Daily Archives: October 24, 2023

24 October 1947

Grumman Model G-64, XJR2F-1 Pelican. (Уголок неба)

24 October 1947: First flight, prototype Grumman Model G-64, the XJR2F-1 Pelican. This amphibian would become the Grumman UF-1 Albatross. (In U.S. Air Force service, the Albatross was designated SA-16A. In 1962, this was changed to HU-16A for Navy, Coast Guard and USAF.)

Interestingly, several months earlier, the National Advisory Committee for Aeronautics (NACA) conducted landing tests using a 1:7-scale model XJ2RF-1 in a test tank at the Langley Memorial Aeronautical Laboratory. Wave heights of 4.4 and 8.0 inches (11.2 and 20.3 centimeters) were used, with wave lengths between 10 feet and 50 feet (3–15 meters). Tests indicated that the amphibian could be expected to experience a maximum of 8.5 gs.

Grumman G-64, XJ2RF-1 Pelican (U.S. Coast Guard)

The Albatross was operated by a crew of 4 to 6 airmen, and could carry up to 10 passengers. The SA-16A amphibian was 62 feet, 10 inches (19.152 meters) long, with a wingspan (before modification) of 80 feet, 0 inches (24.384 meters) and had an overall height of 25 feet, 11 inches (7.899 meters). The wing had an angle of incidence of 5° and the total wing area was 883 square feet (82.03 square meters).

The SA-16A was modified to the SA-16B standard, increasing the wingspan to 96 feet, 8 inches (29.464 meters) and the wing area to 1,035 square feet (96.15 square meters). The wing’s leading edges were altered and larger tail surfaces were added.

The HU-16B had an empty weight of 23,025 pounds (10,444 kilograms), and maximum takeoff weight of 37,500 pounds (17,010 kilograms). For takeoff from water, the airplane’s weight was limited to 34,000 pound (15,422 kilograms), using rocket assist. The maximum weight for landing on water was 32,000 pounds (14,515 kilograms).

The SA-16 was powered by two air-cooled, supercharged, 1,823.129-cubic-inch-displacement (29.876 liter) Wright Aeronautical Division Cyclone 9 826C9HD3 and -D5 (R-1820-76A and -76B) nine-cylinder radial engines with a compression ratio of 6.80:1. 115/145 octane aviation gasoline was required. These engines were rated at 1,275 horsepower at 2,500 r.p.m., and 1,425 horsepower at 2,700 r.p.m for takeoff. The engines drove three-bladed Hamilton Standard Hydromatic full-feathering, reversible-pitch propellers with a diameter of 11 feet, 0 inches (3.353 meters) through a 0.666:1 gear reduction. The R-1820-76A and -76B were 3 feet, 11.69 inches (1.211 meters) long and 4 feet, 6.95 inches (1.396 meters) in diameter, and weighed 1,380 pounds (626 kilograms).

The Albatross could be equipped with two or four Aerojet 14AS1000 RATO units, which produced 1,000 pounds of thrust (4.49 kilonewtons), each, for 15 seconds.

The flying boat had a cruise speed of 134 knots (154 miles per hour/248 kilometers per hour) and a maximum speed of 204 knots (235 miles per hour/378 kilometers per hour) at 3,700 feet (1,128 meters). The service ceiling was 23,800 feet (7,254 meters). The SA-16B had a combat radius of 725 nautical miles (834 statute miles/1,343 kilometers), and 1,130 nautical miles (1,300 statute miles/2,093 kilometers) with two 300-gallon (1,136 liters) drop tanks.

This former U.S. Coast Guard UF-1G (HU-16E) Albatross is now privately owned. (paxdaus)

© 2018, Bryan R. Swopes

24 October 1946

First photograph of the Earth taken from an altitude of 65 miles (105 kilometers). (White Sands Missile Range/Applied Physics Laboratory)

24 October 1946: At 12:18 p.m., Mountain Standard Time (17:18 UTC), a captured V-2 rocket was launched from the U.S. Army’s White Sands Missile Range, east of Las Cruces, New Mexico. The rocket, identified as Upper Air  Rocket Number 13, carried a 35-millimeter DeVry Corporation cine camera set to expose one frame every second-and-a-half.

