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Convair 880 / DC-8 Survivability/Longevity  
User currently offlineBlackbird From , joined Dec 1969, posts, RR:
Posted (7 years 5 months 1 day 9 hours ago) and read 9478 times:

Assuming the Convair 880 was not taken out of service in the 1970's due to the oil-crisis, etc... how would it's fuselage construction have faired in terms of longevity compared to the DC-8.

Andrea Kent
"Private Cowboy, Private Joker -- As soon as you finish your bunks, I want you two turds to clean the head: I want that head so sanitary and squared-away that the Virgin-Mary, herself, would be *PROUD* to go in there and take a dump!
-Gunnery Sergeant Hartman
Full-Metal Jacket (1987)

23 replies: All unread, jump to last
 
User currently offlineL-188 From United States of America, joined Jul 1999, 29832 posts, RR: 58
Reply 1, posted (7 years 5 months 1 day 6 hours ago) and read 9475 times:

Quoting Blackbird (Thread starter):
how would it's fuselage construction have faired in terms of longevity compared to the DC-8.

From what I have read about the aircraft longer then either Boeings and DC-8's.

There are are couple of legends of breakers having to delay parting out CV-880/990's because their tools wheren't strong enough for the job.



OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
User currently offlineSDF880 From United States of America, joined Apr 2007, 130 posts, RR: 0
Reply 2, posted (7 years 5 months 1 day 6 hours ago) and read 9472 times:

Plane was built like a tank! I remember a study to re-engine the parked Convairs,. Who knows, had that happened maybe the 880's would have lived on another 20 years or more? Maybe if the Convairs had JT3C's or even better JT3D's from the get go they might have lived on a bit longer. I don't remember the reason they stuck with the CJ-805's, maybe it was a ground clearance deal I don't know.

SDF880

[Edited 2007-07-21 08:26:36]

User currently offline411A From United States of America, joined Nov 2001, 1826 posts, RR: 8
Reply 3, posted (7 years 5 months 1 day 1 hour ago) and read 9443 times:

Sorry to disappoint those who apparently admire the CV880, but it was a disaster, from a successful program objective, from Convair.
It didn't need more power, it had aplenty, the problem was capacity and range...it simply didn't have these in large numbers together with economy of operation, compared to the Boeing products available at the time.
And, being built like a 'tank' is certainly not a particular virtue to be especially desired in a civil airliner.
These designs need to be constructed so that they are as light weight as possible, yet strong enough for the job intended.
The CV880 was fine as far as it went, but when the B727 came along, it was doomed to extinction.

I have friends who flew the 880 at Cathay Pacific.
All retired now, they look back fondly at the flying qualities of the airplane, but were quite happy to move onto the B707 when given the chance.
Why?

One simple reason...higher pay, together with longer nightstops, which produced additional pay in the form of superb perdiem.

Think of the CV880 as a sports car adaped for sedan use...the sedan built for the purpose is generally more successful.

By the way, the 880 used the same general arrangement for flight control surface assist that the 707 did...balance panels, a type of refined servo tab, which worked surprisingly well, all things considered.


User currently offlineBlackbird From , joined Dec 1969, posts, RR:
Reply 4, posted (7 years 5 months 18 hours ago) and read 9408 times:

411A,

I wasn't asking how it was from an economical standpoint... I know it sucked in that aspect. I'm just asking how it's structure would have faired in terms of longevity compared to the DC-8...

Andrea K


User currently offlineStarglider From Netherlands, joined Sep 2006, 679 posts, RR: 44
Reply 5, posted (7 years 4 months 4 weeks 1 day 17 hours ago) and read 9337 times:

Quoting Blackbird (Thread starter):
Assuming the Convair 880 was not taken out of service in the 1970's due to the oil-crisis, etc... how would it's fuselage construction have faired in terms of longevity compared to the DC-8.

In my opinion, both aircraft fit in the same category and are built like tanks but edging towards the DC-8 as the winner regarding durability. The 880 (and 990) if they were still in service would match the DC-8's ruggedness although not many were built. However, the DC-8 (especially the stretched 60 (70) series), is a more versatile aircraft (longer and larger diameter fuselage) and that is why it is still around in respectable numbers. The DC-8's fuselage is comprised of titanium anti-tear strips around each frame and window/door opening resulting in a fuselage of incredible strength and durability.


