no mag drop in the runup...

bluelake

Well-Known Member
SO, I am embarking on a night IFR lesson with my student in a C-172R, and in the runup we notice no mag drop when we check the left mag. We also notice two other things: airplane runs with ignition OFF, and also that there is a previous squawk on this.

Me: I dont wanna fly. If I lost a mag that I KNEW I could not ground, this could not be a good thing.

My FBO boss: it should not have been a no-go decision.

Any opinions?
 

MikeD

Administrator
Staff member
[ QUOTE ]
I wouldn't go if I had a mag that wasn't grounding.

[/ QUOTE ]

1. Aircraft not operating normally.

2. Specific anomaly a safety hazard.

3. Mission requirements do not override aircraft anomalies in this case.

4. Mission a no-go.

5. CFI final responsibility for mission safety.

Case closed.
 

EatSleepFly

Well-Known Member
I had the same thing happen a few months ago. I taxied in and took the plane down for maint.

Boss was peeved! It was a beautiful Sunday morning, and the mechanics couldn't touch it till Mon. afternoon. I told him tough sh*t, I'm not knowingly taking a plane into the air that clearly isn't right on the ground. Nothing says its just the P-lead...could be the switch or some other wiring. That was my argument.

I say you made the right call.
 

JEP

Malko In Charge
Staff member
I ditto everything else said here. If the FBO boss says it should not have been a no-go decision, tell him to get his CFI and then he can take the plane.
 

bluelake

Well-Known Member
[ QUOTE ]
Nothing says its just the P-lead...could be the switch or some other wiring. That was my argument.


[/ QUOTE ]

Yup, they checked the p-lead and it was hooked up, so there is something else going on. If the mechanics couldnt figure it out in the few minutes they looked at it, then why should I be expected to fly it.

If I can provide some more context, at the exact same time we were doing our run-up and discovering this, my boss was calling me on his weak Unicom telling us to turn off our taxi light (it was dusk enough for the runway lights to be on).

On a Cessna C-172R, is it possible to burn out the taxi light if you don tturn it off for run-up?? I never heard of such a thing


Business owners... they're almost surreal!
 

Jeff_S_KDTW

New Member
[ QUOTE ]
On a Cessna C-172R, is it possible to burn out the taxi light if you don tturn it off for run-up?? I never heard of such a thing


Business owners... they're almost surreal!

[/ QUOTE ]I did my private and instrument in 172R's (5 of them) and have never heard nor experienced a problem doing a runup with a taxi light on. Granted, this would only occur during ~some~ night flights, but again, I've never experience a problem.

Why does your "source" think the two are connected--runup causes burned out light bulb?
 

mtsu_av8er

Well-Known Member
[ QUOTE ]
Why does your "source" think the two are connected--runup causes burned out light bulb?

[/ QUOTE ]

Because he has to pay for the replacement....


Cheap Bastage....
 

Stone Cold

Well-Known Member
The lights on the Cessna, and actually most small airplanes (that I've flown anyways) will actually get too hot and burn out that way if you don't have enough air flowing over them. Since there's no air flowing during a run-up (other than prop blast), I would tend to agree with the owner just on that subject. It's a pet peeve of mine for students to sit still with all lights on. Go through your checklist and you'll see it says to turn off landing lights when clear of the runway and doing your after-landing checklist. It just helps the lights to last longer. Use the lights sparingly to make sure you're not moving, but no more than necessary.

As for the run-up, bad run-up = no-go, in my book. I am not a mechanic, but there's a reason we do the run-up. If things aren't right, then have the mechanic look at it.

Fly safe
 

pilotjww

New Member
You made the right decision. I have cancelled a personal trip after a similar mag experience. You always analyize your actions afterward, wondering if you where thinking correctly. That's OK, part of the learning process.

Just ask yourself: "How would it read in the papers tomorrow, when the reporter says 'The pilot reportedly crashed after ignoring the runup problem with his aircraft'"

Or just ask: "Will I be able to convince the insurance company to pay the loss?"

Like most incidents, it's not just one bad decision that gets you. It's a series of several dings that strip away layers of your safety margin until something bleeds.

