Sundowner Wing Flaps

[A Lieberman]

..... dont retract "on their own".

Beech Sundowner.

I will be talking to my A&P tomorrow, but just curious if anybody knows
whether I am talking major expense or something simple like a spring
that pulls the flaps up that came loose in the innards of the wings.

A gentle nudge on the outside and they go up. No rubbing or noises
noted.

Allen

[Jim Besselman]

The flaps on my Sundowner behave the same way and have ever since I've owned
the plane. I had the A & P that did my prebuy check it out and could find
nothing wrong. I also found an entry in an old squawk booklet that noted the
problem. The maintenance responce was that this was "Normal". The air
movement from the prop is sufficient for them to retract. I am interested in
what your A & P says.

Jim

"A Lieberman" > wrote in message
...
> .... dont retract "on their own".
>
> Beech Sundowner.
>
> I will be talking to my A&P tomorrow, but just curious if anybody knows
> whether I am talking major expense or something simple like a spring
> that pulls the flaps up that came loose in the innards of the wings.
>
> A gentle nudge on the outside and they go up. No rubbing or noises
> noted.
>
> Allen

[BTIZ]

interesting... this is I presume with the flap lever in the "extended and
locked position".. I've flown Sports and Sundowners and never had this
problem.. I "expect" that it is very much the same mechanism on various
Piper models to include the Twin Seneca.

now.. this type of flap can "extend" based on pressure applied externally
(tail wind, hand pressure) and when the props starts fanning the wings.. the
new air pressure is enough to cause a retract..

is there an "air load" on the flaps lock in flight to keep them from self
retracting?

BT

"Jim Besselman" > wrote in message
...
> The flaps on my Sundowner behave the same way and have ever since I've
owned
> the plane. I had the A & P that did my prebuy check it out and could find
> nothing wrong. I also found an entry in an old squawk booklet that noted
the
> problem. The maintenance responce was that this was "Normal". The air
> movement from the prop is sufficient for them to retract. I am interested
in
> what your A & P says.
>
> Jim
>
> "A Lieberman" > wrote in message
> ...
> > .... dont retract "on their own".
> >
> > Beech Sundowner.
> >
> > I will be talking to my A&P tomorrow, but just curious if anybody knows
> > whether I am talking major expense or something simple like a spring
> > that pulls the flaps up that came loose in the innards of the wings.
> >
> > A gentle nudge on the outside and they go up. No rubbing or noises
> > noted.
> >
> > Allen
>
>

[A Lieberman]

BTIZ wrote:
>
> interesting... this is I presume with the flap lever in the "extended and
> locked position"..

HI BTIZ,

Yes, I pull the lever up, and the flaps go down. I put the lever down
to retract the flaps, and they stay down. "Operationally, extending the
flaps feels perfectly normal. When I retract in increments, it feels
normal from the feel of the flap handle (I can feel the indents /
increments.

> is there an "air load" on the flaps lock in flight to keep them from self
> retracting?

I never thought of this, but you raise a good question. What actually
does prevent the flaps from retracting while in flight? When I have the
handle at each increment, the flaps are solidly locked in place. When I
put the handle in the retracted position, a gently nudge retracts the
flaps.

From the personal replies in my email, everything is pointing to a
lubrication fix. (I sure hope so anyway!) as this apparently is a
problem that has been experienced by other Sundowner owners. I will
post the results when the A&P gets to the plane (hopefully tomorrow!).

Allen

[BTIZ]

A Lieberman" > wrote in message
...
> BTIZ wrote:
> >
> > interesting... this is I presume with the flap lever in the "extended
and
> > locked position"..
>
> HI BTIZ,
>
> Yes, I pull the lever up, and the flaps go down. I put the lever down
> to retract the flaps, and they stay down. "Operationally, extending the
> flaps feels perfectly normal.

if you are at Ground speed zero.. on the ground.. no engine running.. than
that is perfectly normal.. just a little "drag" in the mechanism somewhere
that holds them in the down postion.

