Decomposing Behemoth; The Convair XC-99 

Give a six year old a ruler and an A3 sheet of paper, ask him/her to draw "a really big airplane", and the child will unfailingly draw an XC-99.

I swear, even if I watched a plane video every single day until the day I die, with my last breath I'd be muttering "wow, never heard of that one".

This plane had an incredibly successful service life for a prototype. Its a tribute to the expertise of the Convair design team that they could get it so right on the first version. It was also interesting to see the evolution of the landing gear during its development. Correct me if I'm wrong, but I believe the multi-wheel under carriage was pioneered on this plane, a truly ground breaking achievment.

I saw this aircraft for the first time in 1974. I was in tech school at Lackland AFB and ran across the 99 while driving around one day. It was just sitting there by itself with nothing around it. I walked around it for over an hour since I was always an aviation buff. I went back to San Antonio several times in my career and I always went back to visit the 99. It was sad to watch it rotting away all by itself.

The B36 was indeed insanely cool. I love how strange the XC-99 looks. The ‘40s-‘60s were such an entertaining time in aviation designs. Wonder if we’ll ever see something like it again.

My uncle who was in the USAF in the Korean War and for a couple years afterward, said that every time the XC-99 flew, every nut, bolt, and rivet, had to be checked to make sure they were tight. This was due to the vibration from the Wasp Major engines. The crew chiefs at Wright-Patterson told him that the plane was a maintenance nightmare because of that. Combine that with the difficult maintenance of the Wasp Major engines themselves, and you can see what a headache it could be to service this plane.

Sometime around 1974/1975 my mom stopped on our way to Lackland AFB (that sat alongside Kelly AFB) and paid to let me go inside the XC-99. I walked around unsupervised and explored. If I recall, mainly the cockpit area.

Never heard of that plane! I also never heard of a single prototype having such an impressive operational record.

I purchased the movie "Strategic Air Command" on Blu-ray just so I could watch the gorgeous footage of the B-36 and B-47. I still can't believe a plane that darn large was able to fly. It must have been an amazing sight to behold.

It’s really heartbreaking when rare historical artifacts are allowed to degrade to the point that they can no longer be preserved.

The solution isn't to house the XC-99 in a museum-it's to house a museum in the XC-99.

At least the XC99 made it into service and proved that air transport in large quantities was a viable option to the usual sea voyages that were necessary to transport oversized item, and tbh it isn’t a bad looking aircraft either, it was the right aircraft but, as with many prototypes, it was the wrong time for it, as was the Bristol Brabasson, I don’t know how they matched up to each other but they were certainly BIG. Thanks for another excellent article Ed, and as I learned something new today my day has not been wasted, very interesting, informative and BIG. I wow posted onto the Hercules C-130 in the late 80s until after the first Gulf War, and I enjoyed every minute of it, even during the gulf war when we were working 12 hour shifts (officially, but usually more like 14-15) to turn around aircraft from planned maintenance so they could get back to the job they were designed for, carrying stuff. Anyway I digress, thanks again Ed, thumbs up as usual. 😀👍🇬🇧🏴󠁧󠁢󠁥󠁮󠁧󠁿🇺🇸🇺🇦

This aircraft is like an old friend to me. I grew up and still live in San Antonio, TX where the XC-99 was parked on display just to the West of the main runway of Kelly AFB. It was billed as the "Largest land-based airplane in the world" in my youth. My family visited it many times and I even have a picture of me sitting in the pilot's seat (well, co-pilot on the right) at the age of 5. That was 1958! I'm 71 now and was saddened when it was taken apart and hauled away. Thanks for bringing us her history.

I would argue its direct rival (and equally forgotten) was the double-deck Lockheed R6V Constitution, two made and pressed into service by the US Navy.

I grew up in San Antonio,every time we passed Kelly AFB we could see it,what a shame to see it unrestored

I toured in in 1971 when I was 12. It was a wonderland to me. It was quite a trek up the steps to the tip of the tail. The cockpit seemed to be as big as my bedroom. I got to walk inside one of the wings.

Back in 97 I was at Kelly AFB. I just happened to climb out of the top hat of a C-5 and photographed the XC-99. Shot in a million.

