Tail slat question

Okay, maybe you are right, but we always referred to the slatted Es as 556
birds. I thought the ex Thunderbirds E I flew had a solid slab. That was
a long time ago, and I was still a student. All my "real" E model time was
in slats.
--
Les
F-4C(WW),D,E,G(WW)/AC-130A/MC-130E EWO (ret)


"Ed Rasimus" wrote in message
...
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

Les Matheson wrote:

Okay, maybe you are right, but we always referred to the slatted Es as 556
birds. I thought the ex Thunderbirds E I flew had a solid slab.

For sure. The old ex-T-bird F-4s were monstrosities of
missing and mis-matched equipment, exempt from many TCTO
upgrades.

And us maintenance pukes called slatted Es as "-556 birds",
too; it was a clearly visible "dividing line" between two
much-different sets of equipment and weapons system operation.

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.
--

It sure wasn't part of the -556 mod (cockpit switches,
major rework of the armament relay panels, new wire
bundles, improved gunsight, and similar) but a whole
bunch of mods were done at the same time as -556.

I don't recall seeing *many* slotted stabs on F-4Es during
the period 1968-72, though there were a few. Originally,
the LE of the stab was without the fixed, mini-slats up front.
IIRC, the slotted stab mod had its own TCTO - but I have no
idea of the number. Finding it would provide a list of the
applicable tail numbers which hadn't already had it accomplished
on the TCTO issue date.

If I had to guess, it was around the time of the flash-
suppressor extension to the gun fairing, or shortly
thereafter... making it about mid-1971 or later.

.. 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.

All J's and N's did.

R / John

"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.

Thank you in advance!

Jim D


No Jim, never. By your post you seem (like a lot of people) to
believe that the horizontal stabilizers on the tailplane help to
carry the aircraft's weight.

This is not true.

The tailplane is designed merely to control the wing which does
the whole of the lifting job. The tail actually 'pushes down' in
level flight. This produces 'fore and aft' stability just as wing
dihedral produces horizontal stability.
--

-Gord.

What the heck the inverted slat is doing on F-4J then, Ed? It has no gun!

--

Nele

NULLA ROSA SINE SPINA
Gord Beaman wrote in message ...
"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.

Thank you in advance!

Jim D


No Jim, never. By your post you seem (like a lot of people) to
believe that the horizontal stabilizers on the tailplane help to
carry the aircraft's weight.

This is not true.

The tailplane is designed merely to control the wing which does
the whole of the lifting job. The tail actually 'pushes down' in
level flight. This produces 'fore and aft' stability just as wing
dihedral produces horizontal stability.
--

-Gord.

On Fri, 13 Feb 2004 12:25:04 +0100, "Nele VII"
wrote:

What the heck the inverted slat is doing on F-4J then, Ed? It has no gun!

BTSOM! Ask a sailor.

Might be to counter a heavier radar, or maybe a balance to the drooped
ailerons or for better control immediately after cat shot. Dunno.


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

Slots are to raise the lift coefficient (down coefficeint on the
horizontal stab?) at low speeds. Enables raising the nose at lower TO
speeds for more AOA for liftoff at lower speeds. FWIW I never saw an E
without a slotted tail. I first flew LES birds on return to the
cockpit in 76. I was not then and am still not impressed. Can't
remember the exact top speed at 1000 ASl in AB but with 2x275 tanks it
was definitely 50-75 knots slower than our Ds at DaNang - even though
the D was carrying a CL bag, 2 MERs, 2 TERs, 2 x AIM9 and a ECM pod.
Our Ds rang up 745 KIAS at 4000 AGL getting out of Dodge after a
little SAM SEAD, and we were happy to see it. The LES bird could loop
at 300 KIAS from 15,000 in AB - BFD - worthless as a combat maneuver.
You can have all the turn you want - I'll take more speed any day. Ask
the 106 drivers who fought our Dash 19 Zippers about turn vs speed.
Walt BJ

WaltBJ wrote:

Slots are to raise the lift coefficient (down coefficeint on the
horizontal stab?) at low speeds. Enables raising the nose at lower TO
speeds for more AOA for liftoff at lower speeds. FWIW I never saw an E
without a slotted tail. I first flew LES birds on return to the
cockpit in 76. I was not then and am still not impressed. Can't
remember the exact top speed at 1000 ASl in AB but with 2x275 tanks it
was definitely 50-75 knots slower than our Ds at DaNang - even though
the D was carrying a CL bag, 2 MERs, 2 TERs, 2 x AIM9 and a ECM pod.
Our Ds rang up 745 KIAS at 4000 AGL getting out of Dodge after a
little SAM SEAD, and we were happy to see it. The LES bird could loop
at 300 KIAS from 15,000 in AB - BFD - worthless as a combat maneuver.
You can have all the turn you want - I'll take more speed any day. Ask
the 106 drivers who fought our Dash 19 Zippers about turn vs speed.

OTOH, considering the number of hard wing F-4s that were lost to
departures (probably at least 150. The one source I have handy lists
USMC/USN admitted losses to this cause up to August 1971 at 79. USAF
losses were probably higher) and the poor state of high alpha training in
the average USAF pilot from 1967 or so, the slats made a lot of sense as
far as keeping the average pilot from departing due to adverse yaw while
maneuvering with a heavy load. Steve Ritchie's wingman John Markle and
his WSO lost their a/c to this cause while in a fight over NVN on May
20th, 1972 (CSAR got them both out)

Owing to the lack of edge of the envelope training (to keep the safety
stats looking good), pilots often encountered the F-4's departure
characteristics for the first time in combat, and didn't know how to
recognize it until too late. Initially the navy figured that they could
fix the problem with improved crew training, but eventually they went for
the same hardware solution that the USAF had already adopted even though
it was less of a problem for their F-4s, given the different mission
distribution compared to the air force (less A/G, more FAD/AtA).

Ultimately, the departure and flight characteristics of the F-4 (and the
F-8, F-100, F-101 and F-104, among others) led the military to put a great
deal of energy and money into flight control and aerodynamic design to
idiot-proof the next generation of fighter a/c (i.e. F-15/16/18 and to a
lesser extent, F-14), to allow the average pilot carefree handling to near
or on the edge of the envelope, while keeping them out of trouble. The
F-5 was an early nudge in that direction as well. There's no doubt that
a/c like the F-16 with hard FC limits that can't be overridden will
penalize the good sticks on some occasions (I'm reminded of the Top Gun
instructor who used to deliberately depart his F-4, to allow him to make
maneuvers that no one else could match), but the average pilot can use so
much more of the envelope confidently that there's an overall improvement
in capability, and a lower attrition rate. They've also improved the
training, obviously, but training time will always be limited and
expensive.

Guy

"Gord Beaman" wrote in message
...



This is not true.

Maybe for slats it is ... but not for slots.

The tailplane is designed merely to control the wing which does
the whole of the lifting job. The tail actually 'pushes down' in
level flight. This produces 'fore and aft' stability just as wing
dihedral produces horizontal stability.

Like the man said, Gord, the Cessna 177 Cardinal had slots on the leading edge
of the horizontal stabiliser.

They were *inverted*, to keep that tail pushing down at low speeds.

GRIN