Almost two and a half months have passed since United Airlines flight UA328 experienced an engine failure which saw parts scattered over suburbs of Denver, Colorado. This brought increased attention to issues with Boeing 777s powered by Pratt & Whitney-powered PW4000 engines. With most of these jets grounded, where are they being stored?

United Boeing 777
United, and several other carriers', 777s with PW400s are currently on the ground due to the incident. Photo: Vincenzo Pace | Simple Flying

In storage long before UA328

Before we get to the specific location of these jets, it's interesting to note when exactly the aircraft were stored. With all of the issues and alarms raised over PW4000-powered 777s in February, one might expect the type to be mostly grounded in the incident's aftermath. However, that's not what the data shows...

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As you can see from the above graph, the most significant drop in usage took place in April and May 2020 with the rise of the global health crisis. This makes sense, with long-haul international travel seeing the most severe disruptions due to border restrictions.

Therefore, most of this sub fleet went into long-term storage around a year ago and have been there ever since. After the UA328 incident, United decided to send the remaining PW4000-powered 777-200s into storage as well. As a result, almost every United flight with a 777 is powered by General Electric GE90 engines.

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Roswell is the main home of United's PW4000 777s

It looks like Roswell Air Center is where United has chosen to store most of its grounded fleet. Haunting drone footage from the video below shows that many of United Airlines' 777s are parked here, along with its 767s, 757s, and A320s.

The facility, located in New Mexico, also appears to be a major storage site for American Airlines' fleet as well.

This was confirmed to Simple Flying by United's communications team, with a spokesperson saying,

“We are relocating some aircraft to locations where we have the resources and facilities to properly maintain them while in storage.”

The Roswell Air Center is located five miles south of the city's central business district and is considered the core of southeastern New Mexico’s industrial activity. The site began as Roswell Army International Airfield during World War II and Walker Air Force Base during the Cold War. When the military ended its time here in 1967, the 18.6 square km base was the largest of the United States Air Force Strategic Air Command.

With a dry climate, low humidity, and ample space, Roswell is a site that’s ideal for long-term storage.

Other sites (including China)

While the majority of United's jets are at Roswell, we know of a few stored elsewhere. A handful are stored at another major continental US site in Victorville, California - otherwise known as Southern California Logistics Airport.

Data from Planespotters.net shows that many are scattered across United hub-airports, including Denver (Den), Houston (IAH), Honolulu (HNL), Chicago (ORD), and San Francisco (SFO).

The most interesting storage site, however, is located overseas in another country. Indeed, about five PW4000-powered 777-200s are parked up in Xiamen, China - and have been here for around four months.

Hopefully, the overall travel situation will improve in the coming months to allow United to bring some of these aircraft out of storage- assuming all the necessary engine checks have been performed to prevent another UA328-type incident.

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