Daily Archives: May 21, 2024

21 May 1956

Major David Crichlow, USAF, Aircraft Commander, Barbara Grace, 21 May 1956. (LIFE photograph via Jet Pilot Overseas)
Major David M. Critchlow, U.S. Air Force, Aircraft Commander, in the cockpit of another aircraft, B-52B-30-BO Stratofortress 53-383. (LIFE Magazine via Jet Pilot Overseas)

21 May 1956: The second test of the OPERATION REDWING series was REDWING CHEROKEE.

A B-52 Stratofortress assigned to the 4925th Test Group (Atomic), Kirtland Air Force Base, Albuquerque, New Mexico, took off from Eniwetok Island (“Fred Island”), the main island of Eniwetok Atoll in the Marshall Islands. The aircraft commander was Major David M. Critchlow, United States Air Force. Other members of the bomber’s crew were Major Charles T. Smith, pilot; Major Dwight E. Durner, bombardier; Major Floyd A. Amundson, navigator; Lieutenant William R. Payne, timer; Sergeant Richard N. Bingham, radar technician. Colonel Paul R. Wignaff was an official observer.

Boeing RB-52B Stratofortress 52-013
Boeing RB-52B-10-BO Stratofortress 52-013, Barbara Grace. (The National Museum of Nuclear Science and History)

The bomber, named Barbara Grace, was a Boeing RB-52B-10-BO Stratofortress, serial number 52-013. In its bomb bay was a TX-15-X1 two-stage radiation implosion thermonuclear bomb, weighing 6,867 pounds (3,114.9 kilograms). The bomb was approximately 136 inches long (3.454 meters), with a diameter of 34.5 inches (0.876 meters). The target was a point on Namu Island, Bikini Atoll, also in the Marshall Islands.

Major Critchlow’s wife was named Barbara, and his mother, Grace. The B-52 was named Barbara Grace in their honor.

This Mark 15 nuclear bomb is similar to the TX-15-X1 used in Redwing Cherokee.
This Mark 15 nuclear bomb is similar to the TX-15-X1 used in REDWING CHEROKEE.

CHEROKEE was the first test at Bikini, a test event called for by DOD, and the only shot of the series not expressly for weapons development. The shot was rather a demonstration that the United States could air-deliver multimegaton-yield thermonuclear weapons using B-52 jet bombers. The device, designed and developed by Los Alamos Scientific Laboratory (LASL), was airdropped from a B-52 and exploded at a height of 5,000 feet (1.5 km) above Nam on 21 May 1956. Although a demonstration, the shot provided a large-yield burst well above the surface, and it was therefore of considerable interest for airblast effects experiments. However, the explosion was considerably off target, lessening its value.

OPERATION REDWING 1956, DNA 6037F, by S. Bruce-Henderson, et al., Defense Nuclear Agency, Chapter 4 at Page 177

Flying at 50,000 feet (15,240 meters), the aircrew misidentified an observation facility on a different island for their targeting beacon. The bomb missed Namu Island by 4 miles (6.4 kilometers), detonating at 4,350 feet (1,325 meters) over the open ocean to the northeast at 0551 hours, local time (1751 GMT). The explosive force of the TX-15 was rated at 3.8 megatons, but because of the error in targeting, most of the test data was lost.

Redwing Cherokee target, Namu Island, Bikini Atoll, May 1956.
Redwing Cherokee target, Namu Island, Bikini Atoll, May 1956.

The REDWING CHEROKEE test was the first time that a thermonuclear weapon had been dropped from an airplane.

Redwing Cherokee fireball (Wikipedia)
Redwing Cherokee fireball, 0551 hours, 21 May 1956. (Wikipedia)
Redwing Cherokee
Redwing Cherokee condensation rings.

David Madison Critchlow was born at Durkee, Oregon, 17 February 1920, the fourth of six children of J. Ralph Critchlow, a farmer, and Estella Grace Culbertson Critchlow. He enlisted in the U.S. Army Air Corps as a private, 3 December 1942. He was assigned as an aviation cadet, and commissioned a 2nd lieutenant, Army of the United States, 27 June 1944. He was promoted to 1st lieutenant, 18 March 1946. He served in the Air Force during World War II, the Korean War and the Vietnam War.

