Bonanza N618MW, a Beechcraft like the one pictured below, was doing "touch & goes" at Jack Northrop field in Hawthorne.  "Touch and goes" are practice landings where the pilot does not stop on the runway.  Instead, after the wheels touch down, the pilot advances the throttle, takes off again, and then circles around for another landing.  Everything appeared to be fine until, on one of

the "goes", the Bonanza’s engine quit.  The Bonanza crashed into a parking lot.  The three people on board were killed. 

Why did the engine quit?

Fuel?  Most engine failures are the result of either fuel exhaustion (no avgas in any of the aircraft’s tanks), fuel starvation (pilot fails to switch to a full tank when the one he is using runs dry), or fuel contamination (water or jet fuel has found its way into the avgas).  So in any case involving engine failure, fuel has to be considered.

Beech G36 Bonanza - Photo by Jersey AviationWhen, as here, there is no post-crash fire, fuel exhaustion is a prime suspect. No fire often means that there was no avgas (aviation gasoline) on board to burn. But it’s unlikely this accident was caused by fuel exhaustion.  Though it didn’t ignite, there was plenty of avgas spilled on the parking lot where the aircraft crashed. That means there was fuel on board.

Did the pilot fail to switch to a full tank when the one he was using ran dry? That, too, is unlikely.  Witnesses reported that the aircraft was streaming smoke.  An airplane doesn’t stream smoke when it runs out of gas.  So both fuel exhaustion and fuel starvation can probably be ruled out as a cause of the engine failure..

Could the engine have quit because of fuel contamination?  If the avgas was contaminated with either water or jet fuel, the engine would have failed on the first takeoff. It would not have been able to perform multiple takeoffs before quitting. Nor would the engine have smoked. We can likely rule out fuel contamination.

Mechanical Failure.  Once fuel issues are ruled out, mechanical failure appears as the next most likely cause of the engine’s quitting. Aircraft engines are not supposed to fail without warning. When they do, it is often because of something the engine manufacturer did or failed to do. For example, the manufacturer may have designed the engine improperly or carelessly assembled it. Some of the legal theories that the victims’ families can assert to hold the manufacturer responsible are discussed here and here.

The engine installed in N618MW was a model IO-550.  It was manufactured by Teledyne Continental Motors.  Engine manufacturers such as Teledyne often try to avoid liability for causing an accident by asserting the protection of the General Aviation Revitalization Act, or GARA, discussed here.  However, the engine installed in N618MW was manufactured in 2005.  GARA does not apply to engines that are less than 18 years old, such as this one, and so the families will be legally permitted to hold Teledyne responsible for any defects in the engine.

The NTSB Investigation.  The NTSB is investigating the cause of tIO-550 Teardownhe crash.  The NTSB will ask Teledyne Continental Motors to participate in the investigation, and to help it determine the cause of the accident.  As part of the investigation, the NTSB, along with representatives of Teledyne, will disassemble the engine and test its various parts. (Pictured right is an IO-550 engine being disassembled after a crash in 2001.) Of course, since Teledyne itself might be responsible for the crash, it’s participation in the investigation presents a conflict of interest.   It is like the police asking the suspect for help in solving the crime. To make matters worse, the NTSB will not allow the victims’ families or the families’ lawyers to participate in the investigation at all. The conflict of interest is discussed further here.

The conflict of interest makes for biased NTSB reports that tend to favor the manufacturers.  In one recent case, a Teledyne model IO-550 engine — just like the one in this case — was installed in a Beechcraft Bonanza that had departed Van Nuys, Californa.  The engine quit and the plane crashed. The NTSB asked Teledyne Continental Motors to participate in its investigation and help it determine why the engine failed.  Not surprising, after hearing only Teledyne’s side of the story, the NTSB determined that the engine failed because of poor maintenance, and not anything that Teledyne did.  In fact, the NTSB cleared Teledyne completely of any blame.  We investigated ourselves and later brought the matter to trial. After hearing all the evidence in the case — not just the evidence favorable to Teledyne — the jury disagreed with the NTSB.   The jury determined that the engine quit because Teledyne’s IO-550 maintenance manuals were wrong, and awarded the injured passenger $15 million

What to do? Teledyne Continental Motors and its lawyers are already "investigating" the crash.  The families should consider retaining competent aviation lawyers immediately.  The families’ lawyer can begin their own investigation and make sure that important evidence is preserved.  Unfortunately, the families cannot rely on the NTSB to find answers. They need to find their own.