CFI oral intel

gatt wrote:

One of the folks around the hangar took his CFI practical last week. He
had his AGI so they threw out all of the Fundamentals of Instruction
stuff entirely during the oral.

A question the examiner asked him: "You're flying cross-country and
trimmed at 110 knots. You die, and the engine quits. At what airspeed
will the aircraft strike the ground?"

Another was, "You're turning final and you enter a cross-control stall.
Is it better to be in a slip, or a skid?"

I'm wondering what the significance of posting
this question is. Is it because everyone should
know the answer or because on some level it is
nonsensical?

BTW, my instructor covered the issue in-depth in
my pre-solo test. The gist of the discussion being
that a spin will develop much quicker in a skid since
the lower wing will drop, as opposed to a slip,
where the high wing has to drop, giving you more
time to recognize and break the stall.

On May 29, 10:58*am, Bertie the Bunyip wrote:
He's obviously looking at getting an answer that it will be the same
speed, but that's not correct. It probably wouldn;'t be far off it, but
the thrust line and any up or down thrust will play a big part in what
the airplane settles at after the engine dies.

And in a propeller-driven plane with a conventional (as opposed to a T-
tail) empennage, the design and location (relative to the prop blast)
of the horizontal stab will probably swamp the effect of the thrust
line. In most cases, the trim speed will actually be higher when the
engine quits.

This question is a good one - without more information it can't really
be answered, but it's a great jumping-off point for a discussion of
the way pitch, power, and speed interact.

The airplane CFI PTS includes demonstrating and explaining trim stalls
(I remember having to do one on my CFI-ASE ride). So at least the
people who wrote the PTS expected the CFI to have that level of
aerodynamic knowledge, as well they should. It would help him to
explain to the student why certain things happen, and what he should
expect.

But that's probably way beyond what the average ops inspector is going
for (and probably more than he knows) - and it's somewhat depressing
that it's obvious to us that he's going for the wrong answer. You
would think we would give the guy the benefit of the doubt - but
having met several ops inspectors, I find that difficult to do.

Michael

Jim Stewart wrote:
gatt wrote:

Another was, "You're turning final and you enter a cross-control
stall. Is it better to be in a slip, or a skid?"

I'm wondering what the significance of posting this question is.

They're aviation forums. Some people still actually like to discuss
aviation out here.

Is it because everyone should know the answer or because on some level it is
nonsensical?

Actually, it's because if there are CFI candidates on the newsgroup it
might help them to understand what kinds of questions they can expect.


-c

gatt wrote:
Jim Stewart wrote:
gatt wrote:

Another was, "You're turning final and you enter a cross-control
stall. Is it better to be in a slip, or a skid?"

I'm wondering what the significance of posting this question is.

They're aviation forums. Some people still actually like to discuss
aviation out here.

I didn't mean to come off as a smart-ass. As
I said, my instructor and I covered this well
before I soloed. I assumed that every soloed
student would know the answer, let alone a CFI
candidate.

I guess I was wrong.

Is it because everyone should know the answer or because on some level
it is
nonsensical?

Actually, it's because if there are CFI candidates on the newsgroup it
might help them to understand what kinds of questions they can expect.


-c

Jim Stewart wrote:
gatt wrote:
Jim Stewart wrote:

I didn't mean to come off as a smart-ass. As I said, my instructor and I covered this well
before I soloed. I assumed that every soloed student would know the answer, let alone a CFI
candidate.

I guess I was wrong.

Probably not. There's a brief discussion of it in the Airplane Flying
Handbook, Chapter 4, that relates to demonstrating a cross-control
stall. In terms of the CFI checkride, I suppose if you were going to
demonstrate one in a complex aircraft or to a pre-solo student you'd
want to do the one that won't result in an extreme bank or a spin.


-c

gatt wrote:
A question the examiner asked him: "You're flying cross-country and
trimmed at 110 knots. You die, and the engine quits. At what airspeed
will the aircraft strike the ground?"

It all depends on what caused you to die. ;-)

(Actually I'm semi-serious, in spite of the wink.)

gatt wrote:
Jim Stewart wrote:
gatt wrote:
Jim Stewart wrote:

I didn't mean to come off as a smart-ass. As I said, my instructor
and I covered this well
before I soloed. I assumed that every soloed student would know the
answer, let alone a CFI
candidate.

I guess I was wrong.

Probably not. There's a brief discussion of it in the Airplane Flying
Handbook, Chapter 4, that relates to demonstrating a cross-control
stall. In terms of the CFI checkride, I suppose if you were going to
demonstrate one in a complex aircraft or to a pre-solo student you'd
want to do the one that won't result in an extreme bank or a spin.


-c

I think I'm reading in what you are saying that it might be better for a
CFI to demonstrate a crossed control stall in the slip configuration
rather than the skid due to extreme bank or spin?

Just a few thoughts on this if I may.

In my opinion, thinking this way as a CFI is not the optimum way to go,
and might in fact prove a valuable missed opportunity to save a life
down the road.

With cross control stalls, you want to do more than simply demonstrate
(or prove if you wish) that an aircraft can be stalled in a cross
controlled condition. You want to leave a permanent impression on the
student about cross control stall and ALL it's ramifications.

