gliding back to your departure airport

Most gliders can do this and the pilots train to that standard..

Departure problems below 200ft AGL, tow plane power problems.. rope breaks
or tow hook failures.. and the idea is to land straight ahead as quickly as
possible and get stopped.

Above 200ft AGL (which most glider/tow combinations can get to about 3000ft
after start of take off roll), if the rope breaks, tow plane says.. GET
OFF!!.. the glider pilot can pitch down for airspeed and begin a turn back
to the departure runway.. land opposite the direction of take off and have
enough energy to roll back to the starting point.

A nice tow pilot will allow the tow to "Drift down wind the cross wind" on
climb out, so if something does happen the glider can turn into the wind
when returning to the runway.. turning away from the wind can push the
glider to far away (tailwind on base) and make returning to the runway more
difficult.

This maneuver is part of the practical test standards, though most DE's will
wait until 300ft or higher and most CFIGs will review the procedure on BFRs.

Our "Training glider" has a L/d of 23-1. Schweizer 2-33.

BT

"Harold" wrote in message
...
If a small single engine plane can out-climb its engine-out glide ratio
from
take off through the top of climb point, wouldn't it follow that it can
always theoretically make it back to the departure airport in the event of
engine failure ? Assuming straight out departure, no wind, and the
altitude
loss in the 180 turnback is offset by the runway portion you didn't use.
If
my best glide is 85 KTAS and it loses 700 fpm at that speed, shouldn't I
be
guaranteed I can make it back if I climb at 84 KTAS and 701 fpm ?

The glider has a couple of things going for it. Power planes are seldom over
12:1 glide ratio and it is achieved at a higher speed than the glider.
This means that the power plane covers about half the THEORETICAL glide
distance of the glider. Said loudly.

The speed ratio between the wind and the aircraft is a factor. A given wind
speed will be a higher percentage of the glider's best glide speed and will
result in a greater advantage to it's L/D downwind compared to a power plane
with the same wind. The wind also works to advantage for the glider's on tow
part by decreasing the distance that it covers on climb, compared to a power
plane at typical climb speeds.

Finally, for some ancient and illogical reason, power plane standard procedure
is to stay on center line of the runway for climbout. It's considered bad form
to put yourself in a safer position for a turn back to the field. The
exception is an IFR departure. They typically maintain runway heading. Lots
of luck making a turn back under IFR.

You subtract reaction time, reconfiguration time, screw around trying to get
the thing to run, and it is very, very unlikely that a power plane will get
back to the runway at any time during their climb out. Unless it is a long
runway and you started from the end.




In article afjlb.63635$La.24804@fed1read02, "BTIZ"
wrote:
Most gliders can do this and the pilots train to that standard..

Departure problems below 200ft AGL, tow plane power problems.. rope breaks
or tow hook failures.. and the idea is to land straight ahead as quickly as
possible and get stopped.

Above 200ft AGL (which most glider/tow combinations can get to about 3000ft
after start of take off roll), if the rope breaks, tow plane says.. GET
OFF!!.. the glider pilot can pitch down for airspeed and begin a turn back
to the departure runway.. land opposite the direction of take off and have
enough energy to roll back to the starting point.

A nice tow pilot will allow the tow to "Drift down wind the cross wind" on
climb out, so if something does happen the glider can turn into the wind
when returning to the runway.. turning away from the wind can push the
glider to far away (tailwind on base) and make returning to the runway more
difficult.

This maneuver is part of the practical test standards, though most DE's will
wait until 300ft or higher and most CFIGs will review the procedure on BFRs.

Our "Training glider" has a L/d of 23-1. Schweizer 2-33.

BT

"Harold" wrote in message
. ..
If a small single engine plane can out-climb its engine-out glide ratio
from
take off through the top of climb point, wouldn't it follow that it can
always theoretically make it back to the departure airport in the event of
engine failure ? Assuming straight out departure, no wind, and the
altitude
loss in the 180 turnback is offset by the runway portion you didn't use.
If
my best glide is 85 KTAS and it loses 700 fpm at that speed, shouldn't I
be
guaranteed I can make it back if I climb at 84 KTAS and 701 fpm ?

dennis wrote:
snip
You subtract reaction time, reconfiguration time, screw around trying to get
the thing to run, and it is very, very unlikely that a power plane will get
back to the runway at any time during their climb out. Unless it is a long
runway and you started from the end.

