Many passengers try to get some rest during long-haul flights. Like their passengers, crew members are also subject to the effects of fatigue. Airlines therefore staff many long-haul flights with multiple pilots to ensure that they can take turns flying the aircraft and get time to rest while in the air.
What Factors Determine the Number of Pilots Required?
The exact number of pilots required for a flight depends on several factors.
Government Regulations
Laws on pilot rest and duty hours vary between countries. The number of pilots required by law on long flights depends on the specific rules that govern an airline.
Airline Rules
Individual airlines establish their own flight time and duty time limitations. Many airlines make their rules stricter than what is required by law.
Flight Duration
The length of a flight is typically a key factor in rules set out by governments and airlines.
Crew Rest Facilities
In some cases, the rules governing duty hours vary depending on the crew rest facilities available on board the aircraft. Crew rest options could include bunk beds or designated seats in the passenger cabin.
Pre-Flight Rest Period
The amount of time off that a pilot has before a flight can also be a determining factor on how long they can fly for. Consequently, this affects the number of pilots required on long flights.
Time of Day
In some jurisdictions (such as the United States), the time of day at which the crew begins their shift is a relevant factor, as well as whether they are acclimatized to the time zone.
Duty Hours versus Flight Hours
The rules set by governments and airlines typically differentiate between duty and flight hours. Duty hours begin when a pilot signs in for duty, while flight hours only include the time spent flying the aircraft.
An Important Safety Requirement
Pilot fatigue poses a significant risk to the safety of the global air transportation system. Through their respective laws and rules, governments and airlines attempt to ensure that their crews are properly rested when they are flying.
As a result of these restrictions, airlines will sometimes have more than two pilots on their longer flights. This allows pilots to take turns sitting at the controls of the aircraft. Pilots are given assigned breaks, during which they can use the crew rest facilities to get some rest.
How Many Pilots Are Needed for a Long-Haul Flight?
Although the exact requirements vary between jurisdictions, countries typically require at least two pilots for most commercial passenger aircraft. In the United States, for example, Federal Aviation Administration (FAA) regulations stipulate that a minimum of two pilots are required on aircraft weighing more than 12,500 pounds.
The regulations surrounding long-haul flights are complicated. In the United States, the rules governing a particular flight depend on many of the factors described above. A two-pilot crew, for example, can have a maximum of eight to nine flight hours and a maximum of nine to 14 duty hours. The exact numbers within those ranges depend on the start time.
On top of that, the rules are different if the pilots are not “acclimated,” which is defined as “a condition in which a flightcrew member has been in a theater for 72 hours or has been given at least 36 consecutive hours free from duty.”

These regulations mean that some shorter long-haul flights can be flown with two pilots. When it comes to longer flights, U.S. regulations consider the start time, number of pilots, and the type of rest facilities available. For example, a three-pilot crew on an aircraft with proper crew bunk beds who have a scheduled start time of 4:00 p.m. could have a maximum duty period of 16 hours. Meanwhile, a four-pilot starting at 8:00 a.m. on an aircraft where the crew rest facilities consist of lie-flat business class seats separated by a curtain would have a maximum duty period of 18 hours.
While governments set out laws surrounding duty hours and pilot rest, many airlines and unions choose to make their own rules more restrictive than what is legally required. This means that different airlines operating the same route may not have the same number of pilots on their flights.
Generally speaking, flights longer than eight or nine hours will require at least three pilots. Flights that are longer than 13 or 14 hours will typically require a fourth pilot. However, the exact number depends on the specific circumstances of a flight.

