Question for the F4M guys.

[thing]

How bad/good was the jet without the stab augs in? Just had a long chat with an old F4 mate and we got around to stab augs as you do, being as they were part of our trade. We both fly so have a passing interest in the handling qualities of the beast with and without.

[Rhino power]

Bob Prest relates a story of the Stab Aug's cycling in and out after generator failure during a flight from Luqa, Malta in his book, I seem to remember him stating the jet was extremely sensitive in pitch, roll and yaw...

-RP

[Ali Qadoo]

Last flew the F-4 in 1986 so my recall may be a tad rusty. ISTR that the roll stab aug was pretty much optional unless you wanted to use what was laughingly known as the autopilot (would've been better named as 'the unusual position generator'). When tanking or flying in close formation, turning the roll stab aug off was vital as leaving it engaged made it feel like the aircraft was fighting against you. Also have some vague recollection that you were supposed to turn it off during doggers.

Losing the yaw stab aug (happened to me once just after T/O from Wattisham) made the ac try to fly sideways but was nothing dramatic provided you kept the speed at or below 300kts.

Lost the pitch stab aug once at high speed (generator failure I think) and that was quite attention-grabbing, but again, it was liveable with once I got the speed down and the RAT out.

The only other time the stab augs would fail (ahem) on odd occasions is when the nav was having a go at flying the 2-sticker from the back seat. The idea being was that the navs would be in awe of our god-like handling skills in piloting such an uncontrollable beast. However, in reality, all that would happen was a grumpy voice from the boot saying something like, 'Very funny. Now turn the stab augs back on, you b*stard!'

[thing]

Thanks for that Al and Rhino. Your nav story reminds me of a trick played by a mate when he was a DC9 training captain. Apparently there is a one degree speed brake position on the a/c which hardly effects the performance but doubles the amount of aileron movement. So he would quietly pop brakes and then throw the jet around the sky. Then he would pop the brakes back in and give the poor trainees withering looks as they tried to match his piloting prowess ..

[Courtney Mil]

Yeah, Ali Q has it right. Although he will now be beaten close to death for revealing one of the F4 Pilots' secrets. There is no 30 year rule for some of the truly important State secrets.

Anyway, she (the F4M and K) was OK in benign flight regimes without the Stab Augs, just a tendency to hunt a bit in pitch and a lot more secondary effects of controls - I just put that in so the QFIs will think I really did listen to them.

Manoeuvring was a different thing. She would bite your bum if you mishandled her WITH the Stab Augs, way more so without them.

So, back to Ali's little indiscretion. I climbed into the back seat of an F4M at A secret Lincolnshire F4 base in the early 80s to go and fly my first IRET. (Back seat instrument rating and qual as an instrument rating examiner in case you care). Long story short, I was given a port engine failure straight after take off and a diversion to a nearby airfield. My man turned off the Stab Augs. It sucked a bit on a check ride, but was OK. The bastard was that he refused to reset them for the rest of trip. Presumably just for fun - his, not mine.

Bottom line - we weren't doing combat so it wasn't a huge deal. It did make a difference, but it wasn't a big issue in that benign regime.

Contrast: 1v1 doggers, electrical transient made all three channels trip out (assisted by some very heavy-handed pilot inputs). Now that was very different. The clue is in the name - stability. I guess it was actually flying the aircraft and, therefore, a great lesson in what an unforgiving lady she could be.

MacAir wouldn't have put the system there if she didn't need it.

[Bevo]

For air combat maneuvering (dog fighting) we turned off the roll stability aug.

There was actually a set of pressure sensitive switches on the front control stick which cut out the roll aug when the pilot applied more than two pounds of stick force in roll. This prevented the stability augmentation from fighting the commanded roll rate.

The aft stick did not have the force switches. As a result the aircraft roll could have a little hesitation when rolling the aircraft from the rear cockpit as the stab aug “fought” the commanded roll. When I flew as an instructor from the rear cockpit I normally had the front seater turn off the roll aug to allow me to fly the aircraft a little more smoothly at the expense of a little “stability”.



This was for the F-4C, D, E, and J. I believe the F-4M had the same system.

[BEagle]

...a lot more secondary effects of controls - I just put that in so the QFIs will think I really did listen to them.

Further effect of controls these days, Courtney old chap

L00kout....Attitude....Instruments....

[LOMCEVAK]

The QF-4Ns that the US Navy flew from Point Mugu had the roll stab aug disabled/removed (cannot remember which) so it was not even an option. However, they maintained the standard pitch and roll channels.

[gzornenplatz]

Rolling in combat

What's all this talk of using aileron to roll the F4 in combat? The only effective control at high AoA was the rudder, Or has Courtney forgotten everything I taught him?

[Courtney Mil]

NEVER!!! If it buffets, use yer boots.

[thing]

Thanks for all of the info chaps.

The only effective control at high AoA was the rudder

Crikey, you have me thinking of the ARI now. Surprising how all this guff comes back to you with a little prompting.

[Flap62]

Surely if it gets to the stage of "if it buffets, use your boots" was largely obsolescent by the time any modern jet came along? In my (admittedly) limited experience an F4 was a beautiful big target.

How else do you explain 3 20 mile splits against a non radar aircraft that result in 2X F2 and one guns kill?

[Dominator2]

Picking on OCU students isn't all that fair. If the F4 was employed properly much of the time you would have perished without being aware.

[Flap62]

Hmm,

I was on CR work up against a full CR crew but hey ho. Still one of my fave jets ever. Would love to have flown it.

[Dominator2]

It's OK, I was only trying to get a reaction. And yes, in it's day it was a great jet. Throughout the 70s the FGR2 was unrivaled in the Central Region.

[Bevo]

At high AOA, attempts to roll the airplane with aileron result in yaw opposite to the direction of the intended turn or roll. This yaw is partially produced by the drag of the down going aileron; and the dihedral effect, in turn, inhibits the roll. Adverse yaw is more severe at high AOA, and aileron inputs provide very low roll rates. At very high AOA near stall, aileron inputs cause increased adverse yaw and roll opposite to that intended. The natural tendency to raise the wing with aileron should be avoided. A large aileron deflection at the point of departure from controlled flight will increase the probability of spin entry.

In the F-4E with leading edge slats the best roll at high AOA was accomplished by a combination of rudder and aileron in the direction the desired turn.

The F-14, even with its wings swept forward, also required rudder as the primary roll control at high AOA.

[Ex Douglas Driver]

http://www.ukserials.com/pdflosses/m...0108_xv462.pdf

[bike2lv]

They should have watched "unload for control" more often!