FTU checklists DO hurt the engine!

[straightpilot]

No, I'm not talking about running carb heat while airborne. Everyone knows that every time you cycle the carb heat in flight, God kills another kitten.

A student flew a 152 in on a cross-country. When he did the runup before takeoff, the engine ran so rough that he was scared to fly it. Took ground transportation home. Days later, a mechanic arrives, runs it up to burn to crap off the bottom plugs, takes off and goes home.

What a waste. Transport and the FTU's refuse to change their checklists to lean the mixture on the ground, and as a result the bottom plugs foul up, and eventually you get an unacceptable mag drop during runup.

Congratulations, Transport and the FTU's. You're doing great work with your incredibly long and cumbersome checklists - you're screwing up the engines. Great training for future airline pilots.

[767]

No No No.... the student did the right thing. No matter what the situation is, if your not sure, stay on the ground and get it checked.

[Chuck Ellsworth]

As well as the failing to take into consideration the fact these engines are air cooled and work better in the air with proper airflow another mind boggling habit I see and hear far to frequently is the idiotic live mag checks where they turn both mags off to see if there is a live mag.

[System Message]

None of that is as bad as full rich mixture on decent.

[Chuck Ellsworth]

None of that is as bad as full rich mixture on decent.

Shutting off both mags at around a thousand RPM and then waiting before turning them back on is a hell of a lot harder on an engine than descending in full rich.

[straightpilot]

the student did the right thing

No, he didn't. He did what the Transport/FTU checklist told him to do, which was to foul the sparkplugs by running the mixture rich on the ground all the time.

Cessna should have saved the money and not bothered to put a mixture control in, for all the use it gets.

[iflyforpie]

Leaning mixtures doesn't have to be a checklist item. Usually mixtures rich is a before takeoff item.

And rich mixtures don't ruin engines, they foul plugs. Totally different. Carb heat ruining an engine? Please!

Mags both off. Perfectly acceptable if you are at idle. I was taught this way as an AME and have done it from A65 to R1340 without so much as a pop. I've done it at 1700 RPM and avoided catastropy by retarding the throttle and turning the mags on when you see individual blades. I've also encountered two mag switches in my maintenance career that registered a drop on L and R but continued to run on OFF.


The root problem in all of these situations is going by rote rather than thinking about what you are doing. To be fair, student pilots are learning and they have to do a certain amount by rote. But little tips and tricks can go a long way to solving these problems.

FWIW, I knew how to clear plugs before I went solo from my PPL instructors.

[onederwoman]

Maybe it isn't the fault of the checklist as much as the pilot. A person should know how to properly lean an engine before going solo. BLAMING A CHECKLIST is pretty lame. People use them as a guide or memory aid [if they get used at all in a light plane] not as a substitute for instruction.

[onederwoman]

The pilot obviously wasn't taught how to use the mixture control. BLAMING A CHECKLIST for sloppy piloting skills is pretty lame. They bare only a memory aid.

[straightpilot]

A student pilot on a PPL flight test who leaned the mixture for ground ops contrary to the FTU checklist would most certainly fail the flight test.

[Grantmac]

The pilot obviously wasn't taught how to use the mixture control. BLAMING A CHECKLIST for sloppy piloting skills is pretty lame. They bare only a memory aid.

Where I fly (military airfield) often has long delays on the ground. No problems with fouled plugs, I lean agressively anytime I am below 75% power in accordance with Lycoming manuals.
"Its not my fuel/plugs/engine" is a common and poor attitude. Heaven forbid those pilots decide to go somewhere with a high density altitude where leaning may be required to make enough power for a safe take-off.
-Grant

[straightpilot]

long delays on the ground

If you are delayed on the ground:

- nose into wind
- 1100 to 1200 RPM
- lean for max RPM

to avoid fouled spark plugs and reduce valve deposits.

You won't find that on any approved FTU checklist!

[Chuck Ellsworth]

Quote:
long delays on the ground


If you are delayed on the ground:

- nose into wind
- 1100 to 1200 RPM
- lean for max RPM

to avoid fouled spark plugs and reduce valve deposits.

You won't find that on any approved FTU checklist!

Should I be doing that when I am on the water in the Husky?

[straightpilot]

The important thing is that everyone should ignore the manufacturer's recommendations.

Specifically, Lycoming Service Letter 185B should be completely ignored, when it says:

ENGINE GROUND OEPRATION.
The engine ground operation greatly influences formation of lead salt deposits on spark plugs and exhaust valve stems. Proper operation of the engine on the ground (warm- up, landing, taxi and engine shut-down) can greatly reduce the deposition rate and deposit formation which cause spark plug fouling and exhaust valve sticking.