Starglider


User currently offlineBlackbird From , joined Dec 1969, posts, RR:
Reply 6, posted (7 years 4 months 4 weeks 1 day 16 hours ago) and read 9336 times:

Do you think the CV-880 fuselage if stretched would have retained it's incredible strength like the DC-8-60?

Just curious,
Andrea Kent


User currently offlineBoeing767mech From United States of America, joined Dec 2000, 1031 posts, RR: 3
Reply 7, posted (7 years 4 months 4 weeks 1 day 13 hours ago) and read 9321 times:

Strength ws never a problem with the CV880/990 the airframe was built damn near out of boiler plate. I was heard about a 990 and DC-9 that had a midair. Took 18 feet off the 990 and kept flying. The sad thing is the DC-9 went down with all on board lost. When I was will Team Convair we came across the repair blueprints for that airplane.

Quoting Blackbird (Reply 4):
I wasn't asking how it was from an economical standpoint...

Had the oil crisis not killed the 880 economical factors would have. Yes it was built like a tank. But is had bad ways of doing things on this airplane.
Boeing and everyone else design drain masts into the fuselage to deal with waste water from the galley and lav sinks, Convair didn't want to dirty up the airstream so they made the water drain into the belly of the airplane, causing corrision on the stringers and skin where the water collected, I saw this in every 880 I have seen in Mojave and Atlantic City.

Mechanics HATED this airplane. I talked to poeple that worked on them with TWA and told me stories of how you had to pull apart the whole panel just to get a gauge out for a Pilot write up. It have seen the maintainence manual on removing the bleed air shut of valve in the pylon. Talk about building around the part yo uwant to remove it was a nightmre.

TWA did look into a re-engine program for the 880, fitting it with JT3D's but never went off the drawing boards.

But the airplane was built tough it had smaller windows then Boeing and Douglas so there was less fatigue to the fuslage.

Another interesting thing is the 880/990 had a external longeron that ran from the forward cargo pit between the MLG bays and behind the aft cargo pit. I remember it being 5 inchs wide and 2 inchs thick at the thinnest part of the airplane. Now Boeing is putting this on the 787.

I miss my 880 but if we ever did get it flying again maintainence cost would have kill us.

David
Former Chief Mechanic
Team Convair 880 www.convairjets.com



Never under-estimate the predictably of stupidty
User currently offlineBlackbird From , joined Dec 1969, posts, RR:
Reply 8, posted (7 years 4 months 4 weeks 13 hours ago) and read 9261 times:

David,

I thought the CV-880's windows were based on the exact same size as the B-707. At least I remember reading that in a book regarding the CV-880 (by Jon Proctor)

Would a plane of DC-8 or 707-320 size if build with Convair-880 design characteristics... would it have been lighter than the DC-8 or 707 design (asking as the CV-880 was only 184,500 lbs fully loaded on the standard model which although smaller than the 707 or DC-8 weighed a MASSIVE amount less)

Could a plane have been built with the CV-880's technology that would have been less maintenance intensive (access-panels in the right parts so you wouldn't have to cut into the plane and weld the metalback with a doubler) yet have retained the basic strength?

Did the CV-880 use any serious design technology that was patented solely by Convair?


Andrea Kent

[Edited 2007-07-24 01:51:36]

User currently offlineBoeing767mech From United States of America, joined Dec 2000, 1031 posts, RR: 3
Reply 9, posted (7 years 4 months 3 weeks 6 days 13 hours ago) and read 9208 times:

Quoting Blackbird (Reply 8):


I thought the CV-880's windows were based on the exact same size as the B-707. At least I remember reading that in a book regarding the CV-880 (by Jon Proctor)

I tried fitting a window out of a Boeing airplane I think it was a 727 window and it didn't fit, as for a 707 window I don't know, I didn't try to fit one. So this statement maybe right.

Another question to ponder is if the CV990 would have been a better airplane had Convair gone with the JT3D-4 they had considered in a document I have outlining at the time the model 600 which became the CV990. Convair had big plans for the Convair jet line but had a love affair with the CJ-805, I have drawing of a 2 engine version(model 60) of the 880 that was going to go head to head with the 737 and they have 805-23's on the wings. Another drawing to go head to head with the DC-9 had aft fuselage mounted CJ-805-23's (model 61). Interesting things we found on in the desert when we tried to restore ship #23.

