Slats and Fowler Flaps On Light Plane

Dave

They had them on the T-39 which I flew a little. Seemed to work ok on
the light transport.

Only thing I can remember was running a practice GCA on arrivial at
Tyndall AFB, FL, and the air speed was right at the slots out speed.
Was summer time and some turblance and slats kept banging in and out
against stops. We just picked up 5 MPH or so and they stayed retracted
until we slowed down on glide slope and they extended. Work around
was not a problem.

Only other bird I flew with slats was the Helio Courier (U-10). Again
not a problem as we adjusted our A/S up or down to pervent 'banging'
of slats in rough air at slats out A/S.

Big John

On Mon, 28 Jul 2003 23:15:01 GMT, Dave Hyde wrote:

Big John wrote:

Only some series of the F-86 had slats. They found in Korea a problem
with them (may have not come out together and threw aim off or
something when pulling 'G's'). They changed in the "F" model to a
solid wing without any slats.

As I always like to point out when aero-deployed slats come
up in the newsgroup, A-4's had 'em too. The Blue Angels
wired 'em retracted to prevent 'bobbles' when maneuvering
in close formation. Aggressors, IIRC, wired them up too.
SOP for most any flight was a slat ops check before maneuvering.
I've written here before about asymmetric slat departures, and know
at least on person who jumped out of an otherwise perfectly good
jet after having one stick in and cause a departure at the top
of a loop. I didn't know they got rid of them on the F-86,
that's interesting.

I'm not a big fan of them and have fought to keep them out of
designs where I've had input. I still can't see a reason for
not having an interconnect that outweighs safety of flight.

Dave 'thunk *crack*' Hyde

Big John wrote:

They had them on the T-39 which I flew a little. Seemed to work ok on
the light transport.

Was it the T-39 that had them in sections, like 2 per wing, so
that there were four altogether that could deploy at seemingly random
intervals? g

Was summer time and some turblance and slats kept banging in and out
against stops.

Gouge in the A-4 was that 1/2 slat extension was on-speed AOA in the
landing configuration. I never saw an AOA failure (very little time
in 'em, all in the back seat of T's), but I understand it could be
worked into your scan with some difficulty.

Dave 'swivelneck' Hyde

Dave

Not sure. Was over 30 years ago. They hung out on the ground and
remember pushing them into the retracted position and they would fall
out by their own weight, on pre flight. Want to say they were one
piece but ????????????????????

I never kept a Dash One on the T-39 so can't go there in my files to
answer your question. Didn't find anything via Google on the
construction of the slats. Just that they had them (


Big John



On Tue, 29 Jul 2003 01:00:35 GMT, Dave Hyde wrote:

Big John wrote:

They had them on the T-39 which I flew a little. Seemed to work ok on
the light transport.

Was it the T-39 that had them in sections, like 2 per wing, so
that there were four altogether that could deploy at seemingly random
intervals? g

Was summer time and some turblance and slats kept banging in and out
against stops.

Gouge in the A-4 was that 1/2 slat extension was on-speed AOA in the
landing configuration. I never saw an AOA failure (very little time
in 'em, all in the back seat of T's), but I understand it could be
worked into your scan with some difficulty.

Dave 'swivelneck' Hyde

On Mon, 28 Jul 2003 15:29:14 -0500, Big John
wrote:

Roger

Only some series of the F-86 had slats. They found in Korea a problem
with them (may have not come out together and threw aim off or
something when pulling 'G's'). They changed in the "F" model to a
solid wing without any slats.

Thanks for the info John. I had never heard about the change.

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)
Quote from Internet:

"Replacing the earlier 'A' and 'E' models the 'F' featured a new '6 -
3' wing without the slats found on the leading edge of the earlier
models. The increased chord of the wing (6 inches at the root and 3
inches at the tip) and small boundry layer fences gave better
maneuvering at high speed"

Richard

I sure don't remember 5 sections on each wing but so long ago. However
after 'sleeping' on it they well could have had 5 sections??? Would be
easier to build and keep operational (short sections) than one long
section. Next time I see one that I can get up to will look to
refresh my memory. Maybe someone on r.a.h. might see one and be able
to post what the hardware was.

On deicer boots. Don't think the Air Force ever bought any equipped
that way. Never saw on any of the T-39's I was around.

As an engineer looking at the wing with slats, I don't see how they
could have put boots on and still retained the slats???? Never heard
of a hard wing T-39.

Hope all at Osh have a good time and get home safely. That includes
those drinking "muzzle loader" G

Big John

On Mon, 28 Jul 2003 21:18:41 -0700, "Richard Isakson"
wrote:

"Big John" wrote ...
Not sure. Was over 30 years ago. They hung out on the ground and
remember pushing them into the retracted position and they would fall
out by their own weight, on pre flight. Want to say they were one
piece but ????????????????????

