When a plane flight can last up to 19 hours, crossing the international date line and thousands of miles of open sea, it is only reasonable for the pilot to take a nap somewhere along the way.
That is why there are four pilots on board planes that make such lengthy treks, including the Asiana Airlines flight from Seoul to San Francisco that crash landed last Saturday. Usually, one covers the controls while another monitors the navigation systems and communicates with the control tower. A few feet away, two more pilots are squeezed into a closet-like space equipped with bunk beds so they can get a few hours’ sleep before relieving their peers.
The spotlight is on what happens in the cockpit during such long-haul flights following the Asiana accident at San Francisco International Airport. Investigators are still trying to pinpoint the cause of the crash, which killed three people and injured 180, but air disasters often result in new safety measures. A 2009 crash attributed in part to pilot mistakes, for instance, led the Federal Aviation Administration this week to unveil new rules to boost training for pilots of US carriers.
The Boeing 777 that slammed into a sea wall in San Francisco was coming in too low and slow, according to the National Transportation Safety Board. The Korean carrier’s pilots said they thought the autothrottle was controlling their speed, but investigators have not been able to determine if the mechanism was engaged.
“When you have clear skies and unrestricted visibility, it’s hard to imagine how you can get that low without recognizing it,” said Thomas Hoban, a pilot and spokesman for the Allied Pilots Association, the American Airlines union.
US airlines don’t like to talk about pilot protocol following a crash — several declined to comment for this story — but the number of pilots assigned to a flight depends on its duration. Every domestic commercial trip has at least two. Flights of more than eight hours usually have three pilots, and those exceeding 12 hours have four. They work in shifts, with a minimum of two pilots in the cockpit at all times. Those not in command are allowed to rest, in accordance with FAA rules.
On some airlines, the same two-person team takes off and lands the plane, with another crew relieving them in between. On others, pilots switch duties halfway through the flight. All four pilots are in the cockpit during takeoff and landing.
The longest nonstop flight route in the world is the 19-hour trip from Singapore to Newark on Singapore Airlines. The 9,500-mile journey crosses a dozen time zones. That kind of endurance test makes getting rest a challenge, pilots say. It’s easier when the plane is equipped with private bunks, some of which are tucked into such small spaces that pilots have to crawl on their hands and knees to reach them. When there are no bunks, pilots have to try and catch a few winks in First or Business class, sometimes going back into the cabin to gather pillows and blankets before the flight. But it can be tough to fall asleep with babies crying and flight attendants serving meals, pilots say.
Flights over the Atlantic are particularly intense because of the high number of planes flying the same route at the same time.
Among other duties, pilots have to maintain a proper distance from other planes, monitor the fuel and the weather, and request altitude changes to avoid storms. The final half-hour is the most demanding, often involving landing at a busy airport, when pilots are at a “real circadian low,” Hoban said.
“All the coffee in the world isn’t going to bring you to where you were when you departed,” he said.
Automated systems help control nearly every phase of flight, and they are often activated at the click of a button. Aviation analysts say it is crucial that pilots communicate each move they make so the other pilots onboard know what is running and what isn’t.
Some aviation specialists contend pilots rely too much on these mechanisms, causing them to lose some of their stick-and-rudder skills. But it is not as if pilots are not doing anything, said Patrick Smith, a commercial airline pilot and author of the “Ask the Pilot” column on Boston.com.
“The automation isn’t flying the plane,” Smith said. “The crew is flying the plane through the automation.”
Regardless, these mechanisms make pilots’ jobs more manageable. Even short hops can be taxing, Smith said.
“You fly up and down often several times a day, often out of busy airports. And the layovers are really short, often at dumpy hotels,” he said. International flights, on the other hand, he said, have longer calm stretches of time in the air, and more time in between flights.
“Everything about it is just more civilized,” Smith said.
The FAA is implementing several new rules as a result of a Colgan Air crash near Buffalo in 2009, attributed to pilot error, when a plane hit a house and killed 50 people, including one on the ground. New mandated rest periods incorporate fatigue science, taking into account the time of day pilots begin and the number of time zones they cross. There are also new rules requiring pilots to log more hours before they are certified to fly for an airline as a first officer or are promoted to captain. And the most significant training changes in 20 years are being adopted to improve pilots’ reactions in difficult conditions, including how to recover from a stall.Katie Johnston can be reached at firstname.lastname@example.org. Follow her on Twitter @ktkjohnston. Material from Globe wires services was used in this report.