Safe flights require a safe launch... Physics for PG safety!

A rough estimate is about 40% of all PG accidents are during the launch phase. So what changes to 'normal' PG theory/training can we easily make that can remove/reduce this class of PG accidents?

Note: This is not just a solo problem, there have been a significant number of tandem double deaths due to the PIC (Pilot in Charge) launching based on 'normal' practice.

The 1st step in correcting errors is to identify AND understand them, to do this I've quoted the requirments imposed on tandem pilots by New Zealand's version of the BHPA, the NZHPGA.

----------------------------------------

QUOTE:

5. The Brief.
One of the most crucial matters to indoctrinate the passenger with is the absolute requirement for
them to commit themselves to a strong take-off run.
~~~~~
Keep calm in your voice during the brief, exude quiet confidence, however, be "firm" during the run
to impart urgency during the take-off run, i.e. loudly say "run hard".
~~~~~
Some pilots tell the passenger to lean forward and run hard and keep running until
they are lifted into the air.

6. Take Off
~~~~~
"Lean forward, lets go - run! run! run hard!"
~~~~~
"OK we really need to commit ourselves for this take-off, trust me, look at the horizon and this time
~~~~~~

End of QUOTE --------------------------

Conclusion: 'normal' PG training/theory results in the pilots mass being ahead of the wing at launch (pilot pulling the wing). So result the accidents the sport keeps having at launch!

Ok basic Physics.

For the last 12 years been working hard to ensure my students understand a core fact of PG flight, that is that it is the WING that not only supports the pilots weight, but also it is the WING that pulls the pilot forward in flight against the drag due to moving forward through the air.. I.E the wing in steady gliding flight is above and IN FRONT of the pilots mass...

Now it's a VERY bad idea to leave the ground before the aircraft is in safe gliding flight, I.e above & IN FRONT of the pilots mass..

So for a safe PG launch the pilot should ONLY impart just enough effort into the wing to permit it to do it's job of rising up from the ground and building up it's airspeed, and on till the wing is JUST far enough ahead of the pilots mass to be fully working as a 'Three Force' gliding aircraft... PRIOR to the pilot leaving the ground.

I've plenty of 'Lazy & Efficent' PG launches on YouTube showing how easy it is to avoid those 40% of PG accidents!

Basic Physics (vectors): Gravity ONLY ever acts on Mass (the pilot) verticaly downwards, and Pilot/Line Parasitic Drag is 'backwards', hence the Resultant Vector sum (Gravity+Drag) is 'down & back'.

In steady gliding flight the pilot, by is of course not accelerating, so we know (Newton's Laws) there MUST be a ballancing force to the Resultant sum of Gravity & Drag. This ballancing force is 'Lift' from the wing, acting via the lines & risers to pull the pilot FORWARDS (and up)!

Murray Hay

yawn

All 'Guest' poster who contribute to the forum are of course welcome.

However it would be polite to both give a name and perhaps, in the case of the above post, to state more than just 'Yawn'.

I would be intrested in hearing what justification, they have in stating that I am a 'bad scientist'.

I've no doubt the many 100's of re-training ex-BHPA pilots who have come to me over the years would also be intrested in this......

On a personal note, those in the UK that are happy with BHPA accident, injury & death rates are as far as I am concerned perfectly free to stick with BHPA 'science'. However ALL UK PG pilots may wish to consider why the inner front page of Skywings is highlighting yet again the desperate need to change what the BHPA do if the sport is to finaly see a drop in accident rates...

Murray Hay

PS All that is currently known about 'Guest' is they are from Glenrothes, in Fife.

i have not been paragliding yet but i am going to at the end of this month hopefully with murry hay most of the vidios that i have watched( not of murry hay) all look dodgy at takeoff with the pilot running like mad then swinging forward when in the air so gravity/drag v lift/ makes sense to me

Hi see you soon

We've had six days training/flying so far in March, and 14 days in Feb (I was very busy with photoshoots, limiting free time...)

Murray Hay

NOTE Quote: 'all look dodgy at takeoff with the pilot running like mad then swinging forward when in the air'

This should of course read 'Swinging BACKwards as the pilot leaves the ground'

In a 'commited' take off run the pilot (while in contact with the ground) is adding a 'forth force' (Thrust) to the aircraft and in the air the gliding paraglider is of course a THREE force (Gravity/Drag/Lift) aircraft with a 'underslung load' (the pilot/harness/lines)