After getting my private, I was wondering about this, particularly
because the airport I usually fly out of (PDK) is surrounded by
development that leaves no place, at any time of day, to even dream of
setting down safely in the event of an engine failure.

Not getting answers that satisfied me, I went out and did some tests
myself, at altitude. Used GPS, a partner to log altitudes and
waypoints, etc. Came to the conclusion that if everything went
*perfect*, and you *knew* it was going to happen, it would take 500' agl
to make it back, in a Warrior.

But what I did was pick the brains of my friends who were glider pilots,
worked on Vms turns, high bank angle turns, popping 10 degrees of flap
for the turn and popping it out for the glide, etc., etc. After
practicing all that, and knowing what was coming, 500' was the best I
could do. Which to me means 800'-1000' in real life, if you practiced
it a lot.

It was an eye-opener for me to see how little margin for error I have
operating out of PDK. It has changed my standard departure. I climb at
Vx to pattern altitude, just to gain the most altitude while I'm still
within reach of the airport boundaries. The one good thing about PDK is
it has 4 runways aligned 3 different ways, and lots of taxiways and ramp
space between them, so just getting back to the airport itself you have
a better chance of putting it down safely, if not on a runway.

Plus the crash trucks don't have as far to go. :-)

--
David Hill
david at hillREMOVETHISfamily.org
Sautee-Nacoochee, GA, USA

filters, they're not just for coffee anymore
The following needn't bother to reply, you are filtered:
Juan E Jimenez, Barnyard BOb, Larry Smith, John Nada

David Hill writes:

After getting my private, I was wondering about this, particularly
because the airport I usually fly out of (PDK) is surrounded by
development that leaves no place, at any time of day, to even dream of
setting down safely in the event of an engine failure.

Confirm this with someone who knows better, but from what I've heard,
you need only about 20 ft of deceleration to have a chance of
surviving a landing in a Cherokee/172/Musketeer-class aircraft. That
suggests that setting down in a developed area (an unoccupied part,
preferably) might be survivable.

To take a real-world example, an instructor taking a sightseeing
flight out of Buttonville (near Toronto) had an engine failure over
solid development, so she set the plane down deliberately in a grove
of small trees on the front lawn of the IBM plant. The trees smashed
up the plane nicely, but in doing so, they dissipated enough energy
that she and her passengers walked away. Here's the story (with
photo):

http://www.thestar.com/NASApp/cs/Con...l=968793972154

I read afterwards that she went back to work later that day.


All the best,


David

Harold wrote:

If a small single engine plane can out-climb its engine-out glide ratio from
take off through the top of climb point, wouldn't it follow that it can
always theoretically make it back to the departure airport in the event of
engine failure ?

Sure, except that you have to get turned around first. There is always some
altitude below which you will not be able to return to the airport. This tends
to be between 600 and 900' AGL in a typical powered aircraft.

George Patterson
To a pilot, altitude is like money - it is possible that having too much
could prove embarassing, but having too little is always fatal.

David Hill wrote:
dennis wrote:
snip


After getting my private, I was wondering about this, particularly
because the airport I usually fly out of (PDK) is surrounded by
development that leaves no place, at any time of day, to even dream of
setting down safely in the event of an engine failure.

I would think, in a "172" or similar class airplane, if you have your
seatbelts and shoulder harnesses on, flaps down, minimum controllable
airspeed, and *maintain control*, you should be able to land on (or
into) almost anything and survive with minor injury. I know of two
landings on top of houses that were both "walk aways".

Another engine fail on takeoff landing here was at night into a
park full of mature oak trees. Front seat guys were seriously banged
up, but they also were not wearing seat belts. Three rear seat pax,
also unbelted, received minor injuries.

Tom Pappano, PP-ASEL-IA

"Harold" wrote:

If a small single engine plane can out-climb its engine-out glide ratio from
take off through the top of climb point, wouldn't it follow that it can
always theoretically make it back to the departure airport in the event of
engine failure ? Assuming straight out departure, no wind, and the altitude
loss in the 180 turnback is offset by the runway portion you didn't use.
I'm not clear what you mean by that.
If
my best glide is 85 KTAS and it loses 700 fpm at that speed, shouldn't I be
guaranteed I can make it back if I climb at 84 KTAS and 701 fpm ?

