Turns and load factor

What changes when the wing banks into a turn, why steep turns sink so fast and raise the stall speed, how the circle shrinks with bank, and why a steep turn near the ground is a trap.

In this lesson you will

Your first full turn on a high flight is a strange feeling. The horizon tilts, you are pressed into the seat, the wing seems to lean over you, and the ground turns slowly beneath your feet. A few students pull harder, and feel the wing start to dive.

In a turn the wing gets heavier and faster, its stall speed rises, and it sinks faster. With height and space that hardly matters. Close to the ground it matters enormously, and this lesson is the reason your instructor keeps saying: “no turns low down”.

What happens in a turn

To turn, the wing must bank. Its lift then tilts, and the sideways part of the lift pulls you round the circle¹. The whole system banks together: the wing leans in towards the centre of the turn, and your body swings out under it like a pendulum.

The bank angle is how far the system is tilted. You start it with a look, weight shift and the inside brake, and control it with weight shift and the outside brake²; Turning: look, lean, pull is the practical technique.

Figure: Slide the bank angle up and watch the chart: the load factor, the stall speed and the sink rate all rise, slowly at first, then fast above about 45°. The airspeed rises too, so at the same hands the stall margin barely changes in a steady turn. Numbers are for a reference school wing at the same hand position as in straight flight.

Slide the bank angle up and watch the chart: the load factor, the stall speed and the sink rate all rise, slowly at first, then fast above about 45°. The airspeed rises too, so at the same hands the stall margin barely changes in a steady turn. Numbers are for a reference school wing at the same hand position as in straight flight.

You get heavier: the load factor

In a banked turn the lift must do two jobs: hold you up and pull you round. So it has to be bigger than your weight. The ratio is the load factor, measured in g. In a steady, coordinated turn it follows from the bank angle alone: the load factor is 1 divided by the cosine of the bank, the same for every aircraft³. In the smooth-air model⁴:

Bank	Load factor	Stall speed rises by	Sink rises by (same hands)
30°	1.15 g	about 7%	about 24%
45°	1.41 g	about 19%	about 68%
60°	2 g	about 41%	about 2.8 times

You feel it as weight pressing you into the seat: at 60° you weigh twice as much as on the ground.

The stall speed rises

A heavier wing needs more airspeed to fly. The stall speed rises with the square root of the load factor⁵. At the same hand position the wing also speeds up by the same factor, so in a smooth, steady turn your margin barely changes⁴. What eats it is everything else: the inside wing flies slower than the outside on its smaller circle, you usually add inside brake, the load arrives before the extra speed when you roll in quickly or pull harder, and a gust adds load on top⁶. That is why brake that was comfortable in straight flight can stall the inside wing in a tight turn⁵.

This is why turns should start from hands up or light brake, never from deep brake: from minimum speed the inside wing can stall and spin⁷. The German federation names a stall in a turn as one of the commonest accident causes, and its best prevention is easing the outside brake as the turn starts, with weight shift⁸.

The sink rate climbs

Flown at the same hand position, the wing in a turn flies faster, and its sink rate rises faster still: with the load factor to the power 1.5⁴. At 45° you sink about two thirds faster than in straight flight; at 60°, almost three times as fast. Turning with lots of brake adds more: excessive brake only increases the sink rate².

Radius, time and the height of a 360

A steeper bank gives a smaller circle and a quicker turn; a gentle 360° takes much longer than a steep one⁹. Read the radius and the time for each 360 off the figure above.

In the figure’s smooth, steady-turn model the height per circle is lowest at about 45°, and almost the same at 30° and 60°. That is a quirk of an idealised turn, never a reason to bank steeply. A real steep turn also loses height in the dive and swing after it¹⁰; it can tighten into a spiral¹¹; and it leaves no time to stop if anything goes wrong. As a student you will fly about 30° of bank at most¹²¹³. Low down any turn is dangerous: what matters is the sink each second and being able to stop at once, and both favour a gentle turn, or none.

Every system therefore adds 360s only with plenty of height and space. SafePro says 360° turns need extra caution, height and distance from terrain¹⁴. The DHV advises keeping at least 50 m165 ft from the slope whenever possible, because even docile wings can lose 20–40 m65–130 ft in a big disturbance before they settle¹⁵.

The low-turn trap

The classic mistake: low on the approach and not lined up with the field, you pull one brake hard to fix it. Several things happen at once:

The sink rate jumps. A steep bank can double your sink in seconds.
You swing out, then back. Rolling out or reversing the turn sets up a pendulum swing, and the wing dives as it comes out of a tight turn. Manufacturers warn that steep turns or turn reversals near the ground cause a dangerous pendulum swing and rapid height loss¹⁰.
The wind gradient can steepen the bank. As you turn into wind near the ground, the stronger wind higher up pushes harder on the higher wingtip and tilts you further¹⁶.
Deep inside brake courts a spin. A steep or skidding turn can take the inside wing past its stalling angle first¹⁷. In one fatal training accident, a deep-brake approach turn with little weight shift spun, then spiralled, with no height to recover¹⁸.

Figure: A steep turn from about 9 m (30 ft) up. The height trace on the right compares it with flying straight ahead: the turn uses up the seconds you needed, and you meet the ground on the swing. Switch to the second variant for the safe choice.

A steep turn from about 9 m30 ft up. The height trace on the right compares it with flying straight ahead: the turn uses up the seconds you needed, and you meet the ground on the swing. Switch to the second variant for the safe choice.

This is not rare. In European accident data, over-control (stall, spin, parachutal stall) is the second most common first event, most often on the approach and landing¹⁹. In Swiss data the most frequent result of a poor or late approach plan is a stall or spin from over-steering²⁰.

