Does anyone know why ...

AuntPeggy

AuntPeggy

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Boeing aircraft models begin and end with a 7?

707, 727, 787, etc.
 
http://www.aerospaceweb.org/question/planes/q0134.shtml

[FONT=arial,helvetica]The Model 367-80 had never been intended as anything more than an internal designation. Models in the 500s had been reserved for gas turbine engines and the 600 series for missiles. The 700 series was again intended for aircraft, so the company board decided to officially christen the Dash-80 as the Model 707.[/FONT]
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RotaryWingBob said:
I dunno :D

Maybe for the same reason that all Bell civilian turbine helicopters begin with 2 or 4? 206, 206L, 214, 230, 407 (oh, how I want one!), 412, 427, 430...
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Or soon 6 (609). Bell's numbers depend on how many main rotor blades the helicopter has (According to my dad anyway, who retired from there.) The 609 tilt rotor civil version will have 6 blades. The 400 series all have 4, and the 200 series all have 2 unless they were modified after production.
 
ausrere said:
Or soon 6 (609). Bell's numbers depend on how many main rotor blades the helicopter has (According to my dad anyway, who retired from there.) The 609 tilt rotor civil version will have 6 blades. The 400 series all have 4, and the 200 series all have 2 unless they were modified after production.
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Doh! Talk about overlooking the obvious. The connection between the first number and the number of blades never occurred to me :redface:
 
Because there may have been issues when they made it to the "Model 666"? :eek:

I do find it interesting they went from 707 to 727 then 737 which is still in production. Only after they bought out MD did they re-designate the newer design of the Stretch 80 as the 717.

I still think the 72 is the sharper-looking plane of the fleet. :yes:
 
RotaryWingBob said:
Doh! Talk about overlooking the obvious. The connection between the first number and the number of blades never occurred to me :redface:
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Unless of course you talk about the earlier models. I'm pretty sure the 47 didn't have 4 blades. I think the earlier model numbers had more to do with production years (even though the 1947 model production actually started in 1946... go figure). But, the first turbine variant of the 47 was called the 201..thus starting the 200 series model numbers. :D
 
KennyFlys said:
I do find it interesting they went from 707 to 727 then 737 which is still in production. Only after they bought out MD did they re-designate the newer design of the Stretch 80 as the 717.
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I have heard - and would appreciate any confirmation available - that the KC-135, a 707 variant, was officially designated the 717.

It was different from the 707 in some material ways, such as a larger fuselage diameter. There were also a lot of common parts.

The distinction was originally made as Boeing anticipated some civilian sales for the 717/KC-135 airframe. But obviously that never happened - not enough different from the 707 to attract a market. So Boeing retired the 717 model name and stuck with the KC-135 designation.

So the 717 name was eventually hung on the MD-80 variant.

Any truth to this?

-Skip
 
Skip Miller said:
I have heard - and would appreciate any confirmation available - that the KC-135, a 707 variant, was officially designated the 717.

It was different from the 707 in some material ways, such as a larger fuselage diameter. There were also a lot of common parts.

The distinction was originally made as Boeing anticipated some civilian sales for the 717/KC-135 airframe. But obviously that never happened - not enough different from the 707 to attract a market. So Boeing retired the 717 model name and stuck with the KC-135 designation.

So the 717 name was eventually hung on the MD-80 variant.

Any truth to this?

-Skip
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There appears to be so...

The 717 name had in fact been used within the company to refer to the narrower-cabin military version of the 707, which the U.S. Air Force designated the KC-135 Stratotanker. 717 had also been used to promote an early design of the 720 to airlines before it was modified to meet market demands. This left 717 available to rebrand the MD-95.
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Source: http://en.wikipedia.org/wiki/Boeing_717
 
It has been said that the C-135 airframe aka 717 was designed before the 707. It is one of those chicken or the egg debates among many. And there are differences, but many are so subtle they are not detectable to the untrained eye.
 
And all this time I figured it was because seven was the easiest number to write or paint (besides one of course). :D
 
I think the 717 was a varient of the DC-9 after Boeing took over.
 
lancefisher said:
I thought the MD-80 was a variant of the McDonald Douglas DC-9.
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Correct. Boeing bought M-D and inherited the MD-80/82 design, a DC-9 variant. Boeing labelled the current production model (MD-95) the B-717. And to pick the usual nit, the DC-9 was a product of Douglas Aircraft, long before McDonnell merged with/bought Douglas. Also note the spelling of McDonnell.

http://www.boeing.com/commercial/717/index.html

-Skip
 
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lancefisher said:
I thought the MD-80 was a variant of the McDonald Douglas DC-9.
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It is. IIRC, they were originally DC9-80's (renamed as the MD-80), then there were MD-88's, MD-90's, and the MD-95 (renamed Boeing 717).
 
I was under the impression that although the 717 is a similar design on the outside, it is not a direct descendant of the DC-9/MD-8x line. It requires an entirely different type rating, doesn't it?
 
I dont think so PJ. one of our towpilots just got done working for AirTran in the 717. Ill ask him.
 
t0r0nad0 said:
I was under the impression that although the 717 is a similar design on the outside, it is not a direct descendant of the DC-9/MD-8x line. It requires an entirely different type rating, doesn't it?
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It's included on the DC-9 TCDS at the FAA:

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library%5CrgMakeModel.nsf/0/C1817D49C964876886256B1400759D25/$FILE/A6WE.pdf

Ergo, it MUST be a direct descendant...
 