Back in the 1980s, the XC99 was parked in a field across from Kelly AFB. I used to give tours thru that plane! Wish I had pictures. There was this one time a C-5 was getting ready to take off, and the taxiway was right across a fence for the XC99. They looked like a young bull facing off an old one!

You know what this reminds me of? Popular Mechanics/Science artwork of future planes from this period. It has this unbelievable air to it, but its lines are sleek while sort of being...vague? Like it was the 1930's/40's idea of a super-aircraft that came to life from a artist's rendition rather than concrete plans/blueprints.

I took several slide photos of the XC-99 back in the 1980s when the aircraft was still on display at Kelly AFB, San Antonio, TX. It is to be hoped this one-of-a-kind aircraft can somehow be restored to static display. Thanks for sharing this in-depth story on the XC-99!

This plane was parked in a grass field at Kelly AFB IN San Antonio for many years. I walked around it in the 1980s when I heard it was located here. Huge aircraft! I understand it's located at the aircraft storage facility by Davis-Monthan AFB just south of Tucson, Arizona.

I think you mean 4360 not 4340 engines, but still one of the best aviation presenters on Utube.

When I was in Air Force basic training in 1982, I remember this husk at the end of the runway. A couple of decades ago when The Air Museum decided to break it up for restoration, I looked forward to seeing it at least looking like it had in it's glory days. Not sure if will ever reach that now.

Thank you for this. Being a native of San Diego California I remember my mom and uncle’s would take about seeing the B-36 and XC-99 flying around

It was good to see all the vintage videos of this aircraft that I originally posted on RU-vid. The C-99 and the B-36 were designed as a means of taking troops, material and bombing missions to the war with Germany by bypassing the "wolf packs" of German U-Boats in the Atlantic.

Thanks! My father got to fly in this plane once when he was stations in San Antonio, Texas. He said initially they had problems with the fuselage skin "wrinkling" from the stresses each time it was flown. Apparently that issue was worked out. Always enjoy your videos Ed.

Ed, you need to visit the USAF museum in Dayton, Ohio. Stay in Yellow Springs, Ohio and plan about a three day visit at the museum. The museum is massive and packed full of aircraft.

Pan Am not only ordered the Convair 37 but they published in 1946 a Route Map with a fold out front page cover art of a globe circling fleet of the their planes (and evolution) over the years. The latest DC-7 and Constellation are being led into the future by a massive, double decker C-37 in beautiful Blue White and Silver. Ah, the things that might have been!

This was a truly new one on me! This is the first time I have ever heard of the XC-99 and its impressive history.

I grew up near McClellan Air Force Base in the Sacramento area and it was a major repair site for the West Coast. I can remember hearing the XC 99 when it was coming into the base. It had a distinctive sound with six engines. You could hear it long before you could see it. This was in the 1950s and 60s. It seemed like some kind of alien craft!

I was able to see this aircraft twice, once at Kelly AFB, then in pieces at Wright-Pat. I was able to explore the parts, as it was a Sunday and the place was about deserted. It was stored on the active side of the base, outside the restoration hanger. It was amazing ro stand in the nose gear bay, and see everything there. Sneaking around was also kinda fun. Its in sad shape though. I doubt anyone would have a chance to explore it like I did now it's at DM, probably much more restricted access.

Thank you very much! What an incredible service life for a prototype aircraft. You filled in many details of its success and ultimately its fate.

Great backgrounds of San Diego in the late 40s early 50s. Great story of a forgotten plane!! Thanks.

There's a B-36 on display at the Museum of the USAF in Dayton. They have the single wheel landing gear on display. It's massive. The reason they switched to the bicycle landing gear from the single wheel is because the single wheel would tear up the runway concrete when it landed. The bicycle format allowed them to spread its weight. This is the first time I heard that this plane was economical to fly. When Pan Am looked at the operating costs of a transatlantic variant, they didn't walk away, they ran. A spark plug change meant swapping out 356 spark plugs. It gobbled oil. The Wasp Major engines had a prodigious appetite for lubricating oil; each engine required a dedicated 100-gal tank and there were 6 engines. The engines were unreliable and liked to catch fire. The parent craft it was designed from, the B-36, had an aircraft's slogan which was originally "six turning, four burning" into "two turning, two burning, two smoking, two choking and two more unaccounted for. Both aircraft used the same Wasp engines. Somewhere around 2010 the XC-99 was disassembled and moved to the National Museum of the USAF in Dayton. I talked to a volunteer who worked there, and he told me they were working on restoring the Memphis Belle and had no idea when or even if they'll get to the Xc-99. He said when they took it apart the damage from being in the sun and the corrosion caused by residual fuel in the wings meant a restoration was going to be an expensive and time-consuming project. Wikipedia -> It was subsequently transported in the summer of 2012 to Davis-Monthan AFB and is stored in Area 20 of the 309 AMARG complex, the so-called "Boneyard", pending financial resources sufficient to restore the aircraft and return it to NMUSAF for display.

