Fatal glider/tow plane accident, France

On Sat, 19 May 2012 17:09:03 -0700, Frank Whiteley wrote:

Kestrel 19's (at least series 3 & 4) have airbrakes fairly aft on the
chord. The inboard 1/2 span sections of the flaperons have a second
handle to allow landing and ground launching deflections. One notch
will add 200ft+ gain to a 4500ft winch run. This is about 14 degrees
and is enough for most landings with a bit of headwind and airbrakes.
Full inboard deflection is 35 degrees and adds significant lift and drag
when landing.

Thanks for the correction. I thought the Kestrel wing was the same as the
Mosquito/MiniNimbus wing despite the lever collection in the cockpit.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Sunday, May 20, 2012 3:49:39 AM UTC-6, BruceGreeff wrote:
All 19m Kestrels have the same control setup as far as I know. My Series
1 is the same as the 3 & 4 as far as airbrake and drag chute are
concerned. The only difference I am aware of is that there is only one
landing flap setting at 35 degrees.

Throw it all out and the landing point is going to be really close by.

Arguably, because the effect on the Kestrel glide path is so
"noticeable" when you deploy the landing flap, you could argue that the
primary glidepatnh control is the flaps. However, it is unwise to raise
the landing flap unless you have a lot of excess height. So glidepath
control is still finessed by means of the airbrakes, which are
reasonably effective. Ok - my standards may be low given that I the
previous toy was a Std Cirrus.

I didn't want to mention the raising of the 19's landing flaps once deployed because if starts a discussion about whether it can be done safely (in general, not specifically). In my discussions with other Kestrel 19 pilots, it has been suggested that dumping the landing flaps will cost about 150ft in altitude. My impression is that's a fair estimate, so as you say, have plenty of altitude in hand.

"BruceGreeff" wrote in message ...

All 19m Kestrels have the same control setup as far as I know. My Series
1 is the same as the 3 & 4 as far as airbrake and drag chute are
concerned. The only difference I am aware of is that there is only one
landing flap setting at 35 degrees.

Throw it all out and the landing point is going to be really close by.

Arguably, because the effect on the Kestrel glide path is so
"noticeable" when you deploy the landing flap, you could argue that the
primary glidepatnh control is the flaps. However, it is unwise to raise
the landing flap unless you have a lot of excess height. So glidepath
control is still finessed by means of the airbrakes, which are
reasonably effective. Ok - my standards may be low given that I the
previous toy was a Std Cirrus.



On 2012/05/20 2:09 AM, Frank Whiteley wrote:
On Saturday, May 19, 2012 2:11:42 PM UTC-6, Martin Gregorie wrote:
On Sat, 19 May 2012 12:01:09 -0600, BobW wrote:

If you'll excuse the anality, I'll note the "hidden assumption" required
to make your 2nd para above completely accurate (for readers who may be
incompletely informed on glider flap capabilities and use). Hidden
assumption: Martin's statement applies *only* to camber-changing flaps,
and NOT to large-deflection landing flaps. These latter tend to be most
common in the USA.

You're right: I should have spotted that.

Many gliders have both camber-changing flaps (which for landing patterns
should be set to their maximum [smallish] deflection to obtain maximum
reduction of stalling speed) AND airbrakes/spoilers (their primary
glidepath control devices, and which should definitely NOT be "set and
forget" devices [maybe unless one is landing in a perfect calm...]).

The only gliders on our field without airbrakes as a distinct control are
a pair of Kestrel 19s, a Mosquito and a Mini-Nimbus. All use moderate
flap deflection on landing combined with a raised flap LE for added drag.

I haven't flown any of these types. The nearest I've come was an early
ASW-20 which, of course, has both large-deflection flaps and airbrakes.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Kestrel 19's (at least series 3& 4) have airbrakes fairly aft on the
chord. The inboard 1/2 span sections of the flaperons have a second
handle to allow landing and ground launching deflections. One notch will
add 200ft+ gain to a 4500ft winch run. This is about 14 degrees and is
enough for most landings with a bit of headwind and airbrakes. Full
inboard deflection is 35 degrees and adds significant lift and drag when
landing.

Frank Whiteley

--
Bruce Greeff
T59D #1771

Talk about thread creep.
I quote from the Kestrel 19 Pilot Notes
" Approach and landing is possible in many configurations, the best being
with the flaps set to landing flap and +2
or landing flap and 0, using the not very effective airbrakes as a final
approach control"
Ian Kennedy
Kestrel 19 575.
And now owner of Kestrel 22 G BDWZ

about the statement "it is unwise to raise the landing flap unless
you have a lot of excess height":

one has to be careful doing this, but its safe to do this so long as
the nose is raised at the same time (to increase the angle of
attack and compensate the loss of lift otherwise produced by the
reduced flap setting). The glide angle flattens out and the
approach speed remains the same. I used to practice exactly this
in my Kestrel 19, at height, in case I ever needed to do it if a bad
undershoot developed on a real approach. I never had to do it for
real, but after practicing it, it was very comfortable. Its not
something normally taught, so it needs to be practiced well above
the ground initially. If the airspeed remains constant, its being
done right.




At 17:25 20 May 2012, Ian Kennedy wrote:

"BruceGreeff" wrote in message news:jpaenk$i87$1@dont-
email.me...

All 19m Kestrels have the same control setup as far as I know.
My Series
1 is the same as the 3 & 4 as far as airbrake and drag chute are
concerned. The only difference I am aware of is that there is
only one
landing flap setting at 35 degrees.

Throw it all out and the landing point is going to be really close
by.

