Preventing Maintenance Accidents?

[201er]

In this recent ASI video, the narrator brings up an interesting and sobering point, do you know if proper maintenance and inspections were performed by the mechanic at annual? For the more mechanically capable Mooney owners, can you provide incite to beginners and less mechanically knowledgeable pilots of crucial Mooney systems to recheck after maintenance and/or discuss with the IA?

 

Where can Mooney pilots learn more about required maintenance and what can they do?

 

 

[elimansour]

This is pretty scary stuff - also just saw the other post about the fuel leak caused by an undertorqued fitting...really sobering.

[MB65E]

Thanks Mike!

Where is that inlet screen on that engine? Im not familiar with the 520 which I think that’s what that 206 had. 

-Matt

[kortopates]

I think its unrealistic suggest the Pilot owner can double check the work done or especially the work not done after an annual inspection. Its much more sensible IMO for the pilot/owner to take a more active role during maintenance. After all, owners already have a huge advantage to do so, they're responsible for the maintenance of their aircraft per 91.403, 405, 407 and 409.

Its rental pilots that really have to have a lot of blind faith that the owner and maintenance personnel are doing all that's required.

But for owners to best understand what's going on with the aircraft maintenance of their aircraft I don't think there is any better way that participating and learning through owner assisted annuals. Take part and learn what's going on and be sure the Mooney 100 hrs inspection checklist is being used as a minimum along with the current Service manual section on inspections and servicing, supplemented by Mooney Service instructions/bulletins.

If you're still want to take a greater role, enroll in your local community college's A&P program. If you're fortunate enough to have access too. That's exactly how I got into aircraft maintenance. But I can tell you from my own personal experience that getting the required training to fix an airplane is far more rigorous than any pilot license, which is all we need to break them. But for me, A&P school was a lot of fun, (at night after my daily day job).

But you don't have to become an A&P to actively participate in your aircraft maintenance. You can also take advantage of SavvyAviation's contracted maintenance oversight to provide second opinions and get good unbiased advice. 

[N201MKTurbo]

I always thoroughly inspect the plane after anybody else works on it. 

I once found a fuel line that wasn’t even finger tight.

you can never be too careful.       

[RLCarter]

13 minutes ago, N201MKTurbo said:

I always thoroughly inspect the plane after anybody else works on it.       

Depending on the work performed, I might check it several times before and after flights regardless of who performed the work including myself.

[Stephen]

Well, perhaps one could take a systems approach to this and, as a pilot, deep-dive inspect, say the "fuel system" as a critical system. Maybe something like this for a deep review. (this is not a comprehensive list, just ideating here):

Great call @mike_elliott,   retuning the list:

0. Check Pilot as the most important critical system. IMSAFE (Illness, Meds, Stress, Alcohol, Fatigue, Emotion) , WX, how willing am I to do due diligence with MX, WX, Currency (IFR, Medical, BFR) , Competency (rusty?, should I plan ahead to take a few solo hops / circuits before I take the trip with PAX), learning my aircraft systems, reviewing emergency checklists etc? Can I plan ahead, make a calendar of regularized practice as a reminder to keep proficient? AMISAFE?

1. Purchase the MX and parts manuals for your aircraft, get a good flashlight and inspection mirror..also some inspectors paint (https://www.aircraftspruce.com/catalog/cspages/crosschecktorqueseal.php?gclid=Cj0KCQjwgezoBRDNARIsAGzEfe62MiGRRFz-WqqKs6eek8PWajrSiW5tqj29XafWmhUjUKFGUbtnlE4aAkC7EALw_wcB )

2. Remove side and top cowling on the engine

3. Review manuals on all elements of the fuel system from tank to injector with an eye to understanding the complete fuel schematic and the purpose of every component in it.

4. Locate all referenced the fuel hoses, lines, junctions on your aircraft follow the fuel lines  (review manuals for access panel removal). Inspect all junctions and clamps etc for tightness, clamp security, safety wiring, check for chafing, fuel stains/odor etc.

5. Once a fitting has been verified for security/torque, mark it with torque seal, ideally in a way that allows potential for visual inspection during a preflight.

