cargo 707 down in Iran

[Old Boeing Driver]

That same line number, 21128/917 was shown to be in another accident in 2009 as EP-SHK
https://aviation-safety.net/database...?id=20090803-0
The Bureau of Aircraft Accidents said it was damaged beyond repair.
https://www.baaa-acro.com/crash/mishap-boeing-707-ahwaz

[tdracer]

Originally Posted by DaveReidUK

If it had been built on the 717 frame, you would certainly be able to tell the difference.

The (original) Boeing 717 was the model designation for initial variants of the C-135/KC-135 Stratolifter/Stratotanker. The E-3 is based on the 707.

Correct. The Boeing KC-135 civilian designation was 717 (something that was apparently lost on the idiots that were running Boeing after the Boeing/MacDac merger when they renamed the MD-95 but I digress). Several significant differences between the KC-135/717 and the 707 - the most significant being the fuselage (707 is somewhat larger in diameter).
All subsequent military variants where based on the 707 including the E-3 and E-8.

[Chronus]

There is some video footage on

You Tube

[Old Boeing Driver]

Meat?

Originally Posted by A Squared

Does 16 strike anyone else as a rather large crew for a cargo flight?

Not only that, but meat from Bishkek?
There is a picture of a rescuer/helper coming out of one of the 990 doors and there doesn't appear to be anything in the interior.

[megan]

Several significant differences between the KC-135/717 and the 707 - the most significant being the fuselage (707 is somewhat larger in diameter)

tdracer, perhaps you are in a position to confirm that the only similarity between the two aircraft is that they look similar. Have seen it written that structure is even built of a different grade metal, reflecting the difference between commercial and military requirements.

[matkat]

Originally Posted by tdracer

Correct. The Boeing KC-135 civilian designation was 717 (something that was apparently lost on the idiots that were running Boeing after the Boeing/MacDac merger when they renamed the MD-95 but I digress). Several significant differences between the KC-135/717 and the 707 - the most significant being the fuselage (707 is somewhat larger in diameter).
All subsequent military variants where based on the 707 including the E-3 and E-8.

I saw that happening did not know what was going on until it returned and saw the damage, like you I thought it was written off.

[DaveReidUK]

Originally Posted by matkat

I saw that happening did not know what was going on until it returned and saw the damage, like you I thought it was written off.

Presumably that's a reference to post #21, and not to the one that you quoted ?

[aterpster]

Originally Posted by jmelson

The E3 is supposed to be built on a 717 frame, but to the untrained eye, I could not spot the difference.

Jon

The 717 is a variant of the MD80-90 series.

[DaveReidUK]

Originally Posted by aterpster

The 717 is a variant of the MD80-90 series.

The "717-200" is the renamed MD-95, which has no relevance to this thread.

Nothing whatsoever to do with the original Boeing Model 717 (aka C-135/KC-135, see above), which is what the above few posts are discussing.

[Chu Chu]

I found the following paragraph in a National Materials Advisory Board report:

To minimize structural weight and thus maximize payload capability, the Air Force elected to use 7178-T6 aluminum in the lower wing skins as well as in other locations in the aircraft along with 7075-T6 aluminum. The commercial 707 used 2024-T3 aluminum in the lower wing skins at about two-thirds the stress level.

https://www.nap.edu/read/5917/chapter/6#87

[Airbubba]

Report and tweet from Babak Taghvaee that the accident 707 circled before making its fatal final approach:

Babak Taghvaee‏@BabakTaghvaee 14h14 hours ago

More

Before its landing in Fat'h heliport of #IRGC instead of #Payam Intl Airport, the #IranAirForce's Boeing 707-3J9C with EP-CPP register circled over #Karaj several times & then had a sharp descend which wondered everyone. This is the video of the EP-CPP before its accident.

https://twitter.com/BabakTaghvaee/status/1085105619353382912

[tdracer]

Originally Posted by megan

tdracer, perhaps you are in a position to confirm that the only similarity between the two aircraft is that they look similar. Have seen it written that structure is even built of a different grade metal, reflecting the difference between commercial and military requirements.

