Editing Convair XC-99

{{Short description|American prototype cargo plane (1949–57)}}
<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. -->
{{Infobox aircraft
 |name = XC-99
 |image = File:Convair XC-99 in flight c1948.jpg
 |caption = The sole prototype XC-99 off [[La Jolla]] in its early days of operation, before fitment of a nose [[radome]] and four-wheel main gear bogies
 |type = Heavy transport
 |national_origin = United States
 |manufacturer = [[Convair]]
 |designer =
 |first_flight = 24 November 1947<ref>Associated Press, "400-Troop Plane Takes First Hop", ''The Spokesman-Review'', Spokane, Washington, Monday 24 November 1947, Volume 65, Number 194, page 1.</ref>
 |introduction = 26 May 1949
 |retired = 1957
 |produced =
 |number_built = 1
 |status = Canceled
 |unit cost =
 |primary_user = [[United States Air Force]]
 |more_users =
 |developed_from = [[Convair B-36 Peacemaker]]
 |variants =
 |sole example of type?= Y
 |other_names = 
 |construction_number =
 |construction_date = 
 |civil_registration = 
 |military_serial = 43-52436
 |radio_code = <!-- military radio codes where this is a commonly used way of identifying this aircraft (e.g. US, British, and German military aircraft of World War II) -->
 |owners = <!-- listed above -->
 |in_service = 
 |flights = 
 |total_hours = 7,400 hours
 |total_distance = 
 |fate = 
 |preservation = [[Davis Monthan AFB]]{{cn|date=April 2025}}
}}

The '''Convair XC-99''', AF Ser. No. ''43-52436'', is a prototype heavy [[cargo aircraft]] built by [[Convair]] for the [[United States Air Force]]. It was the largest piston-engined land-based transport aircraft ever built, and was developed from the [[Convair B-36 Peacemaker]] bomber, sharing the wings and some other structures with it. The first flight was on 24 November 1947 in [[San Diego, California]], and after testing it was delivered to the Air Force on 26 May 1949.<ref name="Jacobsen & Wagner 1980 p41">Jacobsen & Wagner 1980, p. 41.</ref>  The '''Convair Model 37''' was a planned civil passenger variant based on the XC-99 but was not built.

==Design and development==
Design capacity of the XC-99 was {{convert|100000|lb|kg|abbr=on|-3}} of cargo or 400 fully equipped soldiers on its [[double-deck aircraft|double cargo decks]]. A cargo lift was installed for easier loading. The engines face rearward in a [[pusher configuration]].

===Planned civil passenger variant===
The Convair Model 37 was a large civil passenger design derived from the XC-99 but was never built. The Model 37 was to be of similar proportions to the XC-99; {{convert|182|ft|6|in|m|abbr=on}} length, {{convert|230|ft|m|abbr=on}} wingspan, and a high-capacity, double-deck fuselage. The projected passenger load was to be 204, with an effective range of {{convert|4200|mi|km|abbr=on}}.

Fifteen aircraft were ordered by [[Pan American Airways]] for transatlantic service. However, the fuel and oil consumption of the six {{convert|3500|hp|kW|abbr=on}} Wasp Major radials powering the XC-99 and B-36 meant that the design was not economically viable, and the hoped-for [[turboprop]] powerplants did not materialize fast enough. The low number of orders was not sufficient to initiate production, and the project was abandoned.

==Operational history==
[[File:Convair XC-99 and B-36B in flight c1949.jpg|thumb|right|The XC-99 in flight with a B-36B]]
[[File:XC-99.png|thumb|right|The XC-99 landing during flight test trial]]

