U.S. Air Force Douglas C-47 Skytrain transports unloading supplies at Flughafen Berlin-Templehof, Berlin, 1948. (U.S. Air Force)
26 June 1948: 32 United States Air Force Douglas C-47 Skytrain transports flew 80 tons of supplies to Berlin, the first day of the Berlin Airlift.
At the height of the Cold War, the Union of Soviet Soviet Socialist Republics, occupying eastern Germany following World War II, blockaded the Allied portions of the city of Berlin, cutting off all transportation by land and water. This was followed by the building of the Berlin Wall. The western part of the city was now completely isolated. Josef Stalin hoped to force Britain, France and the United States to abandon Berlin, giving the communists complete control of the devastated country.
Soviet T-55 tanks at Checkpoint Charlie, one of just three access points to the Allied sectors of Berlin. (Central Intelligence Agency)
General Curtis LeMay was asked to transport the needs of the city by air. It was calculated that they would need to supply seventeen hundred calories per person per day, giving a grand total of 646 tons of flour and wheat, 125 tons of cereal, 64 tons of fat, 109 tons of meat and fish, 180 tons of dehydrated potatoes, 180 tons of sugar, 11 tons of coffee, 19 tons of powdered milk, 5 tons of whole milk for children, 3 tons of fresh yeast for baking, 144 tons of dehydrated vegetables, 38 tons of salt and 10 tons of cheese. In total, 1,534 tons were needed daily to keep the over two million people alive. Additionally, the city needed to be kept heated and powered, which would require another 3,475 tons of coal and gasoline.
A U.S. Air Force Douglas C-54 Skymaster on approach to land at Flughafen Berlin-Templehof.
At the height of the airlift, one airplane was landing every 30 seconds. By the end, more supplies were arriving by air than had previously come by rail. The airlift ended 30 September 1949.
2,326,406 tons of food, medicine and coal had been delivered.
101 aviators lost their lives.
A Douglas C-47 Skytrain clears the rooftops after takeoff from Berlin-Templehof. (Unattributed)
26 June 1942: The Grumman XF6F-1, Bureau of Aeronautics serial number (Bu. No.) 02981, prototype for the Navy and Marine Corps F6F Hellcat fighter, with Grumman’s Chief Engineer and Test Pilot Robert Leicester Hall flying, made a 25-minute first flight at the Grumman Aircraft Engineering Corporation plant, Bethpage, Long Island, New York.
The first Hellcat was powered by an air-cooled, supercharged, 2,603.737-cubic-inch-displacement (42.688 liters) Wright Aeronautical Division Twin Cyclone GR2600B676 (R-2600-10) two-row, 14-cylinder radial engine. This engine had a compression ratio of 6.9:1 and required 100-octane aviation gasoline. The R-2600-10 was rated at 1,500 horsepower at 2,400 r.p.m. at Sea Level, and 1,700 horsepower at 2,600 r.p.m. for takeoff. It turned a three-bladed Curtiss Electric propeller through a 0.5625:1 gear reduction. The R-2600-10 was 4 feet, 6.26 inches (1.378 meters) in diameter and 6 feet, 2.91 inches (1.903 meters) long. It weighed 2,115 pounds (959 kilograms).
Beginning with the second prototype, Bu. No. 02982, the Pratt & Whitney Double Wasp SSB2-G (R-2800-10) 18-cylinder engine became the standard powerplant. The R-2800-10 was an air-cooled, supercharged, 2,804.4-cubic-inch-displacement (45.956 liter), twin-row 18-cylinder radial engine with water injection. The engine had a compression ratio of 6.65:1 and was rated at 1,550 horsepower at 2,550 r.p.m. at 21,500 feet (6,553 meters), and 2,000 horsepower at 2,700 r.p.m. for takeoff, burning 100-octane gasoline. The engine drove a three-bladed Hamilton Standard Hydromatic constant-speed propeller with a diameter of 13 feet, 1 inch (3.988 meters) through a 2:1 gear reduction. The R-2800-10 was 4 feet, 4.50 inches (1.334 meters) in diameter, 7 feet, 4.47 inches (2.247 meters) long, and weighed 2,480 pounds (1,125 kilograms), each. The engine weighed 2,480 pounds (1,125 kilograms).
