Lesson Learned

[usafhaynes1]

The good news?  I'm about to hit 100 hours of flight time.  Yah!!!

While I'm still gaining experience, it seems I learn something new every time I fly.

 

Yesterday, I had to do a progress check for the IFR oral exam with my instructor.  The whole time I was biting at the bit to get in my Mooney and test out the overhauled KI-209 (plane getting IFR cert done today).  The prog check went well and off to the plane I went!

 

Pre-flight, taxi, run up, no issues, all gauges in the green.  I take the active, go full power and...nothing.  Engine would simply not produce power...sort of sputtering.  I ensured I was full throttle and after 2000' I called rejected takeoff and taxi over the radio.  My thoughts raced about what had I done wrong.  I remembered reading about members who lean the plane for taxi.  I turned off the boost pump, leaned the mixture and taxied back to run up.  I kept the mixture about halfway out, went full power and the engine sprung to life (brakes work great BTW cause I had to stand on them!!!).  I left boost pump off until on the active, full mixture, full power and the plane almost leapt off the ground.

 

What did I learn yesterday?  I will NOT leave boost pump on during taxi, pre or post run up.  I WILL lean the engine during taxi.  I'm positive I had too much fuel available to the engine at takeoff and it couldn't make proper power. 

 

Afterwards, the KI-209 worked flawlessly and I greased the landing.  First time since I bought the plane two weeks ago. 

 

I credit all the reading I've done on this sight to help me troubleshoot my plane when it doesn't respond 100%.

[Z W]

You can over-rich the C model's engine pretty easily on the ground.  On very hot (100+ dF) days you may even need to leave your mixture leaned by 1 inch to have full power.  If mine was full rich and I had the carb heat on, on a hot day, it would sputter at full throttle for a go-around.  I always left the mixture leaned just a little bit on short final after I discovered that.

[usafhaynes1]

I appreciate the input.  I'll keep that info in my toolkit of knowledge if I encounter the same scenario.

[BigTex]

Acutally it's not just Mooney C-Models that have this characteristic.  Just about any carburated Lycoming will behave this way.  I remember I flew a Cherokee 140 years ago that you had to nurse the power to full everytime or it would stumble and sputter... But that was also back when nobody leaned correctly or in some cases never even touched the red knob.

[Bob_Belville]

... or in some cases never even touched the red knob.

I got my ticket in '69. In those days we never leaned, on the ground or in the air, below 5000'.

[jlunseth]

It is said that the first 100 hundred hours are the safest, so congratulations but it is time to grow eyes in the back of your head.  Take nothing lightly, especially not an engine misbehaving on takeoff.  I don't fly a C so don't know the effect a boost pump would have, but does the C not have a Flight Manual that covers what position the pump should be in for takeoff and/or landing?  In my K, boosts pumps are for emergencies only, primarily failure of the engine driven pump, and I have it in my checklist to check that they are off during takeoff and on landing.

 

However, there are other things that can cause the symptoms you are describing.  A small amount of water in the line.  A magneto or both magnetos nearing the ends of their useful lives, possibly even a mag loose on the stem.

 

So here is my suggestion, and it is what I do with my aircraft.  If you don't have a good checklist for a C, find a good detailed checklist of the type a school would use.  Use that as a form or outline, and then go through your flight manual and figure out what position each of the switches, controls, circuit breakers, etc. needs to be in, during each regime of flight, and put those in your checklist.  Then use that checklist every time, every flight.  I have a checklist in .pdf form for my K I would be glad to send you that you can use as an outline.  It probably has more stuff than your C, and different stuff, but it would be a start.

 

Then on your next flight, I would take care to perform a rigorous preflight and runup, and not accept anything out of standard.  If the standard for you C is a mag drop of no more than 150 RPM's, then don't accept 151.  If the difference between the mags is supposed to be 75 or less, don't accept 76.

 

It is entirely possible the boost pump was the culprit, but it is possible something else was also.  We have all made those mistakes.  I left the mag on "L" instead of "Both" once and then had to abort because the engine ran rough on climb out.  I figured it out, did a runup and test flight and it was ok.  But you need to be fairly certain that you found the solution.  If you are new to Mooneys and new to flying, I would not take for granted that I had found the solution.  We have had people on this Board who are not on this Board any longer, or anywhere else in the living world for that matter. 

