Tail slat question

Hello all,

Just a quick question - do any aircraft have slats installed on the leading
edge of the horizontal tailplane?

Rather like slats would be used on the main wing section but - instead of
providing helpful lift - they're just to counter a very large pitching
moment on approach when wing-mounted high lift devices are deployed.

Thank you in advance!

Jim D

On Thu, 12 Feb 2004 21:16:48 -0000, "Jim Doyle"
wrote:

Hello all,

Just a quick question - do any aircraft have slats installed on the leading
edge of the horizontal tailplane?

Rather like slats would be used on the main wing section but - instead of
providing helpful lift - they're just to counter a very large pitching
moment on approach when wing-mounted high lift devices are deployed.


Can't comment on slats, which implys to me moveable. But, the F-4E at
slots on the horizontal tailplane--fixed sections about two inches
extended from the leading edge of the tailplane sections and running
the entire length.

The slotted slab was one of the mods necessary to compensate for the
longer nose and forward weight addition of the gun. A #7 fuel cell was
added in the tail cone to increase extreme aft weight and the fixed
slots were added to the tail plane to provide increased aerodynamic
downforce to counter the nose gun.



Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
Smithsonian Institution Press
ISBN #1-58834-103-8

Can't comment on slats, which implys to me moveable. But, the F-4E at
slots on the horizontal tailplane--fixed sections about two inches
extended from the leading edge of the tailplane sections and running
the entire length.

The slotted slab was one of the mods necessary to compensate for the
longer nose and forward weight addition of the gun. A #7 fuel cell was
added in the tail cone to increase extreme aft weight and the fixed
slots were added to the tail plane to provide increased aerodynamic
downforce to counter the nose gun.



Ed Rasimus

One of my friends who flew slatted/non slatted wing F-4s and also F-15As at
Holloman, told me at medium altitudes, he thought a non slatted F-4 was
actually a little bit faster than an F-15A.


Ron
Tanker 65, C-54E (DC-4)

On 12 Feb 2004 22:04:13 GMT, 362436 (Ron) wrote:

One of my friends who flew slatted/non slatted wing F-4s and also F-15As at
Holloman, told me at medium altitudes, he thought a non slatted F-4 was
actually a little bit faster than an F-15A.


Ron
Tanker 65, C-54E (DC-4)

That would be a hard call, but I doubt it. Certainly top speed for an
LES version of the F-4E would be lower than a non-slat (and range
would be lower because of the foamed tanks after LES conversion.)

But, I'd bet that with the cleaner airframe overall, the Eagle would
have the edge as well as the bigger engines. Certainly sustainability
of airspeed during manuever would be no-contest in favor of the F-15.

Might be a question of what he meant by "faster"--higher cruise speed?
higher top end? sub-sonic or super? clean or typical load? missiles or
not? etc. etc.

Now, an RF-4....


Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
Smithsonian Institution Press
ISBN #1-58834-103-8

"Ed Rasimus" wrote in message
...
On 12 Feb 2004 22:04:13 GMT, 362436 (Ron) wrote:

One of my friends who flew slatted/non slatted wing F-4s and also F-15As
at
Holloman, told me at medium altitudes, he thought a non slatted F-4 was
actually a little bit faster than an F-15A.


Ron
Tanker 65, C-54E (DC-4)

That would be a hard call, but I doubt it. Certainly top speed for an
LES version of the F-4E would be lower than a non-slat (and range
would be lower because of the foamed tanks after LES conversion.)

But, I'd bet that with the cleaner airframe overall, the Eagle would
have the edge as well as the bigger engines. Certainly sustainability
of airspeed during manuever would be no-contest in favor of the F-15.

Might be a question of what he meant by "faster"--higher cruise speed?
higher top end? sub-sonic or super? clean or typical load? missiles or
not? etc. etc.

Now, an RF-4....

Weasel, super sonic 100 feet off the ground.

Ed Rasimus wrote:

On Thu, 12 Feb 2004 21:16:48 -0000, "Jim Doyle"
wrote:

Hello all,

Just a quick question - do any aircraft have slats installed on the leading
edge of the horizontal tailplane?

Rather like slats would be used on the main wing section but - instead of
providing helpful lift - they're just to counter a very large pitching
moment on approach when wing-mounted high lift devices are deployed.


Can't comment on slats, which implys to me moveable. But, the F-4E at
slots on the horizontal tailplane--fixed sections about two inches
extended from the leading edge of the tailplane sections and running
the entire length.

