JCINTEXAS

The good news is....I've still got my airplane.
This is one time I didn't have to "learn things the hard way".
But something happened this morning which has made me rethink my pre-flight check routine. I've always had an fairly standard procedure for bolting-on the wing, fueling the tank, and starting the engine. But "fairly" isn't good enough. From now on, the procedure is going to me much more than "fairly standard". "Fairly" isn't good enough.

Here's what happened.

I put the wing on, fueled the tank, and performed a routine receiver battery voltage check which I do before every flight. I took-off and had a good flight practicing slow-rolls and
4-points. The second flight also went very well. My "fairly standard" check includes checking the 2 wing bolts, which are metal bolts on my Tower 40 Kaos. (I would usually check the bolts after every two flights.)

That's when it was 'HOLY COW" time.

Only one bolt was holding the wing on!

The other bolt had vibrated out in flight.

WHEW!!!


If I had flown flight number three, the wing would probably have come off in flight.

Lesson Learned:

1. I will perform a detailed pre-flight inspection before EVERY FLIGHT.

(I'm creating a written checklist. I will take it to the field and will follow it completely)



2. No more metal wing bolts. From now on, I will use only nylon bolts...and I will check them before every flight.


I've been flying this plane for more than a year and it's easy to fall into a relaxed attitude

and assume everything is OK. From now on, I'm going to make sure it's OK....every flight.



Regards

JC

dignlivn

Good Catch !


In the Marines, we called it PPPPPP.

Stay ahead of the plane,

Bob

skylark-flier

Bob's absolutely right - GOOD CATCH!!!

I think most all of us are guilty of the "routine checkout" thing most of the time, and about 95% of the time that's fine, but that other 5% is a plane killer. You have definitely beaten the odds on this one. I think it's time for us to take a look at our practices too - might just save us a plane, whether we ever actually come to realize it or not.

Thanks for the wake-up call.

Dave

skyraider71

Pre-flight checks have saved my bacon a few times. I'll be looking at my wing bolts more
closely from now on!

Lomcevak Duck

My Feedback: (14)

Good catch. I haven't been in the habit of checking over my plane before each flight, but I do check it at the beginning of each flying session and after any non-routine landing. I generally only check the RX voltage and fuel the tank between successive flights.

MinnFlyer

My Feedback: (4)

The problem was metal bolts in metal blind nuts. Metal-to-metal contact can easily vibrate loose. For things like engine mounts, wheel collars, etc. you should always use thread locking compound (Like their slogan says: Use Loctite, or your nuts will fall off )

If you switch to using nylon bolts that screw into tapped holes in the wood, you don't need to worry about it anymore. The wood-to-nylon connection won't vibrate loose.

Charlie P.

Nylon have their problems but they do stick in the threads.

I had metal bolts on my Kangke and I found epoxying in 1/2" dia. oak dowel sections and then drilling the bolt holes allowed me to honk down on them tighter without deforming tha balsa trailing edge. Worked great.