In July 1950, the XC-99 flew its first cargo mission, "Operation Elephant." It transported {{convert|101266|lb|kg}} of cargo, including engines and propellers for the B-36, from [[San Diego]] to [[Kelly Field Annex|Kelly Air Force Base]] in [[San Antonio, Texas]], a record it would later break when it lifted {{convert|104000|lb|kg|abbr=on|-2}} from an airfield at {{convert|5000|ft|m|abbr=on}} elevation. In 1951, the aircraft was retrofitted with 3,800hp Pratt & Whitney R-4360-53 engines, landing gear was strengthened and a cargo-loading system installed, including an internal elevator. Bins were developed to enable quick loading of the aircraft - it was estimated the aircraft could be loaded in as little as 30 minutes.<ref>{{cite journal|journal=Aviation Week|date=16 August 1954 |title=Airlift Helps AMC Cut Logistics Knots |url=https://archive.aviationweek.com/issue/19540816|page=140|volume=61|number=7|issn=0005-2175}}</ref>

In August 1953, the XC-99 would make its longest flight, {{convert|12000|mi|km|abbr=on|-3}}, to [[Rhein-Main Air Base]], [[Germany]], by way of [[Kindley Air Force Base]], [[Bermuda]] and [[Lajes Field]] in the [[Azores]]. It carried more than {{convert|60000|lb|kg|abbr=on|-3}} each way. It attracted much attention everywhere it flew. The US Air Force determined that it had no need for such a large, long-range transport at that time, and no more were ordered. The sole XC-99 served until 1957, including much use during the [[Korean War]]. It made twice weekly trips from Kelly AFB to the aircraft depot at [[McClellan Air Force Base]], [[California]], transporting supplies and parts for the B-36 bomber while returning by way of other bases or depots making pick-ups and deliveries along the way.

==Retirement and preservation==
[[File:1700 ATG Convair XC-99 1954.jpg|thumb|XC-99 at [[Kelly AFB]], Texas while attached to the [[Military Air Transport Service]] [[1700th Air Transport Group]], 1954. Note San Antonio Air Materiel Area (SAAMA) tail marking, indicating the aircraft was assigned to the [[Air Materiel Command]].]]

The aircraft was put on display at Kelly AFB near [[San Antonio]], [[Texas]], in 1957. Deterioration of the airframe due to the high [[magnesium]] content was beyond local abilities to address. The aircraft was later moved to a grassy field near the base and in 1993 the USAF moved it back to the Kelly AFB.  In 1995, Kelly AFB was identified for closure via [[Base Realignment and Closure|BRAC]], although some portions would remain under USAF control as the [[Kelly Field Annex]] to adjacent [[Lackland AFB]], it was deemed that a new location be identified for the XC-99.

Disassembly of the aircraft began at Kelly Field in April 2004 and the airframe was moved in pieces from Kelly to the [[National Museum of the United States Air Force]] (NMUSAF) at Wright-Patterson Air Force Base.<ref name="AFL04">{{cite web|last1=Hill|first1=Bruce R. Jr.|title=XC-99 begins piece-by-piece trip to Air Force Museum|url=https://www.af.mil/News/Article-Display/Article/137090/xc-99-begins-piece-by-piece-trip-to-air-force-museum/|website=U.S. Air Force Official Website|access-date=21 April 2016}}</ref> By the summer of 2008, the transfer was complete and the parts were lying outside the museum.<ref name="location">[http://wikimapia.org/21679451/Convair-XC-99-Dismantled "XC-99 Disassembled."] ''Wikimapia.'' Retrieved: 2 November 2011.</ref> The aircraft had continued to suffer additional corrosion during its years in Texas and was found to be in worse condition than expected, with the restoration task being beyond the resources of the museum in a realistic time scale. Some major components such as the wing spar would need to be completely replaced.

The NMUSAF's plans for the restoration and display of the XC-99 are displayed in a case with a 1:72 scale model made by Lt Col Howard T. Meek, USAF (Ret).<ref name="Model">[https://web.archive.org/web/20141019030526/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=13628 "Factsheet: Convair XC-99 Model."] National Museum of the United States Air Force. Retrieved: 9 July 2017. (see subsection: [[#Current situation|Current situation]])
</ref>

