airforce C-17 question

I live in Washington state, home of McCord airforce base. They have C-17's
there, and the local news station just stated what seems to me to be an
unbelievable fact. They reported that th C-17 can descend 20,000 feet in 1
minute. Now I'm a general aviation pilot, and 2,000 feet per minute is a
fast descent in my world. Is 20,000 fpm with a C-17 for real, or did the
news (KOMO channel 4 for you other western Washinton folks) get it wrong?

20,000 feet is about 3.3 nm, so 3.3nm/min*60min/hr is about 198 nm/hr
That's a fast rate of descent!!!

Dan Moos wrote:
I live in Washington state, home of McCord airforce base. They have C-17's
there, and the local news station just stated what seems to me to be an
unbelievable fact. They reported that th C-17 can descend 20,000 feet in 1
minute. Now I'm a general aviation pilot, and 2,000 feet per minute is a
fast descent in my world. Is 20,000 fpm with a C-17 for real, or did the
news (KOMO channel 4 for you other western Washinton folks) get it wrong?

"Dan Moos" wrote in message
news:n_IHd.8859$IP6.2793@trnddc05...
I live in Washington state, home of McCord airforce base. They have C-17's
there, and the local news station just stated what seems to me to be an
unbelievable fact. They reported that th C-17 can descend 20,000 feet in 1
minute. Now I'm a general aviation pilot, and 2,000 feet per minute is a
fast descent in my world. Is 20,000 fpm with a C-17 for real, or did the
news (KOMO channel 4 for you other western Washinton folks) get it wrong?


Sounded like a lot to me, then I began to wonder what the descent rate was
for the EgyptAir 767 that crashed into the Atlantic 6 years ago:

"The maximum rate of descent recorded during the dive was about 39,000 fpm
at 0150:19, as the airplane descended through about 24,600 feet msl..."

This was hit at a 40 degree down angle, but according to the report, either
the descent or recovery or both caused the elevators to work opposite each
other, resulting in a loss of control after the "recovery" that led to a
second dive:

"However, the data indicate that the airplane impacted the ocean about
0152:30, with an average descent rate during the second dive of about 20,000
fpm."

Given that the captain had essentially recovered the aircraft after the
alleged intentional first dive, it almost seems like a descent like that is
possible. I can't imagine a situation in which it is practical, even for a
military supply mission. Maybe an F-16 on a bombing run, but a C-17 loaded
with whatever, trying to get in and out of a hot LZ....I dunno...those
things are heavy!

John K.
Student Pilot

I'm sure if you point the nose down enough, and keep the power in, you
can attain or exceed that rate of descent.

Dave

Dan Moos wrote:
I live in Washington state, home of McCord airforce base. They have C-17's
there, and the local news station just stated what seems to me to be an
unbelievable fact. They reported that th C-17 can descend 20,000 feet in 1
minute. Now I'm a general aviation pilot, and 2,000 feet per minute is a
fast descent in my world. Is 20,000 fpm with a C-17 for real, or did the
news (KOMO channel 4 for you other western Washinton folks) get it wrong?

"Dan Moos" wrote in message
news:n_IHd.8859$IP6.2793@trnddc05...
I live in Washington state, home of McCord airforce base. They have C-17's
there, and the local news station just stated what seems to me to be an
unbelievable fact. They reported that th C-17 can descend 20,000 feet in 1
minute. Now I'm a general aviation pilot, and 2,000 feet per minute is a
fast descent in my world. Is 20,000 fpm with a C-17 for real, or did the
news (KOMO channel 4 for you other western Washinton folks) get it wrong?


My MU-2 will do 10,000fpm in a power off slip (this puts one spoiler up) and
I think that most jets could do better since they have both a higher Vmo and
can deploy spoilers on both sides.

Mike
MU-2

"Mike Rapoport" wrote in message
nk.net...

"Dan Moos" wrote in message
news:n_IHd.8859$IP6.2793@trnddc05...
I live in Washington state, home of McCord airforce base. They have C-17's
there, and the local news station just stated what seems to me to be an
unbelievable fact. They reported that th C-17 can descend 20,000 feet in
1
minute. Now I'm a general aviation pilot, and 2,000 feet per minute is a
fast descent in my world. Is 20,000 fpm with a C-17 for real, or did the
news (KOMO channel 4 for you other western Washinton folks) get it wrong?


My MU-2 will do 10,000fpm in a power off slip (this puts one spoiler up)
and I think that most jets could do better since they have both a higher
Vmo and can deploy spoilers on both sides.

Mike
MU-2


At Flight Safety we bring an "on fire" Falcon 50EX from 41000 feet to a
complete stop on the runway in 4min 21sec. Now THAT is fun in the Sim.

Karl
N185KG

kage wrote:



At Flight Safety we bring an "on fire" Falcon 50EX from 41000 feet to a
complete stop on the runway in 4min 21sec. Now THAT is fun in the Sim.

Karl
N185KG



I bet its fun locating a suitable runway from 41,000 feet and finding
the plates/charts for it...

(kidding... I know the goal is GET ON THE GROUND..)
Dave

"Dan Moos" wrote in message news:n_IHd.8859$IP6.2793@trnddc05...
I live in Washington state, home of McCord airforce base. They have C-17's
there, and the local news station just stated what seems to me to be an
unbelievable fact. They reported that th C-17 can descend 20,000 feet in 1
minute. Now I'm a general aviation pilot, and 2,000 feet per minute is a
fast descent in my world. Is 20,000 fpm with a C-17 for real, or did the
news (KOMO channel 4 for you other western Washinton folks) get it wrong?



I know that the thrust reversers on the C-17 are considered flight controls and can purposely be deployed in flight. I
have heard of C-130s being put into beta (reverse pitch?) while in flight to initiate a very steep descent to avoid SAMS
in Vietnam, so I imagine that the C-17 can do the same sort of tactical maneuver...

"Dan Moos" wrote in message
news:n_IHd.8859$IP6.2793@trnddc05...
I live in Washington state, home of McCord airforce base. They have C-17's
there, and the local news station just stated what seems to me to be an
unbelievable fact. They reported that th C-17 can descend 20,000 feet in 1
minute. Now I'm a general aviation pilot, and 2,000 feet per minute is a
fast descent in my world. Is 20,000 fpm with a C-17 for real, or did the
news (KOMO channel 4 for you other western Washinton folks) get it wrong?


When in doubt assume what a reporter says about airplanes is the result of
clueless people with hairspray poisoning. This rule-of-thumb is virtually
never wrong.

The Navy's S-3 Viking used to be famous for one of the highest rates of
descent. When I got time in the sim at JAX we were told they could set off
ATC alarms with a fast descent. It's a much smaller aircraft than a C-17 so
I assume the C-17 would not "out sink" it.

--

Scott

Liberals love America like OJ loved Nicole. - Ann Coulter

On Sat, 22 Jan 2005 09:03:35 -0600, "tscottme"
wrote in ::

... we were told they could set off ATC alarms with a fast descent.

I don't think it takes too high a rate of descent to set off ATC
alarms. I have done it on short final at KSNA (John Wayne/Santa Ana)
in a Piper PA28-235 in a full rudder deflection slip. The fire
equipment was rolling before I touched down.