David



Never under-estimate the predictably of stupidty
User currently offlineBlackbird From , joined Dec 1969, posts, RR:
Reply 10, posted (7 years 4 months 3 weeks 6 days 12 hours ago) and read 9205 times:

Dear David,

If it would not be too much to ask, please send me these drawings at AVKent882@hotmail.com

Sincerely,
Andrea Kent


User currently offlineBoeing767mech From United States of America, joined Dec 2000, 1031 posts, RR: 3
Reply 11, posted (7 years 4 months 3 weeks 6 days 11 hours ago) and read 9199 times:

Quoting Blackbird (Reply 10):
Dear David,

If it would not be too much to ask, please send me these drawings at AVKent882@hotmail.com

Sincerely,
Andrea Kent

You have mail.

David



Never under-estimate the predictably of stupidty
User currently offlineBlackbird From , joined Dec 1969, posts, RR:
Reply 12, posted (7 years 4 months 3 weeks 5 days 21 hours ago) and read 9167 times:

Thank you very much,

Andrea K


User currently offlineSlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 68
Reply 13, posted (7 years 4 months 3 weeks 5 days 21 hours ago) and read 9161 times:

I've been told by two people, Poddy Mercer and someone at Ports of Call whose name I no longer remember, that the tube and the wings were of very pure aluminum and in the end the metal was worth more than the "seats" with Coors being the final owner of many airframes.

Mercer bought at least half a dozen Convairs from Delta I believe intending to operate them. This was about the same time as their DC-6 crash on the Sepulveda flood control basin which pretty well ended their operations. I have seen CV880s flying on Mercers certificate only a couple of times. Ports of Call and Modern Air were also among the last to fly them.



Happiness is not seeing another trite Ste. Maarten photo all week long.
User currently offlineRFields5421 From United States of America, joined Jul 2007, 7607 posts, RR: 32
Reply 14, posted (7 years 4 months 3 weeks 5 days 18 hours ago) and read 9135 times:

I have no idea if they would have continued in operation - but those were tough aircraft

I saw this one and it hit the ground HARD.

http://www.ntsb.gov/ntsb/brief.asp?ev_id=84705&key=0

I was totally surprised the fuselage stayed intact. It took a lot of work to cut it up and ship it out of the island.


User currently offlineBlackbird From , joined Dec 1969, posts, RR:
Reply 15, posted (7 years 4 months 3 weeks 5 days 13 hours ago) and read 9113 times:

Regarding the comment of it being made of highly pure aluminum alloy... was this something that Douglas or Boeing was not capable of achieving?

Andrea K


User currently offlineSlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 68
Reply 16, posted (7 years 4 months 3 weeks 5 days 12 hours ago) and read 9111 times:

Quoting Blackbird (Reply 15):
... was this something that Douglas or Boeing was not capable of achieving?

I don't know whether they used a different grade of sheetmetal or not. It was really a commentary on their being worth more as beer cans than as airplanes.

BTW the Coors metals division bought a lot of airplanes and their ceramics division that makes their bottles has a few other products as well. My wife has a mortar & pestle that was made by Coors.



Happiness is not seeing another trite Ste. Maarten photo all week long.
User currently offlineHangarRat From United States of America, joined Jul 2005, 633 posts, RR: 0
Reply 17, posted (7 years 4 months 3 weeks 5 days 11 hours ago) and read 9095 times:

Quoting Blackbird (Reply 10):
If it would not be too much to ask, please send me these drawings



Quoting Boeing767mech (Reply 11):
You have mail.

Any chance one of you could post them here? Thanks.



Spell check is a false dog
User currently offlineStarglider From Netherlands, joined Sep 2006, 679 posts, RR: 44
Reply 18, posted (7 years 4 months 3 weeks 5 days 4 hours ago) and read 9076 times:

Quoting SlamClick (Reply 13):
the tube and the wings were of very pure aluminum

I suppose you refer to an aluminum alloy here, alloy types ranging between 1xxx thru 8xxx (e.g. 2024 or 7075)? Pure aluminum is the softest and most corrosion resistant form of aluminum, but is not generally used in aircraft construction because it is not strong enough. The nearest to pure aluminum used in aircraft construction or maintenance would be 1100 alloy with at least 99% aluminum content. However, it can only be used in non-structural applications, such as fairings.


