of 737 Max remains grounded.