Why do Planes Abort Landings?
An aborted landing (which is known as a ‘go-around’ by pilots), can happen for a number of reasons such as bad weather, a blocked runway or an unstabilised approach. Go-arounds are very safe manoeuvres which are regularly practiced by pilots in the simulator. Go-arounds or aborted landings are fairly rare and occur around 1 to 3 times in every 1,000 approaches.
Aborted landings can be referred to using a number of terms. Passengers and the media often use generic terms to describe the aircraft going back up into the air after being established on final approach which covers a range of scenarios. However, technically, there are different types of ‘go-arounds’ depending on at which point the manoeuvre occurs.
Go-around – this is official the term used by pilots to describe the manoeuvre of discontinuing the approach and taking the aircraft back up into the air before making another attempt.
Rejected Landing – The definition of a ‘rejected landing’ slightly differs from a go-around. A rejected landing occurs if the decision is made to reject the landing after the pilots have commenced the ‘flare’. The flare is the point at which the pilots raise the nose of the aircraft at approximately 30ft above the runway to reduce the aircraft’s rate of descent and (hopefully!) get a smooth landing. On some aircraft types, the initial rejected landing procedure differs slightly from the go-around procedures.
Baulked Landing – This is the same as a ‘rejected landing’. It occurs once the flare has commenced and may result in the aircraft’s main landing gear touching the runway before going around.
Aborted Landing – This isn’t a term typically used by pilots, but could be used to refer to either a go-around or a rejected landing.
Discontinued Approach – This is a term sometimes used by the pilots when explaining to the passengers what has happened in the subsequent PA after a go-around has been flown. The term ‘Discontinued Approach’ is considered to be more relatable, understandable and less scary for passengers than ‘go-around’ or ‘aborted landing’.
Touch & Go – This is a planned manoeuvre, typically flown as part of pilot training. During a touch and go, the aircraft will land on the runway (or ‘touch down’) and then take off straight away again without stopping. The difference between this and a rejected landing is that a touch and go is a planned manoeuvre, a rejected landing is not.
What Causes a Plane to Go-Around?
There can be many reasons which would cause an aircraft to go-around which happens many times every day across the world. These are some of the more common reasons, although a go-around can be caused by just about anything.
Air Traffic Control – On occasions, an aircraft may be told to go-around by ATC. This might happen if the spacing between two aircraft landing has become too close. It may also occur if another aircraft gets stuck on the runway due to a technical malfunction or a problem that needs resolving.
Weather – Challenging weather conditions might cause the aircraft to go-around. Some examples include:
- A sudden change in the speed or direction of wind.
- Strong winds. Aircraft have maximum wind limitations. Wind strength outside these parameters might require the aircraft to go-around. This includes a strong tailwind (usually more than about 15kts) or a very strong cross-wind (normally more than 35-40kts).
- Cloud base. Depending on the aircraft, airport and type of approach, the pilots need to see the runway by a certain altitude. If at a certain altitude (200ft for example), the pilots are unable to see the runway, they must discontinue the approach.
- Different runways have differing minimum visibility requirements for landing. Fog, mist, smoke, dust storms, snow and rain can all reduce visibility to below the minimum required for landing.
Unstabilised – Most airlines require the aircraft to be ‘stabilised’ by a certain altitude (typically either 1,000ft or 500ft). If the aircraft is unstabilised, or becomes unstabilised below this altitude, a go-around must be flown. Stabilised refers to the following parameters being met:
- Aircraft in the landing configuration (landing gear down and landing flap set)
- At the correct target speed for landing
- Landing checklist complete
- The aircraft is on the correct vertical profile for the approach being flown (typically a 3-degree descent angle and descending at about 700-800 feet per minute)
- The aircraft is on the correct lateral profile
So, if an aircraft is too high, low, fast etc., then the approach should be discontinued.
Technical Problem – If a technical problem occurs onboard the aircraft during final approach, particularly one that might affect the stopping distance of the aircraft, the pilots may elect to go-around to resolve the problem and/or recalculate the landing distance required.
Deep Landing – The aircraft must touch down within the ‘touch down zone’ which is marked out on the runway. If it looks like the aircraft will miss the touchdown zone, a rejected landing should be flown.