Grasshopper Posted June 13, 2016 Report Share Posted June 13, 2016 Anyone have an answer to vibration initiated on selection of reflex flap setting? Link to comment Share on other sites More sharing options...
Anticept Posted June 13, 2016 Report Share Posted June 13, 2016 Can you feel, or just hear it? How "loose" are the flaps when you move them by hand? Link to comment Share on other sites More sharing options...
Grasshopper Posted June 13, 2016 Author Report Share Posted June 13, 2016 Flaps move about 1/4" by hand, right slightly more than left. My mechanic discounts this as a cause, but??? It's more feel than noise, through the rudders and airframe, but quite marked as the flaps go up. I've experimented diving and turning from height with engine off(well short of vne, I hasten to add), absolutely smooth as silk. Have replaced engine mounts,dynamically balanced prop,checked carby balance and balance tube, replaced CDIs If I set flaps at much slower speed, vibration is reduced, but becomes more marked as speed builds. Over time, it seems to dissipate somewhat. Am about to replace the two blade prop with a three blade.(It doesn't do to run over taxiway cones) Any ideas appreciated. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted June 13, 2016 Report Share Posted June 13, 2016 Hmm, my flaps are very rigid, no movement by hand in any setting. Link to comment Share on other sites More sharing options...
Runtoeat Posted June 13, 2016 Report Share Posted June 13, 2016 Is there a air speed or speed range at which the vibration starts to occur? Do you feel the vibration with power on? Do you feel it with power off? Link to comment Share on other sites More sharing options...
Grasshopper Posted June 13, 2016 Author Report Share Posted June 13, 2016 I usually set reflex flaps at 100kts, vibration is quite marked at this speed. If set at say 80 kts, vibration is less. Related to power- more with added power, less on decreased power. Does dissipate over time, but not completely. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted June 13, 2016 Report Share Posted June 13, 2016 At 100kt, if you put the flaps back to 0 does the vibration stop? Does it *only* occur with -6 flaps? It's a little tricky to test since 100kt is max speed for 0 flaps. Link to comment Share on other sites More sharing options...
Anticept Posted June 13, 2016 Report Share Posted June 13, 2016 There's going to be up to a slight amount of movement due to the construction of the flaps mechanism. I'm still not sure of the vibration you speak of though. Does it sound like a vevuzela? Because I have that vibration and I haven't figured out what the heck that is as it comes and goes. Link to comment Share on other sites More sharing options...
Doug G. Posted June 13, 2016 Report Share Posted June 13, 2016 Some have noted noise coming from lose our missing bowlus tape on wings or gear leg fairing. Could that be related. Also, since we have flaperons, do you feel it in the stick? Link to comment Share on other sites More sharing options...
ct9000 Posted June 14, 2016 Report Share Posted June 14, 2016 I had a similar harshness / vibration on my ctsw with the two blade Neuform . Changed to a three blade cs problem solved . I normally climb at flap 0 then at top of climb 75kt. then select -12 flap then reduce power , it is not as bad . Link to comment Share on other sites More sharing options...
Grasshopper Posted June 17, 2016 Author Report Share Posted June 17, 2016 Thanks for your comments, all. I am about to change to a three blade Nueform. Maybe that will solve the problem. Had a good look at wing root flap connection- all looks good. Very minimal movement on either side. Link to comment Share on other sites More sharing options...
Roger Lee Posted June 17, 2016 Report Share Posted June 17, 2016 Neuform's have weights inside the blades down around the base. They can come loose and even cause sever vibration. Link to comment Share on other sites More sharing options...
gbigs Posted June 17, 2016 Report Share Posted June 17, 2016 I fly with the factory supplied three-blade Neuform and it flew flawlessly before and after it was taken off completely and reinstalled for the Sport Upgrade. There are ZERO issues with the prop. If it comes loose then it's installed incorrectly. I would suspect the cowling on the wheels, the bowlus tape, a loose nut on the engine cowling, a loose door before suspecting an entire wing flap or aileron. Unless you can physically move the flap and it has a LOT of play. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.