By Taylor Rains
Safety Regulators Take Action After United Airlines Engine Failure
The airline industry has acted quickly after a United Airlines 777-200 experienced an uncontained engine failure on Saturday, scattering debris across a Broomfield, Colorado neighborhood. Two Pratt & Whitney PW4000 engines powered the incident aircraft, and Boeing and multiple countries have since grounded 777 jets that feature the engine model. While it is still too soon to say what caused the engine explosion, former NTSB Director of the Office of Aviation Safety Tom Haueter suspects a fan blade may be the culprit. According to Pratt & Whitney, the PW4000 uses unique hollow fan blades designed solely for Boeing 777 airplanes.
Since the incident, Boeing has halted operations of over 100 of its 777 jets “out of an abundance of caution.” Of the jets, 69 were in use, and 59 were in storage. The planes will remain grounded until the Federal Aviation Administration (FAA) can determine the “appropriate inspection protocol.” FAA Director Steven Dickson said that he has “stepped-up” PW4000 inspections after consulting with a team of safety experts.
After the accident, United immediately grounded its fleet of PW4000-powered 777 aircraft. However, this is not the airline’s first issue with the engine model. In February 2018, a PW4000 lost its cover after a fan blade separated from the right engine. Like the event that occurred on Saturday, the aircraft landed safely without any injuries. The airline said that it is working with the FAA, NTSB and Pratt & Whitney to determine the cause of the failure.
Uncontained engine explosions like this are extremely dangerous for both the aircraft and people on the ground. Fortunately, in both United events, debris that separated from the engine did not injure anyone on the ground, and all passengers and crew were safe.
However, that is not always the case. In April 2018, an incident involving a Southwest Airlines CFM56-7B engine turned fatal after a fan blade separated in-flight and hit a fuselage window, killing one passenger. After the flight, the FAA issued an emergency airworthiness directive (EAD) initiating the ultrasonic inspection of all CFM56-7B engines with 30,000 or more engine cycles. The FAA will likely pursue a similar action with the PW4000s.
According to federal officials, the only countries with airlines that operate 777s equipped with PW4000s are Japan, South Korea and the United States. On Sunday, the Japan Civil Aviation Bureau (JCAB) ordered Japan Airlines and All Nippon Airways to ground all 777 aircraft that carry the PW4000 engines. Boeing supported the decision.
South Korean carriers Korean Air Lines and Asiana followed suit Monday morning with the voluntary grounding of their 777s. Korean Air grounded 16 aircraft while Asiana grounded nine. However, Korean low-cost carrier Jin Air has yet to ground its fleet of 777 aircraft carrying the PW4000 engines, saying it is awaiting guidance from federal regulators.
In addition to Japan, the United Kingdom (UK) has also responded to the PW4000 engine failure. While the UK does not have any national carriers that fly aircraft equipped with the PW4000, it announced Monday that it had banned all aircraft that do from its airspace. The UK’s transport secretary, Grant Shapps, explained he would “continue to work closely with the Civil Aviation Authority to monitor the situation.”