Aircraft walkaround vol.55: IAI Kfir C1 (F21A)

Subject: IAI Kfir C1 - F21A

Location: Intrepid Air and Sea Museum, New York, USA 2014.

Comments: The Israel Aircraft Industries Kfir (Hebrew: כְּפִיר, "Lion Cub") is an Israeli-built all-weather, multirole combat aircraft based on a modified French Dassault Mirage 5 airframe, with Israeli avionics and an Israeli-built version of the General Electric J79 turbojet engine.The project that would ultimately give birth to the Kfir can be traced back to Israel's need for adapting the Dassault Mirage IIIC to the specific requirements of the Israeli Air Force (IAF). The all-weather, delta-winged Mirage IIICJ was the first Mach 2 aircraft acquired by Israel from then close ally France, and constituted the backbone of the IAF during most of the 1960s, until the arrival of theDouglas A-4 Skyhawk and, most importantly, the McDonnell Douglas F-4 Phantom II, by the end of the decade. While the Mirage IIICJ proved to be extremely effective in the air-superiority role, its relatively short range of action imposed some limitations on its usefulness as a ground-attack aircraft. Thus, in the mid-1960s, at the request of Israel, Dassault Aviation began developing the Mirage 5, a fair-weather, ground-attack version of the Mirage III. Following the suggestions made by the Israelis, advanced avionics located behind the cockpit were removed, allowing the aircraft to increase its fuel-carrying capacity while reducing maintenance costs. By 1968, Dassault had finished production of the 50 Mirage 5Js paid for by Israel, but an arms embargo imposed upon Israel by the French government in 1967 prevented deliveries from taking place. The Israelis replied by producing an unlicensed copy of the Mirage 5, the Nesher, with technical specifications for both the airframe and the engine obtained by Israeli spies. Some sources claim Israel received 50 Mirage 5s in crates from French Air Force (AdA), while the AdA took over the 50 aircraft originally intended for Israel.The Kfir programme originated in the quest to develop a more capable version of the IAI Nesher, which was already in series production. After General De Gaulle embargoed the sale of arms to Israel, the IAF feared that it might not have an upper hand over its adversaries in the future, which were receiving increasingly advanced Soviet aircraft. The bulk of the Israeli Air Force had been locked into the Mirage but was quickly facing problems because Mirage numbers were somewhat depleted after the Six-Day War. Domestic production would avoid the problem of the embargo completely; efforts to reverse engineer and reproduce components of the Mirage were aided by Israeli espionage efforts to obtain technical assistance and blueprints from third party Mirage operators. Two powerplants were initially selected for trials, the General Electric J79 turbojet and the Rolls-Royce Spey turbofan. In the end, the J79 was selected, not least because it was the same engine used on the McDonnell DouglasF-4 Phantom II, which the Israelis began to acquire from the United States in 1969, along with a license to produce the J79 themselves. The J79 was clearly superior to the original French Atar 09, providing a dry thrust of 49 kN (11,000 lbf) and an afterburning thrust of 83.4 kN (18,750 lbf). In order to accommodate the new powerplant on the Mirage III's airframe, and to deliver the added cooling required by the J79, the aircraft's rear fuselage was slightly shortened and widened, its air intakes were enlarged, and a large air inlet was installed at the base of the vertical stabilizer, so as to supply the extra cooling needed for the afterburner. The engine itself was encased in a titanium heatshield.

Aircraft walkaround vol.54: Lockheed L1049G Super Constelation

Subject: Lockheed L1049G Super Constelation

Location: Flugausstellung Peter Junior, Germany 2012

Comments:The Lockheed L-1049 Super Constellation is an American aircraft, a member of the Lockheed Constellation aircraft line. The L-1049 was Lockheed's response to the successful Douglas DC-6 airliner, first flying in 1950. The aircraft was also produced for both the United States Navy and Air Force as transport and AWACS aircraft.When,in 1953, R-3350 Turbo-compounds were made available for civil use,  Lockheed incorporated them into the L-1049C, which first flew on February 17 of that year. The R-3350-972-TC18DA-1 turbo-compound engines on the L-1049C had a new turbine system, the Power Recovery Turbines (PRT). Each engine's exhaust gas flowed through three turbines, increasing power by 550 hp (410 kW). One drawback of the PRT was the visible flame from the exhaust pipes; this was resolved by placing armor plating 2 in (5.08 cm) thick under the stack. The L-1049C had a higher cruising speed and climb rate. Although still lacking the range of the DC-6B, the L-1049C was now identical in performance to the Douglas and could carry a larger payload. The wings of the new model were strengthened, cabin soundproofing was increased, and the landing gear retraction system was improved. A new series of interior layouts was offered for the new model; "Siesta" (47 Passengers with increased luxury), "Intercontinental" (54 - 60 Passengers) and "Inter-urban" (105 Passengers). Each of these new layouts included reading lights at each seat. 48 L-1049Cs were built, being used by Eastern, TWA, Air France, KLM, Trans-Canada Air Lines, QANTAS, Air India, Pakistan International Airlines, Avianca, Iberia, Línea Aeropostal Venezolana and Cubana de Aviación.A freighter version, the L-1049D, first flew in August 1954. It had two cargo doors on the left side and a reinforced magnesium floor as used on the R7V-1 military variant of the L-1049B. The L-1049D could carry a 36,916 lb (16,745 kg) payload and had a volume of 5,579 ft³ (158 m³). At the time of its first flight, the L-1049D was the largest civil cargo aircraft. In the end four were produced, all delivered to Seaboard & Western Airlines. Two of the four L-1049D aircraft were later converted to L-1049H standards.The L-1049E was more successful; 28 were delivered to eight airlines. Similar to the L-1049C, the L-1049E was able to carry the same load as the L-1049D. The L-1049C and L-1049E could not usually fly Europe to New York nonstop against the wind. Lockheed thought of fitting a new variant based on the L-1049E with more powerful engines, but the project was cancelled. A different variant surfaced: using the L-1049C as a base, R-3350-972-TC18DA-3 turbo-compound engines were fitted. The aircraft could carry 71 to 95 passengers at a speed of 331 mph (533 km/h). Wingtip tanks of 1,037 gallon (3,925 L) total capacity were incorporated, increasing range by 1,110 miles (1,770 km). A new Bendix or RCA weather radar could be installed in the nose, which changed the nosecone shape. New Hamilton Standard or Curtiss Electric propellers were offered. This new version of the L-1049 with over 100 modifications from the L-1049C was unveiled as the L-1049G (the L-1049F being already used for the military C-121C). Over 100 L-1049G aircraft were ordered by sixteen airlines. The L-1049G flew on December 17, 1954 and entered service with TWA and Northwest in 1955. The nickname "Super G" (first used by TWA) was later adopted for the L-1049G.

Walkaround vol.21: Panzerkampfwagen VI Tiger ausf E/H

Subject: Panzerkampfwagen VI Tigar ausf E/H

Location: Musée des Blindés, Saumur, France

Comments:Tiger I  is the common name of a German heavy tank developed in 1942 and used in World War II. The final official German designation was Panzerkampfwagen VI Tiger Ausf. E, often shortened to Tiger. The Tiger I gave the Wehrmacht its first tank which mounted a KwK 36 88mm gun in an armoured fighting vehicle. The KwK 36 is not to be confused with the earlier and similar 8.8 cm Flak 36, a different weapon designed in parallel with the KwK 36 and firing the same ammunition ("KwK" denotes an armored vehicle gun, while "Flak" denotes anti-aircraft artillery). During the course of the war, the Tiger I saw combat on all German battlefronts. It was usually deployed in independent heavy tank battalions, which proved highly effective. While the Tiger I has been called an outstanding design, it was over-engineered, using expensive materials and labour-intensive production methods. Only 1,347 were built between August 1942 and August 1944. The Tiger was prone to certain types of track failures and breakdowns, and limited in range by its high fuel consumption. It was expensive to maintain, but generally mechanically reliable. It was also difficult to transport, and vulnerable to immobilization when mud, ice and snow froze between its overlapping and interleaved Schachtellaufwerk-pattern road wheels in both rasputitsa and succeeding winter weather conditions, often jamming them solid. In 1944, production was phased out in favour of the Tiger II. The tank was given its nickname "Tiger" by Ferdinand Porsche, and the Roman numeral was added after the later Tiger II entered production. The initial official German designation wasPanzerkampfwagen VI Ausführung H (‘‘Panzer VI version H’’, abbreviated PzKpfw VI Ausf. H), with the H being for the designer/manufacturer, Henschel. It was classed with ordnance inventory designationSdKfz 182. The tank was later redesignated as PzKpfw VI Ausf. E in March 1943, with ordnance inventory designation SdKfz 181. Today, only a handful of Tigers survive in museums and exhibitions worldwide. The Bovington Tank Museum's Tiger 131 is currently the only one restored to running order.

Engine Walkaround vol.18: BMW 801

Subject: BMW 801 radial engine
Location: Air and Space Museum, Le Bourget, France 2015; Deutches Museum, Munich, Germany, 2013.

Comments:The BMW 801 was a powerful German air-cooled 14-cylinder-radial aircraft engine built by BMW and used in a number of German Luftwaffe aircraft of World War II. Production versions of the twin-row engine generated between 1,560 and 2,000 PS (1,540-1,970 hp, or 1,150-1,470 kW). It was the most produced radial engine of Germany in World War II with more than 28,000 built. The 801 was originally intended to replace existing radial types in German transport and utility aircraft. At the time, it was widely agreed among European designers that an inline engine was a requirement for high performance designs due to its smaller frontal area and resulting lower drag. Kurt Tank successfully fitted a BMW 801 to a new fighter design he was working on, and as a result the 801 became best known as the power plant for the famous Focke-Wulf Fw 190.The 801 was a radial engine with two rows of seven cylinders.The cylinders had both bore and stroke of 156 millimetres (6.1 in), giving a total capacity of 41.8 litres (2,550 cu in), just a bit less than the American Wright Cyclone 14 twin-row radial of some 1,600 to 1,900 hp output. The unit (including mounts) weighed from 1,010 to 1,250 kg and was about 1.29 m (51 in) across, depending on the model.The BMW 801 was cooled by forced air from a magnesium alloy cooling fan, 10 bladed in the initial models, but 12 bladed in most engines. The fan rotated at 1.72 times the crankshaft speed (3.17 times the propeller speed). Air from the fan was blown into the center of the engine in front of the propeller gearing housing, and the shape of the housing and the engine itself carried the air to the outside of the cowling and across the cylinders. A set of slots or gills at the rear of the cowling allowed the hot air to escape. This provided effective cooling although at the cost of about 70 PS (69 hp, 51.5 kW) required to drive the fan when the aircraft was at low speed. Above 170 miles per hour (270 km/h), the fan absorbed little power directly as the vacuum effect of the airflow past the air exits provided the needed flow.