Can a Passenger Jet Land Automatically by Itself?
Yes, a passenger plane can land by itself using the autopilot through a system that is often referred to as ‘autoland’. The pilots can program the autopilot to carry out the landing automatically whilst the pilots carefully supervise the manoeuvre. However, there are limitations as to when the autoland system can be used and there are occasionally reasons which would stop a commercial jet landing automatically.
Automatic landings probably account for less than 1% of all landings on commercial flights. Many pilots actually think it’s much easier to land the aircraft manually, as monitoring the auto-pilot in the autoland stage of flight is itself very demanding with a very high level of vigilance required at all stages.
The autopilot is typically used to land the aircraft in low visibility conditions such as when dense fog is present or in very heavy rain. The reason for auto-landing in such conditions is that the runway will only be seen in the last few seconds before touchdown, and this is an insufficient amount of time for the pilots to react and safely land the aircraft manually.
When such conditions are present, there are typically little or no winds (fog will seldom form if it’s very windy). As soon as the wind picks up, the average pilot is far better at coping with the conditions and landing the aircraft when compared to the autopilot. The Boeing 737 (the world’s most successful airliner in terms of the number of jets sold) is limited to a maximum crosswind of 25kts (down to 15kts for many airlines) when carrying out an automatic landing (sometimes referred to as a Category 3 / CAT III approach).
Automatic Landing Requirements
The ability to carry out an automatic landing is dependant on a number of factors. All of the following must be met in order to carry one out:
- Aircraft is capable
- Pilots are qualified
- Airport infrastructure is capable
Pilot Capability
Automatic landings require a high standard of automation monitoring by the pilots. As such, pilots must have a specific qualification which allows them to carry out the manoeuvre. They are therefore required to demonstrate their competency in setting up and monitoring auto-lands every 6 months in the simulator.
Aircraft Capability
Whilst the vast majority of commercial aircraft are typically capable of carrying out autolands, not all are. When you buy a commercial aircraft, you spec it up a bit like you would do when buying a new car. If you want it to be able to autoland, some aircraft models will require you to purchase this as an add-on. Most new aircraft will now have it as standard, but some of the older aircraft may not.
Additionally, there are many types of minor technical defects which an aircraft may have that prohibit an autoland being conducted. It isn’t uncommon for an aircraft to be allowed depart with a minor defect but which precludes the aircraft from being able to land automatically until the defect is rectified,
The Airport
The ability to autoland an aircraft isn’t just dependant on aircraft capability and pilot qualifications. The airport must have the radio navigation aid infrastructure installed to support an autoland. This capability is installed at most large hubs, but smaller airports often don’t support autolands. From the perspective of an airport, installing and maintaining autoland capability infrastructure is very expensive and requires regular calibration and therefore it isn’t always deemed necessary. For example, if the local weather dictates that autolands would very rarely be required, or they just aren’t very busy airports, there is little point spending lots of money on installing and maintaining it.
Categories of Instrument Landing System (ILS)
Most airports have some type of ILS, but only certain types of ILS’s support autolands.
The ILS categories are as follows: CAT I, II & III A/B/C.
CAT I (manual landing) requires a manual landing but runway visibility must be more than 550 meters and pilots must be in sight of the runway by an altitude of 200ft.
CAT II (auto or manual landing) requires a minimum of 300 meters and 100ft
CAT IIIA (auto-land) requires a minimum of 200 meters and 50ft.
CAT IIIB (auto-land) requires a minimum of 50 meters and 0ft
CAT III C (auto-land) can potentially go down to zero visibility but this wouldn’t practically be utilised as the aircraft would be unable to taxi off the runway in zero visibility.
Can a plane take-off automatically?
No. Commercial passenger jets are not able to take-off automatically. Currently, no commercial aircraft has an auto take-off capability.
To dispel the myth; the vast majority of commercial aircraft (including all Boeing’s and Airbus’) have no automatic take-off capability. All take-offs must be completed manually by the pilots with the autopilot usually engaged at around 1,000 ft above the ground.