Jeff Wise

The engines on elderly Boeing 777 airliners are blowing up with worrisome frequency.

In 2018, the No. 11 fan blade on the right engine of a United Airlines 777 broke as the plane approached its destination, Honolulu. Its pieces, traveling at high speed, caused a cascade of failures within the engine’s intricate machinery such that within less than a second, the engine’s cover had blown off, leaving the naked core wobbling as it spun. Flying debris caused two punctures in the fuselage but the plane was able to land safely under the power of its remaining engine.

Last December, a Japan Airlines 777 suffered a similar engine failure after the No. 16 fan blade of its No. 1 engine broke en route between Naha, Japan, and Tokyo. That flight, too, landed safely.

And then on Saturday, another United Airlines 777 suffered an uncontained engine failure as it climbed out of Denver en route to Honolulu. Witnesses on the ground reported hearing an explosion before debris rained down on the town of Broomfield, Colorado. The pilot declared mayday and returned to Denver without further incident.

In all three cases, the aircraft were among the oldest in the worldwide 777 fleet, having been delivered in the first two years after the model was introduced in 1995. While the Pratt & Whitney PW-4000 engines in each case were likely not original to each plane — engines are regularly removed from planes for routine maintenance, then installed on different aircraft — the engines are generally of similar vintage to the aircraft on which they fly. In the 2018 incident, the engine that failed had been built in 1996 and had accumulated 77,593 hours flight hours and 13,921 cycles (combined takeoffs and landings). The blade that failed in the 2020 incident had experienced 43,060 flight hours and 33,518 cycles.

Patterns in aircraft accidents can be a sign of trouble. While one-off failures might be attributable to a freak coincidence or just bad luck, patterns suggest that a previously unsuspected danger is lurking. Continue reading New York: Why Do Boeing 777 Engines Keep Exploding?

The United Airlines 777 that suffered an uncontained engine failure this afternoon over Broomfield, Colorado, was the third oldest 777 in operation. The aircraft, tail number N772UA, first flew in 1994 and was delivered to United in September, 1995, three months after the 777 made its first commercial flight for the airline that June.

United Airlines Flight 328 took off from Denver International Airport at 1 p.m. bound for Honolulu and was climbing through 12,000 feet altitude when its right engine suffered an uncontained engine failure, with internal parts breaking through the external casing and sending pieces of it flying.

The pilot immediately made a mayday call and returned for a safe landing at 1:29 p.m. No injuries have been reported on the ground or among the 231 passengers or ten crew.

One Broomfield homeowner got a close call, however, when the ten-foot-wide circular section of engine cowling came within feet of crushing either the house or the pickup truck and RV parked next to it. Other large pieces landed on an athletic field in a nearby park.

UA328’s engines were Pratt & Whitney PW4000s, each 16 feet long, weighing 16,000 pounds, and capable of generating more than 90,000 foot-pounds of thrust. Turbofan engines rarely fail in flight, and even when they do, they are designed such that pieces of the engine will be contained within the surrounding cowling. But the stacks of fan blades that heat and compress air to generate thrust must handle extremely high energies, and if one comes apart due to accumulated mechanical stress it can shatter, spewing a shotgun-like blast of metal fragments that in turn can destroy neighboring blades in a cascading fashion.

Such uncontained engine failures can be extremely dangerous, as flying pieces can hit fuel tanks, shred control surfaces, sever hydraulic lines, pierce an aircraft’s pressure hull, or hit passengers or crew. In 2018, a passenger aboard a Southwest 737 was killed when one of the plane’s engines exploded and a piece of debris shattered her window; the resulting depressurization caused the top half of her body to be sucked out through the breach.

Investigators from the National Transportation Safety Board will collect as many pieces as possible from the ground as well as examine the portion of the engine that remained attached and study flight data recorders in order to determine what caused the catastrophic failure. It’s not currently known if the engine that failed was the original delivered with the plane to United in 1995, but if so its maintenance history will receive special scrutiny. Repeated stresses over time can cause microscopic fractures within metal that will eventually propagate and ultimately break if not detected in time.

Three years ago, an eerily similar event happened to a sister aircraft of the 777 involved in Saturday’s accident. An aircraft with the tail number N773UA, operating as United flight 1175, was also en route to Honolulu when it suffered an uncontained failure of its right engine that resulted in its cowling getting ripped off.

In that accident, the plane was 40 minutes from the end of its flight, and landed safely in Honolulu. The NTSB later determined that one of the fan blades had suffered a fatigue crack that had grown over time despite repeated inspections. Built in 1996, the engine had been installed on the plane in 2015 and had 77,593 hours in operation since new.

That plane was the fourth 777 off Boeing’s production line; N772UA was the fifth. Both aircraft were delivered to United on the same day: September 29, 1995.

This article originally ran on February 20, 2021 in New York magazine.

On February 9 I talked to A Martinez of  KPCC Southern California public radio about the NTSB’s findings concerning the Kobe Bryant crash. You can listen to the audio here.

