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

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"

"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

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.

In rec.aviation.owning Happy Dog wrote:
: "Real world" is with the engine out. Prop stopped or creating drag by
: windmilling.

... as was done on my 4th lesson for my PPL with my instructor.
Not only stopped the engine, but made me slow down to actually stop the
prop. Freaked me out, but he said it was to "prove the airplane doesn't
stop flying when the engine quits." Of course I knew that already, but it
was cool nonetheless. Very (ominously) quiet, too.

-Cory



--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

... as was done on my 4th lesson for my PPL with my instructor.
Not only stopped the engine, but made me slow down to actually stop the
prop.

There is always controversy about how realistic to make emergency training.
I think the risk of doing this training outweighs the benefit.

Engine out and windmilling (low pitch if CS) - yes. Stopping the prop - no.

- Mark

"markjen" wrote

. as was done on my 4th lesson for my PPL with my instructor.
Not only stopped the engine, but made me slow down to actually
stop the prop.

There is always controversy about how realistic to make
emergency training. I think the risk of doing this training
outweighs the benefit.

What experience do you have that indicates that this is a risky
maneuver. I made it a point to do it with every one of my students
at 4-5,000' over the not-too-busy airport. With a few hours of
C-172 gliding time, the worst thing that could happen was to land
like any other glider. My homebuilt MiniMax had a 1/2 VW engine
that could not be restarted in-flight. I regularly practiced landing
with the prop stopped in it. Practice builds confidence!
What do glider pilots do when the prop stops? :-) I certainly don't
concede them any basic skills that I don't possess.

Bob Moore
ATP CFI USN
PanAm (retired)

What experience do you have that indicates that this is a risky
maneuver.

C'mon, common sense says that stopping the prop on an powered airplane is
maneuver that has some risk. As I said there is a tradeoff. Let's not get
into arguing over the tradeoff or what risk is acceptable. This is just a
rehash of the old spin training debate.

And certainly the airplane and environment matters. There is little risk in
practicing very realistic engine-one scenarios in a low-traffic environment
with a plane like a C-172 or VW-powered homebuilt. But it's a whole
different deal in a Bonanza or T210 at a busy field.

You make your own tradeoff, but if I ever have a CFI that wants to practice
the maneuver to the point of stopping the engine, I'll decline and find
another CFI.

- Mark