Pratt & Whitney PW4000 on the Boeing 747

The Pratt & Whitney PW4000-94, named for its 94-inch fan, was one of three engine families offered on the 747-400 — and the one that launched the type.

Key facts
Applications	747-400 (PW4056) and 747-400ER (PW4062A) — only 747 variants
Thrust classes	PW4056 56,750 lbf; PW4062A 62,000–63,300 lbf (rating standard dependent)
Bypass / fan	4.8–5.0:1; 94 in fan (“PW4000-94” family)
Launch customer	Northwest Airlines — ordered December 1985; first aircraft January 1989; first revenue flight 9 February 1989

The PW4000 programme was launched in December 1982 and the engine was FAA-certified in July 1986, first flying on the Airbus A310. Northwest became the launch customer for the PW4000-powered 747-400, and its first aircraft N663US entered revenue service on 9 February 1989, launching the 747-400 programme itself.

The 747-400 was the first type certified with three different engine families in a single flight-test programme — PW4000, CF6-80C2 and RB211-524G/H — receiving FAA certification on 10 January 1989. The 747-400 prototype N401PW (later N661US) served as the PW4056 testbed.

The PW4062A, a higher-thrust derivative with a higher overall pressure ratio, was created for the 747-400ER’s 412,000 lb-weight, longer-range mission. Beyond Northwest, PW4000 customers on the 747-400 included United, Singapore Airlines, Korean Air, and many Asian carriers.

Sources

• 747-400 Airplane Characteristics for Airport Planning — Boeing
• PW4000-94 engines EASA type certificate — EASA
• PW4000-94 fact sheet — Pratt & Whitney
• The 747-400 launch: FAA certification — UPI
• Northwest Airlines Boeing 747-400 — Northwest Airlines History