Well, this is going the negative. How about: "We skipped this flight to fix the problem and to fly happily again another night!"
 

C650CPT

Well-Known Member
If it wasn't important to safe operation then we wouldn't need to check it on preflight / runup. Learn to turn these situations back around on the person asking / telling you what to do. A good resoponse would be ... so I should have flown, sorry I was wrong ... oh help me understand since its ok to fly like this I no longer should do runups? Obviously the boss will back down and say no you should do runups ... then you say OK and if something isn't right what should I do? Keep throwing it back on them ... make them own their stupid words. You did the right thing ... period. Welcome to aviation its all about decision makeing. Not only did you confirm to yourself that you can make the right decision, more importantly you demonstrated sound judgment to your student and believe it or not to the boss. My boss trusts me to take a 6 million dollar airplane cross the US in all WX, not because I'm a good pilot ( which I am ), but because he has confidence in my decision making process.

Good Job.
 

kellwolf

Piece of Trash
I'd have to agree with scrubbing the flight. If it wasn't a P-lead (which would have been the obvious), and the mechanics couldn't find it almost immediately, it's serious enough to fly another day. As far as the light thing, I think the guy was more concerned with the $$$ to replace it. I know of someone else that doesn't even want landing lights used except at night for vision. His response is "landing lights are not anti-collision lights." Hey dude, I'm just following the checklist in the POH.
 

Stone Cold

Well-Known Member
I absolutely use the landing light in the traffic pattern/during low altitude maneuvering/hazy days/ any other time I deem it would be safe for operations. I am not trying to save money, as it's not my airplane, but I know that if I am going on a night flight and I'm getting blinded by another pilot because he's doing his run-up with his light on, I'm not going to be happy. I teach use only as necessary on the ground. Especially if there's another airplane operating nearby. I know I'm reading more into this as nobody said there was another plane nearby, but it's just one of those things that tweaks me.
 

PFactor

New Member
There is no reason to leave the light on during run-up so why wouldn't you turn it off? I agree with the FBO. Just because it is not your aircraft, it does not give you the right to be inconsiderate.
 

SUSPilot

Well-Known Member
My family's plane is on leaseback to a flight school, and You would not believe all of the extra expenses from the What do I care its not my plane crowd.
 

flyguy

Well-Known Member
Who is PIC? Your FBO boss? No, Its your call, don't sweat it. You made the right decision.
 

SteveC

Really?
Staff member
[ QUOTE ]
Who is PIC? Your FBO boss? No, Its your call, don't sweat it. You made the right decision.


[/ QUOTE ]
And don't sweat it when the hourly rate goes up next year....
 

cime_sp

Well-Known Member
One thing that I have seen on a couple of airplanes is that the key "click positions" start to become a little worn. In the "click" position it is still running on both unless you "jiggle" the key (for lack of a better term) This is like when you use the backup set of keys to your car and have to jiggle them a little.

Bit this you will usually see on older airplanes and would not expect on a newer 172R
 

bluelake

Well-Known Member
at least half of the C-172N models I have flown I can pretty much take the key OUT while in any position, including both.

On the light issue, I agree in any opportunity to reduce maintenance bills on our FBO rentals. I did think it was kinda tacky to get on the unicom to inform me of the light being on. I dont think it is "unicom broadcast-worthy" issue, thats all.
 

MikeD

Administrator
Staff member
[ QUOTE ]


On the light issue, I agree in any opportunity to reduce maintenance bills on our FBO rentals. I did think it was kinda tacky to get on the unicom to inform me of the light being on. I dont think it is "unicom broadcast-worthy" issue, thats all.

[/ QUOTE ]

And this is the part I most agree with. Comm brevity, or most pilot's lack of it, is a huge pet peeve and mark of professionalism, or lack thereof, for me. "Not unicom-worthy" is spot on. It's not a safety issue, so the boss should "save it for the debrief". I personally don't leave the taxi light on when waiting for takeoff, but I don't care if someone else does, and I sure aren't going to tell them about it, unless it TRULY is causing some sort of blinding. Agree that your plane or not, always treat each plane as if it's your personal one. It's the professional thing to do too.
 
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