Blown back and cloud suck

Spot the wind building before it beats your airspeed, get out in front and down early, never cross behind the crest, and leave strong lift well below cloud base.

In this lesson you will

The ridge is working beautifully. An hour ago you crabbed along it easily; now you have to point further out to hold your line, and the trees below crawl past. Nothing feels wrong: the wing is quiet and the lift is smooth. That is what makes this moment dangerous, and it is the best moment to leave.

Being blown back over a ridge and being drawn up into a cloud have this in common: the wing flies perfectly well and still carries you where you must not go. Both are avoided by deciding early.

Why you go backwards

Into wind, your groundspeed is your airspeed minus the headwind. When the two are equal you hover; when the wind is stronger, you go backwards¹. Current school wings have a trim speed of about 37–38 km/h23–24 mph and reach about 46–48 km/h29–30 mph on full speed bar²; check your manual. Wind in the high thirties at your height cancels your hands-up speed.

The wind you fly in is usually stronger than the wind you launched in:

Height. The wind usually strengthens as you climb, so good lift can carry you into wind you cannot beat³.
The crest. The wind speeds up over the top. For a smooth ridge 100 m330 ft high, an engineering guideline gives up to about 80% more wind just above the crest⁴; instructors estimate it is often 8–11 km/h5–7 mph stronger on windy days⁵. Either way it can be more than your speed bar adds.
The ground. Many schools warn that the wind on launch can be up to about 10 km/h6 mph weaker than a few metres up⁶.

Behind the crest lies the lee side, full of sink, turbulence and rotor that push you towards the slope. Near a steep ridge in strong wind the sink can reach about 10 m/s1,960 ft/min or more, and a flat top is no refuge⁷. See the penetration margin and rotor.

Figure: As the wind builds the margin shrinks, so the pilot turns straight out into wind, uses the bar, and lands early in front. In the second variant the pilot stays in strong lift and is carried back over the crest. Not to scale.

As the wind builds the margin shrinks, so the pilot turns straight out into wind, uses the bar, and lands early in front. In the second variant the pilot stays in strong lift and is carried back over the crest. Not to scale.

Warning signs

The best escape is not needing one. Manuals advise flying only where you can make progress into wind without the speed bar⁸, so plan with your hands-up speed. Stay well out in front, and move further out as you climb or the wind rises⁹.

On launch, look beyond the windsock: USHPA’s danger signs include high wind, blowing dust, whitecaps, swaying trees, smoke lying flat and lenticular clouds¹⁰. Watch the pilots already up. If they hover or drift back while pointing into wind, their margin is gone, and on a similar wing yours would be too.

In the air, two cues come first: you need a bigger crab angle to hold your line, and your groundspeed along the ridge drops¹¹. Point into wind and watch a spot on the ground: if it creeps back under you only slowly, your margin is small; if it moves forwards, you are going backwards. Wind noise is an airspeed cue (it fades as you slow towards the stall¹²), so it won’t warn you about the wind.

Escape early

Sources agree on the core of the escape: as soon as the wind strengthens, point straight away from the ridge into wind, accelerate as much as conditions allow, never turn towards the hill, and descend or land early in front¹³. Flying out to the landing field is always a legitimate choice¹⁴.

Getting out early

At the first warning sign, turn to face straight into wind and fly out, away from the ridge.
Cue The ridge falls behind you and the ground slides back under you again.
Why Sources agree on acting as soon as the wind strengthens, while you still have a margin¹³.
Push the speed bar as far as conditions allow, if your instructor has trained you.
Cue More wind noise and pressure under your feet; you creep forward faster.
Why More airspeed means more progress into wind¹. Never brake on the bar; if the wing collapses, release the bar first¹⁵.
Lose height out in front and head for the landing field.
Cue The lower you get, the faster the ground moves back under you.
Why The wind is usually weaker lower down³.
Come off the bar well before the ground and land early, into wind.
Cue Hands up, legs down, a normal final.
Why Manufacturers advise against flying accelerated close to the ground¹⁶.

Big ears with speed bar: where sources differ

Big ears raise your sink rate, but folding the tips also slows the wing. The disagreement is whether adding them helps when you are already struggling forward; nobody recommends big ears alone¹³.

