Safety of winch launch vrs. aero tow?

In power planes I often wondered how high I would need to turn around,
and the biggest difference seemed to be how well I was climbing.
In a heavy Piper Arrow on a hot day, We couldn't climb fast enough
to ever glide back regardless how high we went if we did a
straight out or 45 departure. Departing downwind was another story,
of course.

On hot days with heavy loads at Avenal, the tug sometimes turns very
gently at low altitudes to downwind. I recall flying a two seater open
cockpit on a very hot day and seeing miserable climb out of us
and the 150/150. In our case not a problem with all the
flat ground, but still a bit disconcerting to be
so far out and low...

"Mark James Boyd" wrote in message
news:3fa5f571$1@darkstar...
In power planes I often wondered how high I would need to turn around,
and the biggest difference seemed to be how well I was climbing.
In a heavy Piper Arrow on a hot day, We couldn't climb fast enough
to ever glide back regardless how high we went if we did a
straight out or 45 departure. Departing downwind was another story,
of course.

On hot days with heavy loads at Avenal, the tug sometimes turns very
gently at low altitudes to downwind. I recall flying a two seater open
cockpit on a very hot day and seeing miserable climb out of us
and the 150/150. In our case not a problem with all the
flat ground, but still a bit disconcerting to be
so far out and low...

Back in around 1970 a power instructor who had witnessed glider 200 foot 180
turns back to the runway wanted to try some in a Cessna 150. I rode with
him as we tried a few at a safe altitude. The 150 was one of the old ones
with a straight tail and manual flaps.

The glider technique of a 45 degree banked turn was very marginal. We then
experimented with some more aggressive maneuvers. The best seem to be a
sort of diving 180 degree rolling turn with a pullout from the dive on the
reciprocal heading. We came out of the dive headed towards the runway at
high airspeed but in ground effect which got us to the runway with ease.

Once we were confident of our technique, we tried a few at Caddo Mills, TX.
At the time, Caddo Mills was just abandoned runways with no buildings or
fences and surrounded by alfalfa fields. The 45 degree turn never made it
back but the diving roll did work if you were quick and aggressive.

We both agreed that the conventional instruction of not trying a 180 below
about 500 feet was best.

Bill Daniels

"Bill Daniels" wrote:


"Mark James Boyd" wrote in message
news:3fa5f571$1@darkstar...
In power planes I often wondered how high I would need to turn around,
and the biggest difference seemed to be how well I was climbing.
In a heavy Piper Arrow on a hot day, We couldn't climb fast enough
to ever glide back regardless how high we went if we did a
straight out or 45 departure. Departing downwind was another story,
of course.

On hot days with heavy loads at Avenal, the tug sometimes turns very
gently at low altitudes to downwind. I recall flying a two seater open
cockpit on a very hot day and seeing miserable climb out of us
and the 150/150. In our case not a problem with all the
flat ground, but still a bit disconcerting to be
so far out and low...

Back in around 1970 a power instructor who had witnessed glider 200 foot 180
turns back to the runway wanted to try some in a Cessna 150. I rode with
him as we tried a few at a safe altitude. The 150 was one of the old ones
with a straight tail and manual flaps.

The glider technique of a 45 degree banked turn was very marginal. We then
experimented with some more aggressive maneuvers. The best seem to be a
sort of diving 180 degree rolling turn with a pullout from the dive on the
reciprocal heading. We came out of the dive headed towards the runway at
high airspeed but in ground effect which got us to the runway with ease.

Once we were confident of our technique, we tried a few at Caddo Mills, TX.
At the time, Caddo Mills was just abandoned runways with no buildings or
fences and surrounded by alfalfa fields. The 45 degree turn never made it
back but the diving roll did work if you were quick and aggressive.

We both agreed that the conventional instruction of not trying a 180 below
about 500 feet was best.

Bill Daniels

Many years ago a highly respected aerobatic pilot in UK (still working
today) wrote an article in our Pilot magazine on this subject. He
reminded us that three things were required:
1. A rapid 180 degree change of heading.
2. Minimum loss of height.
3. Normal airspeed at the end of the manoever.
Controversially, he maintained that a highly banked slipping turn
satisfies all three criteria. The rate of decent is very high during
the turn, but the duration is so short that it results in less height
loss than either of the two alternatives (eg:slow and gentle or fast
and furious), and the airspeed is normal throughout.
Just don't forget to keep loads of top rudder on.