Grumman XF6F-1 Hellcat Bu. No. 02981 in flight. (Northrop Grumman)
The first prototype was quickly re-engined to the Pratt & Whitney radial and redesignated XF6F-3. Bob Hall flew it with the new engine on 30 July 1942. A few weeks later, 17 August, the Hellcat’s new engine failed and Hall crash-landed at Crane’s Farm. The airplane was moderately damaged and Hall was seriously injured.
Grumman XF6F-3 Bu. No. 02981 after crash landing in a field at Crane’s Farm, Long Island, New York, 17 August 1942. (Northrop Grumman)
The airplane was rebuilt and continued in the test program. It was eventually converted to the XF6F-4 with a two-speed turbocharged Pratt & Whitney Double Wasp 2SB-G (R-2800-27) which produced 2,000 horsepower at 2,700 r.p.m. It was armed with four 20 mm cannon.
The first prototype Hellcat was converted to the XF6F-4 configuration, seen here at NACA, Langley Field, Virginia in 1944. (NASA)
The Grumman F6F-3 Hellcat is single-place, single-engine fighter designed early in World War II to operate from the U.S. Navy’s aircraft carriers. It is a low wing monoplane monoplane of all metal construction. The wings can be folded against the sides of the fuselage for storage aboard the carriers. Landing gear is conventional, retractable, and includes an arresting hook.
The F6F-3 is 33 feet, 7 inches (10.236 meters) long with a wingspan of 42, feet 10 inches (12.842 meters) and overall height of 14 feet, 5 inches (4.394 meters) in three-point position. It has an empty weight of 9,207 pounds (4,176 kilograms) and gross weight of 12,575 pounds (5,704 kilograms).
A Grumman F6F Hellcat ready for takeoff from an Essex-class aircraft carrier, circa 1943. (U.S. Navy)
The F6F-3 Hellcat was powered by a Pratt & Whitney Double Wasp SSB2-G (R-2800-10W) engine with water injection, rated at 2,000 horsepower at 2,700 r.p.m. for takeoff, using 100/130 octane aviation gasoline. The normal power rating was 1,550 horsepower at 2,550 r.p.m. at 22,500 feet (6,858 meters). The engine drove a three-bladed Hamilton Standard Hydromatic constant-speed propeller with a diameter of 13 feet, 1 inch (3.988 meters) through a 2:1 gear reduction. The engine weighed 2,480 pounds (1,125 kilograms).
Two Grumman F6F-3 Hellcat fighters, Summer 1943. (U.S. Navy)
In clean configuration, the F6F-3 had a maximum speed of 321 miles per hour (517 kilometers per hour) at Sea Level, and 384 miles per hour (618 kilometers per hour) at 18,000 feet (5,486 meters). It could climb to 10,000 feet (3,048 meters) in 3.2 minutes, and to 20,000 feet (6,096 meters) in 7.0 minutes. The service service ceiling was 38,800 feet (11,826 meters). It had a combat radius of 335 nautical miles (386 miles/620 kilometers). The maximum ferry range was 1,540 miles (2,478 kilometers).
The Hellcat’s armament consisted of six air-cooled Browning AN-M2 .50-caliber machine guns, mounted three in each wing, with 2,400 rounds of ammunition.
The Grumman Hellcat was the most successful fighter of the Pacific war, with a kill-to-loss ratio of 19:1. It was in production from 1942 to 1945 and remained in service with the United States Navy until 1956. A total of 12,275 were built by Grumman at Bethpage. This was the largest number of any aircraft type produced by a single plant.
