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Run up saves the day!

jhk770

Active Member
(I own a RV7A with an IO-360 with dual electronic ignition with auto spark plugs)

Here is a quick story that I thought was important to share and to emphasize how important run-ups are even though 99% of the times they are un eventful.

My wife and I flew down to SC to visit friends for the weekend. We had a great flight down and our RV7A performed great. After a few day visit, we departed KAND after a thorough preflight and uneventful Run-up. We decided to stop at Lake Norman (14A) to check out the area and grab some lunch. This time my run up detected a very bad ignition issue. I taxied back, uncowled the engine and searched for the issue checking the connections to the coil and then spark plugs. When I got to the left side of the engine, the lower spark plug wire was just dangling!!! I was shocked. The spark plug "cap" had fallen off which led to the spark plug wire to come off. During annual I always make sure that I tighten these 'Caps", but never in a million years would I expect one to come off. Luckily I had spare plugs in my tool kit and was able to replace the "cap" and be on out way home to NJ without any issues. I'm disappointed in myself because I always try scanning my CHT/EGT's but I never saw any indications of poor ignition to indicate a problem during the flight.

I'm so thankful I was trained well to use check lists and I never cut corners and skip Run-ups!!

My question is, has this happened to anybody else and do you think locktite on the threads would help prevent this from happening or is there another solution.
 
You can get the auto plug that does not have the screw on cap, The Taylor plug wires that came with my EFII set up is so tight on the plug, it does not require the clip on the wire to hold it on, the boot is that snug, maybe time for a different plug and new wires?
 
FYI - The EICommander can detect that type of failure whenever your engine is running, as long as you have P-mags installed.
 
nice catch! I hate those little things.

When I was much younger (teens and 20's- so 20 years ago) I used to race karts. I lost a race once for that exact same reason. That little alu cap unscrewed and that was all she wrote that day (single cylinder 2 stroke engines). From then on we'd red loctite those little things on and do a little crush to them with a pair of good pliers so they could never back off again.

BTW- when a mag driven plug wire from a 2 stroke running 17-18K RPM lands in your seat.... you know it! It is a shocking experience to say the least.
 
Keep an eye on that specific coil pack. It may fail soon. Did the spark plug wire arc on anything?
 
Mag Drops

When I was learning to fly a lovely farmer near Dargaville in NZ warned me the dangers of mag drops with the incident that happened to him.
John flew Fairey Barracuda?s in the Fleet Air Arm and was off on a training flight with a practice torpedo.
He ran the Merlin up but had a mag drop but just on the bottom limit. Being a big round WWII grass airfield the take-off run was always into wind. So off he went into wind but the merlin was not developing full power. At the end of his particular take-off run was the mess hut and it was becoming apparent he might not make it. At this he became a bit serious and described his thought processes and decision making. ?I could have easily dropped the torpedo but that would have gone straight through the mess hut and killed the people in it so I decided to yank it into the air and figuring that if I hit the roof just I and my crew would be killed and not everybody in the mess hut. How I cleared the roof I do not know.? He then started laughing, ?As I slowly climbed away I laughed & laughed till I had tears in my eyes.? I enquired why. ?Well as I was fast approaching the mess hut it was like the Keystone Cops aircrew were diving headlong out of all the windows and it looked so hilarious.?

So when I have a mag drop usually due to dirty plugs I?m reminded of John?s advice and sort it before I head off down the airstrip.

Rob
RV 3 G-BVDC
 
(I own a RV7A with an IO-360 with dual electronic ignition with auto spark plugs)
...
My question is, has this happened to anybody else and do you think locktite on the threads would help prevent this from happening or is there another solution.

I would not recommend you use loctite as it might work as an insulator.

It is best to find an acceptable long reach plug with solid caps.
 
I would not recommend you use loctite as it might work as an insulator.

It is best to find an acceptable long reach plug with solid caps.

Or hopefully crimping the thread just enough that the cap won't come lose.
 
I would not recommend you use loctite as it might work as an insulator.

It is best to find an acceptable long reach plug with solid caps.

Or hopefully crimping the thread just enough that the cap won't come lose.
 
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