Wlasne notatki od Tom Payne
FLYING FAST FOR BIG XC AND COMPS BEYOND SPEED TO FLY
DIAGRAMS
1 4 5 6 7 8
15 60 75 90 105 120
20 80 100 120 140 160
25 100 125 150 175 200
30 120 150 180 210 240
Climb Glide Speed Chain
1m/s 40 20 20 40
2m/s 30 30 30 60
3m/s 24 36 36 60
4m/s 20 40 40 60
5m/s 10 50 50 60
2
Thermal cross-section
Thermal cross-section in wind
3
Ridge cross-section with thermals
4
Climb strength with altitude
- normal day
- small clouds
- cloud suck
- inversions
WHAT
Who/what/why
- average speed, not top speed
- most advanced talk I've ever given
- why it is important (key to big XC, comps)
- much of it familiar to experienced competition pilots, however I hope that there will be some nuggets for them
- my goal is to encourage you to step up your game: fly further and to fly faster
- based on my experience flying big triangles and comps in the Alps
- some parts more or less relevant for UK flying - certainly relevant for Slovenia, St Jean and your next XC holiday
- more effective than changing class of glider
- more effective on higher performing gliders
- not an excuse for flying a low-end glider!
Principles
- it's about average speed
- speed is here (head), not here (groin)
- speed is in your decision making, not in having big balls!
- must get very comfortable with flying on bar
- speed bar is 3rd, 4th and 5th gear - who here drives everywhere in 2nd?
- imagine a long ridge, with constant light 1m/s lift all the way along it, with a few good thermals regularly spaced along it
- pilot A climbs in the good thermals and then glides fast, climbs in the next thermal, etc. etc.
- pilot B flies at trim speed along the ridge, just maintaining altitude
- who's fastest? how strong to the thermals have to be for A to be quicker?
WHY
XC example
- length of day
- distance
- required average speed
- average XC pilot 15-20km/h
- good XC pilot 25km/h
- FAI cat 2 speeds 30km/h
- PWC speeds 35-38km/h
- at strongest time of the day!
- 150km @ 25km/h takes 6 hours
- 200km @ 25km/h takes 8 hours
- 300km @ 30km/h takes 10 hours
- 500km @ 50km/h takes 10 hours
Climb and glide
- Let's put some numbers in
- We can use speed to fly theory to compute maximum average speeds
- It is only defined by climb rate and our glider's polar
- Climbing takes time
- Speed bar doesn't compensate enough
- How often have you heard "I was doing really well, but I had to stop and climb"
- We know that climbing is slow!
Cheminement
- Clearly, we can go faster!
- How?
- A turn takes about 20s, so three turns takes a minute
- In a minute you can fly 1km at 60km/h - six turns puts your 2km behind!
- On a comp wing, every three turns you avoid gives you 1km/h more of average speed
- In a Cat 2 comp, the winner is typically over 30km/h, 29kmh/ might get you 10th, 28km/h maybe 30th
- you don't see thirty pilots in the lead gaggle leaving one after another
- 60m on a glide saves a minute - three turns - in a 1m/s thermal
- gliding well translates directly into less climbing, and the effect is amplified - we'll see why later
- climbing well matters
- increasingly, gliding well matters
HOW
Deciding when to turn
- climb selection
- to quote Wagga: "don't waste time". Don't climb in +2 when +4 are around
- set threshold based on experience on the day
- fly on bar to search faster
- 50% more speed = 50% more air searched
- when flying downwind can be less selective about climbs
- when flying upwind must be very selective about climbs
- when flying crosswind, fly upwind when encountering lift
- use light lift to make progress upwind rather than climb
Thermal entry
- use of speed bar on thermal entry
- when you hit lift your angle of attack increases - you're not going to get a collapse, you need to push *more* bar
- make the wing bite into the thermal
- control pitch
- more authority over wing (can't do much when it's behind you)
- don't come off the bar early to search - release smoothly and only when in core
- convert in core
- when flying downwind turn immediately
- when flying upwind keep searching (best cores are on the upwind side)
Thermalling well
- big, strong climbs are easier to climb in!
- always be looking for something better
- moving within cores
- re-finding lost cores (270 degrees)
- keep wing movements smooth, avoid unecessary pitch, roll and yaw movements
- build a mental model of the thermal
Thermal exit
- use of speed bar on thermal exit
- avoids collapse on going over the falls
- blasts through surrounding sink
Gliding well
- reduce drag
- pitch control with bar
- pitch control with rear risers
- never bar + brakes
- weight distribution 60/30/10/0 vs 20/40/30/10
- glide straight
- glide fast
- slow down in lift
- or speed up!
- bouyant glide example
- cloud suck example
Finding lifty lines
- sensitive to glider
- some turn towards, others away
- sensitive to clues (clouds, gliders, birds, haze domes)
- visualize flow over terrain - rocks in a stream - distant effects, especially on unstable days
- visualize sink
- gently find lines
- quickly leave bad lines (turn 45 degrees)
- convergence lines
- horizontal vortex lines
- almost always aligned with wind or perpendicular to it (terrain)
- in flatlands often join areas of lift
- balancing on a knife edge
- almost never wide enough to turn in: you turn you lose
Large scale lift
- ridges
- cloud streets
- cloud suck
- we tend to visualise individual thermals
- visualise areas large areas of lift
- connect them together!
- climb to connect, then dolphin
- climb at end to connect with next
- don't climb in middle
- think areas, not individual thermals
Altitude selection
- thermal strength varies with altitude
- lapse rate
- cloud suck
- inversions
- build mental model of climb rate profile
- wind strength and direction varies with altitude
- surface friction
- terrain effects - slope and valley breezes, venturi, surface friction
- cloud effects (e.g. cloud suck)
- sea breezes
- work out the most efficient altitude for your flight plan
- for XC, plan according to forecast
Effect of flying downwind
- Makes this less important
- Smoothes out peak - what we're doing here is gaining a few km/h of average speed
- percentage wise this is less important if you've got a tailwind
- on the other hand, it's critical for upwind flying, anyone want to fly triangles in the UK this year?
Conclusions
- average speed
- comfort on bar
- decision making
- new approach to flying made possible by recent leaps in glider performance
- sensitivity
Games to play
- fly into wind
- play with speed bar
- play with gliding tactics