High humidity creates visible propeller tip vortices as this Grumman F6F-3 Hellcat prepares to takeoff from USS Yorktown (CV-10), November 1943. (U.S. Navy)
Robert Leicester Hall
Robert Leicester Hall was born at Taunton, Massachussetts, 22 August 1905. He was the son of Bicknell Hall, a mechanical engineer, and Estella Beatrice Lane Hall.
Hall attended the University of Michigan, graduating in 1927 with Bachelor of Science degree in Mechanical Engineering (B.S.M.E.).
In 1929 he went to work for the Fairchild Airplane Manufacturing Company at Farmingdale, New York. While there, Hall met his first wife, Eugenie, a secretary at the plant. They were married in 1930, and lived in a rented home on St. James Avenue, Chicopee City, Massachusetts. Their son, Robert Jr., was born 5 November 1931.
Granville Brothers Gee Bee Model Z, NR77Y, City of Springfield.
Also in 1931, Hall began working for Granville Brothers Aircraft at Springfield, Massachusetts. He designed the Gee Bee Model Z Super Sportster air racer. He left Granville Brothers in 1933 to go to work for the Stinson Aircraft Company in Dayton, Ohio. There he designed the Stinson Reliant.
A Stinson SR-8E Reliant, NACA 94, at the Langley Research Center, 5 August 1936. (NASA)
In 1936, Bob Hall became the Chief Engineer for the Grumman Aircraft Engineering Corporation, Bethpage, Long Island, New York. He designed the F4F Wildcat, F6F Hellcat, F7F Tigercat, and F8F Bearcat fighters, and the TBF Avenger torpedo bomber. As corporate vice president, he supervised the design of the F9F Panther and Cougar jet fighters.
Hall married his second wife, Rhoda C. Halvorsen, 18 January 1939, at New York City, New York.
Hall retired from Grumman in 1970. Two of his sons, Eric and Ben Hall, founded Hall Spars and Rigging of Bristol, Rhode Island.
Robert Leicester Hall died at Newport, Rhode Island, 25 February 1991, at the age of 85 years.
Grumman F6F-3 Hellcat, Bu. No. 4778, Long Island, New York, circa 1942. (Rudy Arnold Collection/NASM)
Grumman F6F-3 Hellcat Bu. No. 26108, Long Island, New York, circa 1943. (Rudy Arnold Collection/NASM)
Northrop XB-35 taking off at Northrop Field, Hawthorne, California. (U.S. Air Force)Max R. Stanley (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers))
25 June 1946: Northrop Aircraft, Inc., experimental test pilot Max R. Stanley, flight test engineer Dale Schroeder and Orva H Douglas, Jr., flight engineer, made the first flight of the Northrop XB-35 “Flying Wing,” serial number 42-13603. They took off from the factory’s airfield at Hawthorne, California, and flew the prototype bomber to Muroc Army Air Field (now, Edwards Air Force Base). The initial flight lasted 55 minutes.
The Los Angeles Times reported:
Gigantic Flying Wing Triumphs in First Flight
Northrop 110,000-Pound Superbomber Soars 44 Minutes, makes Perfect Landing
Unleashed into the future, a huge and spectral devilfish bellowed up from the earth yesterday and soared eastward toward the morning sun—Northrop’s malevolent Flying Wing superbomber on her maiden test flight, Forty-four minutes later the ship made a perfect landing at Muroc Army Airfield.
Eerie, almost supernatural, she trundled to the west end of Northrop’s mile-long Hawthorne runway as the sun burned away the morning mists.
Thundering Take-off
For 45 minutes she stood motionless, a 172-foot knife blade, while her four 3000 h.p. engines turned eight coaxial pusher propellers into life.Then at 10:29 a.m. her whirling blades fused into blurred disks. Her thunder enveloped the field.
Interminably she seemed to hug the ground as Test Pilot Max Stanley held her charging 110,000 pounds down past the hangars, past the flight line, past the midfield control tower.