 

So don't just guess, is my advice.

[usafhaynes1]

I appreciate your advice and yes, I do run my checklist every flight.  My iPad Mini is yoke mounted with three apps running in this order:

1. my flight logbook (it detects takeoff and landing)

2. my checklist (stored in pdf)

3. foreflight

 

I start the flight logbook and set it to new flight.  I then switch over to my checklist and verify everything has been accomplished up to engine start.  My POH states that for engine start, run up, takeoff and landing to have fuel pump on. 

 

After engine start, I switch to flight logbook to touch engine start time; switch over to foreflight to program my route (this is practice for IFR clearances in the future as well as for taxi guide), taxi to run-up, switch back to checklist and perform run-up checklist.  The only time I do not have my checklist up is when I'm on final or in the pattern and I'm running BCGUMPS (boost pump, carb heat, gas, undercarriage, mixture, prop, seatbelts/landing lights, runway lights).  I even speak the words BCGUMPS so I ensure checklist is complete.  When 500' above the runway, I verify landing gear is locked in down position (read about that on this site). 

 

I'm positive that forgetting to turn off fuel pump during taxi and after run up, I had too much fuel when I went full throttle.  I returned to run-up and verified checklist again, this time ensuring fuel pump was turned off after run-up and I did not turn fuel pump back on until I was on runway centerline, at which I turned on fuel pump, verified takeoff trim, mixture full, prop full, throttle full and the plane preformed normal takeoff.  During run-up, right mag dropped about 110, left mag dropped 100. 

 

I absolutely believe complacency and not running checklists the same every time is what can lead to catastrophic events.  I look forward to hitting that 1000 hour mark!!!

[N601RX]

The fuel pump being on has nothing to do with how much fuel is in the engine.  It is just there in case the engine pump fails. It also fills the carburetor bowl for easier cranking. The float in the carburetor keeps the carburetor full and the jets, idle circuit and accelerator pump supply and regulate fuel up to the engine.

[jeckford]

What logbook are you using on your ipad Mini?

 

I use logten Pro but am not aware of one that detects takeoff and landing.

 

 

I appreciate your advice and yes, I do run my checklist every flight.  My iPad Mini is yoke mounted with three apps running in this order:

1. my flight logbook (it detects takeoff and landing)

2. my checklist (stored in pdf)

3. foreflight

 

[BigTex]

I use Cloud Ahoy on my iPad.  It's a great app that you start like a stop watch and it detects takeoff, knows the airport you're departing from and tracks your flight as well as altitude.  It overlays your flight on what looks like GoogleEarth.  It's a wonderful product.  I use it for every flight.

[Z W]

You turn the boost pump on for take-off and landing in a C model.  That's proper procedure in the POH.  But I always did turn mine off at the same time I leaned for taxi after start-up.  It seems to help avoid getting too rich on the ground.  Mine would foul a plug pretty quick if I failed to lean for taxi and turn off the boost.

 

I also left my boost pump off and left it leaned for the run-up.  I don't recall my POH stating boost pump on for the run-up.  Every time I rolled onto the runway I did a GUMPS check, and in the S for switches, I included fuel pump on, landing light on.  Also this is the time to check M for mixture - set as appropriate.  That should be partially leaned, at a high density altitude, which is what you get on a very hot day or at a high elevation.  If you've properly leaned for taxi and you forget to put the mixture knob back in, your engine will start to die as you advance the throttle.  You can't forget that way - the plane won't fly.

 

As stated before, that pump has a very short lifespan and a high rebuild cost.  You will want to leave it off as much as possible.

[DrBill]

 I agree with JimR, use boost pump sparingly. It is probably NOTspecificated for continuous duty (if it's a DUKES) and could be as much as $1000 to replace.

Also agree with N601RX so depending on your DA lean as needed.

BILL

[jetdriven]

Dukes fuel pumps are over 1200-1400$ now, and like Jim, we only use it for priming to start, maybe the occasional low IFR or overwater departure where a fuel flow interruption can get you.