Regards,
Starglider


User currently offlineBlackbird From , joined Dec 1969, posts, RR:
Reply 19, posted (7 years 4 months 3 weeks 4 days 17 hours ago) and read 9040 times:

Hangar Rat,

Sure... here you go

Photo 1
CV-600/CV-990 - Three-Way View (CJ-805 powered)

Description: Photo depicts a particular CV-600/CV-990 variant being pitched as some sort of military-transport for the USAF. Fairings placed on one side of the rear-fuselage are to allow a swing-tail set up. The J-79 X-229 is the military designation of the CJ-805

Photo 2
CV-600/CV-990 - Three-Way View (JT3D powered)

Description: Photo depicts a particular CV-600/CV-990 variant being pitched as some sort of military-transport for the USAF. Fairings placed on one side of the rear-fuselage are to allow a swing-tail set up. The JT3D Pylon used is not all that much unlike the DC-8 design with the fan exhaust directed to the left and right side of the pod, but not over the top or bottom.

Photo 3
Convair Model-60 - Three-Way View

Description: Photo depicts a design-proposal for a scaled-down Convair-880 derivative known as the Model 60, which was conveived as a rival to the Boeing-737. The aircraft was to be powered by a pair of wing-mounted, aft-fanned CJ-805-23 turbofans and utilized virtually the same wing as the Convair-880M.

Photo 4
Convair Model-60 - Artist-Impression

Description: Photo depicts an artist's impression of the Convair Model-60 twin-jet design concept shown in an early Eastern-Airlines livery.

Photo 5
Convair Model-61 - Three-Way View

Description: Photo depicts a conceptual-design for a scaled-down, T-tailed Convair-880 derivative known as the Model-61, which was conceived as a rival to the Douglas DC-9. Aircraft featured rear-mounted aft-fanned CJ-805-23, and a modified Convair-880 wing.

Photo 6
Convair Model-61 - Artist-Impression

Description: Photo depicts an artist-impression of the T-tailed Convair Model-61 twin-jet concept in an early Eastern Airlines livery.



Starglider,

Why were the tubes made out of that particular form of Aluminum if it wasn't that sturdy?

Andrea Kent


User currently offlineStarglider From Netherlands, joined Sep 2006, 679 posts, RR: 44
Reply 20, posted (7 years 4 months 3 weeks 4 days 13 hours ago) and read 9016 times:

Quoting Blackbird (Reply 19):
Starglider,

Why were the tubes made out of that particular form of Aluminum if it wasn't that sturdy?

Andrea Kent

Actually i was stating the opposite. Pure aluminium is not used in aircraft construction, it is too weak. That is why aluminum is alloyed with other metals such as copper (2024) or zinc (7075) which are widely used in aircraft construction. The 1100 aluminum alloy (with at least 99% Al) i mentioned is not used in load bearing components either, it is used as fairing material and for non-load bearing components such as interior decoration.


Starglider


User currently offlineBlackbird From , joined Dec 1969, posts, RR:
Reply 21, posted (7 years 4 months 3 weeks 4 days 13 hours ago) and read 9015 times:

Then why would the wings and tube be made of pure aluminum? The wings are load-bearing...

Andrea K


User currently offlineSlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 68
Reply 22, posted (7 years 4 months 3 weeks 4 days 12 hours ago) and read 9013 times:

Quoting Blackbird (Reply 21):
Then why would the wings and tube be made of pure aluminum?

Nobody said that. Re-read my original post with those words. I'll highlight the key words:

Quoting SlamClick (Reply 13):

I've been told

by two people, Poddy Mercer and someone at Ports of Call whose name I no longer remember, that

the tube and the wings were of very pure aluminum

and in the end the metal was worth more than the "seats" with Coors being the final owner of many airframes.

Now Poddy Mercer is probably long dead and the other person unidentifiable so this statement of mine, though an interesting sidebar to the story, is not really a declarative statement.

Note also that "very pure" is an abstract sort of phrase which I deliberately used because it implies less purity than "pure" or "absolutely pure" would. I took Mr. Mercer' meaning to be that planes being constructed at that time (about 1978 or so) had less aluminum in their sheet metal than did the Convair 880/990 airframes that he owned.

I did not mean to imply that they were constructed of PURE aluminum. I'd always assumed that would have been undesirable for the reasons discussed in the posts above.

Sorry if I didn't make it sufficienty clear that I was relaying a couple of conversations that I had 25 and 29 years ago that were not terribly specific at the time. Most of us will do that in this forum, at least when we are imparting information that is something less than absolute.



Happiness is not seeing another trite Ste. Maarten photo all week long.
User currently offlineBlackbird From , joined Dec 1969, posts, RR:
Reply 23, posted (7 years 3 months 4 weeks 16 hours ago) and read 8764 times:

Was the DC-8 and CV-880 equally resistant to corrosion? If not, which was better?

Andrea Kent


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