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Posted (edited)

Somehow missed this one at the beginning of the year.  This was the first flight by a new owner which also the first flight after the Annual was completed.  1979 M20K, N231GG located at Tullahoma Regional Airport (KTHA), Tullahoma, Tennessee on January 3, 2024.

During climb-out, at about 2,000 ft AGL and about 4 miles from the airport, the engine lost all power.  The pilot turned back to KTHA to glide back to the runway.  He attempted to restart the engine but he could not get the engine to turn over with the starter.  He landed about a half mile short of the runway in rocky terrain.  There are no ADS-B track logs.

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/193598/pdf

The plane was sold at a salvage auction last month.

1979 Mooney M20K, N231GG, S/N 25-0171 - McLarens

Microsoft Word - Salvage Tender - N231GG (amazonaws.com)

k1.jpg.eafad446c94a7688408490d85657cee2.jpg

K2.jpg.22baf2e4a13f6f7c95772694eada35c8.jpg

K3.jpg.276552b0a357f8432ab60fbfc11513c5.jpg

K4.jpg.314d807ff678166b2504628e275d541e.jpg

K5.jpg.417b05c88c10793c403fbf9ff3c8e3ea.jpg

 

Edited by 1980Mooney
Posted

It will be interesting to see why the engine seized if a report ever gets published that says why.

Should we have a practice of circling over the departure airport after annual?   What about if some list of things are done during annual such as if you replace a geared component or a piston/cylinder?       

Do we suspect that the pilot failed to control the aircraft appropriately?  

The underscored phrases in your post seem to indicate that we should be paying special attention to those facts, that they are more likely the underlying cause of the accident and we should make sure we don't make those mistakes.

Posted
3 minutes ago, wombat said:

Should we have a practice of circling over the departure airport after annual?   What about if some list of things are done during annual such as if you replace a geared component or a piston/cylinder?       

If a piston or cylinder is replaced, I'm circling the airport for a minimum of an hour on the post-mx test flight.

  • Like 1
Posted

I did an hour flight at altitude for over an hour to break in my cylinder after annual - A&P said to keep it in the pattern. I like to do that after any maintenance…

-Don

Posted
5 minutes ago, wombat said:

It will be interesting to see why the engine seized if a report ever gets published that says why.

Should we have a practice of circling over the departure airport after annual?   What about if some list of things are done during annual such as if you replace a geared component or a piston/cylinder?       

Do we suspect that the pilot failed to control the aircraft appropriately?  

The underscored phrases in your post seem to indicate that we should be paying special attention to those facts, that they are more likely the underlying cause of the accident and we should make sure we don't make those mistakes.

Another way to look at it is if he had only climbed 2,000 ft and was only 4 statute miles from the runway, then he probably was only in the air 3 minutes.  

What might cause an engine to stop and appear to be seized in 3 minutes?

  • No oil
  • ??

The safe thing after an Annual or major work is to first preflight exhaustively. (it will be interesting to see if there is airport video of that)  Then fly the pattern a couple times.

We don't know the experience of the pilot but the Prelim says it was the first time he had flown that particular plane.  Generally the safe thing would be to fly the pattern and practice landings a few times.

And then - at 2,000 ft AGL an experienced Mooney pilot should be able to glide 11.46:1.  The Prelim says he was 1/2 mile short of the runway so he glided only about 18,500 ft or 9.25:1.  If experienced and at the top of his game he should have made it.

A lot of risks were stacked against the new owner - many that he could have influenced and maybe controlled.

Posted

Im not convinced “staying in the pattern” is best.  After I’ve had cylinders replaced, Ive definitely hung around an airport, but Ive tended to climb to 5-6000’ over the airport and then fly around a bit.  I think adding in traffic and pattern procedures and comm etc as well as being in less than ideal position to glide back to the correct runway (say crosswind to dw turn) might add more issues than it solves.  I live in a relatively less busy area though and climbing that high over an airfield might be a luxury some people don’t have.

  • Like 4
Posted

Circle above TPA, above the Delta or whatever. Im not leaving the lateral confines of the airport with any newley installed components. 
-Matt

  • Like 1
Posted

Agree with this - when I'm circling the airport for a post-mx flight, it's 2500-3000' AGL, ideally at the very top of the Delta if one exists.  Definitely not in the pattern.

Posted
12 hours ago, 1980Mooney said:

Another way to look at it is if he had only climbed 2,000 ft and was only 4 statute miles from the runway, then he probably was only in the air 3 minutes.  

What might cause an engine to stop and appear to be seized in 3 minutes?

  • No oil
  • ??

Running the rough numbers - To attain an altitude of 2000agl by 4sm from the airport, he was likely climbing between 850-1000fpm with a GS between 100-120kts.  That scenario does not seem possible without engine lubrication.  

An engine at idle can survive for quite a while with little to no oil pressure. start up and taxi ops followed by high power take off and climb operations?  I think his performance would have degraded much faster.

  • Like 1
Posted

Staying in the pattern is not a recipe for safety.   For the first ~400' of full power operation you are not going to be able to glide to a runway.  For most of final, unless you are really above the glide slope, you won't be able to glide to the runway if you lose your power source.  Although for that leg you are likely at low power to begin with and powerplant failure is less likely.

 

The last two times I had cylinders replaced (The most invasive engine work I've had done) I didn't actually just circle the airport after I took off, but I did more carefully make sure I could glide to a reasonable landing spot (major highway, low traffic).

  • Like 1

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