This plane has always fascinated me. Probably because the B-36 was not exactly small, but also because there is not a lot of info on it. I wonder if they had some of the same engine/cooling/icing challenges as with the B-36. Thank you for doing this one!

For having such a useful service life, it’s amazing that there was only one. I don’t mean to say that there should have been 50 of the things, but you’d think that there would have been work enough for half a dozen of them.

I grew up in the 1950s near a SAC base. B-36s were often seen in their landing pattern. Sometimes flying in a formation of 3 bombers. I never saw anything as huge until The C-5.

The XC99 was sold for scrap when it was taken out of service. The gentleman that purchased it towed it from Kelly AFB to a lot across from the base where it sat for many, many years. The plane was opened to the public and people were allowed onboard for a small fee. I saw this airplane quite often as I lived on the Southside of San Antonio, Texas very near it's parking place and i passed by it weekly. The owner stopped allowing people from entering the aircraft probably in the 70's and it sat sealed up for many more years. The last I saw and heard about it it was towed from it's location back onto Kelly AFB where it was to be restored to a static display. I have pictures of it sitting in the field. Sad end to a mighty aircraft.

Back in the 60's, my father would take us out for the day and this would become my play ground. I spent many a day with friends and cousins running down the cargo decks and in the cockpit of this of this historic aircraft. As mentioned, it sat across the street form the main runway at Kelly AFB in San Antonio. One of it's unique features were several bubbled out window in the fuselage along the lower cargo deck. I believe it was a feature for aircrews to inspect the engines and lower portion of the aircraft during flight. For us kids, it was a way to be suspended over mid-air and a place to go during games of hide & seek. I remember them moving it to a part of Kelly near Hwy 90 where it sat for a very long time before being dismantled and shipped away. I hope some day one of the many billionaires are country has created sees a need to restore this aircraft for future children to enjoy. It served it's country and it served many kids and families as a static display back in the day. Rest well old girl....

As a kid, I remember my dad taking me to see the XC-99 outside of what was then Kelly AFB. It was a site to behold! Absolutely gargantuan!

Back in the mid to late 60's, my dad would take me and my sister out to the XC-99 static display, on Growdon Road, between Kelly AFB and Lackland AFB, on the southwest side of San Antonio, TX. For a really small fee, you could take a self-guided tour of the inside of the aircraft. You could just stand outside and take photos for free. No matter how many times a year we would go out to see the aircraft, it was always a marvel to this young elementary school boy! I'm 65 years old now, but the memories of seeing that aircraft have stayed with me all these many decades.

I saw this XC-99 when it was on static display on a road between Lackland and Kelly AFB's. Thanks for providing a lot of details about it's service life.

Breaks my heart that this plane still exists but they will display her. She resides at the Air Force Museum in Ohio. I have asked for access to see it but was declined. Would love to see it one day before I’m gone. Truly a one of a kind rare bird.

I went inside that beast in 1967. It was parked in a field south of Hwy 90 W between Kelly AFB and Lackland AFB in San Antonio, Texas. It was just sitting there and anybody could go inside of it. It was amazing! It was so big! I remember it well.

The single tires mains in BOTH B-36/XC-99 were found to have such high ground pressure that initially there were ONLY THREE RUNWAYS that could take them. BOTH were quickly refitted with the quad tire mains.

I seem to recall that the XC99 flew a total of about 9000 hrs, and then a crack was found in the spar of one wing. At that point the Airforce decided to park it rather than fix it.

My dad loved this plane. When I use to live on Kelly and SA you could see it every day (when you weren't distracted by the shuttle). Shame to hear what happened to it.

David R Lentz, Columbus, Ohio, USA (Saturday, 6 July, 2024) I have not forgotten either: the Convair XC-99 USAF Super Heavy Transport: the younger fraternal twin brother of the Convair B-36 Peacemaker USAF Super Heavy Bomber B-36: 186 ft long, 230 ft wingspan, bomb capacity XC-99: 206 ft long, 230 ft wingspan, load capacity

That shot of the man walking out onto the horizontal stabilizer was profound even if it was only a few seconds. 😮

As a young’n I got to go aboard of an XC-99 on static display at Kelly A.F.B , a truly awesome aircraft

In case anyone wants to see it on google maps it's near the intersection of Yuma St and S Kolb Road in Tucsan, Arizona. There is a map marker that reads: "Convair XC-99 Remains" - I thought it was a series of building at first. It's big.

Never heard of it! I was thinking it was going to be another one-off prototype that never went anywhere and then Nash just keeps rolling with the service history of an absolute unit of a transport! That shot at 10:36 of it absolutely DWARFING a squadron of B-29's was hilarious!

As I was researching this aircraft only earlier this week, this video was a great insight into its career.

I was at Kelly AFB in the early 80s and I walked around that beautiful plane many times. It was a real work of flyable art; it was simply amazing to be that "up close and personal" with it.

It would have been VERY interesting to have seen a mash up of the YB60 and the XC99!A truly massive early jet transport...Great video Ed,Thanks!

I find it ironic that the B-36 bombers were a maintenance nightmare, had to have jet engines fitted to help with take offs when fully loaded with weapons, and seemed to always be on the brink of breakdown. And then this beast just, worked as intended and then some. Yes, it does help that it had upgrades to better engines and such over its short life, but it stayed busy with what seems to be little fuss. The fact it was able to just work with that much magnesium in its air frame and that much use is also surprising. I think it is a rather good looking aircraft to boot.

The XC-99 used to pass over my house when it was en route to a nearby Air Force base. We always knew it was the XC-99 because the dishes , and anything mounted to a wall, started buzzing/vibrating. This was also at a time when fighter jocks were creating sonic booms on a daily basis. Civilian complaints put an end to the sonic booms. I saw the XC-99 in the 70s at Kelly AFB and it was in bad condition wasting away.

I used to run by this aircraft as a 2LT when it was parked at Kelly Field in San Antonio. Thanks for the video.

Ed ALWAYS does a FANTASTIC job with his videos. Well researched, great writing, and excellent visuals to make a top notch presentation. Thanks!!!

I remember it on display at Kelly AFB in the early 70's, it was magnificient.

I’ve never heard of this plane before! Great find!

I remember seeing this plane when it was on static display and I was in basic training in 1966 at Lackland AFB.

I was given a tour of the XC-99 sections after they arrived at the Air Force Museum - much of the exterior green with algae from sitting at Kelly for so long. I noticed another possible problem with restoration - the fuselage shell had been held together lengthwise with dozens of cables and turnbuckles, now loose and unconnected. An unusual design and amazing feat of engineering, but I don’t envy whoever has to put it back together.

Ed, you always publish very interesting content. Thank you.

I read somewhere that the 99 was taken out of service as the structure was adjudged to be near the end of its service life. Much sooner than expected and making it uneconomical to make any more of them.

When I was in Air Force field training in San Antonio the mid 90's, I remember seeing this thing abandoned at the end of the runway.

I love this plane, and am so excited to see a video on this unloved giant

Picture at 11:03. I’m in that photo. I was stationed at KELLY AFB, 2954 CLSS when we pulled out of the field and back onto base.

i remember walking around that plane near Kelly AFB, TX in 1980 on weekend leave when I was in OCS before I entered pilot training at LAFB about 200 miles due west! It was off to the west end of as very large grass field nestled against a tree line.

Imagine if we in the UK had a Bristol Brabazon to walk around and through ... these aircraft might be White Elephants but all of them are very preciouse

Great video sir, as usual you do an amazing job in research and produciton….

Excellent Ed thanks

Wow, I never noticed that the engine air/cooling/turbo inlet ducts changed shape the further outboard you went on the wing. That's pretty incredible - shows the lengths they went to with NACA and wind tunnel testing even 3/4 of a century ago.

One of my favorite birds. Well done Ed!👍

I believe that the MUSAF at Wright Patterson has one of those original single wheels on display there. For an aircraft, it's huge. According to the information placard, the plane would sink into the tarmac due to poor weight distribution. The reason they changed the landing gesr to multiple wheeled gear.