Monster Leaves Ground
For 30 thudding heartbeats—and as many seconds—the fantastic silver monster strained at the shackles of earth, hurtling at more than 100 m.p.h. toward the end of the runway.
Then at 3000 feet Stanley eased back the yoke. Sunlight skipped beneath the spinning wheels and the Wing lifted into her element under perfect control.
Vanishes Into Haze
In another 60 seconds she vanished into the haze, her wheels still down as Stanley gently tested her sinews. Below, and to the right of his bubble canopy, Co-pilot Fred C. Bretcher stared ahead through plexiglas in the leading edge, and just aft of the pilot, Engineer O. H. Douglas watched her pulse in the needles of scores of instruments.
In an easy climb, Stanley took the superbomber to 10,000 feet over the flat lands between the San Gabriel Mountains and the sea and then banked her slowly north and inland toward Muroc.
Settles to Runway
At the Muroc test field, the strip was cleared and ready. Spectators watched the incredible ship circle once and then gently settle to the runway as gently as a tuft of cotton and roll to stop in 3000 feet.”She handled beautifully,” grinned Stanley.
The outgrowth of years of engineering, she followed the secret testing of a parade of small wings, and her designer, John K. Northrop, is confident she’ll carry more bombs farther and faster than any other airplane ever built.
Fourteen more of the giants will be built under Northrop’s contract with the Army.
—Los Angeles Times, Vol. LXV, Wednesday Morning, 26 June 1946, Page 1, Columns 5 and 6
The Los Angeles Daily News reported:
Flying wing passes tests
Everybody who had anything to do with it was happy today over the 44-minute maiden flight of Northrop’s flying wing.
The bat-like plane, a 104-ton monster bomber, met all expectations during the 85-mile flight from Northrop Field to Muroc Army Air Base.
“The wing handled just as I expected it would,” veteran test pilot Max Stanley declared after landing the giant ship. “We were delighted with its performance and the plane fully came up to our expectations.”
Officials of Northrop Aircraft, who witnessed the initial take-off, said the flight had justified their confidence in the wing.
The ship, a tailess airplane with a bat-like appearance, is the latest in a series of 15 Northrop designed flying wings and was built at a cost of $13,000,000 for the army.
—Daily News, Wednesday, 26 June 1946, Page 3, Column 1
The flight test crew of the Northrop XB-35 at Northrop Field, Hawthorne, California, 1946. Left to right, Dale Schroeder, flight test engineer; Orva H Douglas, Jr., flight engineer; and Max Stanley, test pilot. (Unattributed)
The XB-35 was designed as an aerodynamically efficient heavy bomber. It had a very unusual configuration for an aircraft of that time. There was no fuselage or tail control surfaces. The crew compartment, engines, fuel, landing gear and armament was contained within the wing. It was 53 feet, 1 inch (16.180 meters) long, with a wingspan of 172 feet (52.426 meters) and overall height of 20 feet, 1 inch (6.121 meters). The prototype weighed 89,560 pounds (40,624 kilograms) empty, with a gross weight of 180,000 pounds (81,647 kilograms).
The Wing defined the airplane. It had an aspect ratio of 7.4:1. The wing’s root chord was 37 feet, 6 inches (11.430 meters). The wing was 7 feet, 1.5 inches (2.172 meters) thick at the root. The tip chord was 9 feet, 4 inches (2.844 meters). There was 0° angle of incidence at the root, with -4° of twist, and 0° 53′ dihedral. The leading edge was swept aft 26° 57′ 48″, and the trailing edge, 10° 15′ 22″. The wing’s total area was 4,000 square feet (371.6 square meters).