The National Transportation Safety Board today made its final determination in the January 26, 2020, helicopter crash that killed Kobe Bryant, his 13-year-old daughter, Gianna, and seven others, finding that the mostly likely cause was that the pilot, Ara Zobayan, became disorientated after flying into clouds, at which point he lost control and flew into a hillside.

A contributing factor, the board declared, was that Zobayan likely felt self-imposed pressure to successfully complete his mission, which was to deliver Bryant and members of his daughter’s basketball team to a tournament taking place in Calabasas, California.

The findings dinged Zobayan’s employer, Island Express Helicopters Inc., for “inadequate review and oversight of the safety management processes.” The conclusions provided on Tuesday were largely consistent with analysis previously published in New York magazine and elsewhere.

The fatal flight had taken off 40 minutes before from an airport in Orange County and traveled north under a low overcast before turning west in an attempt to cross over a mountain pass in order to reach Calabasas, 17 miles to the west. But the pass was shrouded in clouds. Island Express helicopters are only legally allowed to fly under visual flight rules, meaning that its pilots could orient themselves by seeing the ground below them.

At the public hearing held before the NTSB board voted to approve the findings, members noted that Zobayan had ignored his own pilot training. Once he found himself in whiteout conditions, he should have leveled the helicopter, kept flying straight ahead, and slowed down. Instead he maintained high speed and attempted to climb twice as fast as recommended.

He might nonetheless have succeeded in punching up through the thousand-foot-thick cloud layer if he had managed to keep the helicopter flying straight ahead. To do this, he would have had to maintain intent focus on the flight instrument panel in front of him, lest he succumb to “the leans,” an illusion caused by the vestibular sensation that one is in a turn when one is not. However, a few seconds after he entered the clouds, an air-traffic controller asked him to press a button that would signal the helicopter’s location on the controller’s radar screen. This required him to move and shift his attention in a way that “could adversely affect his ability to effectively interpret the instruments and maintain control of the helicopter,” according to NTSB investigator Dujuan Sevillian.

Seconds later, he radioed to the controller that he was climbing to 4,000 feet. But he was already in a steep dive that would cause him to impact the ground at 184 mph.

Far from being an unusual type of accident, crashes resulting from pilots flying into clouds and becoming disoriented are a persistent problem. On average, there have been one of these fatal crashes every six months for the past decade.

The board noted that the fatal crash didn’t mean that Zobayan was a bad pilot, noting that he was generally held in high regard by colleagues and clients. As lead investigator Bill English put it, “Good people can make a bad decision, and we really want to get to the bottom of why.”

This article first ran on February 9, 2021 in New York magazine.

8:45 A.M.

On a Gloomy Sunday Morning last winter, Ara Zobayan stood in the Atlantic Aviation terminal at John Wayne International Airport in Orange County, California, and contemplated his flight-planning app. The helicopter pilot’s software showed a blanket of clouds covering the city. Beneath the thousand-foot-thick layer lay patchy haze. The poor visibility meant that large swaths of the region were unflyable.

This was a problem. The charter company OC Helicopters had hired Zobayan’s employer, Island Express Helicopters, to fly Kobe Bryant and seven companions to Camarillo, an airport on the coast 80 miles to the northwest.

Completing the mission was important to Zobayan. Island Express was a small operation, with six helicopters and as many pilots, and it ran on thin margins, according to former Island Express pilot Kurt Deetz. Its business mostly consisted of shuttling passengers back and forth between Long Beach and Catalina Island, a tourist destination 20 miles off the coast. Custom charter flights for high-net-worth individuals were less frequent but far more lucrative.

Of all the company’s VIPs, Bryant was the I-est. According to Deetz, not only did Bryant fly Island Express regularly—for any crosstown trip that a normal person would just drive—but his patronage lent the company a luster. “Kobe was their pride and joy,” says Deetz. “It was like, ‘Look at us, we’ve made it.’ ” Keeping Bryant happy was job one. And as with any client, that meant getting him where he wanted to go. Continue reading Vanity Fair: Kobe Bryant’s Tragic Flight

Authorities have located the black boxes for Sriwijaya Air Flight 182, the Boeing 737 that crashed Saturday in Indonesian waters after it plunged suddenly and precipitously four minutes after takeoff. The data they contain should clarify why the plane dove 10,000 feet nearly vertically in just 15 seconds and struck the Java Sea at nearly 500 miles per hour, instantly killing the 62 people aboard.

The speed of the descent implies that the plane remained substantially intact, with the engines generating power right until the end. No mayday call was transmitted, nor did the emergency beacon transmit after impact. The speed of the impact likely shredded all but the rearmost portions of the aircraft.

Sriwijaya Air, Indonesia’s third largest airline, was founded in 2003. Before Saturday it had lost three 737s in bad landings but these accidents had not killed any passengers or crew. In 2019, half of its aircraft were temporarily grounded by regulators for safety reasons. Indonesian airlines overall have a notoriously poor safety record. In the past decade, nearly 700 people have died in air crashes in the country. Continue reading New York: Two-Mile Nosedive by a Boeing 737 in Indonesia As Yet Unexplained