The Mitsubishi MU-2 has been involved in 11 accidents in the last 18 months, killing 12 people. Two of those accidents happened in Colorado. Yet, as 7NEWS Investigator John Ferrugia has found, the MU-2 continues to fly with no restrictions and no required special training for pilots.
Neither aviation experts that 7NEWS talked to, nor Mitsubishi, could cite another airplane where more than 10 percent of the entire fleet has been involved in fatal accidents and the plane remains in service.
Federal records show a pattern of MU-2 crashes where pilots report engine problems and a loss of control before going down. That is exactly what happened to Paul Krysiak and Tuck Presba last December as they left Centennial Airport.
And now, Presba's parents want to know why.
His parents tell 7NEWS that Presba was a good pilot and had a good reputation and had always wanted to start his own charter service. Tuck Presba wanted to make sure he had all the prerequisite knowledge, training and skills to be the very best pilot he could be, his father said. That meant he needed to compile many hours of twin-engine flight time. So he began flying the MU-2 cargo planes for Flightline, Inc.
The MU-2, manufactured by Mitsubishi and first imported into the Unites States in the mid-1960s, is now primarily used in Colorado to haul checks and other time-sensitive cargo overnight to destinations around the country.
Presba was satisfying requirements that would allow him to eventually captain an MU-2 on his own.
"He only needed around 200 hours more, which he could have accomplished in just a few short weeks. So they allowed him to fly with them in a right seat or co-pilot capacity," said Jim Presba, Tuck's father. "He flew five nights a week and it was round trip."
Tuck Presba was flying with an experienced MU-2 pilot, Krysiak, last December when Krysiak reported an engine problem on takeoff from Centennial Airport.
Radio traffic indicates the two struggled with the plane trying to get it back to the runway. They never made it. Presba and Krysiak died when the plane crashed and burned.
"You're heartsick. You want to know what there is to know about the circumstances involving the death of your child," said Jim Presba.
For the Presbas, it was an odyssey that began with a simple Google search. What they found after months of inquiry stunned them.
"There are certain times and circumstances in which you can get this aircraft, where it's like trying to fly a brick. It will crash," said Jim Presba.
The Presbas' research led them to Dr. Don Kennedy, a former University of Colorado professor and Ph.D. in aeronautical engineering. Kennedy has studied a number of MU-2 crashes and has testified in several court cases involving the plane.
Kennedy said the MU-2 is different than any other twin-engine aircraft of its type because it uses spoilers rather than ailerons.
"The only airplanes I know of that use spoilers for roll control alone are some military aircraft," said Kennedy.
"With ailerons, you have one aileron goes down and one goes up and what that does is redistribute the lift on the wing," Kennedy said. "The downgoing aileron increases the lift, the upgoing decreases the lift but the overall lift of the airplane is unchanged."
That means, with ailerons, the aircraft turns smoothly, holding its altitude. But it's different with spoilers, he said.
"(The spoiler) just kills the lift on one side -- period. It does not increase the lift on the other side," Kennedy said. "(The airplane with ailerons) is constant, this one (the MU-2) loses lift and as it loses lift, the airplane sinks," Kennedy said.
That means, an engine problem at low speed, fully loaded, will likely doom the plane, as in Presba's crash, Kennedy said. Kennedy said on one engine, the MU-2 has to be traveling almost 150 knots to stay airborne.
"But the problem is, if you lose an engine on takeoff, you cannot get to 150 knots without descending. And if you do it at takeoff, there's no place to descend ... So you're going to crash," Kennedy said.
"It's a dangerous airplane. Aerodynamically, it's a very unusual airplane," Kennedy said.
Kennedy and other aviation experts claim that the fact it is dangerous is evident in these statistics:
According to both Mitsubishi and government records, more than 10 percent of all MU-2s ever built have been involved in fatal crashes.
Federal accident records show many crashes occurred after an engine problem at low altitude -- on take off or landing.
Mitsubishi sent 7NEWS a report showing that the MU-2 safety record was no worse than other twin-engine turboprops. But that's not what 7NEWS' investigation found.
Robert Breiling, a leading expert in aviation accident statistics, compiles information directly from manufacturers, including Mitsubishi, not from the estimates used by the Federal Aviation Administration.
In a five-year period between 2000 to 2004, Breiling found the average fatal accident rate for the MU-2 in North America was more than triple the average of other turboprop models in its class.
And Breiling found the overall accident rate of MU-2 about 78 percent higher.
These numbers don't include the three MU-2 accidents so far this year that have killed six people, including one in Arkansas just two weeks ago.
"I think if Tuck had known. he wouldn't have had been in this airplane. He's so extremely safety conscious, that we just have no doubt he wouldn't have put himself in that situation," said Tuck's father, Jim Presba.
Officials from Mitsubishi declined an on-camera interview but they say the MU-2 is a safe airplane. They claim the major cause of crashes is poorly trained pilots, so Mitsubishi is offering special training classes for pilots and owners at no cost. And as a 1991 letter shows, for the past 14 years Mitsubishi has pressured the FAA for more mandatory flight training for the MU-2, called a type rating.
The FAA rejected the proposal.
But Jim and Linda Presba, and other families who have lost loved ones in crashes, say more training isn't going to solve the problem because when they look at the government's MU-2 crash reports, they see a dangerous airplane.
"Engine failure on takeoff. Crashed on approach to destination airport. Crashed on approach to destination airport. Dual engine failure. Flame-out on approach to destination airport. Engine failure on take-off. There's a consistency there that's disturbing," said Linda Presba, reading from several crash reports.
"It's abysmal safety record is there for anyone to see. We just don't know why it's been ignored and overlooked by all the federal agencies that are supposed to protect us," said Jim Presba.
For the past three weeks, 7NEWS has been pressing the FAA for an on-camera interview to talk about the MU-2. The FAA has refused. But late Monday, it released a statement saying it is now conducting an in-depth safety evaluation of the aircraft.
The statement also warns pilots to be aware that the MU-2 flies like no other similar airplane and to put "special emphasis on operations should an engine fail."
On Wednesday night. find out why NTSB investigations determine nearly all MU-2 crashes are "pilot error." Are investigators too close to the airplane's manufacturer? And Thursday, 7NEWS will have an exclusive interview with the Colorado company that lost two MU-2s in crashes. They, like Mitsubishi, insist it is a good and safe aircraft.
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