C152 Flaps

[caioatpl]

Anyone knows where is located the motor that actuate the flaps of a CESSNA 152 and if there is a motor for each flap or one for both?

I can't find it on the POH

 

[MAKG1]

I believe it's inside the wings ahead of each flap (separately).

An ear to the wing during deployment during preflight ought to isolate it for you.

 

[flyingron]

No, there's only one motor on the (if I remember correctly) left side. It drives both flaps through a small transmission, one side directly to the push rod and the other via cables to the pushrod on that side. The latter is the only part the pilot typically sees.

The real intersting part is the flap handle. It moves two microswitches that track around the flap indicator. If the handle is displaced where the indicator is currently, it actuates either the UP or DOWN microswitches powering the motor.

 

[Dan Thomas]

No, there's only one motor on the (if I remember correctly) left side. It drives both flaps through a small transmission, one side directly to the push rod and the other via cables to the pushrod on that side. The latter is the only part the pilot typically sees.

The real intersting part is the flap handle. It moves two microswitches that track around the flap indicator. If the handle is displaced where the indicator is currently, it actuates either the UP or DOWN microswitches powering the motor.

It's in the right wing, and looks like this:

The motor itself has the Cessna name on it. Above it is a wormdrive gearbox, and the output of that gearbox drives a threaded shaft. The shaft isn't visible in thisphoto; it's inside the long green tube, which has a nut (the black thing) that runs along the threads as the shaft turns. In this shot the flaps are retracted; extending them runs the nut to the right, which turns the bellcrank and pulley assembly on the right side of the photo; a rod from the other end of the bellcrank (holes at 5 o'clock on the pully assembly) pushes the flaps down. Cables around the pulley itself run across the cabin, above the headliner, to the left wing where they drive a similar pulley/bellcrank that moves the left flap.

Below the long tubular nut you can see an aluminum rod with two aluminum blocks on it. Out of sight under the nut are microswitches on those blocks; they stop the motor at both ends of the travel to avoid damage. Older Cessnas had a slip clutch as part of the nut so damage was avoided if the pilot held that little paddle-type flap switch down or up too long.

On the far left you see a bracket with a vertical hole in it. This is the motor mount and a long bolt right through the wing, top to bottom, holds it. The bracket can pivot sideways a bit, which is why it's tilted here. Another long bolt runs through a bushing that fits through the pulley's hole, and both bolts can be seen above and below the wing. Heads of the bolts on top, the nuts on the bottom. Tiny roller bearings in the pulley run on the bushing. Water gets in there, and heat gets in too, and the grease hardens and dries out and reacts with the water to form acids and corrode the bearings and bushing and making flap actuation slow and noisy. And in about three quarters of these airplanes, the cables have stretched and haven't been properly readjusted and the left flap will feel spongy if you move it when it's extended. It might not even retract or extend all the way.

Dan