[lug] Breaking braking?

[Nate Duehr]

On 7/14/2010 10:14 AM, Bear Giles wrote:
> As an aside, anyone who doesn't think 'panic' is an excuse has never
> actually, you know, panicked.   A lot of geeks seem to think it's a
> character flaw or something, not something deep that tosses you around
> like a chew toy in my old dog's mouth.  I don't know how Calvin meant
> his comment but I wanted this on the record.
>
> (I've never had a full panic, just two baby ones.  One was kayak safety
> training where I was upside down and underwater.  Underwater doesn't
> bother me, but being upside down for long enough that the cold water ran
> into my nasal passages/did/.  I had no idea it would hit me so hard.)
>    

The elephant in the room in pilot training is that this is what some of 
our training is actually for... while it's never in a syllabus anywhere, 
requiring a certain number of hours in a cockpit with an instructor will 
eventually lead to a situation that is so far beyond your abilities and 
comfort level, that you will get to see a (hopefully) more experienced 
aviator handle the situation as a teaching/learning experience.

Or as the old aviation joke goes... "Hours and hours of boredom, 
punctuated by moments of stark terror."

I've only had a few of these in over 300 hours of flight time over 19 
years of flying light aircraft.  My favorite was the day we encountered 
a microburst (fast downward rushing air that looks -- if you could see 
it -- just like you pointed your garden hose straight down at the 
concrete... it flows downward until it hits the ground then switches 
direction outward in all directions) that was centered over the approach 
end of a runway).  My training, *might* have saved me.  As you enter a 
microburst, the airspeed of the aircraft will rise dramatically and in 
this case, since we were on a downward glidepath to a runway, it seems 
like "I can't get this aircraft to come down, but I've removed all the 
power!"... as it progresses forward into the downward part of the air 
"stream" the sink begins, as you start being pushed downward from above, 
and now all of a sudden you need full power to overcome the airspeed 
change and accelerate your couple thousand pounds of mass back up to an 
airspeed that will maintain flight as the tailwind starts, and increases.

At this point, most pilots would execute a "go-around" procedure... full 
throttle, pitch for best climb airspeed (Vx) and fly away.  This is PART 
of the proper technique... however... it wasn't 100% of it.  I may or 
may not have survived with the airplane, my pride, and/or myself intact 
if that is ALL I had done to recover.

Next you fly out of the "downward air" and into a rapidly increasing 
tailwind.  Here's where my instructor's experience "outflew" mine... he 
knew that in a single engine propeller-driven aircraft, that at full 
throttle, the propeller itself creates a significant amount of "relative 
wind" over the center of the wing.  As long as the aircraft is given 
time to accelerate back above the speed of the increasing tailwind, 
you'll eventually fly out of the microburst, but at low altitude, you 
may lose enough altitude that you contact the ground (in this case, the 
runway dead ahead) and the job of the engine/prop is to mitigate the 
*amount* of vertical speed loss in the downward direction.

As a student pilot at the time, I would have pitched forward to regain 
flying speed.  As an experienced aviator, he knew that a forward pitch 
would fix the speed problem, but that we didn't have enough time or 
altitude to do that.  Instead he said, "My aircraft, stay with me on the 
controls, I want to show you something, and we'll talk about it here in 
a minute..." and he pitched the aircraft to a normal attitude for a 
climb and held it there with the stall horn blaring, indicating that our 
airspeed through this wacky airmass was now within 20% of stall speed 
for the wing... and he held it there.

Nose-high, full-throttle, and just holding the attitude... the aircraft 
landed "normally" at the end of the runway with just over 1000 feet per 
minute sink rate that was slowly coming up from the 2000 or more that 
we'd just seen on the back-side of the "sinker" on the out-flow side of 
the microburst. A very hard landing, but no worse than a bad initial 
student as far as forces on the landing gear, etc.

