Investigating Old "Incident"

I

inflightfailure

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inflightfailure
Hello everyone. I'm knew here. I'm trying to fact check a story going back to the late 70's. I'm hoping some of you pilots here can help me determine if this story in question lines up. Here are the details.

Man (not a pilot) claims to be on a short commuter flight in a small twin engine plane in which one of the engines had "exploded" and caught on fire. He describes a steep spiral decent which extinguished the flames. The plane then made a safe emergency landing.

Digging into this, there is no NTSB report on this incident. However, I did come across a snippet from a "Civil Aeronautics Boards Report". The date in question from the report lines up with the story, so I believe that this report is describing the incident in question.

"Incident occurred Nov. 11, 1976 involving Piper PA 31 N74985. Pilot experienced rough engine on scheduled flight fight between Salt Lake City and St. George. 3 Passengers on board. Engine was feathered and precautionary landing made at Delta Utah, per instructions in company manual. Investigation revealed cylinder base studs sheared. As result of occurrence Sky west changed maintenance procedures by checking torque studs at each 100 hour inspection. No damage to aircraft. No injuries to crew or passengers."

So, here are my questions.

1) Does the "story" seam to match the report?
2) What would happen if the cylinder base studs sheared? Would this just cause a loss of power? Rough engine? Oil leak? Could this potentially cause a fire?
3) Is the man telling the story exaggerating some of the details here (i.e. fire/steep spiral dive)

Thank you in advance for your comments and responses.
 
inflightfailure said:
Hello everyone. I'm knew here. I'm trying to fact check a story going back to the late 70's. I'm hoping some of you pilots here can help me determine if this story in question lines up. Here are the details.

Man (not a pilot) claims to be on a short commuter flight in a small twin engine plane in which one of the engines had "exploded" and caught on fire. He describes a steep spiral decent which extinguished the flames. The plane then made a safe emergency landing.

Digging into this, there is no NTSB report on this incident. However, I did come across a snippet from a "Civil Aeronautics Boards Report". The date in question from the report lines up with the story, so I believe that this report is describing the incident in question.

"Incident occurred Nov. 11, 1976 involving Piper PA 31 N74985. Pilot experienced rough engine on scheduled flight fight between Salt Lake City and St. George. 3 Passengers on board. Engine was feathered and precautionary landing made at Delta Utah, per instructions in company manual. Investigation revealed cylinder base studs sheared. As result of occurrence Sky west changed maintenance procedures by checking torque studs at each 100 hour inspection. No damage to aircraft. No injuries to crew or passengers."

So, here are my questions.

1) Does the "story" seam to match the report?
2) What would happen if the cylinder base studs sheared? Would this just cause a loss of power? Rough engine? Oil leak? Could this potentially cause a fire?
3) Is the man telling the story exaggerating some of the details here (i.e. fire/steep spiral dive)

Thank you in advance for your comments and responses.
Click to expand...

A Navajo had something similar happen here not too long ago. The engine lost partial power and was running extremely rough. All of the oil dumped out since the cylinder was coming loose from the crankcase. There is potential for fire if the oil got onto the hot turbocharger on the engine. In the one here it luckily didn't.

The story could be true, if not embellished a little over time.
 
One man’s explosion is another man’s “engine done come from together”.

One man’s fire is another man’s engine smoke.

One man’s steep spiral is another man’s emergency descent procedure.

Sounds plausible to me, especially if one version is an aviation expert’s and another is a bystander, passenger, or other layperson.
 
Thank you everyone for your replies. What is the requirement for when an NTSB report should have been generated? If the engine was on fire, would that necessitate an NTSB report?
 
inflightfailure said:
Thank you everyone for your replies. What is the requirement for when an NTSB report should have been generated? If the engine was on fire, would that necessitate an NTSB report?
Click to expand...
Currently, NTSB 830 requires that the NTSB be notified in the event of an in-flight fire, and I can't see them NOT investigating and reporting it.

Whether that requirement existed in the 1970s, I don't know. But I think it likely.

Ron Wanttaja
 
I made a stop there from ID to So Cal. Nice little pilot lounge.
 
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