David Critchlow married Miss Lorraine Calhoun, 9 January 1943. He later married Miss Barbara N. Oder, 9 July 1950. They would have five children.

Major Critchlow, assigned to Detachment 1, 24th Strategic Reconnaissance Squadron, 6th Strategic Wing deployed to Shemya, Alaska, 31 December 1961 with Nancy Rae, a top secret Rivet Ball strategic reconnaissance RC-135S, 59-1491.¹

Colonel Critchlow would later command the 6512 Test Group at Edwards Air Force Base, California, 1 October 1969–29 July 1970. He retired form the U.S. Air Force 1 August 1974.

Colonel David M. Critchlow died 11 December 2002 at the age of 81 years. He is buried at Arlington National Cemetery.

Fifty B-52Bs were built by Boeing at Seattle, Washington. Twenty-seven of these were RB-52B reconnaissance bombers. They were designed to accept a pressurized electronic and photo recon capsule with a two-man crew that completely filled the bomb bay. Without the capsule aboard, they were capable of the same bombing missions as their sister B-52Bs. The change could be made within a few hours.

The B-52B/RB-52B was operated by a six-man flight crew for the bombing mission, and eight for reconnaissance. These were the aircraft commander/pilot, co-pilot, navigator, radar navigator/bombardier, electronic warfare officer and gunner, plus two reconnaissance technicians when required.

The airplane was 156 feet, 6.9 inches (47.724 meters) long with a wingspan of 185 feet, 0 inches (56.388 meters) and overall height of 48 feet, 3.6 inches (14.722 meters). The wings were mounted high on the fuselage (“shoulder-mounted”) to provide clearance for the engines which were suspended on pylons. The wings’ leading edges were swept 35°. The bomber’s empty weight was 164,081 pounds (74,226 kilograms), with a combat weight of 272,000 pounds (123,377 kilograms) and a maximum takeoff weight of 420,000 pounds (190,509 kilograms).

Early production B-52Bs were powered by eight Pratt & Whitney Turbo Wasp J57-P-1W engines, while later aircraft were equipped with J57-P-19W and J57-P-29W or WA turbojets. The engines were grouped in two-engine pods on four under-wing pylons. The J57 was a two-spool, axial-flow engine with a 16-stage compressor section (9 low- and 7-high-pressure stages) and a 3-stage turbine section (1 high- and 2 low-pressure stages). These engines were rated at 10,500 pounds of thrust (46.71 kilonewtons), each, or 12,100 pounds (53.82 kilonewtons) with water injection.

The B-52B had a cruise speed of 523 miles per hour (842 kilometers per hour). The maximum speed varied with altitude: 630 miles per hour (1,014 kilometers per hour) at 19,800 feet (6,035 meters), 598 miles per hour (962 kilometers per hour) at 35,000 feet (10,668 meters) and 571 miles per hour (919 kilometers per hour) at 45,750 feet (13,945 meters). The service ceiling at combat weight was 47,300 feet (14,417 meters).

Maximum ferry range was 7,343 miles (11,817 kilometers). With a 10,000 pound (4,536 kilogram) bomb load, the B-52B had a combat radius of 3,590 miles (5,778 kilometers). With inflight refueling, the range was essentially world-wide.

Defensive armament consisted of four Browning Aircraft Machine Guns, Caliber .50, AN-M3, mounted in a tail turret with 600 rounds of ammunition per gun. These guns had a combined rate of fire in excess of 4,000 rounds per minute. 52-013 was one of eighteen RB-52Bs equipped with two M24A1 20 mm autocannon in the tail turret in place of the standard four .50-caliber M3 machine guns.

The B-52B’s maximum bomb load was 43,000 pounds (19,505 kilograms). It could carry a 15-megaton Mark 17 thermonuclear bomb, or two Mark 15s, each with a maximum yield of 3.8 megatons.

Boeing manufactured 744 B-52 Stratofortress bombers, with the final one rolled out at Wichita, Kansas, 22 June 1962. As of 27 September 2016, 77 B-52H bombers remain in service with the United States Air Force.

RB-52B-10-BO 52-013 was delivered directly to Kirtland Air Force Base, 29 April 1955. In addition Operation Redwing, 52-013 also participated in Operation Dominic in 1962, which involved 24 air drops from B-52 bombers. The airplane carried the name Deterrent I painted on its nose, but flew missions with the call sign “Cow Slip Two.”