The engine should be operated at engine speeds between 1000 and 1200 RPM after starting and during the initial warm-up period. Avoid prolonged closed throttle idle engine speed operation (when possible). At engine speeds from 1000 to 1200 RPM, the spark plug core temperatures are hot enough to activate the lead scavenging agents contained in the fuel which retards the formation of the lead salt deposits on the spark plugs and exhaust valve stems. Avoid rapid engine speed changes after start- up and use only the power settings required to taxi.

Operation at full rich mixture requires more frequent maintenance periods; therefore it is important to use proper approved mixture leaning procedures.

Especially, this should be ignored:

During let-down and reduced power flight operations it may be necessary to manually lean or leave mixture setting at cruise position prior to landing.

Keep shoving that mixture all the way in during descent, too. Lycoming doesn't know anything about their engines.

[Chuck Ellsworth]

I believe I operate the engine in the Husky in a manner that does not go against the engine manufacturers suggestions.

I also do most of the work on the engine for the required maintenance checks and have never had a problem with lead fouling of the plugs.

Maybe you could drop by Pitt Meadows and give me some instruction on engine handling sometime straight pilot?

He'll maybe you could show me how to properly fly it, what do you charge an hour?

[Trematode]

Mags both off. Perfectly acceptable if you are at idle. I was taught this way as an AME and have done it from A65 to R1340 without so much as a pop. I've done it at 1700 RPM and avoided catastropy by retarding the throttle and turning the mags on when you see individual blades. I've also encountered two mag switches in my maintenance career that registered a drop on L and R but continued to run on OFF.

Thank you for posting this -- it's the reason I always make sure to check the OFF position, always at idle, and with care not to accidentally engage the starter. For a while our FTU had a policy not to check the OFF position out of fear that students would engage the starter, but how else are you going to be absolutely sure the mags aren't hot?

I teach my students to reduce power to idle, go to OFF and then make it a distinct step to go back to R, L, then both, that way they wont crank it over all the way.

RE: Plug fowling

I've honestly cant think of a time I've encountered any plug fouling from running rich on the ground -- though I do make sure to lean it out for taxiing anyway (maybe that's why). The times where I have experienced it, have been with misbehaving cylinders, that never seemed to seal properly and end up with a bit of oil on the bottom plugs.

[Chuck Ellsworth]

Why this paranoia about the extremely low possibility of having a live mag?

Do you guys just walk up to airplanes and pull the props through without taking into consideration they may have a live mag?

Even if there is a live mag what else does it take to fire a cylinder?

Just wondering how you people act around airplanes.

[Trematode]

Why this paranoia about the extremely low possibility of having a live mag?

Do you guys just walk up to airplanes and pull the props through without taking into consideration they may have a live mag?

Even if there is a live mag what else does it take to fire a cylinder?

Just wondering how you people act around airplanes.

I don't know that anybody is paranoid... But it's a simple check, and I haven't met an AME that seems to think it would do any harm if done correctly. But I would defer to your experience . seeing as how I'm still relatively new in comparison to most of the regulars here... Why is it so bad?

Is it not accepted practice to check for live mags before shut down? If you do it, can you share your technique? My understanding is that the radial ignition switches have separate grounding wires for each position, so even if you confirm a drop on L, and R, you could still have a live mag at the OFF posititon.

I'm sure you've met a few oddball passengers that might have broken grounding wires of their own -- what happens if they decide to yank on the prop despite your warnings? Obviously the chances are remote, but so are a lot of dangers in aviation.

[Trematode]

Even if there is a live mag what else does it take to fire a cylinder?

Again unlikely, but still possible.

For example, an IO-360 in a 172 will start up just fine in ICO without any priming at all if the engine is still hot. I think a little fuel is left in the injector lines from the previous shut down.

Or what if somebody flooded an engine on start up, gave up and walked away from the plane, and then the prop was foolishly handled after it sat a bit... With the mags live?

I think those are pretty reasonable examples of why it might be prudent to ensure the mags are grounded. I'm still learning though, and always open to rethinking my way of doing things!

[robertsailor1]

Props/mags are like guns boys, treat them like they are hot. In my opinion turning your mags off and on while running is like a lot of other things that really don't need to be done on every run up. Too many idiots flying these days that will eventually induce a back fire.
For years I flew aircraft equipped with Armstrong starters and you learned to always treat the prop as if the mags were hot. Turn it over as many times as you like but as long as you stay out of the prop arc you can never be hurt.

[justwork]

Why this paranoia about the extremely low possibility of having a live mag?

Do you guys just walk up to airplanes and pull the props through without taking into consideration they may have a live mag?

Even if there is a live mag what else does it take to fire a cylinder?

Just wondering how you people act around airplanes.

I don't get it ., this seems pretty hypocritical to some of your previous posts, where you'll rant about something that has just a low possibility of happening.

When I was flying pistons I would do a live mag check every time, and I would consider it bad airmanship if anyone doesn't.

[straightpilot]

When I was flying pistons I would do a live mag check every time

Yes, you certainly did. So does everyone else.