Arguably, because the effect on the Kestrel glide path is so
"noticeable" when you deploy the landing flap, you could argue
that the
primary glidepatnh control is the flaps. However, it is unwise to
raise
the landing flap unless you have a lot of excess height. So
glidepath
control is still finessed by means of the airbrakes, which are
reasonably effective. Ok - my standards may be low given that I
the
previous toy was a Std Cirrus.



On 2012/05/20 2:09 AM, Frank Whiteley wrote:
On Saturday, May 19, 2012 2:11:42 PM UTC-6, Martin
Gregorie wrote:
On Sat, 19 May 2012 12:01:09 -0600, BobW wrote:

If you'll excuse the anality, I'll note the "hidden
assumption"
required
to make your 2nd para above completely accurate (for
readers who may be
incompletely informed on glider flap capabilities and use).
Hidden
assumption: Martin's statement applies *only* to camber-
changing flaps,
and NOT to large-deflection landing flaps. These latter tend
to be most
common in the USA.

You're right: I should have spotted that.

Many gliders have both camber-changing flaps (which for
landing
patterns
should be set to their maximum [smallish] deflection to
obtain maximum
reduction of stalling speed) AND airbrakes/spoilers (their
primary
glidepath control devices, and which should definitely NOT
be "set and
forget" devices [maybe unless one is landing in a perfect
calm...]).

The only gliders on our field without airbrakes as a distinct
control
are
a pair of Kestrel 19s, a Mosquito and a Mini-Nimbus. All use
moderate
flap deflection on landing combined with a raised flap LE for
added
drag.

I haven't flown any of these types. The nearest I've come
was an early
ASW-20 which, of course, has both large-deflection flaps and
airbrakes.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Kestrel 19's (at least series 3& 4) have airbrakes fairly aft on
the
chord. The inboard 1/2 span sections of the flaperons have a
second
handle to allow landing and ground launching deflections. One
notch will

add 200ft+ gain to a 4500ft winch run. This is about 14
degrees and is
enough for most landings with a bit of headwind and
airbrakes. Full
inboard deflection is 35 degrees and adds significant lift and
drag when
landing.

Frank Whiteley

--
Bruce Greeff
T59D #1771

Talk about thread creep.
I quote from the Kestrel 19 Pilot Notes
" Approach and landing is possible in many configurations, the
best being
with the flaps set to landing flap and +2
or landing flap and 0, using the not very effective airbrakes as a
final
approach control"
Ian Kennedy
Kestrel 19 575.
And now owner of Kestrel 22 G BDWZ

On Sunday, May 20, 2012 1:25:07 PM UTC-4, Ian Kennedy wrote:
"BruceGreeff" wrote in message ...

All 19m Kestrels have the same control setup as far as I know. My Series
1 is the same as the 3 & 4 as far as airbrake and drag chute are
concerned. The only difference I am aware of is that there is only one
landing flap setting at 35 degrees.

Throw it all out and the landing point is going to be really close by.

Arguably, because the effect on the Kestrel glide path is so
"noticeable" when you deploy the landing flap, you could argue that the
primary glidepatnh control is the flaps. However, it is unwise to raise
the landing flap unless you have a lot of excess height. So glidepath
control is still finessed by means of the airbrakes, which are
reasonably effective. Ok - my standards may be low given that I the
previous toy was a Std Cirrus.



On 2012/05/20 2:09 AM, Frank Whiteley wrote:
On Saturday, May 19, 2012 2:11:42 PM UTC-6, Martin Gregorie wrote:
On Sat, 19 May 2012 12:01:09 -0600, BobW wrote:

If you'll excuse the anality, I'll note the "hidden assumption" required
to make your 2nd para above completely accurate (for readers who may be
incompletely informed on glider flap capabilities and use). Hidden
assumption: Martin's statement applies *only* to camber-changing flaps,
and NOT to large-deflection landing flaps. These latter tend to be most
common in the USA.

You're right: I should have spotted that.

Many gliders have both camber-changing flaps (which for landing patterns
should be set to their maximum [smallish] deflection to obtain maximum
reduction of stalling speed) AND airbrakes/spoilers (their primary
glidepath control devices, and which should definitely NOT be "set and
forget" devices [maybe unless one is landing in a perfect calm...]).

The only gliders on our field without airbrakes as a distinct control are
a pair of Kestrel 19s, a Mosquito and a Mini-Nimbus. All use moderate
flap deflection on landing combined with a raised flap LE for added drag.

I haven't flown any of these types. The nearest I've come was an early
ASW-20 which, of course, has both large-deflection flaps and airbrakes..


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Kestrel 19's (at least series 3& 4) have airbrakes fairly aft on the
chord. The inboard 1/2 span sections of the flaperons have a second
handle to allow landing and ground launching deflections. One notch will
add 200ft+ gain to a 4500ft winch run. This is about 14 degrees and is
enough for most landings with a bit of headwind and airbrakes. Full
inboard deflection is 35 degrees and adds significant lift and drag when
landing.

Frank Whiteley

--
Bruce Greeff
T59D #1771

Talk about thread creep.
I quote from the Kestrel 19 Pilot Notes
" Approach and landing is possible in many configurations, the best being
with the flaps set to landing flap and +2
or landing flap and 0, using the not very effective airbrakes as a final
approach control"
Ian Kennedy
Kestrel 19 575.
And now owner of Kestrel 22 G BDWZ

I love that comment about the "not very effective airbrakes"

My Kestrel 19's airbrakes make some noise, but not much else. I get about 1 knot of sink out of the them. I rely on judicious setting of flaps and then finesse the glideslope with the airbrakes. If I'm much too high, the drogue comes out and I ride the express elevator to ground level.

Series 1 & 2 had a TI about cutting a notch in the landing flap lever for about 14 degrees of deflection. I don't know if this was factory-done for Series 3 and 4. This helps in take-off for towing and winching, plus for the initial part of the circuit.

-John