6 reasons why pilots might execute a ‘go-around,’ explained by an actual pilot
This post contains references to products from one or more of our advertisers. We may receive compensation when you click on links to those products. Terms apply to the offers listed on this page. For an explanation of our Advertising Policy, visit this page.
If you’ve spent a considerable amount of time on aircraft, you’ve probably experienced a go-around at some point. It is a fairly common occurrence at the world’s busiest airports, with places such as London Heathrow Airport (LHR) and Dubai International Airport (DXB) expecting to see at least one a day.
As a result, pilots are always prepared for this eventuality, practising them regularly in the simulator and talking through their actions before each and every approach.
Even though they are fairly common, the reasons that may cause pilots to perform a go-around are not always entirely clear… so here’s a list of 6 reasons why we might execute a go-around.
Increase in Tailwind
You’ve probably seen the quote attributed to Henry Ford that says “When everything seems to be going against you, remember that the aeroplane (sic) takes off against the wind, not with it”. Mr Ford was spot on with his observation though, I do enjoy the irony – we don’t take off into the wind because it’s more challenging, we take off into the wind because it actually makes life a lot easier.
It’s the same with landing. By landing into a headwind, we can generate the lift required to keep the aircraft flying whilst keeping our speed over the ground as slow as possible. The slower our speed over the ground, the sooner we can stop. Or, seen from the flipside, the faster our speed over the ground, the more runway we need to stop.
In preparation for each landing, we calculate how much runway we will need to stop safely with the weather conditions expected at the time. From this, we can then see if the runway is long enough. If it is not, we can change the configuration of the aircraft, such as using a higher brake setting, to make sure that we are able to stop within the available distance.
A significant part of this is the wind component.
As mentioned, we will endeavour to land into the wind as much as possible. However, certain airports may require us to land with a small tailwind element due to geographic or ATC reasons. What we do in these scenarios is to determine just how much of a tailwind we can accept before the landing distance calculations are no longer acceptable.
In addition to this, most aircraft types have a declared tailwind limit for landing as defined by the manufacturer. For the 787, this is 15kts.
So, if we were due to land on a runway with a tailwind, we would run the performance calculation repeatedly until we found out what the absolute tailwind limit would be that would still enable us to stop safely on the runway.
If during the final stages of the approach ATC told us that the actual wind had increased above this calculated limit, we would know that there is a high chance of going off the end of the runway after touchdown.
As a result, the safest course of action is to go back up into the air and either wait until the wind dies down enough to land safely or to request a runway with a smaller tailwind component.
Not able to see the runway
It may sound obvious, but a key part of landing an aircraft safely is being able to see exactly where we are touching down. On clear days, we can often see the runway from 30 miles away, however, when the weather closes in, we may be in the cloud all the way down to the ground.
In order to ensure the safety of the flight, there are strict rules in place on how close we can get to the ground without seeing the runway, depending on the accuracy of the approach that we are flying. This is known as the minima.
In days gone by, radio beacons on the ground would send out signals that aircraft could pick up and use to guide them towards a runway. However, the earliest of these were not particularly accurate. NDBs (Non-Directional Beacon) and VORs (VHF Omnidirectional Radio) were used extensively, even into the 21st Century, to guide pilots down.
Yet, due to their relative inaccuracy, the position of the aircraft couldn’t be reliably assured so the minima were relatively high, often 500ft or more above the ground.
To give a more accurate position of the aircraft, a new system was devised which is now used at almost all major airports around the world. The ILS (Instrument Landing System) sends out 2 accurate signals which allow pilots to fly the aircraft down toward the runway with pinpoint accuracy, giving minima of 200ft or lower. It’s this system that’s used for autolands in fog.
However, these systems are costly as they require constant maintenance of the ground-based signal generators. So, like in your car, the future is GPS based.
RNP (Required Navigation Performace) procedures use onboard GPS to pinpoint the aircraft’s position down to a fraction of a mile, enabling minima almost as good as ILS approaches.
With all these types of approaches, if we can not see the runway as we reach the minima, we must perform a go-around and either wait until the weather improves or divert to another airport.
Aircraft still on the runway
It may sound obvious, but the objective of every landing is to bring the aircraft down safely to a slow enough speed without colliding with anything, to allow us to turn off the runway and taxi to the gate. Therefore, before we are allowed to land, we must receive a landing clearance from the ATC in the control tower. Depending on where we are flying in the world, this can be done quite differently.
