Your Thoughts

[BillTIZ]

thank you for all your responses.
this, of course, wasn't the end of it.

now, the flight school is not only making me pay for the maintenance done on the airplane when i selected to return back to the point of departure, but they are also charging me for the flight hours the A&P flew the airplane back home from the airport at which we did the emergency landing.

they are claiming that nothing is wrong with the airplane, and therefore all these charges are mine to pay.

what are your thoughts on that? is this standard?

Are you the CFI working for the flight school? They cannot withhold your pay check. Time to walk away and let them try to collect.

Most rental agreements will state that if you leave an aircraft behind for weather, you have to pay for retrieval. Most may not say anything about leaving a plane behind you have deemed not airworthy. Pay up and walk.

 

[PilotAlan]

The power recovery at a lower altitude seems to point toward a too-lean condition,

Going from thinner to thicker air would make the mixture *more* lean, wouldn't it?
Now a too-rich condition would improve as altitude decreases, but it's hard to get so rich the engine quits.

 

[PilotAlan]

Going from thinner to thicker air would make the mixture *more* lean, wouldn't it?
Now a too-rich condition would improve as altitude decreases, but it's hard to get so rich the engine quits.

OK, quoting myself -
Could an unlocked primer cause a failure at high altitude and power recovery at lower?

 

[Henning]

BTW, did you try turning on the fuel pump?

 

[Sac Arrow]

hey,

i have no idea how they flew it back home. probably just like i flew the plane for an hour and a half before the engine failure (home is about 30 minutes from where the engine out was).

i wasn't using the electric pump at cruise, just the engine driven one. turning the pump on was one of the first things i did when the engine cut, so that wasn't the immediate cause.

also, the engine roughness was experienced regardless of whether the electric pump was on or off..

BTW, did you try turning on the fuel pump?

I think that's been ruled out. Doesn't mean it wasn't inop, ineffective or plugged though.

 

[GMascelli]

thank you for all your responses.
this, of course, wasn't the end of it.

now, the flight school is not only making me pay for the maintenance done on the airplane when i selected to return back to the point of departure, but they are also charging me for the flight hours the A&P flew the airplane back home from the airport at which we did the emergency landing. they are claiming that nothing is wrong with the airplane, and therefore all these charges are mine to pay. what are your thoughts on that? is this standard?

Ask them if the phrase get bent rings a bell..........I am so glad I own, renting just stinks at times.

I hope you get it squared away, what a PITA.

 

[John Baker]

After thinking about this, I have run into a similar type thing on the run up. The magnetos check fine, but still not perfect.

The solution is to run up your RPMs to over two thousand, then lean it as much as you can for five or ten seconds without shutting it down. This burns any gunk off the spark plugs.

I have a hunch that this is your problem. If this is the case, then it is indeed operator error.

John

 

[GeorgeC]

The solution is to run up your RPMs to over two thousand, then lean it as much as you can for five or ten seconds without shutting it down. This burns any gunk off the spark plugs.

In the context of a rental, is there a reason why such a burnoff should not be performed during each runup?

 

[Henning]

In the context of a rental, is there a reason why such a burnoff should not be performed during each runup?

Even in the context of ownership I do my runups leaned way back. Heck, I've got them pulled back to 3 when I'm cranking them to start.

 

[denverpilot]

I used to start full-rich as taught until one day I watched my mechanic pull the mixture knob out two inches and turn the key without prime in our airplane and it started in virtually one blade.

It then dawned on me that up here at our altitude, the engine runs rough at full rich anyway and we *are* taught to aggressively lean during taxi, but no one teaches to lean for engine start.

It's likely one of the reasons our battery just got changed, still working fine, after six and a half years when we chickened out a bit and did it.

If our O-470 ever were to start hard, I'd wonder what was wrong with it pretty seriously. Especially leaned for start up here.

Seen more than one fuel-injected Lycoming flat-lander trying to get an engine started on a hot day up here with fuel pouring out the bottom of the cowl too.

 

[zaitcev]

It then dawned on me that up here at our altitude, the engine runs rough at full rich anyway and we *are* taught to aggressively lean during taxi, but no one teaches to lean for engine start.

It seems that in Albuquerque they split the difference: students are taught to start on rich, but then immediately lean, right after glancing at the oil pressure, or even simultaneously. There is no special leaning for taxi. The same procedure applies across several schools except those flying on Rotax power.

 

[PilotAlan]

...no one teaches to lean for engine start.

Sure they do. I start my -180 with the mixture about 2-3 inches out, and two shots of primer. Starts on 2-3 blades every time.

 

[John Baker]

In the context of a rental, is there a reason why such a burnoff should not be performed during each runup?

If, after starting, you keep you RPMs at 1000 or better, you probably will not need to perform a burn off. Taxiing and running at RPMs below a thousand is what causes the gunk to build up. I do not do it every time, but always if I get even a hint of less than perfect on the magneto check.

I learned this lesson the expensive way. After coming in with a rough running engine, my mechanic looked it over, did a burn off, and charged me the fee reserved for stupid people, one hour labor, $80.00.

The $80.00 dollars included a briefing on how and when a burn off is performed.

John

 

[denverpilot]

Sure they do. I start my -180 with the mixture about 2-3 inches out, and two shots of primer. Starts on 2-3 blades every time.

Yeah but who taught you that? Not a single CFI I've ever flown with ever showed me that.

I had to learn it by watching my mechanic start my plane many many years after I started flying.

 

[GeorgeC]

If, after starting, you keep you RPMs at 1000 or better, you probably will not need to perform a burn off. Taxiing and running at RPMs below a thousand is what causes the gunk to build up. I do not do it every time, but always if I get even a hint of less than perfect on the magneto check.

I do this. Makes for brisk taxis.

Apologies for the drift, but while we're on the topic, is there a difference between priming with the primer vs. the accelerator pump, at least for warm/warm weather starts?

 

[Henning]

If, after starting, you keep you RPMs at 1000 or better, you probably will not need to perform a burn off. Taxiing and running at RPMs below a thousand is what causes the gunk to build up. I do not do it every time, but always if I get even a hint of less than perfect on the magneto check.

I learned this lesson the expensive way. After coming in with a rough running engine, my mechanic looked it over, did a burn off, and charged me the fee reserved for stupid people, one hour labor, $80.00.

The $80.00 dollars included a briefing on how and when a burn off is performed.

John

It would probably be a good investment for most pilots, and certainly owners, to get 40hrs worth of training with a good mechanic who knows diagnostics at a busy shop. Pay them $1000 to follow them around for the week and maybe get dirty. It would pay off in spades.

 

[PilotAlan]

Yeah but who taught you that? Not a single CFI I've ever flown with ever showed me that.

When I moved out here from sea level and had to learn to fly at high altitudes, I found the oldest, most grizzled and cantankerous CFI I could.

It paid off in spades.

 

[denverpilot]

When I moved out here from sea level and had to learn to fly at high altitudes, I found the oldest, most grizzled and cantankerous CFI I could.

It paid off in spades.

LOL! I thought I had found all of those! None of 'em have ever said anything about stuffing the mixture all the way forward for the start-up.