The V-2’s engine burned for 59.8 seconds, by which time the rocket had reached an altitude of 17.0 miles (27.4 kilometers) and a velocity of 3,990 feet per second (1,216 meters per second). Continuing upward on a ballistic trajectory, the rocket reached a maximum altitude of 65.0 miles (104.6 kilometers) after 180.0 seconds. This is just above the 100-kilometer Kármán Line which is the arbitrary beginning of Space.

Falling back to Earth, Number 13 impacted approximately 17 miles north-northwest of the White Sands V-2 Launching Site and was completely destroyed. Although debris from the rocket was scattered widely, the film cassette was recovered.

The image above is a still frame from the recovered film. It shows the curvature of the Earth. This was the highest altitude a photograph had been made since Captain Albert W. Stevens photographed the Earth from a balloon, Explorer II, 20 July 1935.

A captured German V-2 rocket is launched from the White Sand Proving Grounds, 10 May 1946. (Popular Science)

The V2, or Vergeltungswaffen 2 (also known as the A4, or Aggregat 4) was a ballistic missile with an empty weight of approximately 10,000 pounds (4,536 kilograms) and weighing 28,000 pounds (12,700 kilograms), fully loaded. It carried a 738 kilogram (1,627 pound) (sources vary) explosive warhead of amatol, a mixture of ammonium nitrate and TNT. The propellant was a 75/25 mixture of ethanol and water with liquid oxygen as an oxidizer.

The complete rocket was 14.036 meters (46.050 feet) long, and had a maximum diameter of 1.651 meters (5.417 feet). The rocket was stabilized by four large fins, 3.945 meters (12.943 feet) long, with a maximum span of 3.564 meters (11.693 feet). The leading edge of these fins was swept aft 60° to the “shoulder,” and then to 87° (30° and 3°, relative to the rocket’s centerline). A small guide vane was at the outer tip of each fin, and other vanes were placed in the engine’s exhaust plume.

Cutaway illustration of a V-2 rocket. (U.S. Army)

When launched, the rocket engine burned for 65 seconds, accelerating the rocket to 3,580 miles per hour (5,760 kilometers per hour) on a ballistic trajectory. The maximum range of the rocket was 200 miles (320 kilometers) with a peak altitude between 88 and 128 miles, depending on the desired range. On impact, the rocket was falling at 1,790 miles per hour (2,880 kilometers per hour), about Mach 2.35, so its approach would have been completely silent in the target area.

The V-2 could only hit a general area and was not militarily effective. Germany used it against England, France, The Netherlands and Belgium as a terror weapon. More than 3,200 V-2 rockets were launched against these countries.

U.S. soldiers examine an incomplete V-2 rocket at Kleinbodungen, Germany, 1945.

As World War II came to and end, the Allies captured many partially-completed missiles, as well as components and parts. Sufficient parts and materiel and been transferred from Germany to construct more than one hundred V-2 rockets for testing at White Sands. No missiles were received in flyable condition. Over a five year period, there were 67 successful launches, but it is considered that as much knowledge was gained from failures as successes.

V-2 rocket body at White Sands.

Along with the rockets, many German engineers and scientists surrendered or were captured by the Allies. Under Operation Paperclip, Wernher von Braun and many other scientists, engineers and technicians were brought to the United States to work with the U.S. Army’s ballistic missile program at Fort Bliss, Texas, White Sands Proving Grounds, New Mexico, and the Redstone Arsenal, Huntsville, Alabama.

Tests of the V-2 rockets led to the development of U.S. rockets for the military and NASA’s space program.

V-2 Number 3 is prepared for launch at White Sands Proving Grounds, New Mexico, 10 May 1946. With a burn time of 59 seconds, the rocket reached an altitude of 70.9 miles (114.1 kilometers) and traveled 31 miles (49.9 kilometers) down range. (The Space Race – Rockets)

¹ V-2 Number 13 had an unfueled weight of, 9,070 pounds (4,114 kilograms); fully fueled, it weighed 28,277 pounds (12,826 kilograms).

© 2019, Bryan R. Swopes