It makes sense that in order to achieve the above objective, it would be ideal for ATC to only give the go-ahead to land when the runway is clear. At busy airports, there will often be a steady stream of aircraft coming into land on the same runway. If the clouds are quite low, we may only see the runway a few seconds before we touch down. As a result, most airports around the world will only issue us with a clearance to land once the aircraft in front has vacated the runway.
There are some countries where they do things slightly differently. In these cases, they will clear us to land as soon as we contact the control tower. This means that there could be several aircraft ahead of us still to land before we touch down.
Ultimately, irrespective of the system, ATC cannot allow an aircraft to land whilst there is another aircraft still on the runway ahead of them. If this is the case, ATC will instruct the aircraft about to touch down to go around.
These types of go around are often at the last moment as ATC will use every possible second to see if the aircraft ahead will vacate in time.
The key to a safe touchdown is an accurately flown approach. As mentioned above, before each landing we calculate just how much runway we will need to stop safely. This relies on us flying the approach accurately and touching down at the right speed in the correct part of the runway. If we do not do this, there is a high chance that we may go off the end of the runway.
To reduce the chance of this happening, most airlines enforce a ‘stable approach’ policy on their pilots. This states that when the aircraft reaches 1000ft above the ground, it must be on the correct vertical profile for the runway, the landing gear and flaps are set for landing and the aircraft is back in its final approach speed.
If any of these criteria are not met, the pilots must perform a go-around.
The best airlines will never criticize their pilots for going around because they were unstable. Sometimes there are factors outside our control that prevent us from achieving a stable approach but these are the exact factors that have led to so many accidents because the pilots decided to continue to land.
It’s far safer to throw the approach away, go back up into the air and prepare to do it again.
Cabin not secure
“Flight attendants, prepare the cabin for landing.” How many times have you heard this as a passenger and sighed with frustration knowing that you’re about to have your movie interrupted and hassled to put your belongings in the overhead locker?
As annoying as this can be, all the actions the crew ask you to take at this stage of flight are for your safety and for those around you.
In the event of an emergency on landing, the Captain needs to know that the cabin is configured in such a way that it gives people the best chance of evacuating the aircraft as quickly as possible.
Tray tables folded down will block the exit of those sitting by the window. A bag on the floor will do the same. An improperly fastened seatbelt could lead to serious injury and an unsecured trolley in the galley could come loose and cause damage to the aircraft, or worse, people.
As a result, before landing, the captain must be informed by the flight attendants that the cabin and galleys are secure. If this is not the case, it could be extremely dangerous to land.
The only safe course of action in this scenario is to go around and give the flight attendants more time to get the cabin secured before making another approach.
Aircraft system failure
Every so often we experience a technical issue with the aircraft. For the most part, these are benign and have very little effect, if any, on the operation of the aircraft. If these occur during the cruise, we have plenty of time to deal with them. We can run through the checklist, make any configuration changes to the aircraft that the checklist requires and then make a plan for the rest of the flight.
If these occur close to the ground, time is not always on our side. Should the aircraft notifies us of a technical malfunction as we are close to touching down, we may not be sure how this will affect the landing. The issue may affect our landing distance calculation, casting doubt over whether we will still be able to stop safely.
As a result, it’s normally safer to take the aircraft back into the air and spend some time solving the problem before making another approach to land.
A go-around is not a failure of the pilots in trying to land the aircraft but in fact quite the opposite. It is proof of their ability to change their mind, quite often at short notice, to adopt a totally different course of action to ensure the safety of the aircraft and all those on board. The scenarios described above are just some of those that may cause a flight to go around.
Even after we have touched down, we may still decide to go around. This is known as a rejected landing and is flown slightly differently from a normal go-around.
Despite the dramatic nature of a go-around, no matter what the cause is, it will always be done as it is the safest option at that given moment. Pilots will always have extra fuel at their disposal to perform the manoeuvre and then position for another landing, or, if necessary, divert to another airfield.
So if you’re on a flight and get to experience a go-around, rest assured that it was done to keep you, and all those around you, safe.
Featured Image- Getty Images
Welcome to The Points Guy!