fuel supply Tecnam

[tecnamdave]

Just had my first splutter after takeoff today stick forward and landed straight ahead made it down ok

 

We had just finished replacing all the fuel lines in the Tecnam including emptying both tanks and replacing the fuel. checked out for any leaks and loose fittings all ok next turned on electric fuel pump every thing ok next fired up the trusty Rotax ran it for a couple of minutes all ok then proceeded to put the cowlings and final cleanup and DI befor taking it out for a check flight Approximately 5 or six minutes for warm up while taxing out all the pre take off checks including mags. check all ok lined up on the runway every thing running smoothly like all ways, lift of at 40 knots flaps up climbing at 65 knots then a splutter. after landing could not find any faults. Question is could it have been air in the fuel lines ? can any one give some input with the same experience

 

 

[Bryon]

Dave,

 

I cant help you with the fuel problem, but congratulations on getting the bird down safe

 

Cheers

 

Bryon

 

 

[tecnamdave]

Dave,I cant help you with the fuel problem, but congratulations on getting the bird down safe

Cheers

 

Bryon

Hi Bryon

 

Well we checked every thing out again this time holding the breaks on and running engine at full revs for app 2 minutes then the same again this time with electric fuel pump on as well. did not miss a beat so lined up and climbed out at around 300 feet the engine started to run rough with loss of power

 

once again stick forward throttle off almost through the boundary fence this time.

 

Another near death experience

 

very day is a good day. some days are better than others

 

 

 

[cherk]

Hi BryonWell we checked every thing out again this time holding the breaks on and running engine at full revs for app 2 minutes then the same again this time with electric fuel pump on as well. did not miss a beat so lined up and climbed out at around 300 feet the engine started to run rough with loss of power

once again stick forward throttle off almost through the boundary fence this time.

 

Another near death experience

 

very day is a good day. some days are better than others

Dave, You could try tying the tail down....nose high......in climb-out attitude to see if its to do with venting,suction or float levels.................just a thought!

 

 

[johnm]

Just been thru replacing all hoses on a Tecnam Bravo - with a L2 - L2 the brains - me the monkey

 

Obvious question ???????? ............... where the 2 tank lines meet at a 'T' the fuel line then forward is a larger internal and external diameter - same for you Tdave ?

 

 

[Bryon]

Hi BryonWell we checked every thing out again this time holding the breaks on and running engine at full revs for app 2 minutes then the same again this time with electric fuel pump on as well. did not miss a beat so lined up and climbed out at around 300 feet the engine started to run rough with loss of power

once again stick forward throttle off almost through the boundary fence this time.

 

Another near death experience

 

very day is a good day. some days are better than others

Dave,

 

Once is bad enough, but to have it happen twice..................I bet your pucker wont relax for at least a week

 

Go and buy yourself a Tatts ticket

 

I would definately be looking at trying to reproduce the problem ...on the ground....

 

The suggestion of tying the tail down sounds like it could be the go for me after you have checked all the lines for low points, humps or slight kinks. Even a slight constriction could do it.

 

Anyway, congratulations on another good save

 

Cheers

 

Bryon

 

 

[flyhi]

Does the Tecnam have a return (bypass) fuel line back to the tank (with or without a tap)? I experienced this once in my Z at 500'. Had the return line turned off. Turned it on & all was good again. I've never turned the bypass off since. My situation was different in that I had just landed & shut the engine down for 5 minutes before starting it & taking off again. I deduced that it was vapour lock due to heat rise under the cowl at shutdown.Cheers

Dexter

My Tecnam has a restrictor in the tee where the return line to the tank tees off the main fuel line from the pump to the carbs.

 

 

[tecnamdave]

My Tecnam has a restrictor in the tee where the return line to the tank tees off the main fuel line from the pump to the carbs.

Yes mine also has a restrictor in the tee for the return working ok

We have just checked out both mech.fuel pump and the electric fuel pump both working ok, as separate units, and in tandem

 

we have also ran a couple of ltrs of fuel thou the system to make sure no air left in the fuel lines

 

we are about to test engine then test fly

 

Cheers Dave

 

 

[Guest Andys@coffs]

Yes mine also has a restrictor in the tee for the return working okWe have just checked out both mech.fuel pump and the electric fuel pump both working ok, as separate units, and in tandem

we have also ran a couple of ltrs of fuel thou the system to make sure no air left in the fuel lines

 

we are about to test engine then test fly

 

Cheers Dave

Dave

Assuming it does it again, can you switch off (engine, punps and feedltaps) at that time and land straight ahead agin, you can then check out the bowl for too much or too little fuel...At least you then know which of thre 2 is the issue.

 

Andy

 

 

[tecnamdave]

DaveAssuming it does it again, can you switch off (engine, punps and feedltaps) at that time and land straight ahead agin, you can then check out the bowl for too much or too little fuel...At least you then know which of thre 2 is the issue.

 

Andy

we have sussed out what we think is the problem, do not think it to be a fuel problem after all, will confirm an Wednesday after we finish all the maintenance issues

Thanks for every ones input all the same

 

Cheers Dave

 

 

[tecnamdave]

I believe we have sussed out the problem just ran out of daylight today, so did not get to test fly the Tecnam. Me being a nervous pilot, who only fly's on very fine calm days, and having a bit of vibration on climb out at app 200ft with a bit of panic thrown in who immediately throttled of and pushed the stick forward and landing straight ahead thinking i had a fuel problem. putting it down to maybe air in the fuel lines, only to do the same again the next day after bleeding the fuel lines to make sure all would be ok and finding the vibration even more extreme. as i lift the flaps at about 2 to 300 ft and making that decision to land straight ahead once again as trained to do in the event of efato or any other event that would effect the the safety of self or the plane

 

we have come to the conclusion that it was the Tyre that i changed the other day causing one of the landing wheels to become out of balance and not doing its chronic boogie until well into lift off. this has now been rectified

 

Doh Dave

 

 

[tecnamdave]

Thank you and every one else for there concern

 

My Mechanic Len checked out the plane this morning upon taking it for a test flight found the same problem, with a bit of vibration and definite lose of power. So back to the hangar and a thorough check of all the fuel system, we found the problem. The fuel line star that's a 4 way section that distributes the fuel to both carburettors and to the fuel pressure gauge had been inadvertently put back the wrong way, with restricted supply to one of the carburettors, instead of to the fuel pressure gauge

 

Once again a lesson learnt one cannot afford to not pay full attention to the smallest of parts This little 4 way piece of junction pipe has a restriction that can be easily overlooked at the best of times

 

Cheers Dave