After a Delta Airlines crash in the 90s in Dallas-Ft. Worth in a 
thunderstorm, airline crews and advanced aviators ARE trained on how to 
deal with the situation in JET aircraft (the problem there is in the 
amount of time it takes for a turbine engine to "spool up" and come back 
to full power.  They have to see the signs of a microburst during an 
approach to land VERY early and execute the missed-approach/go-around 
*immediately*... there is only about 2-3 seconds to do this and 
go-around, or you're going to hit the ground in a large, heavy, 
jet-powered airliner.  In a propeller-driven aircraft, you have that 
"propwash" helping you out, and power is virtually instantaneous when 
the throttle is shoved forward to the stops.

Anyway... the point here is... not just a fun story... but that there's 
nothing ANYWHERE in the training syllabus about going out and simulating 
or finding a real microburst and flying through it in private flying. 
There's nothing in the DRIVING syllabus that covers what to do to drive 
defensively on city streets in slippery, or otherwise challenging 
conditions.  (How about ground fog?)

It is my TRUE belief that drivers should be required to log a certain 
amount of "stick time" with a professional driving instructor at least 
every few years.  There are things you can run into (pun intended? ha!) 
that with a driving instructor on board, they may be able to give you 
pointers, tips, or even help you avoid altogether if they're just 
SITTING THERE watching.  And situations that would cause you to PANIC 
(there we go... finally around to the reason for the reply) that 
wouldn't panic a more experienced driver.  I think most insurance 
companies now require our kids to do time on a skid pad with an 
instructor, sliding the car on purpose, to learn how to control skids... 
but how many millions of adults have never had a car lose traction and 
slide for more than a few feet?

There's nothing like the feeling in the gut/bowles and the freezing of 
the brain that happens when presented with a dangerous situation that 
you don't quite understand, until you've done it a few times.  There are 
certainly people who go through life doing their level-best to avoid 
that feeling, but who also have never been "shown the edge" where their 
vehicle will lose traction and if they're not trained properly... 
control... and who will do the wrong thing when they "brain-lock".

Personally, I'd like to see the requirement that all drivers be shown 
and have to demonstrate more than just how to parallel park and operate 
a turn-signal.  I want to see folks do an emergency lane change at 
highway speeds on a skid pad and on dry pavement.  I don't want folks 
out there UNPREPARED to do the JOB of safely operating a motor vehicle, 
but I know that the vast majority are.

Just as I was unprepared to handle a microburst in a light aircraft.  
Luckily, I not only had my instructor... but my instructor's KIDS on 
board that day.  Think either one of us have EVER forgotten what we 
learned from that flight?

Debrief:
- Don't fly anywhere near thunderstorms.  We all know this, but the 
closest storm was miles away over Boulder.  It was the cause of the gust 
front at Erie Airpark, almost 20 miles away.
- If you see fluctuations in airspeed and power over 10 knots on final 
approach that don't match the known power settings for a normal 
glidepath in your aircraft, go-around sooner, rather than later.  Fly 
away early.  Don't try to "salvage" a high/fast approach that you can't 
explain why you're high/fast.
- In piston-powered/propeller-driven aircraft, the aircraft will stay in 
the air (generally unless you have a down-draft that's too great) with 
full power and the typical "deck angle" for a departure maximum 
performance climb.  If you're looking to reduce the sink-rate and have 
no time/altitude to recover normally with a nose-low attitude, go to the 
pitch attitude for a climb and hold it.  It'll keep flying with all that 
air from the prop flailing away up front there.

And then the half-joking and half-serious one:
- Take your instructor along the first time you plan on flying into a 
microburst.

But seriously -- there's ALWAYS benefits to advanced training in anything.

How many companies DON'T practice paired coding, or peer reviews, and 
let ONE programmer handle critical sections of code?  Think about that 
one for a bit.  Your bank will let one guy write code that affects your 
accounts, but an airline always requires two people in that cockpit up 
there, and that code they're using in those displays in front of them 
had massive formal reviews by multiple programmers.

Both are keeping you alive, just in different ways...

It would be REALLY interesting to know -- if the code that handles the 
brakes in automotive applications was heavily peer-reviewed, or just 
slapped into a microcontroller by a small team with no time, money, 
resources to properly review it for all possible scenarios... wouldn't 
it? :-)

Good, fast, cheap... pick any two! (GRIN...)

Nate
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