In the article is the following comment: "It's a great glider. ... the PC-12
has a 2.7-1 power off glide ratio at maximum gross weight - not bad at all
for a 9,920 pound airplane".
Just for reference, I calculated the glide ratio of the Schweizer 300C
helicopter I was flying and it is not far off from that, engine out. I
never could attain the calculated glide ratio with the helicopter, though.
I would never call anything with a 2.7-1 glide ratio as being great,
although it probably is better than the space shuttle.
Colin
I saw that too and figured it's gotta be a typo.
Shawn
3/1 is not much better than a brick. (1/1)
BT
"COLIN LAMB" <k7...@teleport.com> wrote in message
news:2iTvf.2517$WY5....@newsread2.news.pas.earthlink.net...
> I think that just has to be a typo... most training Cezzna's are about 7 to
> 1.
> But it would be hard to believe the Pc-12 could get 27/1... I'd believe
> maybe 10 or 12 to 1.
>
> 3/1 is not much better than a brick. (1/1)
Thatlooks like a sin <==> tan error. Lift is the component of
aerodynamic force that is perpendicular to the relative airflow, not the
component that is vertically upward. The L/D of a brick is not 1:1 --
which would imply it could fly at an angle of descent of 45 degrees --
but very close to zero.
Well, ok, a canonball has an L/D of zero, if it is not spinning. A
brick would have a slightly better L/D, if you could stabilize it,
perhaps by spinning it, as with a ruler or business card which appear to
have L/Ds of about 1 in stabilized backward-tumbling flight. Maybe a
brick could do that too, at sufficiently high speed?
--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------
I have a friend who has a PC-12 . . . I could ask.
bumper
"BTIZ" <btizn...@cox.nospm.net> wrote in message
news:cR_vf.8501$V.4724@fed1read04...
"Bruce Hoult" <br...@hoult.org> wrote in message
news:bruce-147371....@news.clear.net.nz...
> The January 2006 issue of AOPA Pilot has an article about a Pilatus PC-12
> single engine turboprop. Beautiful airplane.
>
> In the article is the following comment: "It's a great glider. ... the
> PC-12 has a 2.7-1 power off glide ratio at maximum gross weight - not bad
> at all for a 9,920 pound airplane".
According to Pilatus, the actual number is 12:1
http://www.pilatus-aircraft.com/media/PC-12_Performance_English-Imp.pdf
...or 2.6nm per 1000'.
Google "pc12 glide ~performance" = 3rd hit for the info above :)
Happy soaring all!
James
--
The reader this message encounters not failing to understand is cursed.
> The Boeing 707-300 is 19.5:1
As someone pointed out to me recently, that's probably engines at flight
idle, not shut down.
It is a very clean aircraft (as turboprops go), but the wing loading is
35 lb./ft2. 16:1 seems optimistic, but I since it is on the internet,
I am sure that it is true.
Bob Zahradnik
My Mooney 201 is the same, but lots cheaper!
All else being equal, the probability that I might "test" the Mooney's glide
ratio some day is much more than the chance of that PT-6 going quiet.
bumper
<zahr...@bresnan.net> wrote in message
news:1136688395.1...@g43g2000cwa.googlegroups.com...
Using the FAA "definition" of 1 nm = 6000 feet, that equates to
2.6*6000/1000 = 15.6:1 ~3.667 degrees
which matches the 16:1 (not 12:1) I noticed in the above performance
document.
I once heard a 727 had a 27:1 glide ratio, power off, clean...
And some of my co-worker test pilots encountered mountain wave in a
130,000 lb MD-90, and had the opportunity to find out that it would
maintain altitude at idle power...
Billy Hill, Zulu
Billy Hill, Zulu
Remember the 'Gimli Glider', the Air Canada B767, that ran out of fuel?
There is a nice write-up at http://www.wadenelson.com/gimli.html
The author states a 11:1 for this 132t glider with two wind-milling P&W
engines and a RAT hanging out of it's belly.
Just out of curiosity - does anyone have a number for the space
shuttle?
Uli Neumann
Libelle 'GM'
I think that the 3.5:1 of my emergency parachute is good!
Jim
On a French site I saw an l/d of about 12 which seems realistic and not
uncommen for that kind a aircraft.
I've been thru the SIMCOM school on the PC12 and have about five
hundred hours in it. I'm guessing that should have read 12.7 to 1.
Because SIMCOM's program is designed for relatively low time pilots
with not a lot of exprience flying high performance birds, my sim
instructor was letting us shoot most of our approaches with the engine
shut down and the prop feathered. He was also a glider pilot and
understood energy management. By flying a bit fast and a dot and one
half high on the glide slope, (and holding on the landing gear until
DH), it was possible to make dead stick approaches. Non precision
approaches were a bit harder with no engine. Because the sim is
non-motion we also did akro in it, that is loops and rolls. All that
in sunny fla. in the dead of winter. Billy Hill, Zulu
I had several cockpit rides (pre 9/11) in various Airbus types in
Germany. Some of the pilots were actually active glider pilots. They
claimed an L/D in the mid 20's, if they make the engines drag-wise
'disappear' by keeping them going at slightly above idle speed.
Remember the 'Gimli Glider', the Air Canada B767, that ran out of fuel?
Nice write-up at http://www.wadenelson.com/gimli.html
The author states an 11:1 glide ratio for this 132t glider with two
wind-milling P&W engines and a RAT sticking out of it's belly.
Just out of curiosity - does anyone have a number for the
space-shuttle?
Uli Neumann
Libelle 'GM'
The article in AOPA talks about SIMCOM which is the only certified
PC-12 sim school in the US. Their program is designed for relatively
low time pilots transitioning into bigger and faster aircraft. When I
was there I had the good luck to have a sim instructor who was also a
glider pilot, so after getting the basics out of the way, we did most
of our approaches with the engine shut down and the prop feathered.
The glide ratio is about 12 to 1 and if you fly the approach at about
130 kts., stay about a dot and one half high on the glide slope and
hold off on the landing gear until DH, you can make a very nice dead
stick ILS. Non-precision approaches are a bit more difficult. Because
the sim is non motion, we did loops and rolls with it. All this in
sunny fla. in the dead of winter!
The PC-12 is one great aircraft! It runs with a KingAir 200 and will
land almost as short as a Cessna Caravan (which anything but a nice
aircraft.) I've got about 500 hours in one and miss flying it. The
company I was working for, a part 135 operator here in NM went out of
business.
Billy Hill, Zulu
Billy Hill, Zulu
Kris and I hitched a ride to Tocumwal and enjoyed a soaring week while a
new engine was fitted to the Mooney. The ship’s owner had one in Perth
awaiting our return. The glide ratio was sufficient. BTW, that was the
only engine failure so far in 60 years of flying.
--
Charles Yeates
ZS Jezow PW-6U & PW-5
http://www3.ns.sympatico.ca/yeatesc/world.html
> Found a number of docs that refer to it as 22 degrees at 360mph
> I've understood it to be about 4:1, but I don't do much math so I can't
> convert the 22 degrees into a L:D.....
The number I saw was 18 degrees at approach speed, which is about 200
knots. That's 3:1. 22 degrees is 2.5:1.
To go from the angle to the glide ratio calculate 1/tan(angle).