Question for F4 drivers.

[thing]

A pal and I were talking about short field take off technique in light aircraft the other day and somehow or other we finished up talking about the F4 stabilator position on take off. I seem to remember that on the take off roll the stabilator was in the full stick back position. Is this correct and if so why did you do this rather than the usual ease back at rotation speed?

Were there any other FJs where this technique was employed?

[BEagle]

Yes.

F-4 control column position was fully back.
Vulcan control column position was fully forward.

For the F-4, I seem to recall it was something to do with a risk of stab jack stall?

For the Vulcan it was to maintain positive steering - and down elevon helped increase lift.

[thing]

Interesting, thanks for that.

[SpazSinbad]

"Minimum Run Takeoff [A-4E/F/G NATOPS]
To accomplish a minimum run takeoff, full noseup
trim and half-flaps should be employed.
NOTE
Use of full-flaps delays nosewheel lift-off.
After brake release, as the aircraft accelerates down
the runway, a generous amount of aft stick should be
used to effect nosewheel lift-off. During aircraft
lift-off, (about 10 KIAS less than normal), a noseup
rotation of the aircraft will occur, which will require
an immediate reduction in aft stick pressure to control.
As the aircraft accelerates to climbing speed
after takeoff, almost constant retrimming of the
stabilizer will be necessary. The noseup rotation of
the aircraft at takeoff is reduced in abruptness and
severity by an increase in gross weight or by use of
less aircraft noseup trim. However, if less than fullnoseup
trim is employed, the effect will be to increase
the minimum nosewheel lift-off speed about 4 knots
and increase the takeoff run approximately 300 feet
for each 2 degrees of reduced noseup trim."

When using this technique at Canberra Airport / RAAF Fairbairn for my one and only short takeoff with half internal fuel in an A4G (on way back to NAS Nowra in CAVOK) the push forward to stop the rapid nose rotation took a lot of strength, whilst the nose down electric trim took the time to get it under control. Outside observers (in an S-2E to follow + a GoonieBird with A4G support equipment - portable huffer [Palouste] and electrics cart) said it was spectacular to watch.

http://i98.photobucket.com/albums/l261/SpazSinbad/NewerAlbum/th_A-4horizontalStabilizerElevatorComboNATOPSgraphicW.gif (http://s98.photobucket.com/user/SpazSinbad/media/NewerAlbum/A-4horizontalStabilizerElevatorComboNATOPSgraphicW.gif.html)

[Bevo]

For the F-4, I seem to recall it was something to do with a risk of stab jack stall?


The reason for the full aft stick technique in the F-4 was that it was the easiest way to attain the proper takeoff attitude and ensure the shortest takeoff roll.

From the F-4C/D/E - 1

NORMAL TAKEOFF
Sufficient aft stick should be applied prior to nose wheel liftoff speed to attain the desired pitch attitude. As the nose rises, pitch attitude must be controlled to maintain a 10 to 12 deg. pitch attitude nose high attitude for aircraft fly-off. Caution must be exercised to preclude over-rotation due to excessive aft stick rate or an extended takeoff roll due to late lift-off.

MINIMUM RUN/HEAVY GROSS WEIGHT TAKEOFF
A minimum run/heavy gross weight takeoff (aircarft over 50,000 pounds) is accomplished in the same manner as a normal takeoff with the following exceptions. It is recommended that all minimum run/heavy gross weight takeoffs be made with afterburner. During takeoff run, full aft stick must be applied prior to reaching 80 knots. As the aircraft starts to rotate, the stick should be adjusted to maintain 10 to 12 deg. pitch attitude for aircraft fly-off. The possibility of a main landing gear tire failure increases with extended takeoff ground run under heavy gross weight conditions.

[27mm]

Early 80s at Wilders on a winter's day, 15kt headwind in a clean-wing F4; lined up just past the numbers and launched with the SOP max burner and full back stick. Airborne at just past the approach-end cable in 9 seconds. Typhoon - pah! :cool:

[thing]

Reading the above reminded me of a bet I had with a pal on the OCU back in the day. He reckoned that a normal fit OCU kite (2xFletchers, 2xdummy Sparrows) would go brakes off to unstick in less than ten seconds; I reckoned more. We timed about a dozen take offs and the average was 15 seconds. Drinks were on him.

[Dominator2]

I seem to recall that the teaching was stick fully aft by 100kts. As the nose started to rise, check at 10-12 deg and allow the ac to fly off. The main reasons for the F4 not taking off correctly were bad technique, C of G close or out of limits, or a poorly serviced nose oleo.
I recall a high speed abort at 160kts because the pilot thought that there was something wrong with the ac. Although the pilot had over 1000hrs on the ac it was found that he used the wrong take off technique. That and a slightly flat oleo meant that he would achieve a "late rotation". Some long time F4 pilots claimed the ac would always fly by 200kts. The only question was whether the runway was long enough.