Anyone care to make a guess ?

[FullyFlapped]

I flew four times last week in my 172. Lovely, no probs at all.

Today I went to fly again. My usual pre-startup checks failed because when I went to check the flaps, nothing happened. Nothing. No motor noise, no unusual switch tension etc, nothing at all. Just silence.
The circuit breakers were all fine. No obvious reason for the lack of flap travel. Last trip they played fine.

So, anyone care to guess what the problem might be, before I call in the engineers tomorrow?
FF :ok:

[Saab Dastard]

Is this a trick question - early 172s had manual flaps. Just check that you are in the right 172 ;)

Squirrel ate the cable?

[A and C]

Two things to check, first it may be the motor has failed so check the electrical power at the flap motor end of the system.

The next thing to check if there is no power at the motor is the power at the flap lever, this has two microswitches attached to it and failure of one of these swiches is the most common cause of Cessna flap failure.

The good news is that the swiches are cheap (about £10) but it is a pain to change the swiches so expect about 2-3 hours labor to do the job.

[smarthawke]

Another favourite to fail is the earth lead from the motor to the wing structure (skin or rib next to the motor). They just seem to break after a while.

Sometimes the motors have a sad-on in one position and a hefty but well aimed thump is enough to free them.

Limit micro switches on the motor assembly/screw jack can fail. This means that the motor stops working when either fully up or down depending on which switch fails.

[FullyFlapped]

Hmm ... interesting, guys, thanks. Most of those I wouldn't have guessed !

I'll let you know who wins the prize when the engineers have pronounced their verdict !

FF :ok: