Re: Boeing 777 First Flight was today - June 12

From:         gregory@bcstec.ca.boeing.com (Greg Wright)
Organization: Boeing Computer Services
Date:         26 Jun 94 16:18:24 
References:   1 2 3
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In article <airliners.1994.1355@ohare.chicago.com>,
Woodhams <mdw@ccu1.auckland.ac.nz> wrote:
>Stephen L Nicoud <stephen.nicoud@Boeing.Com> writes:
>> Successful completion of the testing program is expected to lead to the
>> certification of Pratt & Whitney-powered 777s in April of next year, with
>> delivery of the first customer airplane to United Airlines scheduled for
>> May 15, 1995.  Certification of GE-powered 777s is expected in August 1995,
>> and certification of Rolls-Royce-powered 777s anticipated in January 1996.
>
>Why does it take so long to certify the plane with the different
>engines? (10 months to certify the whole plane plus P&W engines,
>another 9 months after that before the RR engines are certified.) I
>would have guessed that 80% of the certification testing would be
>independent of which engine was used.

The testing of the Rolls-Royce-powered 777s may not start right when
the testing of the previous engine ends. Also, engines can make a very
big difference in the performace of the wing in areas such as landing
and takeoff.  They really can change the airflow in high-lift/low-speed
areas of the flight envelope. As you know, these are the two most
important part of the flight testing: landing and takeoff performance.

greg.

-- 
 ________Greg Wright________        Software Development 
| gregory@bcstec.boeing.com |       777 Division. 
|    gregory@halcyon.com    |                                           
|___uunet!bcstec!gregory____|      NOT A BOEING SPOKESPERSON.