Reflex wing collapses at high speed
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Keith Pickersgill -Xplorer UltraFlight
Sep 13, 2014, 12:04:57 PM9/13/14
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I still hear from old-style paraglider pilots (including PG instructors!) and some old-school
paramotor pilots as well, that they refuse to believe that these new generation reflexed PPG wings
become completely collapse-proof when flown at max speed of 60kph+
Well, the proof is in the certification test-flights. On most of these wings, the test-pilots are
unable to induce a collapse at maximum airspeed, even with the help of "folding lines" added.
If you have this same issue with some stubborn non-believers, feel free to use this example provided
here, though there are many others too.
See the attached certification test-flight report for the LIFT from APCO.
Notice tests 13 and 15.
13. test of assymetric collapse with trimmers fully open and full use of speed system
Execution: Not Possible
15. test of symmetric collapse with trimmers open and eventual full use of speed system
Execution: Not Possible
If a professional PPG test pilot is completely unable to induce a collapse in this mode, even with
folding lines added to aid him, that tells me that the wing is rock-solid against turbulence induced
collapses at high speed and gives me great confidence in flying such a wing.
The EN/DHV/AFNOR/ACPULS type certification system has failed to keep up with rapidly evolving
technology. They still test ONLY the RECOVERY from collapses, with no indication of how easily the
wings collapse. This also gives no indication of how frequently or how severely they tend collapse in
turbulence.
The new paramotor wing certification system overcomes this problem.
If I had a choice between a wing that recovers quickly, yet it may collapse frequently, versus a wing
that no-one has been able to induce a collapse on, so we do not know how it will recover, my choice
will be for that second wing every time. I am sure that any intelligent pilot would do the same.
In the early days of reflexed wings:
a) They were difficult to launch (manufacturers claimed they never overshoot, but they failed to
mention how badly they tend to undershoot and hang back, and needed to be teased up)...
b) they were difficult to steer and required very high break pressure
c) they had extremely high speedbar pressure and one had to rest your legs after just a few minutes.
d) they had serious limitations on combinations of controls which could not be used, for example no
speedbar while trimmers were set to slow on certain wings.
Well, today's modern reflexed wings are:
a) in most cases, easier to launch from level ground than conventional wings (the acid test is always
launching off level ground in light to zero wind). They still never overshoot, but now they are also
eager to come up all the way without undershooting and no tendency to hang back once you start
running.
b) they offer more agile steering in reflexed mode than in conventional mode. The first generation
offered stabilo steering (aka wingtip steering) which was a bit sluggish, but the new generation
offer outer-brake steering, which can be used at all combinations of speedbar/trimmers, whether in
reflexed mode or not, for far greater agility than using the conventional brakes. The main brakes are
now used just for launching and landing.
c) Speedbar pressure is now on a par with conventional wings and in some cases, even lighter,
allowing for extended flights at full speedbar without tiring.
d) Most of the new generation reflexed wings have eliminated all the limitations and control
restrictions, where any combination of trimmers and speedbar may be used with great confidence.
The only remaining restriction, is to not use the main brakes when in reflexed mode, but then we WANT
to use the alternate steering anyway, for the extra agility and lighter brake-pressure they offer.
The future will surely bring higher and higher performance with increased safety and easy of learning
to fly.
Progress is great!
-----------------------------------------------
Keith Pickersgill
Xplorer UltraFlight
Powered Paragliding
Equipment, Training and Tandem Flights
PO Box 36784, Chempet,
7442 Cape Town, South Africa.
Mobile 082-414-8448
email: ke...@xplorer.co.za
Web: http://www.xplorer.co.za
Facebook Tandem PPG: https://www.facebook.com/TandemPPGCT
SA importer for P.AP. Paramotors - http://www.papteam.com
SA importer for Miniplane paramotors - http://www.miniplane.com
SA importer for MacPara wings - http://www.macpara.com
SA importer for APCO wings - http://www.apcoaviation.com
Dealer for Icom airband Radios
Dealer for Kirisun radios on SAHPA frequencies
Dealer for Garmin GPS navigators
When replying, PLEASE keep the original quoted text so that I can keep track of
the thread and past correspondence.
paramotor pilots as well, that they refuse to believe that these new generation reflexed PPG wings
become completely collapse-proof when flown at max speed of 60kph+
Well, the proof is in the certification test-flights. On most of these wings, the test-pilots are
unable to induce a collapse at maximum airspeed, even with the help of "folding lines" added.
