Lockheed Ventura

The Lockheed Ventura is a twin-engine medium bomber and patrol bomber of World War II.

The Ventura first entered combat in Europe as a bomber with the RAF in late 1942. Designated PV-1 by the United States Navy (US Navy), it entered combat in 1943 in the Pacific. The bomber was also used by the United States Army Air Forces (USAAF), which designated it the Lockheed B-34 (''Lexington'') and B-37 as a trainer. British Commonwealth forces also used it in several guises, including antishipping and antisubmarine search and attack.

The Ventura was developed from the Lockheed Model 18 Lodestar transport, as a replacement for the Lockheed Hudson bombers then in service with the Royal Air Force. Used in daylight attacks against occupied Europe, they proved to have weaknesses and were removed from bomber duty and some used for patrols by Coastal Command.

After USAAF monopolization of land-based bombers was removed, the US Navy ordered a revised design which entered service as the PV-2 Harpoon for anti-submarine work.

Development

Lockheed Ventura/B-34 Lexington

At the start of the war, Lockheed proposed military conversions of the Lodestar for the RAF as replacement for the Hudson reconnaissance aircraft and the Bristol Blenheim bomber. The first British order was placed in February 1940 for 25 Model 32 as bombers. This was followed by an order for 300 Model 37 with Double Wasp engines, then for a further 375 later in 1940. Lockheed needed more production capacity and nearby Vega Aircraft Corporation was contracted for building the Ventura.

The Ventura was very similar to its predecessor, the Lockheed Hudson. The primary difference was not in layout; rather, the Ventura was larger, heavier, and used more powerful engines than the Hudson. The RAF ordered 188 Venturas in February 1940, which were delivered from mid-1942. Venturas were initially used for daylight raids on occupied Europe but, like some other RAF bombers, they proved too vulnerable without fighter escort, which was difficult to provide for long-range missions. Venturas were replaced by the faster de Havilland Mosquito. The Venturas were transferred to patrol duties with Coastal Command as the Mosquito replaced them in bomber squadrons; 30 went to the Royal Canadian Air Force (RCAF) and some to the South African Air Force (SAAF). The RAF placed an order for 487 Ventura Mark IIs but many of these were diverted to the USAAF, which placed its own order for 200 Ventura Mark IIA as the B-34 Lexington, later renamed RB-34.

Lockheed B-37

In August 1941, large orders for Venturas were placed with Lend-Lease Act money. Among the orders were for 550 armed reconnaissance versions of the Ventura. This aircraft was originally planned to be built under the designation O-56. The main differences between the Ventura and the O-56 were in the engines: rather than the 2,000 hp (1,491 kW) Pratt & Whitney R-2800 radials of the Ventura, the O-56 used 1,700 hp (1,270 kW) Wright R-2600-13 radials.

Before completion of the first O-56, the U.S. Army Air Forces dropped the "O-" category used to designate "observation" (reconnaissance) aircraft. The O-56 was redesignated the RB-34B (the ''R'' denoted 'restricted' meaning it was not to be used for combat). Before the first of these flew, the design was redesignated again as the B-37 with a higher powered version of the R-2600, later it also was designated the RB-37.

While 550 were ordered by the Army Air Forces, acquisition by the USAAF stopped after only 18 Venturas were accepted, when the Army Air Forces agreed to turn over exclusive use of the Ventura to the United States Navy.

PV-1 Ventura

The PV-1 Ventura, built by the Vega Aircraft Company division of Lockheed (hence the "V" Navy manufacturer's letter that later replaced the "O" for Lockheed), was a version of the Ventura built for the U.S. Navy (see Venturas in U.S. Navy service below). The main differences between the PV-1 and the B-34 were the inclusion of special equipment in the PV-1, adapting it to its patrol bombing role. The maximum fuel capacity of the PV-1 was increased from 1,345 gal (5,081 L) to 1,607 gal (6,082 L), to increase its range; the forward defensive armament was also reduced for this reason. The most important addition was of an ASD-1 search radar.

Early production PV-1s still carried a bombardier's station behind the nose radome, with four side windows and a flat bomb-aiming panel underneath the nose. Late production PV-1s dispensed with this bombardier position and replaced it with a pack with three 0.50 inch (12.7 mm) machine guns underneath the nose. These aircraft could also carry eight 5-inch (127 mm) HVAR rockets on launchers underneath the wings.

The PV-1 began to be delivered in December 1942, and entered service in February 1943. The first squadron in combat was VP-135, deployed in the Aleutian Islands in April 1943. They were operated by three other squadrons in this theatre. From the Aleutians, they flew strikes against bases in Paramushiro and Shimushu, Japanese islands in the Kurile chain. Often, PV-1s would lead B-24 bomber formations, since they were equipped with radar. In late 1943, some PV-1s were deployed to the Solomon Islands as night fighters with VMF(N)-531, a Marine Corps fighter squadron.

