our DR401 is back to ops, they recalibrated the flapsystem and did some flights and they worked. As all wiring and and all other Parts were already replaced they hope the Flaps issue is solved. So lets see whats coming up next, hopefully nothing…
I know that the topic is a bit old but the DR401 in my airclub has the same problems as luckymaaa.
The aircraft was delivered in march and has made 500hrs of flight. We had big issues with the radiator: coolant leaks detected before a flight and high temperature for the cooling fluid during a flight. The radiator was replaced two times. We now have problems with the electric flaps. During cruise the flaps became full without activating it and, on the ground we succeeded in putting it again in cruise position. I flew the plane to Dijon Darois (where it was built) and the wiring was changed. Yesterday, during take off, it was impossible to retract them so we came back to the ground. Today, the flaps were working correctly again. This erratic behaviour of flaps is a problem for us. My question is for luckymaaa : is the problem with the flaps fixed now ?
During cruise the flaps became full without activating it
That is a life threatening issue… what is the cruise speed and the max speed for full flap? If you over-stress the flaps, more than likely one will come off before the other and then you get a massive roll rate which will probably kill you.
Peter wrote:
That is a life threatening issue… what is the cruise speed and the max speed for full flap? If you over-stress the flaps, more than likely one will come off before the other and then you get a massive roll rate which will probably kill you.
Not an electric flap. Common practice is to use a simple slipper clutch system that slips when the aerodynamic forces becomes too strong. The flaps may activate to full, but the flap will only extend 10-20% maybe.
The Vfe has very little to do with the flap strength in themselves but more with lift distribution over the wing. The different AOA along the wing will cause the outer part to push downwards and above a certain speed that negative load on the wing will be the same as the limiting negative load factor. So speeds above Vfe with flaps will not loose you the flap but maybe a wing tip. Still enough to ruin your day though…
True. On trainers and rental planes, Vfe is busted almost daily. Still, one doesn’t here about flaps coming off regularly. Heck, even among owner pilots, almost everybody of us has forgotten to retract flaps after takeoff and then wondered why the speed was a little low in cruise…
Still, getting an uncommanded full flaps down randomly in flight isn’t nice.
If your flaps are down, the lift potential of the wing goes up. In a gust this may be enough to break the wing.
The flaps don’t have to fall off in order to cause major trouble.
Usually the power available in climb or cruise is not enough to pull much above vfe with flaps extended anyway. A dive maybe.. Sorry for the thread drift, slow day at work :)
Peter wrote:
can tell you that Socata kept no records of which plane was wired to which diagram.
So the wiring diagrams covered all options.
And to make life interesting they did not release post 2000 (GT) diagrams so you had to have contacts…
It creates more work for avionics installers, for sure.
One would think that creating a file for each serial number would save a lot of time for everyone
Beech have individual wiring diagrams for every serial number.
I agree with your different comments that the problem with the flaps is a major issue. The problem is that the builder of the plane did not fix it.
