Stall/spin and ground reference maneuvers

On 3/7/2014 8:24 AM, John Carlyle wrote:
Bob,

I've never experienced vertigo during flight (only on the ground from
illness or alcohol issues), so I'm happy to admit I was wrong by a factor
of 10 in estimating its onset. Can we settle on a vertigo onset of 5-10
seconds for sake of argument?

John - I'm 'happy to settle on any time-interval anyone would like' for
vertigo onset, because - as I've no doubt you well realize - what really
matters is that it WILL happen, and if Joe Pilot doesn't already have a
well-rehearsed Plan B ready for PDQ implementation, he's just transitioned
from a "Crud!" or "Oh s**t!" situation to a deadly one.

Getting back to the original topic, there we are, in our base to final turn
with our ASI reading yellow diamond value plus half the wind speed. Suppose
we shift our gaze from over the nose (where we were looking at pitch, yaw
string and bank angle) towards the inside wing (to check that the airport
hasn't run away). In our peripheral vision we see some unusual motion of
the wing. We can either ignore it and keep on flying the plane, or we can
focus on it. If we ignore it, no problem, but if we focus on it there are
four possibilities as to what can happen next.

First case, we tell ourselves "that's interesting, but I've got a plane to
fly", we shift our gaze back to the nose, keep the turn coordinated and
successfully land. Second case, we tell ourselves "that's interesting, I've
never seen anything like that, I wonder why that's happening, doesn't
matter now, I've got a plane to fly", we shift our gaze back to the nose,
keep the turn coordinated and successfully land. Third case, we tell
ourselves "that's interesting, I've never seen anything like that, I wonder
why that's happening, hmmm, maybe I should put in some more rudder", and we
don't land successfully. Fourth case, we tell ourselves "that's
interesting, I've never seen anything like that, I wonder why that's
happening, hmmm, wow those trees are close and they're really moving funny,
I'm going to have to remember this to tell the guys all about it, I wonder
if I bleed off too much altitude, hey there's a good looking lady down
there, wonder if she sees me up here, whoops, I'm dizzy and don't feel too
good, gee those trees are really close and now they're spinning around and
around, oh I'm sick" and we don't land successfully.

In the first two cases, there's no problem. I think we can agree case four
is very, very unlikely, as no one is likely to fixate on something unusual
for so long (5-10 seconds) when they're low that they'll succumb to vertigo
and crash. It's drummed into us as students that above all else, we need to
fly the plane, no matter what.

But what about case three? Some in this thread have said it's possible, and
that one needs ground reference training to become familiar with the
reverse wing tip movement sensation so you don't try to "correct it".
Maybe, but I'd argue no. First, you're going to have to quit doing
something very important (maintaining a coordinated turn while low) to
focus on something secondary in order to realize what's happening. Next
you're going to have to "do something" impulsively without cross-checking
with a quick gaze at your yaw string that something really needs to be done
to maintain your coordinated turn. If you're the sort that would be
susceptible to these actions, I'd suggest there's training in other areas
that needs to be accomplished first before you consider ground reference
training.

I don't fundamentally disagree with your assessments one bit. The trick for an
instructor (or Joe Pilot, for that matter, if J.P. is vaguely insightful) is
to decide if Joe Pilot is in fact susceptible to life-threatening
distractions. I pretty quickly in my 'pilot career' concluded I was not (or
for darned sure intended to make certain I didn't fall prey to that stupid
trap), and my motivation was the dead pilots whom I suspected WERE for some
reason or other. In either case, additional training on SOMEthing related to
'how to properly fly a (definitionally non-standard) pattern' seems in order. :-)


Now, let me follow your topic drift. Suppose it takes 5-10 seconds without
outside orientation references for vertigo to set in. Why wouldn't all the
passengers in the center section of a widebody at night get nauseous? If
your answer is "they use the cabin as an orientation reference for their
inner ear", then why can't the pilot use his cockpit features for the same
purpose? He'll probably still lose control of the aircraft, but he
shouldn't become nauseous.

Indeed...

For the record, I've not yet experienced nausea with my vertigo incidents
(in-glider, on-ground, in FAA 'IFR chair', etc.). In any event, small comfort
hitting the ground comfortably and out of control as opposed to queasily and
out of control, eh? ;-)

Bob W.

On Friday, March 7, 2014 9:24:21 AM UTC-6, John Carlyle wrote:
But what about case three? Some in this thread have said it's possible, and that one needs ground reference training to become familiar with the reverse wing tip movement sensation so you don't try to "correct it". Maybe, but I'd argue no. First, you're going to have to quit doing something very important (maintaining a coordinated turn while low) to focus on something secondary in order to realize what's happening. Next you're going to have to "do something" impulsively without cross-checking with a quick gaze at your yaw string that something really needs to be done to maintain your coordinated turn. If you're the sort that would be susceptible to these actions, I'd suggest there's training in other areas that needs to be accomplished first before you consider ground reference training.

I don't understand why the motion of the wingtip over the ground is such a big deal? Who looks (focuses) at their wingtip in flight? I'm looking way beyond it at some other object - who cares what my wingtip is doing? In a steady turn, once established, it would take a lot of rudder to significantly move the nose and create dangerous yaw - who boots the rudder while in a steady turn? I think there is something more basic going on here - poor/lazy airmanship! Get out and fly more; practice stalls/departures/spiral dive recoveries, be aggressive in your pattern - fly down to the flare (fast, steep, in control), instead of being scared to get close to the ground, etc....

Now, let me follow your topic drift. Suppose it takes 5-10 seconds without outside orientation references for vertigo to set in. Why wouldn't all the passengers in the center section of a widebody at night get nauseous? If your answer is "they use the cabin as an orientation reference for their inner ear", then why can't the pilot use his cockpit features for the same purpose? He'll probably still lose control of the aircraft, but he shouldn't become nauseous.

Because the airliner is always in coordinated flight and the turn/roll rates as very slow. Trust me, every passenger in an airliner doing turns in clouds or at night has vertigo, but since they are unaware of it, unless they are looking out the window when they pop out of a cloud in a turn they will not become aware of it or get nausious. Next time you fly commercial, focus your gaze forward down the cabin during the takeoff acceleration, and you will sense the plane pitching up significantly BEFORE rotation (acceleration effect on inner ear - vertigo), then look out the window and note how fast your equilibrium reestablishes. This really was fun in something like a C-130 or C-141 with no windows and good acceleration, it felt like you pitched up 10 degrees immediately!

Kirk
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