Passengers aboard a United Airlines flight from Denver to Honolulu had several moments of terror on Feb. 20 when their aircraft, a Boeing 777-200, suffered a right engine failure shortly after takeoff, causing a massive bang and debris rained down on a quiet suburb of Denver. Passengers recorded videos of the plane’s Pratt & Whitney engine, much of which was shared on social media. The cover was torn off, the turbine oscillated and was on fire. The aircraft with 231 passengers and 10 crew members returned to Denver and landed safely.

An eerily similar incident occurred on the same day in the Netherlands with a Boeing 747-400 cargo jet. The engine on this aircraft, while different from the Boeing 777 in Colorado, was also manufactured by Pratt & Whitney. It also caught fire and spat out pieces of metal before the plane made its own safe emergency landing.

And on Friday, a long-haul Boeing 777 with cargo and 25 people landed in Moscow after an indicator warned of a possible failure of the General Electric engine.

The events in Colorado and the Netherlands were the latest in a series of dramatic high altitude failures in recent years. In 2018, another United Airlines flight, which also flew to Honolulu, had an almost identical engine failure as the one over Colorado. One of them was a flight from Japan Airlines from Tokyo to Okinawa in 2020. Both aircraft were also Boeing 777-200s with Pratt & Whitney engines.

Other planes have had major incidents: A Southwest jet’s explosion in the air in 2018 caused the death of a passenger, Jennifer Riordan. (That plane, a Boeing 737, was equipped with an engine made by CFM International, a joint venture between General Electric and France’s Safran Aircraft Engines.) And then there were the two devastating Boeing 737 Max plane crashes who altogether killed 346 people and caused the entire fleet to be grounded for nearly two years.

On Sunday, United ordered the only U.S. airline whose 777s are powered by that particular Pratt & Whitney engine to thoroughly check all of them before they could fly again, while Boeing said 128 of its 777 jetliners worldwide are temporarily out of service should be asked. An initial investigation found that the engine’s fan blades were tired from metal, and the FAA said Tuesday that the Boeing 777’s Pratt & Whitney engines must be inspected before the planes return to the sky.

Statistically, commercial air travel has been shown to be extremely safe, and episodes like the one over Colorado on Saturday are rare. But anxious fliers who feel an added jolt of nervousness may now wonder how commercial aircraft are serviced and maintained, and how much they can learn about the aircraft they are supposed to fly before boarding. Here are some answers.

Depending on the airline you fly, determining which aircraft is assigned to you is often as easy as taking a closer look at your reservation. Most airlines list this information right on their online booking page near the flight details.

If you can’t find it there, sites like SeatGuru, which has seat maps and customer reviews for most aircraft models, and FlightRadar24, which allows visitors to follow every flight in real time, make it easy to see the make and model of the aircraft associated with any flight .

When looking for the engine model of an airplane, you need to dig a little deeper. will give you this information, but you will need the tail number of your aircraft. It’s a series of six numbers and letters starting with N, and you can find them by either searching for your flight on SeatGuru or FlightRadar24, or, if you’re already at the gate, actually looking at your aircraft. As the name suggests, the number is visible on the tail of the aircraft.

But don’t be surprised if your airline makes a last minute change that puts you on a completely different aircraft. Such changes are common, so there is no point in booking an itinerary based on a preferred aircraft model.

“What you book today is not necessarily the plane you will be taking when the trip comes,” said Brian Kelly, founder and director of travel loyalty website The Points Guy.

Covid-19, which changed many airlines’ flight schedules, made this practice even more common. It also makes it easier for passengers to change flights if they don’t feel comfortable when boarding the aircraft assigned to them.

“There’s no consumer law that says that if you don’t want to fly a certain aircraft, you need to be accommodated, but most airlines have waived their change fees,” said Kelly. “It’s easier to switch flights than ever before.”

All the time. Before each flight, the pilots perform a tour inspection of the aircraft and its equipment. The Federal Aviation Administration mandates that more in-depth inspections of aircraft be performed at least every 100 flight hours. After about 6,000 flight hours – the timing depends on the aircraft – aircraft are given a so-called C-Check that puts them out of service for a whole week or more while technicians perform a thorough inspection of all their parts. AD Check, the most intensive maintenance visit, involves the complete disassembly of the aircraft to look for damage in every nook and cranny. These occur every six to ten years.