This view of the first prototype Northrop XB-35, 42-13603, the “Flying Wing,” on the ramp at Muroc Air Force Base shows the pusher arrangement of four-bladed contra-rotating propellers. In the background, a turbojet-powered Northrop YB-49 is in a steep bank. (U.S. Air Force)
The XB-35 was powered by four air-cooled, supercharged and turbocharged 4,362.49 cubic-inch-displacement (71.49 liter) Pratt & Whitney Wasp Major TSB1P-RGD (R-4360-17 or -21) four-row 28-cylinder radial engines with a compression ratio of 7:1. The R-4360-17 was rated at 2,500 horsepower at 2,550 r.p.m at 40,000 feet (12,192 meters), and 3,000 horsepower at 2,700 r.p.m., for takeoff. It could maintain the takeoff rating to an altitude of 40,000 feet (12,192 meters) for Military Power. The engines were mounted completely inside the wing and were connected to a remote propeller drive unit by drive shafts. The engines were direct drive, while the propeller gear boxes had a 0.381:1 reduction ratio. The R-4360-17 was 5 feet, 7.00 inches (1.702 meters) long, 4 feet, 4.50 inches (1.334 meters) in diameter, and weighed 3,306 pounds (1,499.6 kilograms).
Northrop XB-35 42-13603 in flight with early contra-rotating propellers. (U.S. Air Force)
The propellers were dual three-bladed contra-rotating assemblies located in pusher configuration at the wing’s trailing edge. (These were quickly changed to four-bladed propellers, which were smoother in operation and more efficient.)
Northrop XB-35 42-13603. (U.S. Air Force)
The XB-35 had a cruising speed of 183 miles per hour (295 kilometers per hour) at 39,700 feet (12,100 meters) and maximum speed was 391 miles per hour (629 kilometers per hour) at 35,000 feet (10,668 meters). With a crew of nine, and another six relief crewmembers, the bomber had a range of 8,150 miles (13,116 kilometers).
The production Northrop B-35 would have been armed with twenty .50-caliber machine guns for defense and a maximum bomb load of 51,200 pounds (23,223 kilograms).
Underside of a Northrop XB-35. (U.S. Air Force)
The XB-35 was plagued by unresolved problems with the propeller gear boxes which eventually forced Jack Northrop to ground the aircraft until the engine and propeller manufacturers could come up with a solution, which was to change from piston to turbojet engines. That version became the YB-49. Because of the continuing problems, though, 42-13603 was grounded after only 19 flights, and with its sister ship, XB-35 42-38323, was scrapped in August 1949.
25 June 1937: Leg 25. After flying from Bandoeng to Soerabaya the previous day, a problem with Amelia Earhart’s Lockheed Electra 10E Special, NR16020, could not be repaired there, forcing her to return to Bandoeng.
“In the air, and afterward, we found that our mechanical troubles had not been cured. Certain further adjustments of faulty long-distance flying instruments were necessary, and so I had to do one of the most difficult things I had ever done in aviation. Instead of keeping on I turned back the next day to Bandoeng. With good weather ahead, the Electra herself working perfectly, the pilot and navigator eager to go, it was especially hard to have to be “sensible.” However, lack of essential instruments in working order would increase unduly the hazards ahead. At Bandoeng were the admirable Dutch technicians and equipment, and wisdom directed we should return for their friendly succor. So again we imposed ourselves upon these good people to whom I shall be grateful always for their generosity and fine spirit. A particular niche in my memory is occupied by Colonel L.H.V. Oyen, Commander of the Air Force, H.A. Vreeburg, chief engineer, and so many K.N.I.L.M. personnel to whom I would like again to say ‘Thank you’.”