Source	Big ears plus speed bar to get away
Gin and skywalk manuals	A way to sink faster while keeping forward speed, or to leave a dangerous area¹³
BHPA Foundation syllabus (after Club Pilot)	Listed for a faster descent, with awareness of its limits¹³¹⁷
Advance manual, XC Magazine	Head out with big ears and as much bar as conditions allow¹⁴
DHV (German federation)	Not suitable: sink rises, but forward speed drops by 3–8 km/h2–5 mph, depending on the wing¹³

In DHV tests on school wings, big ears alone flew 0–5 km/h0–3 mph slower than trim and ears with bar 0–8 km/h0–5 mph faster¹⁸, while full bar alone reaches about 46–48 km/h29–30 mph². So adding ears to full bar costs forward speed, the DHV’s point, but ears with bar still beat trim and sink much faster, the manufacturers’ point. Big ears also cut your stall margin¹⁹, and manuals disagree on the order: Gin and Ozone say never pull the ears with the bar already pushed, while Skywalk, following the DHV method, pushes half bar first²⁰. Follow your wing’s manual and your instructor, and practise in calm air with plenty of height²¹; see Speed bar and big ears.

Never behind the crest

Safety-critical Never cross behind the crest

Don’t fly on the crest or behind it, and make every turn away from the ridge: a downwind turn, even above the top, can carry you over into heavy sink²². If you are going backwards, keep facing into wind and get lower out in front; never turn towards the hill¹³.

If you can’t reach the landing field, land in front of the ridge rather than be carried behind it. The DHV says a controlled tree landing can be less risky than landing in a clearly dangerous lee²³; see Trees, water and power lines.

Instructor's note “Over the back” is not an escape

You will hear experienced pilots talk about going over the back. One instructor’s advice is that it is only an option where a landing can be reached without crossing rotor²⁴. That is a decision for experienced pilots with a local briefing, not an escape for a student. For you, the answer is always out in front and down²²¹³.

Cloud suck

Cloud suck is strong lift under a cloud that draws you up towards it; Clouds and weather hazards explains how to recognise it. Avoiding it matters far more than escaping, because pilots have been sucked in even on big ears and full speed bar²¹.

Leave lift early, well below the base, at the ceiling your instructor sets²⁵.
One school advises working lift under big clouds on the side with open blue sky, so the way out is short²⁶.
If you are being drawn up, fly out from under the cloud towards blue sky and descend early, for example with big ears and speed bar if your instructor has trained you, looking for sinking air²⁵.

Never throw your reserve to escape a cumulonimbus, because you would most likely be carried up into it, hanging helplessly underneath²⁵.

Common mistake Waiting for the wind to ease

Symptom: Your crab angle keeps growing, but the lift is lovely, so you stay a little longer.
Cause: Hoping it is only a gust, while the wind usually gets stronger the higher you climb³.
Fix: Leave at the first sign. Landing early is a good flight, not a failure.

Common mistake Counting the speed bar as your margin

Symptom: You launch into a strong wind, sure the bar will get you out if you need it.
Cause: Planning with the bar instead of your hands-up speed. On the bar the wing also collapses more easily⁸.
Fix: Fly only where you can make progress into wind with your hands up. The bar is a way out, not a reason to go.

Standards differ Descent techniques in training

Common ground: Everyone starts soaring under an instructor’s control, in smooth, steady wind²⁷. Big ears and the speed bar are the descent aids taught in basic training; spiral dives and B-line stalls belong to advanced or SIV training²⁸.

USHPA (USA): P2 tasks include big ears (symmetric tip folds) and speed-bar use²⁹.
BHPA (UK): Club Pilot training includes a phase on active flying, rapid descent and collapses³⁰. The optional Foundation syllabus, flown after the Club Pilot rating, lists big ears with speed bar for a faster descent, with awareness of its limits¹³¹⁷.
APPI (international): Adventure-level students judge their glide by watching a still point on the ground, including with big ears³¹. Spirals are taught in APPI’s SIV course²⁸.
FAI/CIVL SafePro (international reference): Big ears and the speed bar are Stage 3 skills²⁸.

Summarised from each body’s published material, which changes over time. Check the current official documents and follow your school.

Questions students ask

What if I’m already going backwards?

Keep facing into wind with as much bar as conditions allow, and lose height in front, where the wind is usually weaker¹³³. Land in front of the ridge, even if it isn’t the landing field.

How strong is too strong for me?

Your instructor sets your limits. The published student limits are in Reading the wind, and setting your own is in Go/no-go and personal minimums.

Key points

Into wind, groundspeed is airspeed minus wind: when they are equal you hover, and stronger wind blows you back.
The wind is stronger higher up and over the crest than on launch: watch your crab angle and progress along the ridge.
At the first sign, point out into wind, use the bar as trained, lose height in front and land early.
Never turn towards the hill or cross behind the crest; landing in front, even in a tree, beats the lee.
Big ears with bar: some sources teach it, the DHV calls ears unsuitable here. Follow your manual and instructor.
Leave lift well below cloud base, on the blue-sky side, and never throw the reserve to escape a cumulonimbus.

Ground to Solo is a study aid. Paragliding is learned in person with a qualified instructor at a recognised school; nothing here certifies you to fly.