If you have this same issue with some stubborn non-believers, feel free to use this example provided
here, though there are many others too.
See the attached certification test-flight report for the LIFT from APCO.
Notice tests 13 and 15.
13. test of assymetric collapse with trimmers fully open and full use of speed system
Execution: Not Possible
15. test of symmetric collapse with trimmers open and eventual full use of speed system
Execution: Not Possible
If a professional PPG test pilot is completely unable to induce a collapse in this mode, even with
folding lines added to aid him, that tells me that the wing is rock-solid against turbulence induced
collapses at high speed and gives me great confidence in flying such a wing.
The EN/DHV/AFNOR/ACPULS type certification system has failed to keep up with rapidly evolving
technology. They still test ONLY the RECOVERY from collapses, with no indication of how easily the
wings collapse. This also gives no indication of how frequently or how severely they tend collapse in
turbulence.
The new paramotor wing certification system overcomes this problem.
If I had a choice between a wing that recovers quickly, yet it may collapse frequently, versus a wing
that no-one has been able to induce a collapse on, so we do not know how it will recover, my choice
will be for that second wing every time. I am sure that any intelligent pilot would do the same.
In the early days of reflexed wings:
a) They were difficult to launch (manufacturers claimed they never overshoot, but they failed to
mention how badly they tend to undershoot and hang back, and needed to be teased up)...
b) they were difficult to steer and required very high break pressure
c) they had extremely high speedbar pressure and one had to rest your legs after just a few minutes.
d) they had serious limitations on combinations of controls which could not be used, for example no
speedbar while trimmers were set to slow on certain wings.
Well, today's modern reflexed wings are:
a) in most cases, easier to launch from level ground than conventional wings (the acid test is always
launching off level ground in light to zero wind). They still never overshoot, but now they are also
eager to come up all the way without undershooting and no tendency to hang back once you start
running.
b) they offer more agile steering in reflexed mode than in conventional mode. The first generation
offered stabilo steering (aka wingtip steering) which was a bit sluggish, but the new generation
offer outer-brake steering, which can be used at all combinations of speedbar/trimmers, whether in
reflexed mode or not, for far greater agility than using the conventional brakes. The main brakes are
now used just for launching and landing.
c) Speedbar pressure is now on a par with conventional wings and in some cases, even lighter,
allowing for extended flights at full speedbar without tiring.
d) Most of the new generation reflexed wings have eliminated all the limitations and control
restrictions, where any combination of trimmers and speedbar may be used with great confidence.
The only remaining restriction, is to not use the main brakes when in reflexed mode, but then we WANT
to use the alternate steering anyway, for the extra agility and lighter brake-pressure they offer.
The future will surely bring higher and higher performance with increased safety and easy of learning
to fly.
Progress is great!
-----------------------------------------------
Keith Pickersgill
Xplorer UltraFlight
Powered Paragliding
Equipment, Training and Tandem Flights
PO Box 36784, Chempet,
7442 Cape Town, South Africa.
Mobile 082-414-8448
email: ke...@xplorer.co.za
Web: http://www.xplorer.co.za
Facebook Tandem PPG: https://www.facebook.com/TandemPPGCT
SA importer for P.AP. Paramotors - http://www.papteam.com
SA importer for Miniplane paramotors - http://www.miniplane.com
SA importer for MacPara wings - http://www.macpara.com
SA importer for APCO wings - http://www.apcoaviation.com
Dealer for Icom airband Radios
Dealer for Kirisun radios on SAHPA frequencies
Dealer for Garmin GPS navigators
When replying, PLEASE keep the original quoted text so that I can keep track of
the thread and past correspondence.
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