A Lieberman wrote:
On May 18, 5:34 pm, Dudley Henriques wrote:

Where I was referring to the sensations issue was directly concerned
with one pilot who commented that verifying an instrument reading with a
physical sensation was important. My point was that instrument
verification should be done against other instruments with the EXCLUSION
of physical sensation from that equation.

I think my point was when there is an action, there should be a
reaction, and if I don't feel the reaction (which is faster then
registering on the instrument), then I need to explore further.

I am talking the very subtle changes, not changes requiring large
power changes.

For example, I come down the ILS at 90 knots with 1900 rpm. If
headwinds cause my groundspeed to drop below 90 knots and I add lets
say 25 RPM to recapture the glideslope and I DON"T feel it in my seat
of the pants, first place I will look is the temperature probe.
Again, talking subtle 25 RPM just finger tip touch to the controls.

If I feel the extra oomph / firmness in my seat of the pants with the
extra 25 RPM and the glideslope starts to recapture, that is a
verification of my action and reaction.

Again, very subtle changes I am look and feeling for. I am not saying
make turns by the seat of my pants, primarily verifying actions of
power settings.

In my Friday incident, I could tell my attitude indicator of 20 to 30
degree pitch up AND not feeling the extra G's in my rear end, that
something was discrepant having flown this plane for over 600 hours..
That had me going to my backup instruments IMMEDIATELY (VSI and
airspeed) for my analysis and quickly identifying the vacuum as
suspect..

It's not that I even remotely navigated by the seat of my pants, but
something was amiss was felt.

I absolutely agree based on time and time again history, that any
feelings in the head absolutely has to be ignored, instruments are
there for that, but for verification of power adjustments, I see no
reason why AS A TOOL, the feeling in your rear end cannot be used as a
verification of the reaction of your actioin (adding or reducing
power).

The feeling of the seat of your pants is NOT to be used in determining
upright status in IMC, that I will say, and don't want to mislead
anybody that I condone that, just using it to verify my action of
power is working and the reaction of instrumentation TRENDS are
following what my seat of the pants feel is.

Not faulting anyone. I just want to make it absolutely clear that in my
opinion, the ONLY relationship between physical sensation and IFR is in
understanding how physical sensations can harm you and how to deal with
them by instrument referencing all the way through the scan down to
primary panel.
I would NEVER attempt to verify an instrument reading by referencing a
physical sensation. In ANY situation where an instrument reading was
suspect, I would immediately extend my primary scan to include
peripheral instruments to verify the quality of the data that was
suspect. Under NO circumstance, would I EVER allow the time line
necessary to include a physical sensation in this equation. To do so in
my opinion is dangerous not only in a possible erroneous attitude input,
but as well extends the time line to a recovery input.
Physical sensation as relates to IFR is to be understood for it's
hazzards, but avoided when in the soup.

--
Dudley Henriques