If by your statement above, you mean that the runway is long enough
that if you can't turn back, you can land straight ahead, then of
course your statement is trivially true. If not, how can you turn back
from 10'?
--
Alex
Make the obvious change in the return address to reply by email.

On Wed, 22 Oct 2003 01:52:18 GMT, Tom Pappano wrote
in Message-Id: :

Front seat guys were seriously banged up, but they also were not wearing
seat belts. Three rear seat pax, also unbelted, received minor injuries.

Life may be "like a box of chocolates for some folks," but the laws of
physics are seldom broken. :-)

Anyone who doesn't faithfully use lap and shoulder belts, is a damn
fool.

True on all counts...

BT

"dennis" wrote in message
k.net...
The glider has a couple of things going for it. Power planes are seldom
over
12:1 glide ratio and it is achieved at a higher speed than the glider.
This means that the power plane covers about half the THEORETICAL glide
distance of the glider. Said loudly.

The speed ratio between the wind and the aircraft is a factor. A given
wind
speed will be a higher percentage of the glider's best glide speed and
will
result in a greater advantage to it's L/D downwind compared to a power
plane
with the same wind. The wind also works to advantage for the glider's on
tow
part by decreasing the distance that it covers on climb, compared to a
power
plane at typical climb speeds.

Finally, for some ancient and illogical reason, power plane standard
procedure
is to stay on center line of the runway for climbout. It's considered bad
form
to put yourself in a safer position for a turn back to the field. The
exception is an IFR departure. They typically maintain runway heading.
Lots
of luck making a turn back under IFR.

You subtract reaction time, reconfiguration time, screw around trying to
get
the thing to run, and it is very, very unlikely that a power plane will
get
back to the runway at any time during their climb out. Unless it is a long
runway and you started from the end.




In article afjlb.63635$La.24804@fed1read02, "BTIZ"
wrote:
Most gliders can do this and the pilots train to that standard..

Departure problems below 200ft AGL, tow plane power problems.. rope
breaks
or tow hook failures.. and the idea is to land straight ahead as quickly
as
possible and get stopped.

Above 200ft AGL (which most glider/tow combinations can get to about
3000ft
after start of take off roll), if the rope breaks, tow plane says.. GET
OFF!!.. the glider pilot can pitch down for airspeed and begin a turn
back
to the departure runway.. land opposite the direction of take off and
have
enough energy to roll back to the starting point.

A nice tow pilot will allow the tow to "Drift down wind the cross wind"
on
climb out, so if something does happen the glider can turn into the wind
when returning to the runway.. turning away from the wind can push the
glider to far away (tailwind on base) and make returning to the runway
more
difficult.

This maneuver is part of the practical test standards, though most DE's
will
wait until 300ft or higher and most CFIGs will review the procedure on
BFRs.

Our "Training glider" has a L/d of 23-1. Schweizer 2-33.

BT

"Harold" wrote in message
. ..
If a small single engine plane can out-climb its engine-out glide ratio
from
take off through the top of climb point, wouldn't it follow that it can
always theoretically make it back to the departure airport in the event
of
engine failure ? Assuming straight out departure, no wind, and the
altitude
loss in the 180 turnback is offset by the runway portion you didn't
use.
If
my best glide is 85 KTAS and it loses 700 fpm at that speed, shouldn't
I
be
guaranteed I can make it back if I climb at 84 KTAS and 701 fpm ?

George.. where do you get all these neat quotes for your sig line

BT

"G.R. Patterson III" wrote in message
...


Harold wrote:

If a small single engine plane can out-climb its engine-out glide ratio
from
take off through the top of climb point, wouldn't it follow that it can
always theoretically make it back to the departure airport in the event
of
engine failure ?

Sure, except that you have to get turned around first. There is always
some
altitude below which you will not be able to return to the airport. This
tends
to be between 600 and 900' AGL in a typical powered aircraft.

George Patterson
To a pilot, altitude is like money - it is possible that having too
much
could prove embarassing, but having too little is always fatal.