In an effort to preserve the aircraft for future restoration, the XC-99 was later moved incrementally to the [[309th Aerospace Maintenance and Regeneration Group]] (309 AMARG) storage facility at [[Davis–Monthan Air Force Base]], in [[Tucson, Arizona]], where it will remain, in an area containing other aircraft belonging to the NMUSAF until the museum is able to restore it.<ref name="location"/> In 2014, [[Lieutenant General]] [[John L. Hudson]], [[USAF]] (Ret), director of the NMUSAF said that there would be insufficient resources for restoration for the foreseeable future.<ref name="flightjournal.com">Dorr, [http://www.flightjournal.com/blog/2014/11/19/aviation-insider-a-tale-of-the-times/ "We’ll lose the XC-99 and it won’t be alone"]</ref>

===Current location of the aircraft===
*XC-99, AF Ser. No. ''43-52436'' is now part of the National Museum of the United States Air Force collection at Wright-Patterson AFB. The aircraft was disassembled at Kelly AFB, Texas and its sections transported to NMUSAF for anti-corrosion preservation and reassembly there.<ref name="Goleta">Lockett, Brian. [http://www.air-and-space.com/xc99.htm "Convair XC-99 and Model 37."] ''Goleta Air and Space Museum'' via ''air-and-space.com'', 19 February 2011. Retrieved: 2 November 2011.</ref><ref>{{cite news |last1=Hill |first1=Bruce R. |title=XC-99 begins piece-by-piece trip to Air Force Museum |url=https://www.af.mil/News/Article-Display/Article/137090/xc-99-begins-piece-by-piece-trip-to-air-force-museum/ |access-date=9 July 2018 |work=U.S. Air Force |date=22 April 2004}}</ref> 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.{{cn|date=December 2021}}

==Specifications (XC-99)==
[[File:Convair XC-99 3-view line drawing.png|thumb|3-view line drawing of the Convair XC-99]]
{{Aircraft specs
|ref=''General Dynamics Aircraft and their Predecessors''<ref name="Wegg p98">Wegg 1990, p. 98.</ref>
|prime units?=imp
<!--
        General characteristics
-->
|crew=5 (with a relief crew of 5)
|capacity= up to 400 troops / {{cvt|100000|lb}} cargo
|length ft=182
|length in=6
|length note=
|span ft=230
|span in=0
|span note=
|height ft=57
|height in=6
|height note=
|wing area sqft=4772
|wing area note=
|swept area sqft=<!-- swing-wings -->
|swept area note=
|volume ft3=<!-- lighter-than-air -->
|volume note=
|aspect ratio=<!-- sailplanes -->
|airfoil='''root:''' [[NACA airfoil|NACA 63(420)-422]]; '''tip:''' [[NACA airfoil|NACA 63(420)-517]]<ref name="Selig">{{cite web |last1=Lednicer |first1=David |title=The Incomplete Guide to Airfoil Usage |url=https://m-selig.ae.illinois.edu/ads/aircraft.html |website=m-selig.ae.illinois.edu |access-date=16 April 2019}}</ref>
|empty weight lb=135232
|empty weight note=
|gross weight lb=265000
|gross weight note=
|max takeoff weight lb=320000
|max takeoff weight note=
|fuel capacity={{cvt|19112|USgal|impgal l}}
|more general=
<!--
        Powerplant
-->
|eng1 number=6
|eng1 name=[[Pratt & Whitney R-4360-41 Wasp Major]]
|eng1 type=28-cylinder air-cooled radial piston engine
|eng1 hp=3500

|prop blade number=3
|prop name=Curtiss-Electric constant-speed fully-feathering pusher propellers
|prop dia ft=<!-- propeller aircraft -->
|prop dia in=<!-- propeller aircraft -->
|prop dia note=
<!--
        Performance
-->
|max speed mph=307
|max speed note=
|cruise speed mph=
|cruise speed note=
|stall speed mph=
|stall speed note=
|never exceed speed mph=
|never exceed speed note=
|minimum control speed mph=
|minimum control speed note=
|range miles=8100
|range note= with {{cvt|19112|USgal|impgal l}} and {{cvt|10000|lb}} payload
|combat range miles=
|combat range note=
|ferry range miles=
|ferry range note=
|endurance=<!-- if range unknown -->
|ceiling ft=
|ceiling note=
|g limits=<!-- aerobatic -->
|roll rate=<!-- aerobatic -->
|climb rate ftmin=
|climb rate note=
|time to altitude=
|wing loading lb/sqft=
|wing loading note=
|fuel consumption lb/mi=
|power/mass=

