Production and testing

Final assembly of the first 747-400 began at Boeing's Everett factory, the longtime site of 747 production, in September 1987.^[15] More than fifty percent of the aircraft was produced by subcontractors, with major structures, engine nacelles, and sub-assemblies supplied by Northrop, and upper deck fuselage frames from Daewoo.^[16] All components were integrated during the final assembly process at the Everett factory. The first aircraft, equipped with PW4056 engines, was completed over the winter months of late 1987.^[15] On January 26, 1988, the first 747-400 rolled out at the Everett factory, while the first 737-400 rolled out at Boeing's Renton factory on the same day, marking the first double jetliner rollout in the manufacturer's history.^[15] By the time of the rollout, the 747-400 program had amassed more than 100 orders.^[15]

An aerial view of Boeing Field, one of the sites used for 747-400 flight testing.

The 747-400 flew for the first time on April 29, 1988, under the command of test pilot James Loesch and co-pilot Kenneth Higgins.^[17] The first flight was six weeks behind schedule, owing to subcontractor delays in supplying components, and extra troubleshooting on the aircraft's electronics systems.^[15] The maiden flight took off from Paine Field, site of the Everett factory, and landed at Boeing Field, south of Seattle, after an uneventful 2 hours and 26 minutes.^[17] The 747-400's flight test program utilized the first four aircraft built, one over the minimum number necessary to certify the aircraft's three engine options.^[17] One test aircraft each was fitted with the CF6-80C2B1F and RB21-524G/H engines, while the other two featured PW4056 engines, with the fourth aircraft serving as a backup.^[17] Federal Aviation Administration (FAA) certification was received on January 9, 1989 with Pratt & Whitney PW4000 engines, May 18, 1989 with General Electric CF6-80C2s and June 8, 1989 with Rolls-Royce RB211-524Gs.

As the flight test program proceeded, Boeing encountered problems in the 747-400's production process, leading it to disclose delivery delays of up to one month for the first 20 aircraft built.^[15] A primary reason for the delays was the unprecedented complexity of interior configurations offered to airlines, which ranged from lavatory and galley locations to the color shades of cabin warning labels.^[15] Coupled with new, relatively inexperienced workers, a lack of veteran technicians, interior configurations needing costly re-work, and teething problems with electronics integration on the advanced flight deck, 747-400 production fell behind schedule.^[15] However, the company managed to resolve early production issues by mid-1989, with all three 747-400 engine variants delivered within four months of each other, and overall delays not exceeding several weeks.^[15]

[edit]