Daily Archives: August 10, 2017

10 August 1961

Republic F-105D-5-RE Thunderchief 58-1173 carrying sixteen 750-pound M117 general purpose bombs. (U.S. Air Force)

10 August 1961: A Republic F-105 Thunderchief lifted the largest load ever carried aloft by a single-engine aircraft when it carried a payload of over 14,000 pounds (6,350.3 kilograms) during a test.

In this photograph, F-105D-5-RE Thunderchief 58-1173 is loaded with sixteen 750-pound M117 general purpose bombs, which actually weigh approximately 820 pounds (372 kilograms) each.

A color image of F-105D 58-1173. (U.S. Air Force)
A color image of F-105D 58-1173. (U.S. Air Force)

The Thunderchief is the largest single seat, single engine aircraft ever built. It was a Mach 2 fighter-bomber, designed for NATO defensive tactical nuclear strikes with a nuclear bomb carried in an internal bomb bay. It is best known, though, as a fighter bomber used in the Vietnam War. Because of its very high speed it was employed as a “Wild Weasel”, attacking surface-to-air missile sites.

A color image of F-105D 58-1173 from below. (U.S. Air Force)
A color image of a Republic F-105 Thunderchief, possibly 58-1173, seen from below. (U.S. Air Force)

Republic Aviation Corporation built 833 F-105 Thunderchief fighter bombers at its Farmingdale, New York factory. 610 of those were single-seat F-105Ds. The F-105D Thunderchief is 64 feet, 3 inches (19.583 meters) long with a wingspan of 34 feet, 11 inches (10.643 meters) and overall height of 19 feet, 8 inches (5.994 meters). It has an empty weight of 27,500 pounds (12,473.79 kilograms) and a maximum takeoff weight of 52,546 pounds (23,834.47 kilograms).

The Thunderchief was powered by one Pratt & Whitney J75-P-19W engine. The J75 is a two-spool axial-flow afterburning turbojet with water injection. It has a 15-stage compressor section (8 low- and and 7 high-pressure stages) and 3-stage turbine section (1 high- and 2 low-pressure stages.) The J75-P-19W is rated at 17,200 pounds of thrust (76.51 kilonewtons), and 26,500 pounds (117.88 kilonewtons) with afterburner. It is 20 feet (6.1 meters) long, 3 feet, 7.0 inches (1.092 meters) in diameter, and weighs 5,960 pounds (2,703 kilograms).

The maximum speed of the F-105D is 836 miles per hour (1,345 kilometers per hour)—Mach 1.1—at Sea level and Mach 2.15 (1,420 miles per hour, 2,285 kilometers per hour) at 38,000 feet (11,582 meters). The combat ceiling is 48,500 feet (14,782.8 meters) and combat range is 778 miles (1,252.07 kilometers).

The F-105D is armed with one 20 mm M61A1 Vulcan rotary cannon and 1,028 rounds of ammunition. It has an internal bomb bay and can carry bombs, missiles or fuel tanks on under wing and centerline hardpoints. The maximum bomb load consisted of sixteen 750-pound (340 kilogram) bombs.

The F-105 Thunderchief was designed as a supersonic tactical fighter bomber rather than an air superiority fighter. Still, during the Vietnam War F-105s shot down 27 enemy MiG fighters. 24 of those were shot down with the Thunderchief’s Vulcan cannon.

Of the 833 F-105s, 395 were lost during the Vietnam War. 334 were shot down, mostly by antiaircraft guns or missiles, and 17 by enemy fighters. Another 61 were lost due to accidents. The 40% combat loss is indicative of the extreme danger of the missions these airplanes were engaged in.

Republic F-105D-30-RE (S/N 62-4234) in flight with full bomb load. (U.S. Air Force photo)
Republic F-105D-30-RE Thunderchief 62-4234 with a full bomb load. (U.S. Air Force)

© 2017, Bryan R. Swopes

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10 August 1912

Lieutenant Colonel Sir Francis Kennedy McLean, A.F.C., 18 September 1919. (Flight)
Lieutenant Colonel Sir Francis Kennedy McLean, A.F.C., 18 September 1919. (Flight)

10 August 1912: Frank McLean (later, Lieutenant Colonel Sir Francis Kennedy McLean, A.F.C.) flew his modified Short S.33 float plane, and, according to his obituary in the London Times, 12 August 1955, “. . . created a record by flying up the Thames in a seaplane, passing between the upper and lower parts of Tower Bridge and under London Bridge without touching the water.”

