Lycoming AD

[Jaybird180]

This is the AD report:
http://rgl.faa.gov/Regulatory_and_G...0cdfa782862578df004e3f4c/$FILE/2011-15-10.pdf
Check your maintenance records for this fuel servo

And this is the accident that prompted the AD, 1 fatality:
http://dms.ntsb.gov/aviation/AccidentReports/lhisvw55ox1akhruqowcsk551/O08052011120000.pdf

As I read the report, it appears that the pilots actions were reasonable and prudent, however Friday morning quarterbacking suggests that attempting to reach the closest field was the wrong choice. Not sure I read this right. What does the forum think about my assessment? The flightaware data is does not agree with the NTSB report: http://flightaware.com/live/flight/N220ST

Also, during my general study of NTSB reports, I've noticed a high number of engine failures soon after an overhaul. I'd suspect that 200 hours is enough to be able to trust the parts and workmanship of the OH. Comments please?

 

[Fearless Tower]

As I read the report, it appears that the pilots actions were reasonable and prudent, however Friday morning quarterbacking suggests that attempting to reach the closest field was the wrong choice. Not sure I read this right. What does the forum think about my assessment? The flightaware data is does not agree with the NTSB report: http://flightaware.com/live/flight/N220ST

What else would you if you lost an engine in cruise flight?

Unless there was obvious hostile terrain in between me and the nearest airport, I would have done the same, at least initially. Lose power, pitch for best glide, do some initial troubleshooting (boost pump on/switch tanks...etc) and as I am doing that I am talking to ATC and turning toward the nearest field. Once I do that, I am continuing to re-evaluate progress and options. If it becomes apparent that I am not going to make the airport, I will be looking for a good spot to put down on the way. In a PA32RT, I am probably looking for something really close since it doesn't glide too well, but I still wouldn't necessarily fault him for turning toward the nearest in the first place.

Be careful about judging emergencies based on Flightaware tracks. Alot of times the tracking can be sporadic and often in emergencies, we have seen the track end early (I think someone recently speculated that if you change your squawk to 7700, Flightaware will stop tracking you.

Also, during my general study of NTSB reports, I've noticed a high number of engine failures soon after an overhaul. I'd suspect that 200 hours is enough to be able to trust the parts and workmanship of the OH. Comments please?

I don't know what the exact numbers are, but one thing that happens often in overhauls is that folks re-use many old serviceable parts from the previous engine installation when they install the new or overhauled one out of economical reasons. So not all the parts are as thoroughly inspected at overhaul.

Another factor is that you are indeed taking a chance any time you take apart a functioning engine. As far as a time when it is 'safe' to trust it....that can often depend on the quality of the shop that did the work. I've known of engines failing at just about any point in their useful life. Bottom line, though, I would be extra alert and cautious flying any airplane that had come out of significant maintenance.

 

[Jaybird180]

I don't know what the exact numbers are, but one thing that happens often in overhauls is that folks re-use many old serviceable parts from the previous engine installation when they install the new or overhauled one out of economical reasons. So not all the parts are as thoroughly inspected at overhaul.

Another factor is that you are indeed taking a chance any time you take apart a functioning engine. As far as a time when it is 'safe' to trust it....that can often depend on the quality of the shop that did the work. I've known of engines failing at just about any point in their useful life. Bottom line, though, I would be extra alert and cautious flying any airplane that had come out of significant maintenance.

I've noticed a lot of double-digit times SMOH in NTSB reports. Do you know if there exists stats from (engine manufactuturers maybe) on Mean Time Between Failures after OH?

 

[Henning]

This is the AD report:
http://rgl.faa.gov/Regulatory_and_G...0cdfa782862578df004e3f4c/$FILE/2011-15-10.pdf
Check your maintenance records for this fuel servo

And this is the accident that prompted the AD, 1 fatality:
http://dms.ntsb.gov/aviation/AccidentReports/lhisvw55ox1akhruqowcsk551/O08052011120000.pdf

As I read the report, it appears that the pilots actions were reasonable and prudent, however Friday morning quarterbacking suggests that attempting to reach the closest field was the wrong choice. Not sure I read this right. What does the forum think about my assessment? The flightaware data is does not agree with the NTSB report: http://flightaware.com/live/flight/N220ST

Also, during my general study of NTSB reports, I've noticed a high number of engine failures soon after an overhaul. I'd suspect that 200 hours is enough to be able to trust the parts and workmanship of the OH. Comments please?

Flightaware data is not considered to be accurate, if it disagrees with the NTSB, the Flightaware data would be suspect as incorrect.

Engines themselves will come apart in much less than that, it's the accessories that are typically the issue once you get outside 50 hrs.

 

[poadeleted20]

I think it worth noting that this only applies to fuel-injected Lycoming engines -- you folks with carburetors can ignore it.

 

[Fearless Tower]

I've noticed a lot of double-digit times SMOH in NTSB reports. Do you know if there exists stats from (engine manufactuturers maybe) on Mean Time Between Failures after OH?

I haven't seen any, but the big factor is that there are alot of overhaul shops with a big fluctuation in quality which can skew the numbers. I would think that Lyc has some data on the factory overhauls, but alot of folks go to inpdependent shops because they are cheaper.

 

[poadeleted20]

As I read the report, it appears that the pilots actions were reasonable and prudent, however Friday morning quarterbacking suggests that attempting to reach the closest field was the wrong choice.

At 0215 local over "heavily wooded terrain," what other choice would you have?

 

[Jaybird180]

At 0215 local over "heavily wooded terrain," what other choice would you have?

That's where the wreckage was located. I do not have the data to even approximate his flight (glide) path.

 

[Fearless Tower]

That's where the wreckage was located. I do not have the data to even approximate his flight (glide) path.

Until Ron posted it, I didn't even notice the time of the accident.

In a situation like that, you really need to point the plane somewhere, and unless the nearest airport is ridiculously out of reach, I'd still point in that direction at least until I could identify a better option.

Not sure how far away he was when the engine gave out. The report says he ended up 1.6 miles from the airport. He couldn't have been too far away when he lost the engine (IIRC glide ratio for a PA32RT is something around 1nm per 1000 feet).