Re: Help: 737-300 Max Air Speed ?

From:         drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard)
Organization: The Boeing Company
Date:         16 Nov 95 03:48:38 
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JKD214 <jkd214@aol.com> wrote:
>I an currently working on a product for a  Boeing 737-700 aircraft. My
>design requirements seem a bit excessive and are driving my cost through
>the roof. I am questing the max air speed of this aircraft. I would like
>to know the max air speed of this aircraft if any one knows. If any Boeing
>engineers are reading this please disreguard (Al, Cathy, Tom).

I'm a Boeing design engineer, but I'm afraid I can't disregard this
question.  It gives me the feeling that you are intending to cut some
really potentially nasty corners with your product, thereby possibly
endangering my aircraft at a time when every little bit would help, near
top speed.

I guess the question is how fast can the airplane be going, with you and
your mother onboard, and have your part fail?  How much money are you going
to save?  Is it worth it?  Are you willing to risk being a party to some
really ugly litigation after the crash?

Now it is obvious, with a little thought, that your part is probably
structural.  Otherwise, the airspeed, and the dynamic loads created by the
airspeed, would most likely be irrelevant to your design.  So, we aren't
talking about seatback tables here.  If you can't do the design to the
requirements for the money you bid, see your lawyer and back out of the
contract and let someone else in there who can do the job.  Please
understand that the above is not the official position of the Boeing
Company.  It would take them two weeks and 200 pages to give you that
position.  This is just my opinion.

Maximum airspeed is a pretty knotty question.  There is Maximum Operating
Velocity, Maximum Operating Mach Number, Dive Velocity, Never Exceed
Velocity, etc.  And those are all within the certified operating envelope
of the airplane, I think (depending on how you want to demonstrate Vne).
We haven't even talked about out of the ordinary stuff, yet.  Now, don't
misunderstand, the airplane is highly unlikely to ever go faster than
Vdive, but you can get into some really interesting attitudes that will
affect local Mach numbers and dynamic loads on various parts.

In short, believe the number you were given, design to the requirement, and
if at all possible, add in a little extra capability to bring that airplane
back if it ever gets in trouble.  Engineers just like you have been doing
that for over 75 years.  We have a great tradition here.  We do, in fact,
build the world's finest heavy jet transports.  Don't jeapardize those
people, that airplane, or the industry just to save yourself some money.

Terry


--
Terry
drinkard@bcstec.ca.boeing.com
"Anyone who thinks they can hold the company responsible for what I say has
more lawyers than sense."