Convair CV-340 / 440
Illustrative image; it may differ from the actual aircraft.The Convair CV-340 and its refined successor, the CV-440 Metropolitan, are American twin piston-engined airliners built by Convair in San Diego from 1951 to 1958 as a development of the CV-240, with a longer fuselage for 44 seats, a larger wing and more powerful Pratt & Whitney R-2800 engines. The 340 first flew on 5 October 1951 and entered service with United Air Lines in November 1952; the quieter 440, nearly always fitted with weather radar, followed in 1956. A total of 510 were built — 311 Model 340s and 199 Model 440s, including C-131 and R4Y military versions. From 1960, close to 200 were converted to turboprop power as Convair 580s and 640s, and in mid-2026 the last examples were still at work as freighters and firefighting tankers.
Specifications
Figures for the CV-440 Metropolitan variant, the most representative of the family
The type first flew in 1951 (75 years ago) · About 510 units built · Production ended in 1958
Figures for the type, not for this particular aircraft: each variant and each configuration changes something. They are shown in both systems used in aviation.
The story of the type
From "Super 240" to 340
The last fifteen CV-240s proved so hard to sell that Convair considered closing the programme, but the success of the pressurised Martin 4-0-4 with Eastern and TWA pushed it to refine the design. After abortive talks with those two airlines over a "Super 240", an enquiry from United Air Lines shaped the new model, announced on 28 November 1950 as the Convair 340. The fuselage grew by 1.37 m to take an extra row of four seats, for 44 in all, and the span went from 27.97 to 32.11 m, for better performance at high-altitude airports and more fuel. It had Pratt & Whitney R-2800-CB16 or CB17 engines, propellers interchangeable with the DC-6's and all passenger doors on the left. United, which had asked for many of these changes, was the launch customer.
First flight and service
The prototype, N3401, flew on 5 October 1951 with Sam Shannon at the controls. Certification followed on 27 March 1952 and United put the type into service on 16 November that year; it went on to fly 52 of them for sixteen years without a single fatal accident. Braniff, Continental, Delta, National and Hawaiian followed in the United States and, abroad, KLM, Alitalia, Finnair, Garuda, JAT, Ansett, Avensa, Cruzeiro do Sul and Saudi Arabian Airlines; it was especially popular in South America. In all, 209 were built for civil customers and 102 for the US Air Force and Navy.
The Metropolitan
To compete with the Vickers Viscount turboprop, Convair unveiled the 340B in 1954, soon renamed the 440 Metropolitan: cleaner cowlings, rectangular exhausts that reduced cabin noise, more soundproofing, a higher maximum weight and optional weather radar, which most received. It seated 44, or 52 with an extra window on each side. A modified 340 flew on 6 October 1955 and the first production aircraft on 16 December; Continental introduced it on 8 March 1956. Most were sold outside the United States, to Swissair, Lufthansa, SAS, Sabena, Iberia, Sweden's Linjeflyg and Finnair, which flew it until 1980, and it let many airlines skip the turboprop stage altogether. More than a hundred 340s were brought up to 440 standard with factory kits. Production ended in 1958 after 510 aircraft: 311 Model 340s and 199 Model 440s.
A second life with turbines
The airframe had been designed with turbines in mind. The first commercial conversion, with Napier Eland engines, flew in England in February 1956 and, as the Convair 540, entered service with Allegheny Airlines in 1959; the programme died when Rolls-Royce absorbed Napier in 1962. Allison's conversion was far more successful: PacAero fitted two 501-D13s, the first aircraft flew on 19 January 1960 and Frontier Airlines, which named it the Convair 580, put it into service in June 1964. By 1969, 170 had been converted, flying with Allegheny, North Central and Avensa, among others. From 1965 Convair also offered the Rolls-Royce Dart-powered 640, and 31 aircraft were converted; Caribair began services with it on 22 December 1965.
Still at work in 2026
Rugged and easy to maintain, the family moved from the airlines to cargo companies, research laboratories and firefighting. In Canada, Kelowna Flightcraft stretched six former US Navy C-131Fs into CV-5800 freighters, the first in 1992. In mid-2026, more than seventy years after the first flight, a last CV-5800 and a few 580 air tankers in Saskatchewan were still working, all with their retirement announced.
Variants
The basic 1951 model: a CV-240 with a 1.37 m (4 ft 6 in) longer fuselage, a 32.11 m (105 ft 4 in) wingspan, R-2800-CB16 or CB17 engines and 44 seats. United was the launch customer, and 209 were built for airlines and corporate operators.
The 340 refined to compete with the Viscount: cleaner cowlings, rectangular exhausts, extra soundproofing, a maximum weight of 49,700 lb (22,540 kg) and optional weather radar in a longer nose. It seated 44, or 52 with an extra window on each side. It first flew on 6 October 1955 and served with many European airlines, among them Finnair from 1956 to 1980.
Military versions built on the 340 and 440 for the US Air Force (C-131B transport and electronics test-bed, C-131D transport, C-131E electronic-warfare trainer) and the US Navy (R4Y-1 and R4Y-2, later C-131F and C-131G). They accounted for 102 of the 340s and part of the 199 Model 440s.
Conversion to Napier Eland turboprops. Allegheny Airlines used six from 1959, but the programme was dropped after Rolls-Royce took over Napier and the aircraft reverted to piston power. Canadair, which had received the 440 tooling, built ten new Eland-powered aircraft for the Royal Canadian Air Force as CC-109 Cosmopolitans (first flight 7 January 1960), later re-engined with Allisons.
The most successful conversion: two Allison 501-D13 turboprops with four-blade propellers, a taller fin and a wider tailplane. PacAero did the work for Allison (first flight 19 January 1960), and 170 aircraft had been converted by 1969. Frontier, which coined the name 580, introduced it in 1964; Allegheny, North Central and later American Eagle flew it too, as did cargo and firefighting operators.
Conversion of 340s and 440s to Rolls-Royce Dart 542 turboprops, carried out by Convair from 1965; 31 were converted. Caribair and Hawaiian Airlines introduced it in December 1965.
A former US Navy C-131F stretched by 4.98 m by Kelowna Flightcraft (now KF Aerospace), with Allison 501-D22G engines, a new cargo door and digital avionics. The prototype flew on 11 February 1992 and six were converted, mostly for freight work.
Overview and history adapted from Wikipedia (CC BY-SA) · technical figures from the manufacturer’s published specifications and standard aviation references
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This page was last updated on October 11, 2026
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BibTeX
@misc{vuelopedia_en_model_cv340,
author = {{Vuelopedia}},
title = {{Convair CV-340 / 440}},
publisher = {Fundación Poderia},
year = {2026},
date = {2026-10-11},
url = {https://vuelopedia.org/en/model/cv340},
howpublished = {\url{https://vuelopedia.org/en/model/cv340}},
urldate = {2026-10-16},
note = {Accessed 2026-10-16}
}Wikipedia
{{cite web |url=https://vuelopedia.org/en/model/cv340 |title=Convair CV-340 / 440 |website=Vuelopedia |publisher=Fundación Poderia |date=2026-10-11 |access-date=2026-10-16 |language=en}}