Design and development

The design began life in a production requirement by American Airlines for an airliner to replace its Douglas DC-3s. Convair's original design, the unpressurised Model 110 was a twin-engined low-wing monoplane of all-metal construction, with seats for 30 passengers. It was powered by Pratt & Whitney R-2800 Double Wasp radial engines and was fitted with a tricycle landing gear, while the aircraft was fitted with a ventral airstair to aid passenger embarkation. The prototype Model 110, registration NX90653 first flew on July 8, 1946.  By this time, American had changed their requirements to require pressurization and deemed the design to be too small. The first prototype was subsequently used by Convair for development work for the 240 series before being broken up in 1947.

To meet the requirements of airlines for a pressurized airliner Convair produced a revised design, the Model 240. This had a longer but thinner fuselage than the Model 110, accommodating 40 passengers in the first pressurized twin-engined airliner. The 240 first flew on March 16, 1947.

The Model 240 was followed into production by the Model 340 that had a longer fuselage, longer span wings and more powerful engines. The 340 first flew on October 5, 1951.  In 1954, in an attempt to compete with turboprop-powered airliners like the Vickers Viscount, Convair produced the Model 440 Metropolitan, with more streamlined cowlings and new engine exhausts and improved soundproofing for the cabin.  As the "Super 240" evolved into the CV-340 and CV-440 the limit of piston-engine performance was reached and the next developments centered on conversion to turboprop power.

Operational history

The first delivery of a production Convairliner was to American on February 29, 1948.  A total of 75 were delivered to American, with another 50 going to Western Airlines, Continental Airlines, Pan American Airways, KLM, Swissair, Sabena and Trans Australia Airlines.

A CV-240 was the first private aircraft used in a United States presidential campaign. In 1960, John F. Kennedy used a CV-240 named Caroline (after his daughter) during his campaign. This aircraft is now preserved in the National Air and Space Museum.

After the aborted negotiations with TWA and Eastern for "Super 240" orders, the production of the 240 series was temporarily halted. In response to a United inquiry, however, Convair redesigned the Super 240, calling it the CV-340. United ordered 55, and more US orders came from Braniff, Continental, Delta, Northeast and National. Other orders came from abroad, and the CV-340 proved popular in South America. The CV-340 earned an enviable reputation for reliability and profitability, and was developed into the CV-440 Metropolitan, the final piston-engined variant of the "Convairliners."

Variants

Civil variants

Convair Model 110

Unpressurized prototype with seats for 30 passengers. 89 ft (27.13 m) wingspan, 71 ft (21.64 m) length, powered by two 2,100 hp (1,567 kW) Pratt & Whitney R-2800-SC13G engines. One built.

Convair CV-240

Initial production version. Powered by two Pratt & Whitney R-2800 engines.

Convair CV-240-21 Turboliner

turboprop-powered conversion fitted with Allison T38 engines. It became the first turboprop airliner to fly in the United States (on December 29, 1950), but problems with the engines resulted in development being terminated and the prototype being converted back to piston power.

Convair CV-300

a conversion from a Convair CV-240 with two R-2800 CB-17 engines and nacelles as used on the CV-340. A CV-300 was involved in an accident that killed three members and the manager of the rock group Lynyrd Skynyrd.

Convair CV-340

Built for United Airlines and other operators including KLM, was basically a CV-240 lengthened to hold an additional four seats. The wingspan was also extended for better performance at higher altitudes. The CV-340 replaced the DC-3 in United service. The airline flew 52 340s for 16 years without a fatality. KLM operated the type from spring 1953 until mid-1963. Many CV-340 aircraft were converted to CV-440 standard.

Convair CV-440 Metropolitan

CV-340 with improved soundproofing and an option of weather radar. Maximum weight rose to 49,700 lbs. An optional increase from 44 to 52 passengers was facilitated by the replacement of the carry-on luggage area with two more rows of seats, marked by the addition of an extra cabin window. This option was taken up by several airlines including Lufthansa and SAS.  Finnair operated the type from 1953 until 1980 without a single accident.

Convair CV-540

Conversion from a Convair CV-340 aircraft with two Napier Eland turboprop engines in place of the piston engines. Six aircraft were converted by Napier for Allegheny Airlines.  Cost for the conversions was £160,000 per-aircraft. 12 built as new builds by Canadair for RCAF as CC-109 in 1960 for £436,000 per-aircraft. First flight February 9, 1955.

Convair CV-580

conversion from Convair CV-340 or CV-440 aircraft with two Allison 501 D13D/H turboprop engines with four-bladed propellers in place of the piston engines with three-bladed propellers, an enlarged vertical fin and modified horizontal stabilisers. The conversions were performed by Pacific Airmotive on behalf of the Allison Engine Company.  Cost of the conversions was around £175,000 per aircraft and took 60 days.

Convair CV-600

Conversion from a Convair 240 aircraft with Rolls-Royce Dart turboprop engines with four-bladed propellers in place of the piston engines with three-bladed propellers. CV-600 conversions were performed by Convair. The CV-600 first flew with Central Airlines on 30 November 1965. The CV-600 aircraft that flew with Air Metro Airways was configured as a 40-passenger airliner. In 2012 the last Convair CV-600 (Rhoades Aviation) went out of service.

Convair CV-640

Conversion from a Convair CV-340 or -440 with Rolls-Royce Dart turboprop engines with four-bladed propellers in place of the piston engines with three-bladed propellers. The conversions were performed by Convair. In 2012, a total of seven Convair CV-640 aircraft remain in airline service, with Rhoades Aviation (one) and C&M Airways (six).

Convair CV5800

Conversion from a C-131 Samaritan by Kelowna Flightcraft Ltd. in Canada. The CV5800 is a C-131 Samaritan stretched by 14 ft 3 in with the Samaritan's original tail unit rather than the enlarged tail of the CV-580. These conversions also have a new freight door, digital avionics with EFIS and Allison 501-D22 engines in place of the original R-2800 engines.

Military variants

Convair C-131 Samaritan

The CV-240/340/440 series was used by the United States Air Force for medical evacuation and VIP under this designation

Convair T-29 trainer

A trainer model of the C-131 was used to instruct navigators and radio operators

Convair R4Y Samaritan

The United States Navy used the Samaritan under this designation

Canadair CC-109 Cosmopolitan

Conversion from CV-440, with Napier Eland turboprops in place of the piston engines. The conversions were performed in Canada by Canadair. In Royal Canadian Air Force and later in Canadian Armed Forces (Canada) service they were known as the CC-109 Cosmopolitan. All were re-engined in 1966 with Allison 501-D13 engines.

Canadair CL-66

Company designation for the CC-109 Eland powered variant