Re: Boeing historian?

Date:         17 Sep 99 10:52:40 
From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
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>>Can someone tell me briefly about,
>>or direct me to a definitive site or book
>>concerning, Boeing jets regarding
>>historical evolution and interrelation of
>>707, 717, 720, and KC-135?

>The DASH 80 is the prototype, and emerged largely unchanged as the KC135.

There actually were quite a few changes between the 367-80 and the KC-135.
The most notable was the 12" increase in upper lobe (cabin) width, from
132" on the Dash 80 to 144" on the KC-135 family.  The KC-135 is also
8'3" longer, a 14" greater wingspan, and has a greatly increased MGTOW,
316,000 lbs versus only 190,000 lbs on the Dash 80.

>To compete carriers wanted 3 x 3 seatings,
>which forced Boeing to increase the fuselage diameter.

This was a further increase from even the KC-135, to 148".

>The 707-137 is essentially the Dash 80/KC135 with the wider fuselage.

The 707-137 would be a 707-120 series built for Air India had any
existed.  (They only bought the -320 and -420 series new, and also
picked up the 720 on the used market.)

The 707-120 was the first 707 series.  It's both longer and wider than
the KC-135, which as noted above is both longer and wider than the -80.
It has the same wing as the KC-135.  The 707-120B is similar with JT3D
turbo-fan engines instead of the original non-fan JT3C engines being the
most significant change.  They also had additional leading-edge flaps,
an increased tailspan, and, optionally, the 720's modified wing.

>The 138 was a special build for QANTAS, about 3 meters shorter to reduce
>weight and improve operating margins at some pacific Island locations.

Another special was the 707-220 series, built only for Braniff (as the
707-227).  These were the 707-120 airframe equipped with JT4A-3 engines
from the 707-320.

>The US domestic carriers wanted a lower cost, lighter weight version of
>the 707 for domestic use, which lead to the 707-120, which simply
>became known as the 720.

No, the 707-120 was the original version of the 707.  The 720 is just
that, the 720 (and a turbo-fan version, the 720B).  It's 9 feet shorter
than the 707-120 and was further lightened by using lighter gauge metal
in many places.  It also has a modified wing, with greater area.

>The original 707 was actually marginal for many
>routes, and the carriers asked for a larger, longer range version. The
>aircraft underwent substantial modifications, and a large increase in
>weight to produce the 707-300 and 707-400 series (300's have P&W engines,
>400's have RR engines).

Right, though Boeing refers to them as the 707-320 and -420 series.  The
707-320 came in several variations.  The original version had a greater
span and other wing modifications relative to the original 707-120, plus
an increased tail span, greater fuel capacity, higher MGTOW, and more
powerful and efficient JT4A-3 engines.

The 707-320B had even further wing refinements, which combined with
JT3D-3 turbo-fan engines resulted in a 15% range increase over the

The 707-320C was originally a -320B with a cargo door and provisions for
convertible use -- what's usually known as a Combi today.  Later versions
were built for cargo-only use.

There was also a single 707-720 built, with CFM56 engines.  After
testing it was converted to 707-320B specifications and sold.  (There
are also CFM56-equipped KC-135s, the KC-135R and perhaps others.  All
of these were upgrades from the original PW engines.)

>The 717 was originally the McDonnel Douglas MD95, a low cost, 100 seat MD80
>family member, renamed by Boeing as the 717.

The 717-200 to be precise.  Given the context, the original question
probably refers to the 707-100, which was Boeing's designation for what
is more widely known as the KC-135.

Karl Swartz	|Home
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