Month: November 2018

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I received a voice message the other day from John, a Mooney owner.  He was asking for some discussion on the podcast about using “torque plates” when removing cylinders from airplane engines.  He mentioned that Mike Busch was a proponent of this practice.  John also mentioned the concept of using torque plates had come up in an IA meeting recently.

So at lunch time that day, I did a google search and typed in “torque plates mike busch.”  And I found an article that appeared in the Mar/Apr 2009 issue of the Cirrus Pilot magazine.  It was a very interesting article… the problem was very serious, but thankfully, it turned out well.  The B36TC Bonanza that was featured in the article, had a severe engine problem causing it to come apart soon after takeoff.  TCM’s analytical report said it was an engine failure for unknown reasons.  However, Mike Busch traced it back to improper maintenance during the removal and reinstallation of cylinders 2, 4, and 6 just 9.1 hours prior to the engine failure.  Here’s a link where you can download and read the full article.  It’s well worth your time.

https://www.cirruspilots.org/copa/tech/m/magazine_articles/563618/download.aspx

And here’s another one of Mike’s articles from the June 2014 edition of the Sport Aviation magazine.  This one’s titled “Cylinder Work – Be Afraid.”

https://www.savvyaviation.com/wp…/EAA_2014-06_cylinder-work-be-afraid.pdf

I suppose the procedure of removing and reinstalling a piston engine cylinder on an airplane deserved at least a healthy dose of fear to remind us all of using all the best practices to ensure the safest possible outcome when the task is completed.

John’s message came a really good time for me, since I had just removed cylinder #5 on an A36 Bonanza.  I’m planning to talk about WHY that cylinder was removed, at some point in the future.  It was the most out of the ordinary thing I’ve ever seen during a routine borescope inspection during the annual.  The moral of this story is, “Don’t rely on compression testing only.  A borescope inspection should be done along with every compression test.  Otherwise the results are not complete and not very reliable.  But compression testing and borescoping together, can be a powerful combination for evaluating the health of a cylinder.

This whole idea of using torque plates, or stacks of washers, and torquing the nuts on the through studs when a cylinder is removed, is something that deserves far more attention than it has had in years past.  Let’s all do our part to make people aware of the importance of not allowing the crankshaft bearings to shift during cylinder maintenance.

As an airplane owner, you would do well to talk with your A&P about using torque plates, if you ever need to have one or more cylinders removed from your engine for repair, and then reinstalled.

Have a wonderful week, and by all means, if you have to change a cylinder, use torque plates!

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This week, I inspected a Cessna 172.  From a distance it appeared to be a really nice airplane, and it is.  But at closer examination, as is often the case, there were a number of issues that needed to be addressed.  In today’s episode, we’ll cover those issues and talk about what was discovered.

When I ran the engine on this airplane, I discovered the fuel primer nozzle was very stiff to move.  The following picture is a similar primer nozzle I recently resealed on a Cessna 182.  Notice how brittle one of the o-rings was… it broke in two!  These primer nozzles are easily resealed with two new o-rings (MS 29513-012) and a very light coating of Krytox grease.  After this, they work like new.

Here’s a one minute video of how stiff the primer was in that Cessna 172 when I was preparing to run the engine:

Here’s one of the two items I found on this airplane that were safety wired backwards.  This oil drain plug safety wiring was quite nice-looking, but it was in the wrong direction.  I corrected this after draining the oil.

If you need to learn how to perform safety wiring on your own airplane, check out my video tutorial course, Safety Wire Like A Pro!  This course will teach you everything you need to know about quality aircraft safety wiring.

This Cessna 172 fuel strainer (gascolator) also needed a good cleaning.

And, when Dave, another A&P, removed the fuel strainer, he noticed the fuel would not shut off, so we’ll also need to reseal the fuel selector valve to make sure it will shut off the fuel when it’s in the “OFF” position.

The fuel tank drain valves also need attention, since the left one was leaking, and the right one would not even operate properly (it would not press to drain.)

Listen to the audio of today’s episode to get more details on these issues, and many more.

How about you?  Has your airplane had a thorough inspection recently.  I find there’s a wide range in the quality of inspections that are done on airplanes, depending on the inspector or the shop.  Some are very detailed.  Others are not nearly detailed enough.  Yet another good reason to get your airplane inspected by a different set of eyes every few years!

Until next time, fly safely!