A video on the YB-60 would also be appreciated.

Thanks Ed , I believe many of us knew little to nothing about this aircraft. Learned something new today! Impressive aircraft even by today’s standards. Would have been a great airliner.

Much like the SS United States liner, it is not considered important enough to be called a “National Treasure”

No in flight refueling because there was no demand for it. Beats head on desk.

pumping out the content Ed well done

My dad worked at Lackland AFB, which back then, butted up against Kelly AFB. One Saturday my brothers and I went with dad to the Kelly Golf course. Afterwards, for sum of $1 each, we got to climb into the XC-99’s flight deck and sit at the controls. This was after she was taken out of service and moved “off base.” It was quite an experience. Too bad it’s deteriorating in the boneyard. She was some kind of bird.

When we were out in California when Dad was recalled to active duty for the Korean War, he took my mom and I to Oakland Naval Air Station (Now Oakland International) to see the C-99 on the ramp. It was massive! For a 5-year old kid, it was an inspiring sight!

I didn't know the USAF would just take a test model and put it into service without even taking off the "X" from the designation.

Never heard of this one, mind you, I could say that about most of the planes you cover. Outstanding

a great fantastic very interesting video and aircraft Mr.Ed.have a good one.

I remember seeing this plane at San Antonio (former Kelly AFB, next to Lackland AFB) in 1998.

You were correct, Mr. Nash. Very obscure, nicely done.

My Dad and his Navy anti submarine squadron flew from San Diego to Quonset Point Rhode Island on this aircraft. They had just rounded Cape Horn on the USS Oriskany. Considering this was the prototype and no production aircraft were built, it’s amazing how many real life missions it completely.

As a retired USAF C-5 pilot and seeing this aircraft on Kelly AFB for may years, what an amazing aircraft. I hope it can be restored...

Great video. P.S Could you please make a video on the Brabazon?

retired USAF, 1980 -83 daily drive from Kelly AFB to Lackland AFB passed XC 99 impressive acft. disassembled and now at Davis -Monthan AFB Arizona. former reciprocating engine aircraft crew chief

The US Navy was considered in case England was invaded and we had no bases close to Europe, but this was also the height of U-boat action in the Atlantic. The government feared losing its carriers to torpedo attacks. This was a big reason for the Lend-lease act, (including giving old WWI destroyers to England in exchange for bases in the Caribbean and other locations), which was mainly to keep England an ally with the US for when we would enter the war. Better later than never. The main contributing factor by the US wasn't its military power, though substantial, but its ability to produce weapons, aircraft, ships, and supplies in such quantities in such a short time. Manpower was helpful, supplies were essential. IMHO.

I used to play in it when I was a kid.

I went with my parents to San Antonio Texas in 1968, my dad for work but also a bit of a vacation (and maybe possibly a new job?) We went to the Hemisphere World's Fair (saw Louis Armstrong play) but somehow, I don't know how I was walking around Kelly AFB - I was a 12 yo kid - and saw this behemoth sitting out there by itself, I was enthralled. The usual story for planes like this is that it would pass all the tests and the government was ready to place an order but then technology evolved, this one, to my surprise actually had a short, but reasonably productive life. Thanks for filling me in.

We went through it in San Antonio early ‘60’s.

Only one ever built, but used actively for years.

You learn something every day.

I live in Tucson. I didn't know it was here. I'll keep an eye out, but I'm not active duty, so I have no pull to get on base. DMAFB 86'ed AMARG tours last year. Didn't notice any at PASM this January. If the external skin were replaced with aluminum panels, where the rotting magnesium was, would it still be an XC-99? I know the manpower costs would be astronomic, let alone the Alcoa bill, but the Spirit of Ft Worth is testament to the power of volunteerism. And that B-36 still exists on the line at Pima Air & Space Museum. [And we're wondering if a lot of clapped out B-36s didn't already get turned into those 4'' Survival Kit Magnesium bars with Ferrocerium strikers?]

Excellent! 3:57 Ocean Beach to the south, Mission Bay to the north and no I-5 freeway.

“Never heard of this plane” is what I feel is the reason they have not restored her. She simply won’t bring in the visitors than say, the Swoose, etc.