Chicago-based United Airlines is set to reactivate its sub-fleet of Pratt & Whitney PW4000-powered Boeing 777-2000s to service after more than a year of grounding them following an uncontained engine failure in February 2021. United Airlines plans to return its 52 PW B777 aircraft to commercial operations at the end of May.
The comeback of PW4000-powered B777s
On May 13, the major US airline United reported to gradually resume the operation of B777 aircraft for revenue services from May 26. Pending approval by the regulators on safety concerns related to PW4000 powerplants, the airline is committed to returning its PW B777 aircraft to active service. According to United’s chief communications officer Josh Earnest, the airline continues to work conscientiously with Boeing, Pratt & Whitney, and the FAA. It plans to begin flying grounded aircraft safely on May 26, all of which will depend on the rigorous assessment conducted by the FAA. United continues to have close coordination with the safety regulator on this aspect.
In-flight fan blade failure
On February 20, 2021, United Airlines Flight 328, flying from Denver to Honolulu, suffered an explosive engine failure that showered debris over a Denver suburb. It was a scheduled US domestic passenger flight carrying 231 passengers and ten crew members. Four minutes after takeoff, it suffered an engine failure, dropping debris in a residential area and significantly damaging a parked vehicle. The cracking of two fan blades due to metal fatigue caused the catastrophic engine failure, resulting in an in-flight engine fire and extensive damage to the engine nacelle. The plane returned to Denver safely with no reported injuries to persons on board or on the ground, yet the incident prompted FAA to ground all PW4000-powered B777s. Several national aviation authorities and airlines (Japan Airlines, All Nippon Airways) retired the aircraft type.
FAA’s three safety directives
Federal Aviation Administration (FAA) has finalized three safety directives to allow reactivation of PW400-powered Boeing 777s, which were grounded after the in-flight fan blade failures. The new directives proposed in December include strengthening engine covers and enhanced inspections and modifications of Boeing 777-200 and -300 airplanes powered by PW engines. The three directives are:
- The fixture of debris shields on the thrust reverses the inner wall and the examination of cowl doors for humidity ingression. Operators need to perform repetitive go-through of the hydraulic pump shutoff valves.
- Regarding fan blade, customization of the engine inlet to resist possible fan blade failure events.
- Taking particular corrective actions which are up to inspection results
United’s plan with 777s
United’s senior vice-president of international network and alliances, Patrick Quayle, informed that the airline would resume operation of a handful of Boeing 777s for domestic missions in the initial phase. In a month’s time, i.e., mid-June, the carrier plans to operate international routes and US mainland-Hawaii flights using a number of airplanes in the teens. United will gradually expedite the aircraft number ‘in the twenties’ by the end of June if all goes well.
Upon the return of affected aircraft, United Airlines won’t introduce any new routes but rather create schedule integrity with a buffer for its customers, he added. The carrier also informed to file an application to the US authorities to operate a new thrice-weekly service between the Washington-Cape Town route. It anticipates having a meaningful economic benefit for the national capital region by connecting the capital cities of the two countries.
The US carrier United Airlines is getting ahead of Atlanta-based rival Delta Air Lines in terms of flight applications, hoping to leap opportunity of a handful of nonstop connections between South Africa and America, given the bilateral air service agreement between the two countries. Not only does the flight from the nation’s capital avail a better proposal than Delta, but it also complements United’s current portfolio of flights to other African destinations, viz. Lagos, Nigeria, and Accra, Ghana.
The sooner the sub-fleet of Boeing 777s comes back to active service; the faster United Airlines will retain the capacity to fly as many travelers as possible in a bustling travel season, including a resurgence of international travel. The strong signs of long-haul travel recovery blended with a busy summer travel season will pick up demand in the US. The reintroduction of the 777 fleets minimizes disruptions to United’s current operations and expands its capacity to serve more customers. FAA must give a go-ahead signal to bring back United’s P&W-powered 777s in May.