Testing your glide. Are people doing this?

("Yossarian" wrote in the Catalina Perep thread)
My first trip I was that low too, but now my FBO insists on a continuous
climb to the middle of the channel for better glide distance if your
engine
quits. 4500' in a 172 is only like 7 miles glide.


I wonder how many people have actually glided their planes (rentals or
otherwise) and so know what their real world glide range numbers will be -
from say, 6,000 ft AGL down to 3,000 ft AGL? Into the wind vs tailwind, etc?

I'm under the impression that 5:1 is a good (safety) number to have in your
head for an average 172 flying at 3,000 ft AGL, and below. Gives you some
"what the hey?" room and *some* turning room.

Can't quite make a 3 mile target with exactly 5:1 at 3,000 ft AGL....15,000
ft. Leaves you 840 ft short of 3 miles. Still, (a mile glide per 1,000 ft of
altitude) seems like a good number to keep in your head for lower altitudes.
Almost 5:1.

I wonder how much better (than the made up safety number 5:1) people will
see up at 6,000 ft AGL. Are people getting book numbers, in their planes,
when they go up and practice real world glides - from say 6k down to 3k?


Montblack
Happy Birthday Kristen
October 25

Are people getting book numbers, in their planes,
when they go up and practice real world glides - from say 6k down to 3k?

Be careful up there! I fly at 2900 feet.

all the best -- Dan Ford
email: www.danford.net/letters.htm#9

see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com

Good thing to do after you have verified your glide (I found the book
numbers on my 172 quite close) is to go to your typical altitude and pick
out a landmark and appropriate distance away. Hold your arm out, put the
tip of your thumb on the horizon, and note where the landmark falls. With
some correction for wind, you now know that you can glide to anything within
that radius.

--
Roger Long

"Montblack"

I wonder how much better (than the made up safety number 5:1) people will
see up at 6,000 ft AGL. Are people getting book numbers, in their planes,
when they go up and practice real world glides - from say 6k down to 3k?


"Real world" is with the engine out. Prop stopped or creating drag by
windmilling. (Little low? Just use a slightly more aggressive engine
warming.)Which makes me wonder: What if someone, trying this (and it
doesn't sound completely crazy), couldn't restart the engine? (And had a
less than perfect landing...) Is it just the same as a glider making an off
field landing accident?

le moo

good number to keep in your head for lower altitudes.

Not sure why you refer to "lower altitudes". The glide angle is
constant with altitude.

"Greg Esres" wrote in message
...
good number to keep in your head for lower altitudes.

Not sure why you refer to "lower altitudes". The glide angle is
constant with altitude.

Because there's "overhead". Gliding from a higher altitude, one normally
will be able to spend a larger proportion of the glide at the optimal best
glide speed. The glide angle is only theoretically constant with altitude.
In reality, no one goes directly to best glide the instant the engine fails
and the glide angle after engine failure varies as the pilot reacts.

Pete

Because there's "overhead".

Ah, gotcha.

I'd love to try it in my Pa24 but am worried about thermal shock and
would have to make the prop full coarse to get a good idea of things.




On Sat, 25 Oct 2003 23:06:14 GMT, Greg Esres
wrote:

Because there's "overhead".

Ah, gotcha.

Happy Dog wrote:

What if someone, trying this (and it
doesn't sound completely crazy), couldn't restart the engine? (And had a
less than perfect landing...) Is it just the same as a glider making an off
field landing accident?

No. It gets you a suspension for reckless operation of an aircraft. If you
survive.

Oh. By the way. To me, this does sound completely crazy. IMO, someone trying
this should get a revocation, not a suspension.

George Patterson
You can dress a hog in a tuxedo, but he still wants to roll in the mud.

Good thing to do after you have verified your glide (I found the book
numbers on my 172 quite close) is to go to your typical altitude and pick
out a landmark and appropriate distance away. Hold your arm out, put the
tip of your thumb on the horizon, and note where the landmark falls. With
some correction for wind, you now know that you can glide to anything
within
that radius.

Well, Roger, on a flight to Pella, IA (yep, home of the window manufacturer)
today, I practiced some slow flight and turns around a point, for the first
time in ages.

Not only was it educational for myself and my two young passengers (my son
and his school buddy), but it was fun, too. We were able to do several
turns around a huge fire out in rural Iowa, which gave the kids something to
oooh and aaah about. Seeing a dozen fire trucks from the air is always a
good thing for a couple of 13 year old boys to yack about at school
tomorrow... ;-)

Thanks for the reminder that all of our flights shouldn't be
"droning-to-brunch" flights...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"