Ok, I'll accept that it's a descendant, but IIRC after talking to some 717 pilots, they've said that it's a completely different a/c with a different type rating.
 
Skip Miller said:
I have heard - and would appreciate any confirmation available - that the KC-135, a 707 variant, was officially designated the 717.

It was different from the 707 in some material ways, such as a larger fuselage diameter. There were also a lot of common parts.

The distinction was originally made as Boeing anticipated some civilian sales for the 717/KC-135 airframe. But obviously that never happened - not enough different from the 707 to attract a market. So Boeing retired the 717 model name and stuck with the KC-135 designation.

So the 717 name was eventually hung on the MD-80 variant.

Any truth to this?

-Skip
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the 135 models, KC, RC, C, EC, all used the original Dash-80 fuselage which I *thought* was actually narrower than the 707 not wider.
 
smigaldi said:
the 135 models, KC, RC, C, EC, all used the original Dash-80 fuselage which I *thought* was actually narrower than the 707 not wider.
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I'm not really sure about which is larger, but I was pretty sure that they were different.

-Skip
 
This was posted on another board. So I cannot vouch for it's accuracy

the KC-135 and 707/720 are all different:

1) 367-80 has an upper lobe width of 132 inches and a fuselage
cross-sectional height of 164 inches.

2) The 717/KC-135 upper lobe is 144 inches wide and the height is 168
inches.

3) The 707 upper lobe is 148 inches wide and the height is 170.5 inches.

Additionally:

1) The KC-135 fuselage is the same length as 367-80's. The 707-138 and
720 are 20 inches longer, the 707-120 is 120 inches longer and the
707-320 and -420 are 200 inches longer.

2) The 707-120 has essentially the same wing as the KC-135 (and
367-80). The 720 has a glove over the root area of the inboard wing,
which increases the max cruise Mach number of the aircraft. The
707-320/-420 doesn't have this glove, but it has a root plug extending
the span and a different planform to the inboard wing area.
Additionally, it has a different tip planform and some of the wing
airfoils has been modified.

3) The type of Aluminum used in the construction of the KC-135 is
different than the 707 series. Sorry, I don't remember the alloy
numbers off the top of my head.

4) KC-135s first had J57s (JT3Cs) without thrust reversers. Some were
reengined with TF33s (JT3Ds) with thrust reversers (taken off of
scrapped 707s), while others got F108s (CFM56s), without thrust
reversers. 367-80 and all early 707s and 720s were powered by JT3Cs,
with thrust reversers. Most were reengined with JT3Ds, with thrust
reversers. 707-320s were powered by JT3Ds, while -420s were powered by
RR Conways, both with thrust reversers. There was one 707-700 built
with CFM56s (with thrust reversers), but this was later reengined with
JT3Ds and sold as a -320. Some military 707s (RAF and French E-3s, USN
E-6s and one E-8C) were built with F108s (CFM56s). I am not certain if
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these latter aircraft have thrust reversers.
 
t0r0nad0 said:
Ok, I'll accept that it's a descendant, but IIRC after talking to some 717 pilots, they've said that it's a completely different a/c with a different type rating.
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It has different engines than the earlier DC-9's, it has a glass cockpit that the original DC-9's don't have (the MD-88's and MD-90's were glass as-delivered, and I think most of the earlier MD-80's were either glass or retrofitted as glass). The wings and fuselage are the same or derivative - not much difference that's obvious, though the control system, IIRC, has been updated. The MD-80/88's and MD-90's were much longer with higher passenger capacity - the difference is obvious if you see them side-by side - and would expect to fly somewhat differently.
 
Did anyone answer the question about why the 7s at the beginning and end of Boeing numbers? I didn't see it.
 
wsuffa said:
IIRC, the passenger versions of the 707 were made larger in order to compete with Douglass's DC-8. There are a lot more DC-8's still flying than 707's.
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Didn't the 707 predate the DC-8? Wikipedia, here I come....

OK, I'm back. The 707 entered passenger service on 10/26/1958, whereas the DC-8 entered passenger service in September 1959. And the 707 outsold the DC-8 by a wide margin because Boeing was willing to make many 707 variants whereas Douglas refused to do so for many years. Finally Douglas started with the variants, the most successful of which was a cargo plane that is still frequently seen in service. Boeing let this market go as they were hot in development of the 747...

-Skip
 
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AuntPeggy said:
Did anyone answer the question about why the 7s at the beginning and end of Boeing numbers? I didn't see it.
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Peggy,

All your questions are answered here:

http://www.boeing.com/news/frontiers/archive/2004/february/i_history.html

It appears that the assignment of the first "7" in the model number was arbitrary to denote a jet transport. It appears that the last "7" in the model number was a marketing decision.

This is not out of line for Boeing, as the other piece of trivia is that for any given model number, there is a trailing dash and 3 digits. The trailing digits relate to the particular model series (100, 200, 300...) and airline for which the plane was manufactured. The 777-222 is a 777-200 delivered to United Airlines.
 
smigaldi said:
This was posted on another board. So I cannot vouch for it's accuracy


these latter aircraft have thrust reversers.
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All of the E-8s are former comercial 707's from various points around the globe. One even used to be a cattle hauler and still smells like one sometimes. IIRC they all have th JT3D w/TR. The E-3 however was built as an E-3 with a 707-320B airframe.
 
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