I never kept a Dash One on the T-39 so can't go there in my files to
answer your question. Didn't find anything via Google on the
construction of the slats. Just that they had them (

According to the 1969-70 Janes:

"North American

T-39

Wings:
Aerodynamically-operated leading-edge slats in five sections on each wing.
Optional full-span pneumatically-operated de-icer boots."

Now there's an interesting trick.

Rich

"Brock" a écrit dans le message news:
...
I feel there is a real advantage to the use of slats and flaps in
order to have things happen slowly during landing and yet still have a
good cruise speed. Of course the problem is in the complexity and the
extra weight. For rails I was thinking about something like standard
kitchen drawer rails or perhaps a tube within a tube design. I
wouldn't think their would be a lot of force on the slat at low
takeoff speeds so the structure wouldn't have to be bullet proof,
their would probably be a lot more force on the flaps though. I
haven't been able to find information if the necessary airplane
hardware is available commercially, perhaps it would have to be custom
made. Any ideas on how to go about building something like this?

Brock

I fear that if flaps has some aerodynamic effect, they HAVE to be bullet
proof.
Just imagine what could happen in cas of disymetrical openning. Or one side
flap locked in landing configuration, the other side retracting. I dont
think aileron whould have enought authority to overcome the roll.

And for fowler flaps, I unterstand it is the ones that go aft before
rotating.

What about ordinary rotating flaps, but with a very low rotation points. Say
rotation point one feet below the wing. at 45° extention, the leading edge
of the flap would be (sin (45°)) aft. No need for rails. A bunch of slotted
flaps on certified planes just act like this.

Other point to consider a
-Tail should have enough authority to compensate the pitching moment.
-your plane should have enough power to have a positive climb rate, at full
load with flaps, fowlers, landing gear fully extented.

On Mon, 28 Jul 2003 21:18:41 -0700, "Richard Isakson"
wrote:

"Big John" wrote ...
Not sure. Was over 30 years ago. They hung out on the ground and
remember pushing them into the retracted position and they would fall
out by their own weight, on pre flight. Want to say they were one
piece but ????????????????????


It's been a long time for me also, but I'm sure the slats were one
piece, with five roller guides per wing. I've never seen a de-ice
boot on one.

An interesting story that I heard, again a long time ago, was from a
pilot that had flown the F-86D and got checked out in the T-39. The
wings look a lot the same, and the plane flew about the same. Well,
they would roll and loop and dogfight the T-39s until they found out
that they were only designed for something like 3.8 Gs.

Mike Weller

Mike

Your comments on slats now seem to track with what I remember.

I flew the 'D','H' & 'J' at Hamilton and the 'J' as AFA to Maine ANG
(Bangor, ME). Flying the 'J' I've launched a MB-1, in practice, past
vertical and just above the stall speed. (IFR at night in the middle
of the clouds). Interesting flying the bird back to level flight
starting with zero A/S and going straight up IFRG

On '39. Was told that the wing came off the F-86 line (no new
engineering) and was tough as hell. Where the lower limits were on
bird I don't know but know they were there. Always flew the '39 as a
transport not as a fighter as always had passengers on board, unless
repositioning bird. It was the General's personal bird so we couldn't
tear it up very bad (go inverted and spill the coffee G.

Miss the 'old' days

Big John


On Thu, 31 Jul 2003 18:31:17 GMT, Mike Weller
wrote:

On Mon, 28 Jul 2003 21:18:41 -0700, "Richard Isakson"
wrote:

"Big John" wrote ...
Not sure. Was over 30 years ago. They hung out on the ground and
remember pushing them into the retracted position and they would fall
out by their own weight, on pre flight. Want to say they were one
piece but ????????????????????


It's been a long time for me also, but I'm sure the slats were one
piece, with five roller guides per wing. I've never seen a de-ice
boot on one.

An interesting story that I heard, again a long time ago, was from a
pilot that had flown the F-86D and got checked out in the T-39. The
wings look a lot the same, and the plane flew about the same. Well,
they would roll and loop and dogfight the T-39s until they found out
that they were only designed for something like 3.8 Gs.

Mike Weller

It's been a long time for me also, but I'm sure the slats were one
piece, with five roller guides per wing. I've never seen a de-ice
boot on one.


I saw them on a USMC or Navy T-39 in the mid 1990s. I bet they add a ton of
drag.

I used to work on A and B model T-39s at Langley AFB in the mid 70s. The slats
may have been made up of 5 segments each, but they were one piece as far as I
could tell. They pushed in as one anyway.

Dan, U.S. Air Force, retired