Challenger Crashe at TEB

"kage" wrote in message I'm betting on an emergency AD for
winter operations.

There was no visible moisture. The sky was crystal clear. The only wing
contamination possible would have been light frost on the bottom of the wing
where the fuel had cold-soaked after landing- if the plane had made a
quick-turn. No other aircraft had requested de-icing. I doubt that the cause
was wing ice.

D.

wrote:
: This is one of the few safety advantages of light piston singles. When you
: reach takeoff speed in a single, pull back, but the plane doesn't want to
: fly for whatever reason, you will most often have ample runway left to abort
: the takeoff (assuming a runway of 3500 ft or longer). And if you do run off
: the end, it will be at low speed, so chances are there will be no injuries.
: In a jet, once you exceed V1 on takeoff you are committed. Then if the
: plane won't fly at Vr, due to wing contamination or some other cause, you
: are screwed unless you are on an exceptionally long runway.

You, sir, get the prize. With reduced thrust takeoffs the V1/Vr speed is set
so that an abort at V1 will use the entire remainder of the runway. An abort
beyond V1 guarantees a trip into the woods.

The airfoil shapes on aircraft with a top speed of less than 0.2 mach
really aren't all that sensitive to minor surface contamination such as one
1mm particle per square cm. I have seen many aircraft with paint worse than
that flying. There's even a 150 with *moss* on it's wings that flies
occasionally.
--
Aaron C.

"Capt.Doug" wrote:

There was no visible moisture. The sky was crystal clear. The only wing
contamination possible would have been light frost on the bottom of the wing
where the fuel had cold-soaked after landing- if the plane had made a
quick-turn.

Interesting that I have read the "there was no visible moisture" point a
few times in relation to this crash. Based on my experience, no visible
moisture is no guarantee.

I only have about 750 hours of flying in the Northeast US, but during this
short time I have experienced three different situations where frost
appeared over top of the entire aircraft (twice in a C172 and once in a
Bonanza) within 10 minutes of landing in weather that was crystal clear, no
visible moisture.

This happened twice at Niagara Falls and once in Plattsburgh, NY. In all
cases, the sun had either just set or had been down a few hours and outside
temperatures were well below freezing (10 degrees F or so).

--
Peter







----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

"Capt.Doug"
There was no visible moisture. The sky was crystal clear. The only wing
contamination possible would have been light frost on the bottom of the
wing
where the fuel had cold-soaked after landing- if the plane had made a
quick-turn. No other aircraft had requested de-icing. I doubt that the
cause
was wing ice.

Frost on top of the wings, and more importantly - on top of the T-tail is
highly likely. I have flown a T tail jet for 25 years and you can get frost
on top of the wings and tail very easily in the early morning with the right
conditions.

To Peter R. and Gary Mishler. Say for sake of argument that the pilots
missed a thin layer of frost. If discovered, are there any remedies short
of a full, formal deicing?

Joe Johnson wrote:

To Peter R. and Gary Mishler. Say for sake of argument that the pilots
missed a thin layer of frost. If discovered, are there any remedies short
of a full, formal deicing?

I am not qualified to answer as I have no experience in anything greater
than a single engine piston aircraft.

That said, when my aircraft was frosted over in those three incidents, my
only fly-able option was to request a complete aircraft deicing.

Fortunately, in all three cases the line crew was available, had the deice
fluid nearby, and did it for free. I tipped them generously.

If deicing were not an option, I would have had to get a hotel and wait
until the frost melted off the next day, or some liquid deicing were
available. In no case would I have attempted to take off with it on the
wing surface.

--
Peter







----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

"Joe Johnson" wrote in message
. com...
To Peter R. and Gary Mishler. Say for sake of argument that the pilots
missed a thin layer of frost. If discovered, are there any remedies short
of a full, formal deicing?

They used to say you could "polish" the frost smooth with a rag or gloved
hand, although I have not heard of that in a long time and I would never do
it on a supercritical wing shape. *Maybe* a light single engine, but never
a business jet.

But even so, that still leaves the question of the top of the T tail.

Best answer is a quick spray down with the deice truck - wouldn't take much
to get rid of a morning frost.

"Capt.Doug" wrote in message
...

There was no visible moisture. The sky was crystal clear. The only wing
contamination possible would have been light frost on the bottom of the
wing
where the fuel had cold-soaked after landing- if the plane had made a
quick-turn.

When I walked past my car in the driveway about a half hour before dawn this
morning, the sky was crystal clear with no visible moisture and there was no
frost on my car. When I left for work about a half hour after sunrise, the
sky was crystal clear with no visible moisture but enough frost had formed
on my car during that time that I needed to lightly scrape my windows off
before I left.

Had the same thing happen in SFO once in the lear on a "dawn patrol"
departure. Clear sky, no visible moisture but frost started to form on the
wings and top of the fuselage right about sunrise. When the passengers
arrived we had the line crew use their "garden sprayer" deice setup to
lightly spray the frost off the wings and top of tail and away we went with
no problem.

Not speculating, but an area they will be looking at with the TEB incident.

Thank you for pointing this out. The "visable moisture" requirement is for
in-flight icing, not frost. Temp/Dewpoint at TEB yesterday morning was
M04/M08. Obviously the "collecting surface" was below freezing and the temp
dewpoint spread was narrow enough for the humidity to sublimate and create
frost on the wings.

Jim

They used to say you could "polish" the frost smooth with a rag or gloved
hand, although I have not heard of that in a long time and I would never
do it on a supercritical wing shape. *Maybe* a light single engine, but
never a business jet.

But even so, that still leaves the question of the top of the T tail.

Best answer is a quick spray down with the deice truck - wouldn't take
much to get rid of a morning frost.

"They" still say you can polish, at least for 135 operations!

Sec. 135.227 - Icing conditions: Operating limitations.

(a) No pilot may take off an aircraft that has frost, ice, or snow adhering
to any rotor blade, propeller, windshield, wing, stabilizing or control
surface, to a powerplant installation, or to an airspeed, altimeter, rate of
climb, or flight attitude instrument system, except under the following
conditions:

(1) Takeoffs may be made with frost adhering to the wings, or stabilizing or
control surfaces, if the frost has been polished to make it smooth.



Karl