BOEING HAS reached the 75% design release point on engineering for the 737-700, the first of its next-generation family of small twins. The company's development plan calls for the production of all three versions of the family within 18 months.
"Boeing has never done anything like this," says Bill Lochow, director of operations for the 737 next generation at Wichita, Kansas. Unlike previous Boeing "family" plans, which unfolded over several years, the three new 737 versions, are set to be developed, within months of one another. "The first -700 [fuselage] will be delivered to Renton in September 1996. Six months later, the stretched -800 will be delivered, and the shorter -600 will follow six months after that."
Wichita produces all 737 fuselages, fins and stabilisers, but unlike the current versions, it will deliver the new fuselages complete pre-assembled units. A mock-up of the largest fuselage, the 737-800, has been shipped by rail to Seattle so that clearances along the line could be checked. The -800 is 39.47m long, compared to 31.24m of the -600 model.
"We've started to build parts for the first aircraft," says Lochow. The first engine strut has been shipped to General Electric for fit tests with the CFM International CFM56-7 turbofan. "We're in the process of building a second strut for tests, and we're also making the first pre-production thrust reversers," he adds.
Lochow says that, apart from the obvious differences in overall length, the new 737 versions are considerably different in structural detail, mainly because of the higher altitudes at which they will be operated.
"Although a lot of parts are common, we've taken a lot of parts and altered them by increasing the skin gauge to cope with the different loads," he adds.
Source: Flight International