My memory is a bit fuzzy on the subject, but I'll try .
I do know it's a popular myth that the 707 is just a civilian version of the KC-135 and that gave Boeing a big commercial advantage in that the USAF paid for the 707 development - the reality is far more complex. The KC-135 derived directly from the "Dash 80" prototype - which Boeing developed on their own, paid for out of Boeing's pocket. The cost of the Dash 80 development was more than the net worth of Boeing at the time - hence the line "they bet the company" on the Dash 80 was literally true - but it worked and the USAF launched the KC-135 program.
At about the same time Boeing launched the 707, Douglas launched the DC-8 - which had a wide enough fuselage for six across seating - something the Dash 80/KC-135 didn't allow. So Boeing completely changed to fuselage to also allow six abreast seating. The flight deck layout was different on the 707 - the wing layout and structure was pretty much the same, and the original engines were pretty much the same. But that was only for very first 707s. Things were evolving quickly, and by the time they got to the turbofan powered 707-320 (the most common version), there were very few parts common with the KC-135 - even the wing shape was different.

[megan]

To both Chu Chu and tdracer, thanks for the input. I found on the Boeing site they had this to say,

The Dash 80 prototype led to the commercial 707 and the military KC-135 tanker. Both planes shared the basic design of the Dash 80 but were very different airplanes, neither one being a derivative of the other.

Elsewhere I found that the only thing they shared was the basic wing box.

https://www.nationalcoldwarexhibitio...-stratotanker/

[CONSO]

Originally Posted by Chu Chu

I found the following paragraph in a National Materials Advisory Board report:

To minimize structural weight and thus maximize payload capability, the Air Force elected to use 7178-T6 aluminum in the lower wing skins as well as in other locations in the aircraft along with 7075-T6 aluminum. The commercial 707 used 2024-T3 aluminum in the lower wing skins at about two-thirds the stress level.

https://www.nap.edu/read/5917/chapter/6#87

And a bit more - some of the KC fuselage skins were spot welded- but later replace due to fatigue issues early on, and at one time a ' laminate" of aluminum and ' cold BONDING of aluminum was used- later found to cause problems due to entrapment of moisture- it was the late 60's before the COLDWORK process was developed (which involved prestressing the fastener holes via a disposable sleeve and an expansion mandrel pulled thru ) the inventor was Lou Champoux ( sat next to me in the 60's ) working with a local vendor later to become Fatigue technology . There is often confusion between the cold BONDING process, and the coldWORKING process.

And a lot of the tooling for the KC135 was also used for 707- and vice versa via a complicated lease arrangement...

[DaveReidUK]

Originally Posted by tdracer

So Boeing completely changed to fuselage to also allow six abreast seating.

Which directly led to the most obvious external difference between the two aircraft: the 707 has what became the classic Boeing double-bubble; the C-135/KC-135 has what appears to be a circular fuselage cross-section (it isn't, in fact, but there's no visible demarcation between the upper and lower lobe).

[aterpster]

Originally Posted by DaveReidUK

The "717-200" is the renamed MD-95, which has no relevance to this thread.

Nothing whatsoever to do with the original Boeing Model 717 (aka C-135/KC-135, see above), which is what the above few posts are discussing.

Glad you clarified that.

[NWA SLF]

Dash 80 132 inch fuselage, KC-135 144 inch, 707 148 inch. Is the reason such different planes can't be put into production in such short time today due to tooling cost, regulations, or something else? My family has an engineering history. I asked a cousin of my father's why he guided his son on a business career instead of engineering. He said no loyalty in the engineering business. Started with Boeing after graduating in the late 40's, worked on those jets and more until '71 and the end of the 2707, then axed. Retired as a contract engineer for Northrup working on the B-2 and returned to the Puget Sound area but remained bitter about Boeing.

[flash8]

Who does their heavy checks?