Verifying flap retraction

In article , "Julian Scarfe"
wrote:

How exactly do Piper manual flap systems work then?

extend flaps against the spring. retract flaps an exercise
in making they don't snap back (push the button and let the
bar down slowly).

--
Bob Noel
Seen on Kerry's campaign airplane: "the real deal"
oh yeah baby.

In article ,
"C J Campbell" wrote:

Most of the problems that I have had on Cessna 172s have been with
flaps. I
agree that pilots should verify flaps up on touch and goes.

Cessna used to have manual flaps. Why did they ever go to this flakey
electrical system in the first place?

"Roy Smith" wrote in message
...

I did my initial training in Cessnas, and "verify flaps retracting" was
drummed into me as part of the touch-and-go procedure.

Now I fly mostly Pipers. I really like the manual flaps instead of
Cessna's electric ones, and curse the electric trim Piper uses instead
of Cessna's manual trim system.

Simple stuff just works better.

How exactly do Piper manual flap systems work then? We have a Piper Twin
Comanche with an electric flap system. The flaps are pushed down, but come
back up using springs, in effect after latches are removed. We've now had
two asymmetric flap retractions, where one of the springs failed to do its
job. This is Not Good.

So when you lower the flap handle in a manual Piper system, does it drag the
flaps up or does it merely take the latch away and allow the spring to do
its job, as in the electrical equivalent?

Julian Scarfe

How exactly do Piper manual flap systems work then? We have a Piper Twin
Comanche with an electric flap system. The flaps are pushed down, but come
back up using springs, in effect after latches are removed. We've now had
two asymmetric flap retractions, where one of the springs failed to do its
job. This is Not Good.

Was this on the ground after landing, or in flight? I'd think that the air
load on extended flaps would help push them up in flight.

Barry opined

How exactly do Piper manual flap systems work then? We have a Piper Twin
Comanche with an electric flap system. The flaps are pushed down, but come
back up using springs, in effect after latches are removed. We've now had
two asymmetric flap retractions, where one of the springs failed to do its
job. This is Not Good.

Was this on the ground after landing, or in flight? I'd think that the air
load on extended flaps would help push them up in flight.

It won't. I had one flap not retract once. It just got hung up half way for some
reason. So I just lowered the flaps until they were symmetric and landed.

It helped that it was a test flight and I was in the pattern at the time.



-ash
Cthulhu for President!
Why vote for a lesser evil?

We've now had
two asymmetric flap retractions, where one of the springs failed to do
its
job. This is Not Good.

"Barry" wrote in message ...

Was this on the ground after landing, or in flight? I'd think that the
air
load on extended flaps would help push them up in flight.

It was in flight. I'm not sure what the magnitudes of the airloads are.

Julian

"Julian Scarfe" wrote in message
news
"Barry" wrote in message
...

Was this on the ground after landing, or in flight? I'd think that the
air
load on extended flaps would help push them up in flight.

It was in flight. I'm not sure what the magnitudes of the airloads are.

Not answering the original question, I've noticed something recently with
my plane. It has electric flaps. It has two "notches", 15 degrees and
45 degrees, marked "take off" and "landing". When I'm on the ground
and set the flaps to "take off", the motor runs for a certain distance,
stops, but the flaps continue moving for a second and end up in the
correct position.

When I'm in flight, when I select the first notch, the motor runs for the
same distance but presumably because of the air loads, the flaps
stop there, i.e. no run on. This means the flaps aren't extended the
correct amount when set to 15 degrees in the air.

Apart from adding friction to the motor/mechanism so there's no run-on
on the ground, then re-adjusting for the correct position, is there any
way round this?

Paul

"Julian Scarfe" wrote in message
...
So when you lower the flap handle in a manual Piper system, does it drag
the
flaps up or does it merely take the latch away and allow the spring to do
its job, as in the electrical equivalent?

Hardly a definitive answer but I seem to remember pre-flighting
something (may have been a PA28) where the flaps stuck down
when I put the lever back down. A quick nudge freed them.

Paul

Are you sure there is a problem? If the flaps end up in the correct position
the motor run duration may simply be a part of the way things are designed.




"Paul Sengupta" wrote in message
...
"Julian Scarfe" wrote in message
news
"Barry" wrote in message
...

Was this on the ground after landing, or in flight? I'd think that
the
air
load on extended flaps would help push them up in flight.

It was in flight. I'm not sure what the magnitudes of the airloads are.

Not answering the original question, I've noticed something recently with
my plane. It has electric flaps. It has two "notches", 15 degrees and
45 degrees, marked "take off" and "landing". When I'm on the ground
and set the flaps to "take off", the motor runs for a certain distance,
stops, but the flaps continue moving for a second and end up in the
correct position.

When I'm in flight, when I select the first notch, the motor runs for the
same distance but presumably because of the air loads, the flaps
stop there, i.e. no run on. This means the flaps aren't extended the
correct amount when set to 15 degrees in the air.

Apart from adding friction to the motor/mechanism so there's no run-on
on the ground, then re-adjusting for the correct position, is there any
way round this?

Paul

In article ,
"Paul Sengupta" wrote:


Not answering the original question, I've noticed something recently with
my plane. It has electric flaps. It has two "notches", 15 degrees and
45 degrees, marked "take off" and "landing". When I'm on the ground
and set the flaps to "take off", the motor runs for a certain distance,
stops, but the flaps continue moving for a second and end up in the
correct position.

When I'm in flight, when I select the first notch, the motor runs for the
same distance but presumably because of the air loads, the flaps
stop there, i.e. no run on. This means the flaps aren't extended the
correct amount when set to 15 degrees in the air.

Are you flaps driven by a jack-screw?

Are you sure that the flaps are going to 15 when on the ground? Perhaps
they are adjusted to give you 15 with airloads on them but overrun
slightly on the ground.

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

"Dale" wrote in message
...
In article ,
"Paul Sengupta" wrote:

Not answering the original question, I've noticed something recently
with
my plane. It has electric flaps. It has two "notches", 15 degrees and
45 degrees, marked "take off" and "landing". When I'm on the ground
and set the flaps to "take off", the motor runs for a certain distance,
stops, but the flaps continue moving for a second and end up in the
correct position.

When I'm in flight, when I select the first notch, the motor runs for
the
same distance but presumably because of the air loads, the flaps
stop there, i.e. no run on. This means the flaps aren't extended the
correct amount when set to 15 degrees in the air.

Are your flaps driven by a jack-screw?

Um, I presume so. Haven't looked.

Are you sure that the flaps are going to 15 when on the ground? Perhaps
they are adjusted to give you 15 with airloads on them but overrun
slightly on the ground.

Maybe. But then they'd be in the wrong position for take-off! :-)
Handbook says to take off with take-off flap and gives the technique
for doing so. It does not mention take-off without flap at all. Mind
you, it takes off just fine without them! :-)

There's a flap position indicator dial and it points exactly to the take-off
position when lowered on the ground. When lowered in the air, it
stops slightly before. Adjusting the motor cut-off point is easy, there's
an adjustable microswitch under the floor just behind the seats.

In the real world, this isn't a problem...I doubt an extra/fewer couple
of degrees of flap movement makes much difference to my flying!

Paul