Philippine Airlines Flight 434, sometimes referred to as PAL434 or PR434, was a scheduled flight on December 11, 1994, from Manila to Tokyo with a quick stopover in Cebu on a Boeing 747-283B that was seriously damaged by a bomb, killing one passenger and damaging vital control systems, although the plane was in a repairable state. The incident was a test run of the unsuccessful Bojinka terrorist attacks. The Boeing 747 (tail number EI-BWF) was flying the second leg of a route from Mactan–Cebu International Airport in Cebu, Philippines to Narita International Airport, in Tokyo, Japan. After the bomb detonated, 58-year-old veteran pilot Captain Eduardo "Ed" Reyes was able to land the aircraft, saving it and the remaining passengers and crew.

Authorities later discovered that Ramzi Yousef, a passenger on the aircraft's prior flight leg from Manila's Ninoy Aquino International Airport, had placed the explosive. Yousef boarded the flight under the fake Italian name "Armaldo Forlani", an incorrect spelling of the name of the Italian legislator Arnaldo Forlani, in order not to get caught. Yousef was later convicted of the 1993 World Trade Center bombing.

The aircraft operating Flight 434 was a 15-year-old Boeing 747-283BM Combi owned by Guinness Peat Aviation (GPA), registration EI-BWF, serial number 21575. It made its first flight on February 17, 1979, and was delivered to Scandinavian Airlines (SAS) on March 2, 1979, as SE-DFZ, operating the plane as "Knut Viking". After occasional lease periods with Nigeria Airways and Malaysia Airlines between 1983 and 1988, the plane was sold to Guinness Peat Aviation and leased to Philippine Airlines on September 7, 1988.

The flight crew consisted of the following:

Captain Eduardo "Ed" Reyes (1936 – 14 February 2007), a 58-year old veteran pilot who served in the Philippine Air Force from 1958 to 1964, and had flown with Philippine Airlines since 1964.
First officer Jaime Herrera (1948 – 27 March 2021), also a veteran pilot who had flown with Philippine Airlines since 1970. Herrera was 46 years old and was serving as co-pilot at the time of the incident.
Flight Engineer Dexter Comendador (born 6 November 1960), who, like Reyes, was also a Philippine Air Force pilot, serving from 1983 to 1992. He had flown with Philippine Airlines since 1992. Comendador was 34 years old at that time.