071 Operational Procedures topic guide
Windshear and Microburst
Windshear is simply a change in wind speed or direction over a short distance, and on its own it is a normal feature of the atmosphere that aircraft cope with constantly. The reason it earns a dedicated block of the syllabus is one specific source: the microburst, a small, intense downdraft that spreads out on hitting the ground and produces a wind change so sudden and so large that an aeroplane can run out of the energy needed to correct for it.
The danger sits in the sequence, not just the strength. An aeroplane flying through a microburst on approach first meets an increasing headwind, which briefly increases lift and airspeed and can tempt a pilot to reduce power. Moments later, in the same encounter, the wind reverses to a tailwind as the aeroplane crosses into the outflow, and both airspeed and lift fall away at the same time the aeroplane is already low, slow, and close to the ground.
Recognising an encounter
Cues that a windshear encounter is under way include airspeed fluctuations larger than normal turbulence would produce, an unexpected and sustained deviation from the intended glidepath or pitch attitude despite normal control inputs, and a rate of climb or descent that will not respond the way power and pitch changes normally command. Visual cues near thunderstorms, such as a rain shaft with a sharp-edged gust front, or dust being lifted in a ring pattern on the ground, are the outside-the-cockpit version of the same warning.
Two kinds of onboard system exist to catch this before it becomes a handling problem. A reactive system detects the windshear only once the aeroplane is already in it, comparing inertial and air-data measurements to sense the energy loss and issue a warning. A predictive system looks ahead of the aeroplane, typically using weather radar returns, and can warn of a windshear-producing cell before the aeroplane reaches it, buying time to avoid the encounter altogether rather than merely reacting to it.
The escape manoeuvre
Once a windshear warning fires, or the recognition cues make it clear an encounter is happening, the response is a fixed priority order rather than a judgement call. Thrust goes to maximum immediately, the pitch attitude is increased towards the margin defined by the stall warning system rather than towards a fixed pitch number, and the aircraft configuration, gear and flap, is frozen exactly as it is until the aeroplane is clear of the shear.
Where the aeroplane is fitted with flight director windshear guidance, that guidance is followed in preference to a manually flown pitch target, since it is computed from the aeroplane's actual energy state rather than a generic value. The manoeuvre prioritises staying away from the ground and away from the stall over holding an approach or a runway; if either margin is in doubt, a go-around, or a rejected take-off if still on the ground and within the accelerate-stop distance, is always the correct call rather than pressing on and hoping the shear passes.
- Maximum thrust immediately
- Pitch towards the stall warning margin, not a fixed pitch attitude
- Configuration frozen: no gear or flap changes until clear
- Follow flight director windshear guidance if fitted
- Go around, or reject the take-off, whenever margins are in doubt
Worked example
Worked example: the escape manoeuvre sequence
During an approach, the crew receives a windshear warning at 300 ft. The aircraft is in landing configuration. What is the correct immediate response?
- ARetract the flaps to the take-off setting to reduce drag, then apply maximum thrust
- BApply maximum thrust, pitch up towards the stall warning margin, and hold the current configuration
- CReduce thrust slightly to avoid overspeeding, since the initial headwind is increasing airspeed
- DContinue the approach unchanged and reassess at decision height
Show the answer and walkthrough
Correct answer: B
- A. Changing configuration during a windshear encounter is specifically avoided. The escape manoeuvre is flown in whatever configuration the aeroplane is already in.
- B. Correct: this is the fixed order of the escape manoeuvre, maximum thrust and pitch to the safety margin defined by the stall warning, with the configuration left exactly as it was.
- C. This is the classic trap the sequence sets: the transient airspeed increase from the initial headwind surge is not real performance margin, and reducing thrust removes energy just before the tailwind phase takes it away again.
- D. A windshear warning calls for an immediate escape manoeuvre, not a wait-and-see approach continued to decision height, since the shear can consume the remaining altitude before that point is reached.
Step by step
- Recognise the trigger: a windshear warning during approach calls for the escape manoeuvre without delay, not a wait-and-see response.
- Apply maximum thrust first, since restoring energy is the priority over any other action.
- Pitch towards the margin defined by the stall warning system rather than a fixed number, maximising climb performance without stalling.
- Leave the configuration untouched throughout the manoeuvre; gear and flap changes are deferred until clear of the shear.
Common mistakes
Reducing thrust when the initial headwind briefly increases airspeed
That airspeed gain is transient and belongs to the entry phase of the encounter. Reducing power removes exactly the energy margin needed moments later when the tailwind phase reduces airspeed again.
Changing gear or flap configuration during the escape manoeuvre
Reconfiguring mid-shear adds drag and control changes at the worst possible moment. The manoeuvre is flown in the existing configuration until clear.
Confusing predictive and reactive windshear systems
A predictive system, generally radar-based, can warn before the encounter and allow avoidance, while a reactive system only confirms an encounter already under way. A question asking which system allows avoidance is testing this distinction specifically.
Related topic guides
Practise Operational Procedures the way the exam asks it.
SkyStudy turns Windshear and Microburst and every other Operational Procedures topic into exam-style practice questions with explanations, spaced repetition, and timed mock exams. Free to start.
This page is general educational information for student pilots and may be out of date. Aviation rules, training requirements, costs, medical standards, and exam details change over time and vary by country, authority, and training organisation, so details here may no longer be current or may differ in your case. Always confirm the current details with your approved training organisation (ATO) and national aviation authority before relying on them. SkyStudy is an independent study aid, is not affiliated with EASA or any aviation authority, and does not guarantee any exam or licence outcome.
Last reviewed July 2026