This individual airplane has dropped more than a dozen live nuclear bombs during weapons testing. Withdrawn from service in 1963, 52-013 was transferred to the National Atomic Museum (now, the National Museum of Nuclear Science & History) at Kirtland in 1971, where it has been restored.

Boeing RB-52B-10-BO Stratofortress 52-013 at the National Museum of Nuclear Science & History. (U.S. Air Force 161010-F-ZZ999-007)

¹ See: “A Tale of Two Airplanes,” by Lieutenant Colonel Kingdon R. Hawes, USAF (Ret) at http://www.rc135.com/0000/INDEX.HTM

© 2019, Bryan R. Swopes

21 May 1955, 05:59:45–17:26:18 PST

1st Lieutenant John M. Conroy, 115th Fighter Interceptor Squadron, California Air National Guard, checks the time after arriving back at the point of departure, 21 May 1955. (LIFE Magazine via Jet Pilot Overseas)
1st Lieutenant John M. Conroy, 115th Fighter Interceptor Squadron, California Air National Guard, checks the time after arriving back at the point of departure, 21 May 1955. (Ralph Morse, LIFE Magazine, via Jet Pilot Overseas)

21 May 1955: At 05:59:45 Pacific Standard Time (13:59:45 UTC) 1st Lieutenant John M. (“Jack”) Conroy, U.S. Air Force, a World War II B-17 pilot and former Prisoner of War, took off from the California Air National Guard Base at the San Fernando Valley Airport (re-named Van Nuys Airport in 1957). His airplane was a specially-prepared North American Aviation F-86A-5-NA Sabre, USAF serial number 49-1046. His Destination? Van Nuys, California—by way of Mitchel Field, Long Island, New York. His plan was to return to the ANG base in “The Valley” before sunset.

North American Aviation F-86A-5-NA Sabre 49-1046, "California Boomerang." (California State Military Museum)
North American Aviation F-86A-5-NA Sabre 49-1046, “California Boomerang.” (California State Military Museum)

Several weeks of planning and preparation were involved in “Operation Boomerang”. Five refueling stops would be required and Air National Guard personnel across the United States would handle that. A deviation from peacetime standards would allow the Sabre to be refueled with the engine running to minimize time spent on the ground. (The F-86 was not capable of inflight refueling.) The six-year-old F-86A was polished to ensure that all rivet heads were smooth, seams in the fuselage and wing skin panels were adjusted for precise fit, then were sealed. The gun ports for the six .50-caliber Browning machine guns in the fighter’s nose were filled then covered with doped fabric and painted. This was to reduce aerodynamic drag as much as possible. The General Electric J47-GE-13 turbojet was overhauled, then tested and adjusted for maximum efficiency.

Arrangements for official timing of the West to East and Back Again speed run were paid for by North American Aviation, Inc., whose personnel also provided technical support to the Air National Guard.

Jack Conroy’s F-86A was nicknamed California Boomerang, and had a map of the United States and a boomerang painted on the fuselage. The Sabre remained in its overall natural aluminum finish but had green stripes on the fuselage, vertical fin and wings.

North American Aviation F-86A-5-NA Sabre 49-1046, California Boomerang, being readied for its record flight at Van Nuys, California. (LIFE Magazine via Jet Pilot Overseas)
North American Aviation F-86A-5-NA Sabre 49-1046, California Boomerang, being readied for its return flight at Mitchel Air Force Base, New York. (LIFE Magazine via Jet Pilot Overseas)

After takeoff, Lieutenant Conroy climbed to approximately 40,000 feet (12,192 meters) and headed to his first refueling stop at Denver, Colorado. He landed at 7:48 a.m. PST and the Sabre was refueled and off again in just 6 minutes. From Denver he continued eastward to Springfield, Illinois, arriving at 9:32 a.m. PST. Refueling there took 5 minutes. The next stop was Mitchel Field, Long Island, New York. He touched down at 11:19 a.m., PST and remained on the ground for 39 minutes.

