On 4/8/04 12:17 AM, in article ,
"Mary Shafer" wrote:

On Thu, 08 Apr 2004 00:49:00 GMT, "Doug \"Woody\" and Erin Beal"
wrote:

On 4/7/04 10:52 AM, in article ,
"Mary Shafer" wrote:

This discussion is going round and round, but my point is... that the stick
forces do not change whether in CAS, MECH or DEL--i.e. any "break out" force
in the cockpit is incidental to what the pilot normally experiences when
pulling on the pole.

I thought the feel system changed in the spin recovery mode, with more
surface deflection per inch of stick displacement, but there's a good
chance that was either a non-standard F-18 or some other airplane. I
mean, I could have been thinking of the F-16 deep stall recovery mode,
you know.


It may, but I wouldn't know because I never move the stick more than about
1/2 an inch in that mode. I sort of doubt it though because pulling the
stick back or cycling it in a cold/dead airplane feels (force wise) exactly
the same as moving it around in a live running airplane.

I should explain here that the only time I've USED SRM is when I'm doing an
FCF A. The SRM check starts at 30K and 200 KCAS. Basically, turn the SRM
switch to RCVY, and hold the stick back. Then the aircraft hits the correct
numbers (which embarrassingly escape me right now... Circa 150 KCAS), SRM
actually engages. You basically hold 10-20 alpha for the rest of the
recovery while accelerating through 250 so that SRM will auto-disengage.
Basically, we're just diving in SRM in level flight and checking that it
engages and disengages when it's supposed to.

We used to do these checks on C and A FCF's. Now just on A's.

SNIP

I wouldn't dare even attempt to discuss it with you, Mary unless I were in
receive only mode. |:-)

Did you know, for example, that you have a different tolerance for
time delay in the feel system than you do for time delay in the flight
control system? If asked, you probably don't even know you can tell
the difference, but you can.


Ow.

SNIP

I think this is all exactly right, except that my crummy memory for
numbers means I can't say about them. I don't think you can get the
jet to explode on transient excursions outside the limit, although I
know that no one should ever underestimate the fleet pilots, but you
can get it to depart again if you botch the recovery (usually by being
a little too enthusiastic too soon). If you do it just right, you can
get it to depart into a worse mode, like oscillatory instead of flat.


The explode thing was a poor attempt at humor.

I'll give you my standard stall-departure-spin warning, which I give
to every fighter pilot and test pilot I know. Be careful if you're
flying a two-seat version with a centerline tank. It will depart and
spin much more easily than a single-seat jet or a clean jet. You're
not guaranteed to depart and spin, of course, but you're at greater
risk. It also probably won't recover as well or as quickly and it may
have more spin modes.


Concur with the two-seater/single C/L.

Departing I have done (single-seat)... Twice. Once was fairly eye-opening.
460KCAS (probably much slower 350 or less when it stopped flying) at 15000
feet with a full load of back stick and a full boot of top rudder--a real
ham-fist piece of work. The airplane recovered after disappearing into its
own cotton-ball and some real bang-me-up PSG's. I felt pretty sheepish.
Jet was just fine. The immediate action procedures (basically let go and
wait) worked like a champ.

I used to have a couple of plots that really made this point clear,
but I left them with one of the flying qualities engineers when I
retired. I wasn't sure if all the data was generally available.

It's kind of a squirrelly deal to fly in. Nauga, where are you?

They're all squirrelly in stall-departure-spin. Maybe it's because
it's all forebody flow so there's a lot of moment arm or something.
The F-16 deep stall procedure is odd, to say the least, because you
get out of the stall by pulling up the nose and increasing the stall
angle before you push over and "rock" the airplane out of the stall.


Weird. Do those guys still do that with the 25 alpha limiter installed?

Yo, Nauga, over here!


If he's lurking, this is usually the point where he shows up.

--Woody

Mary