|more performance=
|avionics=* Weather radar
}}

==See also==
{{aircontent
|related=
* [[Convair B-36]]
|similar aircraft=
* [[Bristol Brabazon]]
* [[Lockheed R6V Constitution]]
* [[Saunders-Roe Princess]]
|lists =
*[[List of military aircraft of the United States]]
|see also=
}}

==References==

===Notes===
{{Reflist}}

===Bibliography===
{{Refbegin}}
* Dorr, Robert F. "Saving the XC-99." ''Air Force Times,'' 12 August 1998.
* Dorr, Robert F. "XC-99 is a treasure." ''Air Force Times'', 10 June 2000.
* Jacobsen, Meyers K. ''Convair B-36: A Comprehensive History of America's "Big Stick"''. Atglen, Pennsylvania: Schiffer Military History, 1997. {{ISBN|0-7643-0974-9}}.
* Jacobsen, Meyers K. ''Convair B-36: A Photo Chronicle''. Atglen, Pennsylvania: Schiffer Military History, 1999. {{ISBN|0-7643-0974-9}}.
* Jacobsen, Meyers K and Ray Wagner. ''B-36 in Action (Aircraft in Action Number 42)''. Carrollton, Texas: Squadron/Signal Publications Inc., 1980. {{ISBN|0-89747-101-6}}.
* Jenkins, Dennis R. ''Convair B-36 Peacemaker''. St. Paul, Minnesota: Specialty Press Publishers and Wholesalers, 1999. {{ISBN|1-58007-019-1}}.
* Johnsen, Frederick A. ''Thundering Peacemaker, the B-36 Story in Words and Pictures''. Tacoma, Washington: Bomber Books, 1978.
* Miller, Jay and Roger Cripliver. "B-36: The Ponderous Peacemaker." ''Aviation Quarterly,'' Vol. 4, No. 4, 1978.
* Wegg, John. ''General Dynamics Aircraft and their Predecessors''. London: Putnam, 1990. {{ISBN|0-85177-833-X}}.
{{Refend}}

==External links==
{{Commons category}}
*[http://www.air-and-space.com/xc99.htm Goleta Air and Space Museum Convair XC-99 and Model 37]
*[https://books.google.com/books?id=KS0DAAAAMBAJ&pg=RA1-PA129 'U.S. To Europe With 50 tons", ''Popular Science'', March 1950, early article with drawing of first layout of XC-99]
*[https://books.google.com/books?id=JyEDAAAAMBAJ&pg=RA1-PA58 "Biggest Air Freighter Goes To War" 1951 article on first operational use of XC-99, photos and drawings]
*[https://web.archive.org/web/20141019030526/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=13628 National Museum of the USAF, XC-99 photos, along with the photo of the 1/72nd scale XC-99 model by Lt. Col. Howard Meek]
*[http://www.airforcemag.com/MagazineArchive/Documents/2004/February%202004/0204fella.pdf Big Fella – Air Force Magazine]
*{{HAER |survey=TX-23-A |id=tx0728 |title=Kelly Air Force Base, XC-99 Airplane |data=22}}

{{Convair aircraft}}
{{Consolidated aircraft}}
{{USAF transports}}
{{Authority control}}
{{Coord|32.14870|N|110.84233|W|display=title}}{{DEFAULTSORT:Convair XC-99}}
[[Category:Convair aircraft|C-099]]
[[Category:1940s United States military transport aircraft|Convair C-099]]
[[Category:Six-engined pusher aircraft]]
[[Category:Mid-wing aircraft]]
[[Category:Aircraft first flown in 1947]]
[[Category:Convair B-36 Peacemaker|XC-99]]
[[Category:Double-deck aircraft]]
[[Category:Aircraft with retractable tricycle landing gear]]