Flight Training Manoeuvres

Pilot training uses a set of standard flight training manoeuvres to teach what straight and level flight never exercises: control near the edges of the envelope, co-ordination at changing speeds and loads, correction for wind over the ground, and judgement of height and energy. Some are practical techniques every pilot uses, such as the short-field landing. Others, such as the chandelle and the lazy eight, have no direct use in everyday flying but are demanding tests of feel and planning.

The FAA's Airman Certification Standards name these exercises as tasks for the private and commercial pilot practical tests, and most of the vocabulary here is American. European training under Part-FCL covers the same skills through its own syllabus exercises and skill tests, and British schools teach the HASELL check flown before them. The aerodynamics behind the manoeuvres are covered in turning flight, stall and spins and spiral dives.

HASELL pre-manoeuvre checks

Manoeuvres that may lose height or approach the stall are preceded by a structured check. British training teaches it with the mnemonic HASELL, used by many schools that follow British practice:

FAA training uses clearing turns in the same way before each manoeuvre. In the United States, 14 CFR 91.307 requires each occupant to wear an approved parachute when a pilot carrying anyone other than a crew member deliberately exceeds 60° of bank or 30° of pitch, except on flight tests and for spins and other manoeuvres required for a certificate or rating when given by a certificated flight instructor. The commercial manoeuvres below are flown within those limits; the FAA commercial steep turn, for instance, uses 50° of bank.

Short-field take-off and landing

A short-field take-off is flown when the runway is short or an obstacle lies beyond it. The flaps are set as the flight manual specifies, full power is applied before the brakes are released, the aeroplane is rotated at the stated speed and the climb is flown at Vx, the best angle of climb speed, until the obstacle is cleared. Only then is the nose lowered to accelerate to Vy, the best rate of climb speed. Vx gives the most height for distance, Vy the most height for time; with altitude Vx rises slightly and Vy falls, until they meet at the absolute ceiling.

Take-off charts are produced by test pilots flying exactly this technique in a new aeroplane. A normal technique, a rolling start, a late rotation or a climb at Vy will not achieve the charted distance, which is why a generous margin is prudent.

The short-field approach and landing aims to touch down at a chosen point, at minimum speed, without float. The approach is stabilised early with full flap at the recommended speed, which in many light aircraft is close to 1.3 VSO. That speed lies in or near the region of reversed command, where flying slower needs more power: power controls the rate of descent and pitch controls the airspeed, and a power reduction produces a large increase in sink. Any excess speed at the threshold becomes float, and 10 per cent too fast adds about 20 per cent to the landing distance.

Soft-field take-off and landing

A soft surface such as long or wet grass, sand, mud or snow drags at the wheels and can dig in the nose wheel. The soft-field take-off keeps the aeroplane rolling and takes the weight off the wheels as early as possible. The flaps are set as the flight manual specifies, back pressure raises the nose wheel clear of the surface, and the aeroplane is allowed to lift off at a low speed. It is then held level a few feet above the surface, in ground effect, and accelerated to Vx or Vy before the climb begins.

Ground effect is the reason. Near the surface the wingtip vortices are restricted and induced drag is much lower, so the aeroplane can fly at a speed that will not sustain it higher up. A pilot who climbs out of ground effect too early finds the aeroplane settling back towards the runway.

The soft-field landing touches down at the lowest possible speed in a nose-high attitude, often with a little power to soften the contact. The nose wheel is held off as long as elevator authority allows, and heavy braking is avoided.

STOL aircraft and techniques

A short take-off and landing (STOL) aircraft is designed to operate from runways far shorter than conventional aircraft of its size need. The usual ingredients are a low wing loading, powerful high-lift devices such as leading-edge slats and slotted flaps, large control surfaces, a high power-to-weight ratio and landing gear strong enough for rough strips.

The techniques are the short- and soft-field techniques taken further: slow, steep approaches flown with power on the back side of the power curve (see power curves and speed stability), precise speed control, touchdown on a spot and firm braking. Steep approaches are also flown by airliners at a few airports, London City's 5.5° ILS being the best-known example, and under EASA's CAT.POL.A.245 a glideslope of 4.5° or more with a screen height below 60 ft needs prior approval.

Ground reference manoeuvres

Ground reference manoeuvres teach the pilot to fly a planned path over the ground at constant height while the wind drifts the aircraft, and to divide attention between the ground reference, the aircraft and the lookout. They are flown low enough for drift to be obvious, over open country with a field for a forced landing.

• The rectangular course follows the boundary of a field at a constant distance, like a circuit, with crab angles on each leg and turns adjusted for the wind.
• S-turns cross a straight road with a series of half-circles of equal radius on each side.
• Turns around a point fly a constant-radius circle around a ground feature.

The rule for all three is that bank follows groundspeed. The steepest bank is needed where the groundspeed is highest, downwind, and the shallowest upwind, so that the radius over the ground stays constant.

The commercial exercise eights-on-pylons flies a figure eight around two ground points with the pilot's line of sight to the pylon held fixed on a wingtip reference. That is only possible at the pivotal altitude, about the groundspeed in knots squared divided by 11.3: about 717 ft above the ground at 90 kt and 885 ft at 100 kt. Groundspeed rises downwind, so the pilot climbs there and descends upwind. If the pylon appears to move ahead of the reference the aeroplane is above the pivotal altitude and must descend; if it moves behind, climb. Height, not rudder, keeps the pylon in place.

Chandelle and lazy eight

The chandelle is a maximum-performance climbing turn through 180°. The bank, about 30°, is established at entry and held through the first 90° while the pitch attitude is increased to its maximum at the 90° point. Through the second 90° the pitch attitude is held constant and the bank is rolled out gradually, so that the aeroplane arrives wings level at 180° with the airspeed just above the stall. The manoeuvre is complete when the wings are level.

The lazy eight is two 180° climbing and descending turns in opposite directions. In each, the maximum pitch-up comes at the 45° point, the maximum bank of about 30° with the pitch passing through level at the 90° point, and the maximum pitch-down at 135°. At 180° the aeroplane is back in level flight with wings level, at the entry airspeed and altitude. Control pressures change constantly, and the manoeuvre is never stabilised.

Both are flown at low speed and high pitch, so a skid can lead to a stall and a spin. The recovery is the flight manual procedure, commonly remembered as PARE: power idle, ailerons neutral, rudder opposite, elevator forward.

Steep spiral

The steep spiral is a constant-airspeed gliding turn of at least three full turns around a ground reference point, keeping a constant radius over the ground. As in turns around a point, the bank varies with groundspeed, steepest downwind and shallowest upwind, and it should not exceed 60°. The engine is cleared periodically during the descent, and the pilot rolls out towards a specified heading or object at a specified altitude. The manoeuvre teaches a rapid, controlled descent over a chosen landing area, for example after an engine failure. It is deliberate and controlled, unlike the inadvertent spiral dive, in which speed and load factor build unchecked.

Power-off 180° accuracy approach

In the power-off 180° accuracy approach, a commercial task, the power is closed abeam a chosen touchdown point on the downwind leg. The aeroplane glides through a 180° turn to touch down at or within 200 ft beyond that point. The pilot manages the energy from the abeam position: judging the wind, lowering intermediate flap late rather than early, and slipping or S-turning to lose excess height.

The lesson is the one every forced landing teaches. A glide that is too low cannot be stretched by raising the nose, which only increases induced drag and the rate of descent. It is better to arrive high and lose the surplus than to arrive short.

Library articles are written for study and exam preparation. They do not replace your aircraft's approved documentation, your operator's procedures or the regulations themselves.