When you do the runup and during the magneto check, observed an RPM drop on L and R, you verified that the p-lead was working just fine, and that neither of the magnetos were hot.

If you do not observe an RPM drop on either of L or R, then yes, you have a hot magneto. Most pilots sweat the RPM drop, but if it doesn't drop at all, then you've got a problem.

The only other failure mode is the switch itself - internally. If it doesn't ground out both p-leads in the OFF position, then yes you could have a hot magneto. If you must test this, please do it at the lowest possible RPM to reduce the amount of unburned fuel pumped into your expensive exhaust manifold, which lights off with a BANG when the mags are turned on again.

Your odds as a pilot of encountering a bad switch (failure in OFF position) is about the same as you winning the lottery. If you want to become an amateur AME there are lots of other things on the airplane you should look closely at, which will give you far better return for your effort and time.

The amateur AME's here would be better off by simply cleaning their airplanes. Start with the windscreen. The prop. The wing leading edges. Next, de-grease the belly. Look carefully for cracks that are developing and need stop drilling before they progress. Get the shop-vac and clean the aircraft interior.

[iflyforpie]

If you want to become an amateur AME there are lots of other things on the airplane you should look closely at, which will give you far better return for your effort and time.

Far better return for your time than a 1 second check? It takes 2 or 3 seconds to go BOTH L BOTH R and hopefully not engage the starter if the aircraft is so configured. Then you've checked everything. As I've said before, I've won the lottery twice!

It's not that I am overly paranoid of an engine firing over (done quite a few hand props and it takes a lot to get the bigger engines to go--if it is a booster coil or shower of sparks forget it), but for the a) (less) time, and b) the better thoroughness of the check, and c) the lack of harm done when done properly, why not. Sure if you've got a Citabria or something else with individual toggle switches do them one at a time, but otherwise just turn them off.

The amateur AME's here would be better off by simply cleaning their airplanes. Start with the windscreen. The prop. The wing leading edges. Next, de-grease the belly. Look carefully for cracks that are developing and need stop drilling before they progress. Get the shop-vac and clean the aircraft interior.

Excellent advice, but difficult to do when you are in the aircraft with it running.


Another thing that I see pilots doing is shutting down their engines at low RPM. 1000 to 1200 for opposed engines so that your engine will be nicely coated with fresh oil (not contaminated with fuel or exhaust) when it is shut down.

This actually is in most FTU checklists, but the reasoning behind it is not. It often gets forgotten if the pilot does their live check at idle and then immediately shuts off the engine.

[Chuck Ellsworth]

I don't get it ., this seems pretty hypocritical to some of your previous posts, where you'll rant about something that has just a low possibility of happening.

I don't believe I am being hypocritical at all if you read my posts and the words I used.

First off I said doing live mag checks at high RPM and pausing to long can produce a backfire and you can damage the exhaust system, I have had it happen to my training airplanes because the instructors did not have the faintest clue about what they were teaching.

A live mag or mags could be argued as the best mechanical failure you can have on an airplane because no matter where the thing happens you can start it and fly home.

Now lets walk through how to treat a prop on the ground or the water.

NEVER,NEVER,NEVER move it unless you move it thinking it is live and can fire.

When you do move a prop on the ground hold the blade so as should it fire your hands will come clear of the blade and you will still have all your fingers attached to your hands.......DO NOT curve your fingers around the blade.

Stand in a position where you are clear of the blade arc and the surface is not slippery.

When hand propping an airplane and it fires on the first movement of the prop you have won the lottery......it often takes a lot of blade swinging to start them.

This subject is very serious and needs to be taught properly......paranoia is not a good reason without lots of background knowledge.

Radials are generally easier to swing start than the little four bangers.....especially the radials on the DC3.

[Big Pistons Forever]

I am with . on this one. I do not teach the dead mag check to my students, I just get them to set 1200 RPM, check left and right mags for a drop and then go to ICO. As for leaning on the ground.....well it is very airplane dependent. My Grumman AA1B must be leaned immediately after start up or the plugs will foul every time, yet I have never seen a D2J powered C 172 foul the plugs (caveat: my airport is near sea level). So my default is mixture full rich unless there is reason not to.

However if you are going to lean on the ground then it is very important that you lean very aggressively for two reasons:

1) Getting the EGT's up at low RPM requires a much leaner mixture lever position on the ground then in flight and,

2) If the mixture is aggressively leaned and you forget to enrichen the mixture for takeoff the engine you will know it as soon as you go to full throttle and before engine damage occurs.

Finally as a general observation, I am surprised at how many students, even at the CPL level do not know how to do a burn out. This should be taught at the post solo PPL level.

The bigger issue IMO is the fact that most students do the runup checks as a series of rote actions without any understanding of what the airplane is telling them. This IMO is one area where FTU's could do better especially at the CPL level, and it is absolutely unacceptable IMO to have instructors who can't explain exactly what is happening at every step of the runup.