The vertical distance between the upper walkways and the deck of the draw bridge is 141 feet, 0 inches (42.977 meters).

Diagram of Tower Bridge, with dimensions. (Wikipedia)
Diagram of Tower Bridge, with dimensions. (Wikipedia)

Flight reported the event:

By Hydro-aeroplane up the Thames

     ALTHOUGH London was deprived by the appalling weather of the sight of M. Beaumont piloting his hydro-aeroplane up the Thames, the visit of Mr. F.K. McClean more than compensated for the loss. Remembering an appointment in town on Saturday morning, Mr. McClean thought it would be a good idea to come up on his Short machine, and so at 6 a.m. he had it out of its shed at Harty Ferry, in the Isle of Sheppey, and after seeing everything in order he started off. Following the coast round Leysdown, Warden Point to Sheerness, he continued over the Thames. At Gravesend the smoke of various factories rather troubled the aviator but he made good progress. Approaching London Mr. McClean brought his machine lower down and negotiated the Tower Bridge between the lower and upper spans, but the remaining bridges to Westminster he flew underneath, the water just being touched at Blackfriars and Waterloo bridges. He reached Westminster about 8.30 and was taken ashore to Westminster Pier on a Port of London Launch.

The return journey on Sunday afternoon was not so successful—owing to restrictions as to rising from the water which had been imposed by the police. The bridges had all been safely negotiated, and when near Shadwell Basin Mr. McClean started to manœuver to get into the air at the point designated by the river authorities. He had made one circuit when the machine side-slipped, and either through hitting a barge or by sudden contact with the water one of the floats was damaged. The machine was then towed into Shadwell Dock, this operation being superintended by Mr. McClean from the driving seat, and dismantled for its return by road to Eastchurch.

FLIGHT, No. 190. (No 33, Vol. IV.) 17 August 17 1912 at Page759, Column 1

Frank McLean flying through the Tower Bridge, 10 August 1912. (Clan Maclean)
Frank McLean flying through the Tower Bridge, 10 August 1912. (Clan Maclean Heritage Trust)

The Short S.33 was a variant of the S.27 biplane, built specifically for McLean. It is a two-place, single-engine four-bay biplane with the engine in a pusher configuration. An elevator is forward. Although it had been fitted with two floats for operating from the water, McLean had it converted to a land plane by installing two wheels on a tube axle attached to the lower wing with four struts. Two wooden skids are also installed. The fuselage is an open rectangular framework. At the aft end is a horizontal stabilizer and elevator, and two rudders. There were two tail skids.

The Short S.33 was 36 feet, 0 inches (10.973 meters) long (following conversion) with an upper wingspan of 70 feet, 6 inches (21.488 meters). The upper wing had a maximum chord of 6 feet, 7 inches.  The outer 16 feet (4.877 meters) of the upper wing was swept aft and had a slight dihedral, as did the outer panels of the lower wings. The lower wing had a shorter wingspan and narrower chord—5 feet, 9 inches (1.753 meters)—than the upper wing. The biplane had a gross weight of 1,600 pounds (725.75 kilograms)

The S.33 was powered by an air-cooled 10.292 liter (628.05-cubic-inch-displacement) Société des Moteurs Gnome Gamma 7-cylinder rotary engine producing 70 horsepower at 1,200 r.p.m. It turned a two-bladed, fixed-pitch wooden propeller with a diameter of 8 feet, 6 inches (2.591 meters) through direct drive.

Three-view diagram of Frank McLean's "70-H.P. Short biplane.: (FLIGHT, No. 232. (No. 23, Vol. V.), 7 June 1913 at Page 614)
Three-view diagram of Frank McLean’s “70-H.P. Short biplane.” (FLIGHT, No. 232. (No. 23, Vol. V.), 7 June 1913 at Page 614)

Sir Francis was a civil engineer, astronomer, pioneering photographer and aviator. He received the Royal Aero Club’s  Aviator Certificate Number 21 on 20 September 1910.

McLean served in the Royal Naval Air Service during World War I and became an officer of the Royal Air Force when RNAS and the Royal Flying Corps were combined in 1918. He is considered to be the founder of the Fleet Air Arm. McLean was decorated with the Air Force Cross in 1919.

For his services to aviation, McLean was knighted by George V, 3 July 1926 and later appointed High Sheriff of Oxfordshire.

Sir Francis McLean died 11 August 1955 at London, England, after a lengthy illness. He was 79 years old.

Francis McLean’s Short S.33 biplane, which he used to fly through and under bridges on the Thames, 10 August 1912.

© 2017, Bryan R. Swopes

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