Re: stretch DC-8 landing gear

Date:         31 Jan 97 14:29:23 
From:         Steve Lacker <>
Organization: applied research laboratories
References:   1 2
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Kenneth Quek wrote:

> Apparently, the early DC-8 series (-10 to -50) had main landing gear which
> were tall enough to accommodate the stretch. This problem of needing to
> extend the landing gear for a stretch was partly why Boeing abandoned the
> stretched 707-700 competitor to the DC-8. Of course they were also already
> designing the 747!

Point of clarification- the 707-700 first flew in 1979, at which time
the 747 was not only fully designed but flying all over the world. I
assume you typo'ed 747 instead of 757. The 707-700 was shelved because
the 757 would offer the same sort of performance/capacity with better

To quote 'Boeing Aircraft since 1916' by Bowers:

"Model 707-700- This single aeroplane was used by Boeing as a test-bed
for the new CFM-56 turbofan... Aside from testing the CFM56 engine,
Boeing planned to offer new 707-700s with CFM56 engines to the market
and to upgrade existing 707s through kits consisting of new engines and
nacelles. This programme was not carried through in view if the fact
that upgraded 707s would reduce the market for new Boeing Model 757s.
The kit conversion idea was taken up by Douglas, however, which extended
the service life of some DC-8s with new power packages.  Although Boeing
did not apply the CFM56 engine to further civil 707s, it did adopt that
power plant to some military 707 variants, specifically KC-135s
converted to KC-135Rs and to newly built  KE-3As and E-8As. *
  The 707-700 first flew as such on November 27, 1979.  After
completeing the CFM56 test program, the aeroplane was converted to a
707-3W6C with P&W JT3D engines and delivered to the government of
Morocco in 1982. This was the last delivery of a commercially-configured
Boeing 707."

*Note from my foggy memory- the KC135 is technically not a 707 airframe,
but a 717 though both derived from the original Dash 80 prototype. The
KE-3A and E-8s as well as all later military 707 variants are actually
derived from the civil 707, not the military KC-135.

Stephen Lacker
Applied Research Laboratories, The University of Texas at Austin
PO Box 8029, Austin TX 78713-8029