Long solo XC and my first "incident"

flyguy

Well-Known Member
Long solo XC and my first \"incident\"

For those of you that don't know, I am working on my private and am almost done. I had my long solo XC today. I flew from OAK to OVE. It was a lot of fun and I think I can say it was the most satisfying time I've had flying yet. I also had my first "incident". As I was taking off from OVE on my way back to OAK, the engine ran very rough and I had to abort the takeoff. I taxied back and did a mag check. Sure enough when I checked the left one, the engine just about jumped right out of the cowling. I burned off the deposit checked the mags again and both of them were running smoother than they had all day. I then decided it was safe to try the takeoff again, and I was able to fly back to OAK without any further incident. Although it was pretty scary at the time, as I look back on it, its satisfying that I was able to recognize the problem and safely abort the takeoff, and then was able to identify and remody the problem. Its the first time I'd ever had to make a real "PIC" decision, and I'm pleased with how I handled it.

One thing that puzzles me though, is that I did a mag check before I attempted the first takeoff and didn't notice any roughness. There was a period of only about 2 or 3 minutes between the time I checked the mags and began the takeoff. Do deposits really develop that quickly?
 
Re: Long solo XC and my first \"incident\"

Good job on aborting the takeoff. I wonder if I would have had the presence of mind to do that as a student pilot. One thing I would reccomend is for you to give each mag a longer time to run on it's own during the runup check. Most people only wait about 5 seconds or so and turn the ignition back to both as soon as the RPM drop stabilizes. I've been trying to get in the habit of giving each mag at least 20 seconds to make sure they're both really stable.
 
Re: Long solo XC and my first \"incident\"

Sounds like you did the right thing. It won't be the last time you burn or try to burn the carbon off the plugs.

A couple of things that can foul the plugs in short order. At higher elevation airports or high density altitude days, failing to lean the mixture for taxi can do it, especially if you sit at idle for a long time in that condition. (Long runups, waiting to take off behind 10 other planes etc.) Sometimes flooding the engine can do it too. Running too rich in flight. Well used spark plugs, etc. etc. Plus who knows what the guy who flew the plane before did with the mixture. It seems like some engines are more prone to this than others.
 
Re: Long solo XC and my first \"incident\"

Aaaahhhhhh.....this is making sense. OVE's elevation is only 192 and the density altitude was actualy below field elevation, but now that you mention it... I did have to sit at the hold short lines for a couple minutes waiting for a couple guys to land, and I did my pre-takeoff check (mixture rich) as soon as I got there, so that's probably what did it. Good to know for future reference, thanks.
 
Re: Long solo XC and my first \"incident\"

i like to lean the mixture back out after runup regardless of how long i anticipate waiting, Just remember to push it back in!
wink.gif
 
Re: Long solo XC and my first \"incident\"

Yeah, I lean it before taxiing after the runup also, but what I did yesterday was I did my pre-takeoff check while wiating for the other guys to land, and ended up sitting there idling full-rich for a couple minutes. From now on I'll try to remember to wait until I actually take the runway.
 
Re: Long solo XC and my first \"incident\"

[ QUOTE ]
I've been trying to get in the habit of giving each mag at least 20 seconds to make sure they're both really stable

[/ QUOTE ]
Just realize that the other mag is cooling down while you're doing that and it could be damaged when you go back to both
 
Re: Long solo XC and my first \"incident\"

Oh yeah? maybe I'll go back to the normal way then.
 
Re: Long solo XC and my first \"incident\"

I suggest that before taking off, you hold the brakes as you add full power. Relax, look at all of the engine instruments, listen to the engine. Everything in the green? Everything sound normal? OK, release the brakes and go. If something doesn't sound or look right, you haven't started your roll, and it is a heckuva lot easier to abort.

Of course, holding the brakes is standard for short fields or maximum perf takeoffs, but it also gives you a moment to assess things before you are "on the run!"
 
Re: Long solo XC and my first \"incident\"

[ QUOTE ]
the engine just about jumped right out of the cowling.

[/ QUOTE ]

That's not a fun feeling to have. I flew from the LA basin out to Needles, CA last year and during the runup the right mags produced a whopping 800 rpm and a violent bucking. I'm religious about leaning during taxi on hot days, so I was confused, especially when my attempts to burn it off failed. I taxied back to the FBO, where (luckily) an A&P was on duty. He called the problem perfectly before popping the cowling: someone hadn't attached the wires from the right mag to the spark plugs properly, and they had just become completely disconnected. Problem solved in two minutes, and the FBO I rented from gave me an hour of flight time free for my trouble.

-Zach
 
Re: Long solo XC and my first \"incident\"

Love those 'character building' experiences, huh? Lucky you were still on the ground. Kudos on your PIC decision making experience.

Sometimes it's not just the mags that causes such a scenario. My first flight with my license I had a valve stick in the #4 cyclinder. Seemed like a bad mag. Went from 2400 rpm down to 1500 in a heartbeat. The dash shook pretty violently too. Luckily, I made it back to an airport- barely (NAS Miramar).
 
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