This can be done safely in BOTH the slip and skid condition, and it
requires an instructor who is sharp in stall recovery which you should
be to begin with.

Of PARAMOUNT importance to the cross control demonstration is having the
student EXPERIENCE the DIFFERENCE between the two configurations as they
relate to recovery response from the wing drop. To do this, the
instructor should demonstrate BOTH stalls, emphasizing the aircraft
behavior in each configuration.
To shy away from the skid configuration because of an aversion to
extreme bank or spin, whether that be on the student's side or the
instructor's side of the equation in my opinion is wrong.

To achieve the optimum instructional benefit, the instructor should
first of all be COMPLETELY familiar with the stall behavior of the
aircraft being used. Different types have VERY different cross control
stall behavior and it's incumbent on every CFI to be completely
proficient in the cross control behavior of the type being used before
any cross control demonstration or instruction is done. Some high
performance singles have a very brisk stall break when cross controlled,
ESPECIALLY in skid!.
The method of instruction should be a thorough ground pre- brief with
the student on what will be done, addressing ny apprehension the student
might have. Then in the air, the student should follow through with the
instructor first through a slip stall, then in the skid stall.

What's important here is that the instructor should treat BOTH sides of
the demonstration as routine and as such, not to be feared IF UNDERSTOOD!

I also advocate letting the student do the stalls to both sides. If the
instructor can't control that situation, he/she shouldn't be in the
airplane teaching these stalls to begin with.

For the instructor, emphasis is on recovery technique requiring
immediate angle of attack reduction to break the stall IN COORDINATION
with immediate control application to break any roll onset. Although the
slip side stall can usually be broken before going past wings level,
there is absolutely no reason to fear the skid side. If proper recovery
is initiated from the skid side, there might be a faster break and a
deeper entry into roll that can exceed wings level, but if recovery is
done correctly, the stall can be broken and recovered without alarming a
properly prepared student.
The secret to all of this is PREPARING THE STUDENT, then presenting
these stalls in a calm,and totally routine manner.

I have never turned a student loose to aviation without teaching them
these all important stall recoveries.
--
Dudley Henriques

Dudley Henriques wrote:

Just a few thoughts on this if I may.

In my opinion, thinking this way as a CFI is not the optimum way to go,
and might in fact prove a valuable missed opportunity to save a life
down the road.

With cross control stalls, you want to do more than simply demonstrate
(or prove if you wish) that an aircraft can be stalled in a cross
controlled condition. You want to leave a permanent impression on the
student about cross control stall and ALL it's ramifications.

This can be done safely in BOTH the slip and skid condition, and it
requires an instructor who is sharp in stall recovery which you should
be to begin with.

Of PARAMOUNT importance to the cross control demonstration is having the
student EXPERIENCE the DIFFERENCE between the two configurations as they
relate to recovery response from the wing drop. To do this, the
instructor should demonstrate BOTH stalls, emphasizing the aircraft
behavior in each configuration.
To shy away from the skid configuration because of an aversion to
extreme bank or spin, whether that be on the student's side or the
instructor's side of the equation in my opinion is wrong.

....[snipped for brevity]

Another one for the archives. Thanks, Dudley.

I got the information about the question second-hand (the candidate told
the chief instructor who told me) so I'm not sure exactly what the
examiner as getting at. Now I'm really curious. It probably boils down
to the difference between a cross-control stall behavior in a slip
versus a skid. The FSDO examiners out here really hammer CFI candidates
on aerodynamics, or so I'm told, and less on the FOI if the candidate
appears reasonably capable of teaching. Seems appropriate enough.

-c

"Bertie the Bunyip" wrote in message
...
gatt wrote in
:
He's obviously looking at getting an answer that it will be the same
speed, but that's not correct. It probably wouldn;'t be far off it, but
the thrust line and any up or down thrust will play a big part in what
the airplane settles at after the engine dies.

If it ever settles down. The process of losing the engine thrust will likely
trigger a phugoid oscillation, which may or may not dampen out before you reach
the ground. Your airspeed would depend on just where you happened to be in the
cycle when airframe meets ground.

Those of you who have never broken the monotony of a x-country by exploring
the phugoid characteristics of your steed have missed a good opportunity to
learn something about your airplane. (Don't forget to see how it differs with
CG.) BTW: Some gliders have rather exciting phugoids.

Vaughn

gatt wrote:


Another one for the archives. Thanks, Dudley.

I got the information about the question second-hand (the candidate told
the chief instructor who told me) so I'm not sure exactly what the
examiner as getting at. Now I'm really curious. It probably boils down
to the difference between a cross-control stall behavior in a slip
versus a skid. The FSDO examiners out here really hammer CFI candidates
on aerodynamics, or so I'm told, and less on the FOI if the candidate
appears reasonably capable of teaching. Seems appropriate enough.

-c

You're welcome.

What they probably want is be assured that the CFI fully understands the
dangers involved with skidding turns, especially at low altitude.

To do it right, the CFI should use the necessity to impart this
information to discuss and teach cross controlled stall in ALL
configurations so that a BETTER understanding of the various
ramifications involved be more understood.
--
Dudley Henriques