PV-2 Harpoon

The PV-2 Harpoon was a major redesign of the Ventura with the wing area increased from 551 ft² (51.2 m²) to 686 ft² (63.7 m²) giving an increased load-carrying capability, and which first flew on 3 December 1943. The motivation for redesign was weaknesses in the PV-1, which had shown itself to have problems in taking off when carrying a full load of fuel. On the PV-2, the armament became standardized at five forward-firing machine guns. Many early PV-1s had a bombardier's position, which was deleted in the PV-2. Some other significant developments included the increase of the bombload by 30% to 4,000 lb (1,800 kg), and the ability to carry eight 5-inch (127 mm) HVAR rockets under the wings.

While the PV-2 was expected to have increased range and better takeoff, the anticipated speed statistics were projected lower than those of the PV-1, due to the use of the same engines but an increase in weight. The Navy ordered 500 examples, designating them with the popular name ''Harpoon''.

Early tests indicated a tendency for the wings to wrinkle dangerously. As this problem could not be solved by a 6 ft (1.8 m) reduction in wingspan (making the wing uniformly flexible), a complete redesign of the wing was necessitated. This hurdle delayed entry of the PV-2 into service. The PV-2s already delivered were used for training purposes under the designation PV-2C. By the end of 1944, only 69 PV-2s had been delivered. They finally resumed when the redesign was complete. The first aircraft shipped were the PV-2D, which had eight forward-firing machine guns and was used in ground attacks. When World War II ended, all of the order was cancelled.

With the wing problems fixed, the PV-2 proved reliable, and eventually popular. It was first used in the Aleutians by VP-139, one of the squadrons that originally used the PV-1. It was used by a number of countries after the war's end, but the United States ceased ordering new PV-2s, and they were all soon retired from service.

Civil conversions

Ex-military PV-1 Venturas from Canada and South Africa were converted by Howard Aero in San Antonio, Texas, in the 1950s and 1960s as high-speed executive transports. The earliest conversions, called Super Venturas, incorporated a 48 in (122 cm) fuselage stretch, extra fuel tankage, large picture windows, luxury interiors, and weapons bays transformed into baggage compartments. The landing gear was swapped for the heavier-duty units from the PV-2. Later conversions, of which eighteen were completed in the 1960s, were called Howard 350s.Taylor 1965, p.244.

At least nineteen PV-1s were further modified, including cabin pressurization under the designation Howard 500. A final PV-1 modification by Howard was the Eldorado 700, with longer wings, a pointed nose, and streamlined engine cowlings.

A notable crash of a civilian version occurred on December 17, 1954, killing four, including Fred Miller, president of the Miller Brewing Company and grandson of founder Frederick Miller. The company plane was bound for Winnipeg, Manitoba, but had trouble with both engines and crashed shortly after takeoff from Mitchell Field in Milwaukee, Wisconsin. Also killed were his oldest son, 20-year-old Fred, Jr., and the two company pilots, Joseph and Paul Laird.

Oakland Airmotive (later Bay Aviation Services, based in Oakland, California) also offered a PV-2 executive aircraft conversion dubbed Centaurus starting in 1958. The cost of the conversion was $155,000 in addition to the airframe.

Operational history

Portuguese Air Force

The Portuguese Air Force received 42 Lockheed PV-2C Harpoons from 1953, which replaced the Curtiss SB2C-5 Helldiver as an anti-submarine aircraft. The Harpoons equipped squadrons 61 and 62 at the Montijo Air Base. In 1960, the Harpoons were replaced as maritime patrol and anti-submarine aircraft by Lockheed P2V-5 Neptunes. The remaining Harpoons were sent to Angola and Mozambique, where they formed Squadron 91 operating from Luanda Air Base and Squadron 101 from Beira Air Base. The Harpoons were used on operations in the Angolan and Mozambican theatres of the Portuguese Overseas War (1961–1974). They served mainly as light bombers and ground attack aircraft, with occasional reconnaissance, transport and maritime patrol sorties. The last Portuguese Harpoons were retired in 1975. The Museu do Ar (Portuguese Air Museum) has what is believed to be the only remaining Lockheed PV-2C Harpoon in Europe.

Royal Air Force

The first Ventura Mark Is were accepted by the Royal Air Force (RAF) in September 1941, with aircraft being delivered to Britain from April 1942.Francillon 1982, p. 198.Bowyer 1974, p. 254. By the end of August, enough Venturas had arrived to equip No. 21 Squadron RAF, No. 487 Squadron RNZAF and No. 464 Squadron RAAF.Bowyer 1974, pp. 254–256. The Ventura flew its first operational mission for the RAF on 3 November 1942, when three Venturas of 21 Squadron attacked railway targets near Hengelo in the Netherlands.Bowyer 1974, p. 261.Carey 2002, p. 12. On 6 December 1942, 47 Venturas from 21, 464 (RAAF) and 487 (RNZAF) squadrons participated in Operation Oyster, the large daylight 2 Group raid against the Philips radio and vacuum tube factories at Eindhoven