Make sure mags are back to BOTH before takeoff

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RPM was in the green, airspeed was alive, takeoff roll seemed a LITTLE longer than usual but then climbout was sluggish. I start going through the list.... throttle wide open... fuel selector both.... mixture rich.... carb heat offf.... primer in-and-locked... mags ?both? wait? what?

I feel like such an idiot. All I can say is that just because checks are routine and you've done them what feels like a million times doesn't mean you can't somehow screw it up. Reflecting on it, I think I've always looked for the RPM drop carefully, but the RPM RISE after you switch back to both is very important, too.
 
Can't say I've ever done that.

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The green arc for RPM is pretty large in most planes, I'd say you should be looking for full static RPM (there should be a number for that) vs just in the green.

Glad you're ok.
 
I always teach the mag check as back 2, check drop, back to both, back 1, check, back to both. It seems like a less likely way to accidentally leave it on one since you wouldn't aciddentillay leave it on one if you at least move the switch back one.
 
And, I know a guy ;) that didn't figure out he was on one mag for quite a while on a short trip. Was sure something was wrong, didn't catch it on the checklist, the key looked right, but the EGT's were higher than normal. Finally caught it and all was well.
 
James331 said:
The green arc for RPM is pretty large in most planes, I'd say you should be looking for full static RPM (there should be a number for that) vs just in the green.

Glad you're ok.
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+1, I need to see 2300 or I abort. Your POH should have the value.
 
83Golf said:
I always teach the mag check as back 2, check drop, back to both, back 1, check, back to both. It seems like a less likely way to accidentally leave it on one since you wouldn't aciddentillay leave it on one if you at least move the switch back one.
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The problem with that is, if the first mag is dead the engine will backfire as the switch goes through the position. That can blow a hole in the muffler. I like the OP's check for RPM rise back to the starting value after two clicks.

dtuuri
 
dtuuri said:
The problem with that is, if the first mag is dead the engine will backfire as the switch goes through the position. That can blow a hole in the muffler. I like the OP's check for RPM rise back to the starting value after two clicks.

dtuuri
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If the first mag is dead, why keep going with the test, you aren't going anywhere now anyway.
 
I don't let go of the key.

1 click, watch tach; back to Both, RPM back up; 2clicks, watch RPM; back to Both, RPM back up; let go of key, check vacuum. Double check door, passenger seatbelt, look both ways, key the radio and pull onto the runway.

As you can tell, the runup is at the end of my Pre-Takeoff checklist.
 
The way to perform a mag check has been beaten to death. Everyone has their own way. He made a mistake. Oh well. Good to hear it all turned out fine.

Like James said, look for the max static rpm and you'll be all set.
 
There is a first time for everything, don't feel like an idiot..it happens.
 
Thanks for the idea of a specific RPM check on takeoff roll vs. in-the-green. The experience was sufficient to ensure the mag switch will always be in the correct position before future takeoffs.
 
I did this once when taking a flight with my daughter. After takeoff, I noticed limited climb ability. I notified the tower, and he cleared the pattern to let me come back to land on any runway. I taxied back to the tie down and only then realized what I had done.

I debated just shutting down and ending the flight so as to avoid further embarrassment, but since my daughter was with me and was really looking forward to the flight, I told tower that I cleared the issue, and was ready to taxi for departure.

Fortunately, tower never asked what the "issue" was.
 
83Golf said:
If the first mag is dead, why keep going with the test, you aren't going anywhere now anyway.
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The law of intertia. With a mindset to check the furthest mag, they pass through the closest (dead) mag and backfire before they know it. Seen it done. I don't recommend your way because of it.

dtuuri
 
It's ok to make mistakes....just don't make ones that will kill you. That's called learning....its a good thing,,,,,


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Another trick for us carb drivers is to check carb heat after mags. That calls attention to starting RPM being different.

How does it idle on one mag? I don't like to see the idle test go below 600 RPM.
 
83Golf said:
I always teach the mag check as back 2, check drop, back to both, back 1, check, back to both. It seems like a less likely way to accidentally leave it on one since you wouldn't aciddentillay leave it on one if you at least move the switch back one.
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I thought everybody was taught to do it this way...:dunno:
 
83Golf said:
I always teach the mag check as back 2, check drop, back to both, back 1, check, back to both. It seems like a less likely way to accidentally leave it on one since you wouldn't aciddentillay leave it on one if you at least move the switch back one.
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This is how I do it as well.
 
Been there. Done that. CHT's were higher than normal, EGT's were going through the roof, about sheeoot my pants until I figured it out.
 
There's a first time for everything. You won't make the same mistake again. :)
Though you are probably still in for the forgotten carb heat on a go-around ... or full flaps ... or no electric pump ... or door not latched ... you catch my drift. :)

Don't beat yourself up and learn from the mistake. That's what it's for.
And good job on the troubleshooting. That's what matters, that you found it!
 
Hank S said:
I don't let go of the key.
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Great tip!

Cpt_Kirk said:
look for the max static rpm and you'll be all set.
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Not with a constant speed prop.

Before turning onto the runway I do a final flow check, starting on the floor. I touch each item and my hand flows smoothly down, over, up, and left. Takes all of 5 seconds and is a great double check for the things that can kill you.

Flow: Fuel Selector BOTH, Cowl Flaps OPEN, Pax Seat Belt ON, Pax Door LOCKED, Flaps 10, Autopilot OFF, Mixture IN, Prop IN, Carb Heat IN, Trim SET, Lights ON, Magnetos BOTH, Primer IN and LOCKED, Pilot Door LOCKED
 
83Golf said:
I always teach the mag check as back 2, check drop, back to both, back 1, check, back to both. It seems like a less likely way to accidentally leave it on one since you wouldn't aciddentillay leave it on one if you at least move the switch back one.
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I had an old chief pilot demand that I switch to this method for the reason you mentioned. So I switched.

By the next training event I was back to "1-1-2-2 booger booger avenue". So of course he chewed me out. I replied that a) if you check the rise as well as the drop, you won't take off on one, and b) in the month or so that I made a conscious effort to change, I either checked the same mag twice or took off on one mag far more often than I was comfortable with.

Change is often worse than the alternative. ;)
 
OP back.... I flew again and I think I know what happened. I use the 2 clicks left, 2 clicks right, 1 click left, 1 click right pattern. When I noticed the last drop (1 click left) my right hand started reaching for the carb heat because that's the next check. It was a matter of moving to the next check (right hand) before finishing off the last action by turning the switch back to both (left hand.) It was a reminder that I need to slow down and THINK about what I'm doing every time, not just go through the motions.
 
I had a student pull this on me. It was well into his lessons - the point where you start to think they can do the run-up by themselves while you fill out some paperwork. He said we were ready to go, but when we were approaching mid-field and we still weren't of the ground I called an abort takeoff. Taxiing back we found the switch was not on both. Lesson learned: Pay attention!
 
All pilots, except me, have made these simple mistakes.:rolleyes: Just a lesson to learn and go on with your flying, you won't likely repeat this particular mistake! :D But, don't fret you'll find other mistakes to make before long! :D
 
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