Jump to content

Fiti In-flight Adjustable


Guest Bristell

Recommended Posts

Just had a  thought (dangerous):

 

Bristell stated he had the cruise (course) setting to 5500rpm WOT.

 

He made no mention of the take off/climb (fine) setting which should be 5200 rpm Static - could this have some any sort of impact on the pitch motor?

Link to comment
Share on other sites

31 minutes ago, BirdDog said:

I know this thread is old. But wondering what the outcome was?

I will guess that no AD (airworthiness  directive) was issued. This is good $$ wise for the owner not so good if a crash results.  This is a known issue. Disclaimer,I fly certified and non certified aircraft. Constant speed or in flight adjustable propellers will mask engine performance issues. There were crashes in ww2 when pilots  attempted takeoff with the propeller set incorrectly.   

Link to comment
Share on other sites

14 minutes ago, skippydiesel said:

Just had a  thought (dangerous):

 

Bristell stated he had the cruise (course) setting to 5500rpm WOT.

 

He made no mention of the take off/climb (fine) setting which should be 5200 rpm Static - could this have some any sort of impact on the pitch motor?

No

Link to comment
Share on other sites

1 minute ago, skippydiesel said:

Educate me.

The pitch adjustment motor on this type of electric variable pitch propeller runs between the fine and coarse limits. Both the fine and coarse limits have a switch to stop the motor at the limits. It doesn't give a shit what the pilot is requesting if it is within the limits. 

  • Like 1
Link to comment
Share on other sites

Yeah as above. It’s a pretty rudimentary system. Just a 3 way rocker. In the middle there is nothing. Push it forward and it runs the motor to full fine until the stopper stops the motor.  Pull it backwards and it goes full course the same way. 
 

Regards having it set too course for take off - after my run up and I’m all, I have added a step to my checklist to run up to make sure it hits more than 5200 on the ground.  Takes 5 seconds to do and confirms the prop is in full fine. 

Edited by BirdDog
  • Like 2
Link to comment
Share on other sites

14 hours ago, Thruster88 said:

The pitch adjustment motor on this type of electric variable pitch propeller runs between the fine and coarse limits. Both the fine and coarse limits have a switch to stop the motor at the limits. It doesn't give a shit what the pilot is requesting if it is within the limits. 

 

13 hours ago, BirdDog said:

Yeah as above. It’s a pretty rudimentary system. Just a 3 way rocker. In the middle there is nothing. Push it forward and it runs the motor to full fine until the stopper stops the motor.  Pull it backwards and it goes full course the same way. 
 

Regards having it set too course for take off - after my run up and I’m all, I have added a step to my checklist to run up to make sure it hits more than 5200 on the ground.  Takes 5 seconds to do and confirms the prop is in full fine. 

Thanks guys -  Although I have a CS endorsement, it was achieved in GA/hydraulic systems. I think I understand the  principals but have little practical experience with electric CS/IFA.

 

On an erlier point - replacing a $700 motor. I do know that there is a huge selection of stepper/linear drive motors in the market place - would one of these not be a cost effective substitute for the obvi0sly problematic one supplied by Fitti.

 

And

 

Could this be a motor overload, coursed by a misalignment/binding in the mechanism, rather than a motor problem?

Link to comment
Share on other sites

1 hour ago, BirdDog said:

I don’t know but I’m also going to ask the question of Fitti as to what happens if the motor dies at full course. 
 

My last woodcomp would go full fine if it failed in flight. 

Would speculate, that neither full fine (as in take off/climb setting) or full course (as in cruise) would not really present as much of a drama - you could still proceed to the nearest suitable landing ground/airfield and land (not crash).

  • Like 1
Link to comment
Share on other sites

1 hour ago, BirdDog said:

I don’t know but I’m also going to ask the question of Fitti as to what happens if the motor dies at full course. 
 

My last woodcomp would go full fine if it failed in flight. 

On another speculative idea; could your motor somehow be being repeatedly and very briefly being energised, (pulse not registered by pilot) in the cruise pitch setting? If this was happening the motor to act against a spring under tension and possibly overheating.

Link to comment
Share on other sites

  • 1 year later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...