The flap lever, extends the flaps.. and it releases the flaps to either
retract or reduce to a lower flap setting.. the prop wash is enough to get
the flaps up.. the flaps are not mechanically connected to an "up lever", it
only holds and locks them down.. does that make sense.

Air loads in flight push against the "down stops" so the flap is more
responsive to the flap lever.

There are two reasons why the flaps are marked "No Step", one is they may
not support weight without being damaged, the second, if in the up position,
they may go to the down position when you step on them. (floor falling out
from under you) (trap door)

If the mechanic has looked and said they are ok.. I tend to agree.. I am not
a mechanic.

BT

[Dave Butler]

BTIZ wrote:

> If the mechanic has looked and said they are ok.. I tend to agree.. I am not
> a mechanic.

I likewise am not a mechanic. I have owned a Cherokee whose flaps behaved in the
same way, and I was told it was not a problem. It's only annoying on the ramp
after you complete your preflight check and want to retract the flaps.

Occasionally if I put the flap handle in the fully retracted position, after
several seconds or minutes the springs would suddenly overcome the friction that
was holding the flaps extended, and the flaps would retract with a loud bang.
Scares the *%&@$ out of you, and can't be good for the flap mechanism.

Dave
Remove SHIRT to reply directly.

[A Lieberman]

Jim Besselman wrote:
>
> The flaps on my Sundowner behave the same way and have ever since I've owned
> the plane. I had the A & P that did my prebuy check it out and could find
> nothing wrong. I also found an entry in an old squawk booklet that noted the
> problem. The maintenance responce was that this was "Normal". The air
> movement from the prop is sufficient for them to retract. I am interested in
> what your A & P says.

Update on flap situation

A&P lubed all moving parts and up they go on command. A&P said that no
prop wash should be needed to raise flaps. Problem solved.

Thanks to all that posted and emailed me privately!

Allen

[Nathan Young]

A Lieberman > wrote in message >...
> .... dont retract "on their own".
>
> Beech Sundowner.
>
> I will be talking to my A&P tomorrow, but just curious if anybody knows
> whether I am talking major expense or something simple like a spring
> that pulls the flaps up that came loose in the innards of the wings.
>
> A gentle nudge on the outside and they go up. No rubbing or noises
> noted.


I have found that a strong tailwind while doing a preflight will keep
my flaps down after the handle has been released. This is on a PA28.
Running the engine up will provide enough 'headwind' to release the
flaps.

-Nathan

[Javier Gorordo]

Just curious...What makes you think is the prop wash and not the
vibration of the engine?

Javier

[Not an A&P, haven't flown Sundowners in over 15 yrs]


"BTIZ" > wrote in message news:<ipuyb.333$yf.222@fed1read01>...

SNIP
> The flap lever, extends the flaps.. and it releases the flaps to either
> retract or reduce to a lower flap setting.. the prop wash is enough to get
> the flaps up..
UNSNIP
> BT

[John Roncallo]

Jim Besselman wrote:
> The flaps on my Sundowner behave the same way and have ever since I've owned
> the plane. I had the A & P that did my prebuy check it out and could find
> nothing wrong. I also found an entry in an old squawk booklet that noted the
> problem. The maintenance responce was that this was "Normal". The air
> movement from the prop is sufficient for them to retract. I am interested in
> what your A & P says.
>

Our club's Piper occasionally does this. I was told this is normal but
personally I believe that is BS. But I'm not an A&P I'm only an
Aerospace Engineer so what would I know. My guess without taking the
system apart is that this is a worn linkage allowing some bellcrack to
go over center at full extension. Will the air loads retract the flap?
Probably. Is this the mechanism the engineer had in mind for flap
retraction when it was designed? I doubt it.

John Roncallo

I read an article one time about pilot squawks and A&P responses. My
favorite one goes like this.

Pilot: Prop #3 seeping oil
Mechanic: Oil seepage is normal
Pilot: Props #1, 2, 4 lack normal seepage.

John Roncallo