— Amelia Earhart
Amelia Earhart’s Lockheed Electra 10E Special, NR16020, at Bandoeng, Java, Dutch East Indies, June 1937. (Purdue University Libraries, Archives and Special Collections)Bandoeng to Soerabaya, 352.26 miles (566.91 kilometers). (Google Maps)
First flight of the Junkers F.13 at Dessau, Germany, 25 June 1919. (Junkers)
25 June 1919: Junkers Flugzeugwerke Aktiengesellschaft test pilot Emil Monz made the first flight of the Junkers F.13 at Dessau, Saxony-Anhalt, Germany. It was the first airplane to be built of all-metal construction specifically for commercial passenger service. The the first flyable prototype, constructor’s number (c/n) 533, carried the identification mark D 183. Professor Junkers had named the airplane Herta in honor of his oldest daughter.¹
Up to this time, airplanes had been primarily constructed of wood. Wood is susceptible to changes in dimension because of temperature and humidity, and it can warp over time. This effects the flight characteristics of the aircraft. Wood is also vulnerable to termites.
By building the airplane of metal, a much more rigid structure was created. The airplane’s flight characteristics did not change over time. Also, because metal is so much stronger than wood, an all-metal airplane could be significantly lighter than one built of wood.
The cockpit of the Junkers F.13 accommodated a crew of two. (Junkers)Otto Reuter (Junkers)
Designed by Chief Engineer Otto Reuter, the F.13 was a single-engine, low-wing monoplane (tiefdecker) with a corrugated duralumin skin over a duralumin structure. It had a flight crew of two and four passengers could be carried in a comfortable enclosed cabin of the same size as automobiles of the time. The single wing was cantilevered and, unusually for the time, used no braces or support wires.
The prototype had a wingspan of 14.47 meters (47 feet, 5.7 inches). The wingspan was increased to 14.82 meters (48 feet, 7.5 inches) in production airplanes. The airplane was 9.59 meters (31 feet, 5.6 inches) long and 4.10 meters (13 feet, 5.4 inches) high. It had a maximum takeoff weight of 1,800 kilograms (3,968 pounds).
The first of three prototypes to fly, Junkers F.13 D 183, Herta, photographed on 19 August 1919. (Junkers)
The first F.13 was powered by a water-cooled, normally-aspirated 14.778 liter (901.81 cubic inch) Daimler Motoren Gesellschaft Mercedes D.IIIa vertical inline six-cylinder engine. This was a single overhead cam right-hand tractor direct-drive engine. It used two valves per cylinder and a compression ratio of 4.64:1. It produced 174 horsepower at 1,400 r.p.m., and drove a two-bladed, fixed-pitch laminated wood propeller. The D.IIIa weighed 660.0 pounds (299.4 kilograms), including the propeller hub and exhaust manifold.
Production airplanes used BMW and Junkers engines.
The F.13 had a maximum speed of 170 kilometers per hour (106 miles per hour).
The passenger compartment of the Junkers F.13 seated for passengers. (Junkers)
In production from 1919 to 1932, a total of 332 Junkers F.13s were built. Some remained in service in the late 1930s.
In 1920, D 183 was confiscated by the Inter-Allied Control Commission. Later, the F.13 flew for Lufthansa. The registration mark was changed to D 1 and it was named Nachtigall (Nightingale).
Junkers F.13 D 1, Nachtigall, in Luft Hansa livery at Berlin-Templehoff.Emil Monz
Emil Monz was born 9 June 1893, in Stuttgart, Germany. He was the son of Karl and Mathilde Monz. He married Fräulein Maline Georgine Erhardt, 24 January 1915, at Weingarten u. Wilhelmsdorf, Württrmberg, Deutschland.
During World War I, Monz was a reconnaissance pilot for the German Empire.
On 13 September 1919, Monz flew the second F.13, with seven passengers on board, to an altitude of 6,750 meters (22,146 feet). This was an unofficial world record.
Emil Monz died 18 February 1921 when the Junkers F.13 that he was flying, D 128, crashed in a snowstorm enroute to Stuttgart.
¹ While it is believed that Professor Junkers named the prototypes after his daughters Herta and Annelise, sources vary over which name was applied to which aircraft. The confusion may be a result of the serial numbers. The first F.13 to fly was c/n 533, while the second had an earlier number, c/n 531.