6. Review your engine logs, when was the last time your fuel system screens were serviced? Fuel control / injection system rebuild? Injectors cleaned? Verify with your mechanic.

7. Have your (assumed Mooney literate) A&P show you how/where he checks filter/strainer conditions and review replacement schedule.

8. Remove your side walls covers in your interior and inspect the inboard fuel sending units. Check for leads/odor. 

9. Review any outstanding questions, concerns with your mechanic and learn your airframe. 

10. When MX is to be performed discuss what areas of the aircraft will be worked on , observe if you can, and put a second set of eyes on the work area to validate critical systems...even on systems that were not (theoretically) part of the work. (Found a nice snap-on ratchet that way....).

11. Make a MX calendar for your plane and check time/tach state. Put your next upcoming tach/time based MX items in a place you will notice. Put time based items in your email calendar as a reminder.  

All the above as supplemental to your annual inspections and other MX activity and inspections... just creating knowledge here and a second "thin blue line" to catch those finger tight fuel fittings and other unhelpful surprises so we don't find them in flight. 

This type of thing could be done for other critical and support systems.  Flight Controls. Electric. Landing Gear. Propeller. Engine Cooling etc, but special attention on anything that would make the propeller stop turning in flight. 

 

Edited July 3, 2019 by Stephen

[mike_elliott]

As critical as quality maintenance is to our aircraft, the #1 cause of accidents is the quality of the pilot. Dont ignore this critical system. It has ways of failing caused by ego, external pressures, systemic issues, and bad attitudes. Keep this system tuned up for maximum, proper performance. Dont just be current, be competent

 

[steingar]

Yeah, the ship is more likely to come to grief because of me than my mechanic.  The problem is it just isn't reasonable for your's truly to do assisted annuals, and even if it were I doubt I'm as careful as the guy I have doing it.  Nor is it reasonable to decowl the ship before every flight.  Takes a good half hour to get the aluminum off the front end, longer to get it back on.  All I can really do is check the stuff I can check and trust my guy.

Obviously all you guys are made of time and can spend lots of it wrenching on your aircraft.  We aren't all as fortunate.

[kortopates]

Maybe to ground this discussion with a bit of reality from the latest incident data, over the last 10 days of Mooney incidents and accidents the FAA is reporting 5 gear-ups/gear collapses. Of the 5,  3 were reported as gear up landings with 2 as gear collapses. Basic gear maintenance or malfunctions lead the pack of issues leading to Mooney incidents by far, and pilot error is the bigger contributor over maintenance.

[ilovecornfields]

Hmm...the CFIs are saying that we’re the problem, not the mechanics! And they even have the data to prove it.

It’s interesting to me how dysfunctionally we assess risk and end up spending our time and money on interventions that focus on the wrong thing. My sister-in-law won’t allow plastic toys from China in her house, but she’s ok on delaying vaccinations. One of those is clearly harmful...

I’ve invested a lot of time and money into finding mechanics that I trust and arm comfortable with. Even then, I have found mistakes. Not surprising because, like me, they’re only human.

 Based on the suggestions posted, it seems that the best way of minimizing your risk is to find a mechanic you trust, double-check the work to the best of your abilities, and spend as much time as possible becoming proficient in your airplane. For example, I don’t need a commercial rating but I’m getting one because I think it will make me a better pilot. Maybe instead of spending hours in the hangar with the cowling off, your time would be better spent with the cowling on and an instructor in the right seat?

[bonal]

And all this time I thought you were only half human 

[Yetti]

There is probably another thread for preventing pilot induced accidents.

Here is how I approach it.

Work practice:

Let's say you are putting an inspection port back on.  ( have only left one loose so far on four annuals)

Hand start the screws.  Define a start point and use the same point for each.   Go around and snug, Go back around final value them.   Go back around and check.   Tap panel listen/look for loose things

What is hard is "replaced starter with new starter"   To replace the starter you have to remove and replace many other items including but not limited to the bottom cowl, the Alternator, the landing light  Plus sheet metal work.  The alternator connections.   So you get a why is my alternator not working when they replaced the starter?