- Colin

Colin wrote:

Many years ago a highly respected aerobatic pilot in UK (still working
today) wrote an article in our Pilot magazine on this subject. He
reminded us that three things were required:
1. A rapid 180 degree change of heading.
2. Minimum loss of height.
3. Normal airspeed at the end of the manoever.
Controversially, he maintained that a highly banked slipping turn
satisfies all three criteria. The rate of decent is very high during
the turn, but the duration is so short that it results in less height
loss than either of the two alternatives (eg:slow and gentle or fast
and furious), and the airspeed is normal throughout.
Just don't forget to keep loads of top rudder on.

- Colin


I don't see why the turn should be a slipping one, you certainly will
loose more height in a slipping turn than in a normal one. And height
loss is what make the turn possible or not.

Robert Ehrlich wrote:

Colin wrote:

Many years ago a highly respected aerobatic pilot in UK (still working
today) wrote an article in our Pilot magazine on this subject. He
reminded us that three things were required:
1. A rapid 180 degree change of heading.
2. Minimum loss of height.
3. Normal airspeed at the end of the manoever.
Controversially, he maintained that a highly banked slipping turn
satisfies all three criteria. The rate of decent is very high during
the turn, but the duration is so short that it results in less height
loss than either of the two alternatives (eg:slow and gentle or fast
and furious), and the airspeed is normal throughout.
Just don't forget to keep loads of top rudder on.

- Colin


I don't see why the turn should be a slipping one, you certainly will
loose more height in a slipping turn than in a normal one. And height
loss is what make the turn possible or not.

1. A slipping turn can be made at a high bank angle and low airspeed.
2. Rate of turn is dependent on angle of bank and airspeed, such that
the highest rate of turn is achieved with a high bank angle and a low
airspeed.
Brian illustrated this by inviting us to compare the rate of turn
achieved by a C150 and a jet fighter at the same angle of bank.
It has to be a slipping turn or we would stall, so the maximum bank
which can be used is dependent on the amount of top rudder available.

- Colin

Colin wrote:


I don't see why the turn should be a slipping one, you certainly will
loose more height in a slipping turn than in a normal one. And height
loss is what make the turn possible or not.


1. A slipping turn can be made at a high bank angle and low airspeed.

I don't understand this: at any given bank angle, how can you achieve a
lower airspeed when you are slipping? Doesn't that require more elevator
power? How would a slipping turn enable that?

On Thu, 06 Nov 2003 00:02:30 +0000, Colin wrote:

1. A slipping turn can be made at a high bank angle and low airspeed.

I believe in (and teach) a few basic principles when flying close to the
ground.

- Stall/spin accidents kill more pilots than any other single cause.

- Stalls occur when you fly too slowly.

- Spins occur when you stall and the glider is not "co-ordinated" ie
either slipping or skidding.

Therefore if you are flying close to the ground, keep the airspeed
comfortably above stalling speed. And if you can't do that, keep the
aircraft co-ordinated.

(When instructing, close to the ground, if the student can't maintain a
steady airspeed, I take over control at the first sign of loss of
co-ordination).

Using a low airspeed slipping turn to turn 180 deg when less than 200 ft
above the ground sounds like the advice that a legendary grandmother is
once said to have given "now son, be careful when you go flying, don't fly
to high and don't fly too fast!"

Maybe some aerobatic super pilot can prove me wrong, but if you have to
resort to these measures to get back to the field then I think you would
probably be better off taking your chances going in straight ahead.


Ian

(I have seen gliders “land� in some unusual places and get away with
relatively minor damage and no injuries. Provided the glider is flown in a
controlled manner to the point of touch down, and the landing is done with
lowest possible energy - full flaps, into wind, air brakes closed - damage
is often minor. On the other hand I have seen two crashes where the glider
went in wing tip first and cartwheeled. Both were right-offs with serious
injuries.)

Ian Forbes wrote:

On Thu, 06 Nov 2003 00:02:30 +0000, Colin wrote:


- Spins occur when you stall and the glider is not "co-ordinated" ie
either slipping or skidding.

I used to think this, but I soon discovered our club Blanik would
happily spin from a coordinated turn by using a shallow bank and simply
reducing the airspeed. Since then, I've done this with other gliders.

A coordinated turn doesn't prevent the inner wing from flying at a
higher angle of attack than the outer wing, which is why it stalls
first, and a spin can begin. I haven't experimented with it enough to be
certain, but I suspect a slipping turn would reduce the tendency for the
inner wing to stall first.