There are additional, mandatory maintenance and service inspection schedules set by the manufacturer of the many parts of each aircraft. And there are surprise inspections too.

“The FAA conducts random checks on all certified operators so we can review maintenance records, the aircraft itself, or both,” said Ian Gregor, a public affairs specialist with the FAA

In the case of United’s 777-200, the metal fatigue that caused the engine’s fan blades to break was likely invisible to the naked eye. However, these blades should have been examined relatively recently using thermal acoustic imaging, which can reveal microscopic cracks. In March 2019, the FAA ordered additional checks on Pratt & Whitney engines following an engine failure on another United flight.

“We have known metal fatigue since the industrial revolution,” said Mark Baier, managing director of AviationManuals, which creates safety manuals and software for flight safety management. “It’s just something that happens. However, this has shown how incredibly safe these planes are as the planes continue to fly normally. “

Not in the United States. “The FAA regulations apply uniformly to all airlines,” said Gregor.

This does not mean that violations will not occur.

“It’s not uncommon for airlines to work with maintenance problems or cut corners,” said Loretta Alkalay, a former FAA attorney and associate professor at Vaughn College of Aviation in Queens, NY. “There are definitely some operators that are doing this.” less meticulous than others. “

When an airline violates regulations, the FAA takes enforcement action that comes with penalties. These are published on their website and can be read by the public.

Travelers interested in learning more about an airline’s safety ratings can check out Airline Ratings, which rank safety on a seven-star scale based on accident and pilot incidence data, International Civil Aviation Organization audits, and even Covid-19 compliance evaluate. The website even offers a function for comparing selected airlines.

But the safety records of all U.S. airlines are so consistently excellent, said Patrick Smith, a commercial pilot and host of the aviation website Ask the Pilot, that obsessing over whether one airline poses greater risk than another is a waste of time.

“You can drive yourself crazy thinking about the fractions of a percentage that separates one porter’s death rate from another,” he said. “They are the same in every way.”

The 777 that was involved in the Colorado incident had flown since 1995. The United 2018 flight to Honolulu, which also suffered an engine failure, was built in 1996. A Boeing plane that crashed into the Java Sea in Indonesia in January was 26 years old. Should passengers be careful about flying in aging planes?

“The data doesn’t really confirm that,” said Mr. Baier. “And a lot of older aircraft are being upgraded with new equipment or systems.”

The more an aircraft flies, the more maintenance checks it receives. “Commercial jets are built to last more or less indefinitely,” said Mr. Smith, the pilot. “The older an aircraft gets, the more and better care it needs and the inspection criteria are becoming stricter.”

Mr. Kelly of The Points Guy states on his website that anyone can check the age of an aircraft on FlightRadar24 as long as they have paid for a Silver membership on the website. For his part, however, he says that he does not take the age of an aircraft into account when booking. “The 737 Max was a brand new aircraft,” he said, “and it was very problematic. I wouldn’t say old planes are any less safe than new ones.”

The pilot will call a maintenance team who will try to fix the problem on the ground (often while passengers are waiting at the gate). If the problem is minor but cannot be resolved immediately, the aircraft may still be flying. The airlines follow a document called the Minimum Equipment List, a list of systems and parts that may not be functional and the aircraft can continue to fly.

If the maintenance problem is critical and the aircraft cannot be flown until after the repair, it will be taken out of service until it is resolved. Safety issues with parts and aircraft are causing the FAA to issue airworthiness directives informing all airlines using similar equipment that inspections and possibly corrective actions are required.

Before the aircraft in question is put back into service, the crews will conduct several series of tests, including likely a flight or two, before regulators sign off the mechanics’ work.

And what if there is a problem during the flight, as it did on February 20th? Pilots are prepared for moments like this, said Dan Bubb, former pilot and aviation history expert at the University of Nevada, Las Vegas.

“When you fly you always expect what could go wrong so you can get ahead of it,” said Mr Bubb. “Pilots are trained regularly for all possible scenarios. And when it happens, your workout begins. The pilots made a textbook on how to land the plane safely. “