Best thing you can do is be the final inspector for the entire engine compartment.   What you are checking for is loose connections, blue fuel stains, things that don't connect on each end.   many things can be found just standing and looking with a flashlight.   make sure everything connects at both ends.

 

Return to service flight:

Just write your check and take off to the flight to the Bahamas with the family right.   Nope.

Depending on the work done.

Start with fast taxis down the runway.   One or two.    Then you can come back and decowl and do another inspection.

Then take it up over the top of the airport.  I usally go up 5000 or 7000 feet.

Then come back down and do another inspection of the engine compartment.

Then I put the plane in quarantine status for  a couple of local flights just solo.  

Now you are ready for the family and trip to Bahamas.

 

 

 

 

 

[bonal]

Other than adding air to the tires or a quart of oil as needed I bring Snoopy into my shop but typically do most of the work myself or along side with my mech. I have been turning wrenches longer than I can remember and find most tasks our planes require to be pretty basic and having done several annuals have learned many of the tricks specific to our brand. It has been mentioned that distractions take place in busy shop environments so one of my primary functions during owner assist annuals is to keep a respectful eye on things and if my mechanic is called away from something unfinished I will make certain he completes whatever was being done before moving on to the next task. There have been things that had to wait for whatever reason and when this happens I put a big strip of bright yellow tape on the unfinished part and use a highlighter on the inspection sheet for that item. Pulling these old airplanes apart and putting them back together again year after year creates its own form of wear and tear.

[Guest]

An interesting video.  The finger screen in question on the TSIO/ IO-520 series engine is in the mixture body.  Not really native to Factory built Mooneys, however the TSIO 520 from a C-340 as transplanted to a Rocket may have one.  

The first picture shows it, a 7/8” brass nut with a brass screen attached.  New gasket every time.

The second picture is the finger screen in Bendix fuel injection servos typical in Lycoming IO series engines.  New O rings every time.

The third picture shows the screen location in the servo.

The fourth picture is the finger screen in Marvel Schebler carburetors.  It’s attached to the 3/4” stainless steel nut.  New copper crush gasket every time.

Clarence

 

[hmasing]

How was I to know that the cotter pin locking in a castle nut was missing on my mixture cable - and even moreso, to know to look for it when you can't see it even with the cowling off?

Serious question.  I have to trust that my A&P/IA know what they're doing, and they have to trust that I'll work with them to ensure a safe aircraft to the best of our combined ability.

[Yetti]

15 hours ago, hmasing said:

How was I to know that the cotter pin locking in a castle nut was missing on my mixture cable - and even moreso, to know to look for it when you can't see it even with the cowling off?

Serious question.  I have to trust that my A&P/IA know what they're doing, and they have to trust that I'll work with them to ensure a safe aircraft to the best of our combined ability.

Mirrors and cell phones will help you out.   How do I know mine are there?   cause I put them there.  One of them I put there twice since I had to adjust cable travel.

[irishpilot]

Other than adding air to the tires or a quart of oil as needed I bring Snoopy into my shop but typically do most of the work myself or along side with my mech. I have been turning wrenches longer than I can remember and find most tasks our planes require to be pretty basic and having done several annuals have learned many of the tricks specific to our brand. It has been mentioned that distractions take place in busy shop environments so one of my primary functions during owner assist annuals is to keep a respectful eye on things and if my mechanic is called away from something unfinished I will make certain he completes whatever was being done before moving on to the next task. There have been things that had to wait for whatever reason and when this happens I put a big strip of bright yellow tape on the unfinished part and use a highlighter on the inspection sheet for that item. Pulling these old airplanes apart and putting them back together again year after year creates its own form of wear and tear.

Getting involved in your aircraft's mx is the best way to learn about your systems and how the aircraft works. Additionally, no one cares more about your plane than you do. Quality A&Ps are worth their rates. Even if you have minimal mechanical skills you can still remove panels and help hold flashlights.

Additionally, study the active AD and SDs for your model. Finally, don't defer maintenance...like bad news, open mx items don't get better with time.

Fly Safe,
Safety Forum Mod