The rule is simple: no steep or tight turns low down. One manufacturer advises against tight turns below about 30 m100 ft; SafePro tells students to strictly avoid turns close to the ground¹⁰. If you are low and off line, keep the wing level, make only gentle corrections, land ahead as much into wind as you can, and flare²¹. A long walk beats a steep low turn every time. Final approach and the flare covers the final glide.

When a turn keeps tightening

A turn that is held and steepened can become a spiral dive: the nose drops, the turn speeds up and you are pressed harder and harder into the seat. Sink rates of 14–27 m/s2,760–5,320 ft/min and loads of 3–4 g are possible, enough to disorient a pilot; the BHPA found this tends to be worse on low-aspect-ratio EN A and B wings, and the spiral may not stop by itself when you release the brakes¹¹.

So keep turns moderate and leave any turn that starts to steepen or speed up smoothly and early: ease the inside brake and bring your weight back towards the centre. Leaving a spiral should be gradual, because snapping straight out turns the speed into a big surge and dive, and leaning further into the turn can lock the wing in¹³. If you are in a stable spiral and cannot recover at once, throw the reserve without delay¹³²²; see Priorities and the reserve. Spiral technique itself is learned only on an SIV course with qualified instructors.

Turning with margin

Before every turn, look where you will go and check your height and space.
Cue Clear air on the inside of the turn, and room below and around you.
Why A turn sinks faster than straight flight and carries you sideways.
Start from hands up or light brake, never from deep brake.
Cue Light, even pressure in both hands.
Why The inside wing is slower and turns add load; deep brake leaves no margin for either⁷.
Lean in first, then pull the inside brake smoothly, easing the outside brake.
Cue The wing banks smoothly; the inside brake never gets heavy.
Why Coordinated turns need less brake and keep the inside wing flying²⁸.
Keep the bank moderate.
Cue Pressed gently into the seat, not squashed into it.
Why Above about 45° the load, stall speed and sink rise steeply; 30° is plenty for normal flying¹³.
Roll out smoothly, a little before your new heading, and let the swing settle.
Cue The wing comes back overhead without a big swing.
Why Abrupt exits turn the speed into a surge and dive¹³.
Low down, keep the wing level and make only gentle corrections.
Cue Hands up, upright, looking ahead.
Why There is no height to absorb the sink and the swing of a steep turn¹⁰.

Common mistakes

Common mistake One more turn, low on the approach

Symptom: Low and off line, you crank the wing round to reach the target, swing hard and land fast and sideways.
Cause: A late plan, then a low turn to save it.
Fix: Plan the approach early so you reach final high enough. If it goes wrong, land straight ahead²¹.

Common mistake Turning on the brake alone

Symptom: The turn is flat and slow, the inside brake feels heavy and the wing feels mushy.
Cause: Deep inside brake with little or no weight shift, often with the outside brake held down too.
Fix: Look, lean, then pull smoothly, easing the outside brake⁸. If the inside brake gets heavy, let it up.

Instructor's note Certification is the smooth-air version

Certification tests are idealised, like the bank figure: a class-A wing must come out of a developed spiral by itself within two turns²³, yet in real air, with your harness, a spiral may not stop by itself¹¹. Never count on the test.

Instructor's note The same wing, a different character

Near the top of its weight range a wing is more agile and dynamic, but it damps itself less in turns²⁴. A student who borrows a smaller wing, or flies heavy, often finds it reacts more briskly in turns and swings more after them. Tell your instructor when anything changes.

Standards differ Bank limits and when 360s begin

Common ground: All the systems start with gentle turns and add 360s only with height and space. SafePro, the international reference, asks for shallow turns with gentle to medium bank at Stage 2, and says 360s need extra caution, height and distance from terrain¹⁴.

USHPA (USA): Recommended P2 limits: bank no more than 30°, turn speed no more than 1.5 times the hands-off speed, and exit smoothly any spiral that starts to steepen¹². P2 pilots explain how to fly a 360 safely rather than demonstrating it²⁵.
BHPA (UK): The BHPA says 30° of bank is more than enough for normal flying, including thermalling¹³.
APPI (international): Turns are built up in steps: 90° and 180° turns at Open Sky level, 360s and figure-eights at Adventure level¹⁴, and thermal flying, with attention to bank angle, at APPI Pilot level²⁶.

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

Questions students ask

How much height does a 360 cost?

It depends on the bank, your wing and how you fly it; real turns cost more than the figure’s smooth-air model. Ask your instructor for the minimum height for your first 360s.

What if I am low and not lined up with the field?

Keep the wing level and land ahead, as much into wind as you can, with only gentle corrections, and flare²¹. Walking back is the easy part.

Can a normal turn turn into a spiral?

A turn that is held and steepened can, especially on low-aspect-ratio school wings¹¹. Leave any turn that starts to steepen or speed up early and smoothly.

Key points

To turn, the wing banks; you swing out under it, and the lift must carry more than your weight.
The load factor is 1 ÷ cos(bank): 1.15 g at 30°, 2 g at 60°. Stall speed and airspeed rise together; the slower inside wing, extra brake and gusts eat the margin. Sink rises faster still.
Steeper turns make a smaller, quicker circle. Real turns cost more height than the smooth-air model.
Start turns from hands up or light brake, lean first and ease the outside brake.
No steep turns low down. Low and off line, keep the wing level and land ahead.
A turn that keeps tightening can become a spiral: leave it early and smoothly. Spiral technique is for an SIV course.

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.