The slotted slab was one of the mods necessary to compensate for the
longer nose and forward weight addition of the gun. A #7 fuel cell was
added in the tail cone to increase extreme aft weight and the fixed
slots were added to the tail plane to provide increased aerodynamic
downforce to counter the nose gun.

Ed, I tend to doubt the extra forward weight was responsible for the fixed
inverted slot (not slat) on the tail, as the navy's F-4J, with the short nose
and No.7 tank, also had it from the beginning, indeed before the F-4E entered
service. The F-4J also removed the inboard section of the LEFs and had drooped
ailerons, so that may have had something to do with it, but I'm cross-posting
this to r.a.m.n. to see if anyone over there knows why.

Guy

The slotted stabs were only on the slatted (post -556) birds. Most Es, all
Fs,Gs and subsequent models. Hard wing F-4s didn't have slotted stabs.
--
Les
F-4C(WW),D,E,G(WW)/AC-130A/MC-130E EWO (ret)


"Ed Rasimus" wrote in message
...
On Thu, 12 Feb 2004 21:16:48 -0000, "Jim Doyle"
wrote:

Hello all,

Just a quick question - do any aircraft have slats installed on the
leading
edge of the horizontal tailplane?

Rather like slats would be used on the main wing section but - instead of
providing helpful lift - they're just to counter a very large pitching
moment on approach when wing-mounted high lift devices are deployed.


Can't comment on slats, which implys to me moveable. But, the F-4E at
slots on the horizontal tailplane--fixed sections about two inches
extended from the leading edge of the tailplane sections and running
the entire length.

The slotted slab was one of the mods necessary to compensate for the
longer nose and forward weight addition of the gun. A #7 fuel cell was
added in the tail cone to increase extreme aft weight and the fixed
slots were added to the tail plane to provide increased aerodynamic
downforce to counter the nose gun.



Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
Smithsonian Institution Press
ISBN #1-58834-103-8

On Thu, 12 Feb 2004 14:22:53 -0800, "Tarver Engineering"
wrote:


"Ed Rasimus" wrote in message

That would be a hard call, but I doubt it. Certainly top speed for an
LES version of the F-4E would be lower than a non-slat (and range
would be lower because of the foamed tanks after LES conversion.)

But, I'd bet that with the cleaner airframe overall, the Eagle would
have the edge as well as the bigger engines. Certainly sustainability
of airspeed during manuever would be no-contest in favor of the F-15.

Might be a question of what he meant by "faster"--higher cruise speed?
higher top end? sub-sonic or super? clean or typical load? missiles or
not? etc. etc.

Now, an RF-4....

Weasel, super sonic 100 feet off the ground.

Would you mean F-100F Weasel, F-105F Weasel, F-105G Weasel, F-4C
Weasel or F-4G Weasel??? I've flown next to four of those five (in
combat) and will testify that none of them have any particular
advantage for going fast. In fact, the Weasel conversions for all five
aircraft add bumps and blisters for antennae that increase drag.

Yes, an F-105 is fast and I will testify that the airplane is capable
of supersonic flight at extreme low altitude, but I'd opt for
single-seat D model to really go fast and not a wart-encrusted
two-seater.

The F-4G Weasel, of course was LES.


Ed,
Society of Wild Weasels #2488


Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
Smithsonian Institution Press
ISBN #1-58834-103-8

On Thu, 12 Feb 2004 16:56:53 -0600, "Les Matheson"
wrote:

The slotted stabs were only on the slatted (post -556) birds. Most Es, all
Fs,Gs and subsequent models. Hard wing F-4s didn't have slotted stabs.

Better go out and dig up the old dash-1s, Les. First, TCTO -556 was
the change of the conventional weapons control panel and the
incorporation of the pinkie switch for A/A weapons selection and the
forward push button on the throttle to let the front-seater quickly
take control of the radar to five mile boresight and auto-acq.

The LES mod was TCTO -566. I never got to fly a LES airplane, since
the Korat E's didn't get converted and when I went to Spain, I watched
the last of the 401st hard-wing E's depart and only flew the F-4C
during my tenure there. Let me assure you that the hard-wing E model
had a slotted slab. The C and D model didn't have a slotted slab (and,
of course, they were all hard wings.)


Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
Smithsonian Institution Press
ISBN #1-58834-103-8

Cessna's 177/RG Cardinal series had slots installed in the stab to keep
the tail from stalling before the wing. The first batch didn't have them
& were installed after the fact which led to later production 177s
having them installed.