Conroy departed Mitchel Field on the westbound leg at 11:58 a.m. PST and arrived at Lockburne Air Force Base, Ohio at 12:58 p.m., PST. This refueling stop required 7 minutes. Next on the flight plan was Tulsa, Oklahoma. The airplane landed there at 2:26 p.m. PST, and was refueled and airborne again in 6 minutes. The last refueling took place at Albuquerque, New Mexico. Lieutenant Conroy landed at 3:58 p.m., PST. After another 7 minute stopover, California Boomerang took off on the final leg of the round-trip journey, finally landing back at Van Nuys, California at 5:26:18 p.m., PST.

John Conroy’s Coast-to-Coast-to-Coast “dawn to dusk” flight covered 5,058 miles (8,140.1 kilometers). The total elapsed time was 11 hours, 26 minutes, 33 seconds. His average speed was 445 miles per hour (716.2 kilometers per hour). Weather across the country caused some delays as Jack Conroy had to make instrument approaches to three of the airports.

California Boomerang, 1st Lieutenant Jack Conroy's California Air National Guard F-86A-5-NA Sabre, 49-1046, being refueled at an intermediate stop, 21 May 1951. (LIFE Magazine via Jet Pilot Overseas)
California Boomerang, 1st Lieutenant Jack Conroy’s California Air National Guard F-86A-5-NA Sabre, 49-1046, being “hot” refueled at an intermediate stop, 21 May 1951. At least six fueling hoses are simultaneously filling the fighter’s fuselage, wing and drop tanks tanks while the jet engine remains in operation. Note the fire fighting apparatus standing by in the background. (LIFE Magazine via Jet Pilot Overseas)

California Boomerang, North American Aviation F-86A-5-NA Sabre 49-1046, is on display as a “gate guard” at the entrance to the Channel Islands Air National Guard Station, adjacent to Naval Base Ventura County, Point Mugu, California.

North American Aviation F-86A Sabre 49-1046 at the entrance to the Channel Islands National Guard Station, Point Mugu, California. (Goleta Air and Space Museum_
North American Aviation F-86A Sabre 49-1046 at the entrance to the Channel Islands National Guard Station, Point Mugu, California. (Brian Lockett, Goleta Air and Space Museum)

© 2016 Bryan R. Swopes

21 May 1949

Captain Hubert D. Gaddis, USAAF with teh Sikorsky S-51-1. NAA representatives check baraographs. (Sikorsky Archives)
Captain Hubert D. Gaddis, United States Army, with the Sikorsky S-52-1 NX92824. NAA representatives Walter Goddard and Charles Logsdon check the barographs. (Sikorsky Archives)

21 May 1949: Captain Hubert Dale Gaddis, Field Artillery, United States Army, flew a prototype Sikorsky S-52-1 helicopter, serial number 52003, registration NX92824, to a Fédération Aéronautique Internationale (FAI) World Record for Altitude Without Payload of 6,468 meters (21,220 feet) over Bridgeport, Connecticut. ¹ The flight was observed by National Aeronautic Association representatives Walter Goddard and Charles Logsdon.

The Sikorsky S-52-1 was a completely new design based on the company’s experience with the earlier R-4 and R-5/S-51 models. It was a two-place light helicopter of all metal monocoque construction, using primarily aluminum and magnesium. With Sikorsky test pilot Harold Eugene (“Tommy”) Thompson at the controls, the prototype made its first flight 4 May 1948.

The three-bladed fully-articulated articulated main and two-bladed tail rotor were also of all metal construction. The main rotor had a diameter of 33 feet (10.058 meters) and rotated counter-clockwise as seen from above. (The advancing blade is on the right side of the helicopter.) It had an extruded aluminum spar, covered with sheet duralumin, riveted and glued in place. The blade used a NACA 0012 airfoil with -6° twist. The two-bladed semi-rigid tail rotor was mounted on the left side of the tail boom in a pusher configuration. It had a diameter of 6 feet, 4 inches (1.930 meters) and rotated counter clockwise, as seen from the helicopter’s left. (The advancing blade is at the top of the tail rotor arc.)

The S-52-1 was powered by an air-cooled, normally-aspirated, 425.29-cubic-inch-displacement (6.97 liter) Franklin Engine Company 6V6-245-B16F (O-425-1) vertically-opposed 6-cylinder overhead valve engine. The engine was rated at 245 horsepower at 3,275 r.p.m.

On 27 April 1949 Tommy Thompson flew the same helicopter to an FAI speed record of 208.49 kilometers per hour (129.55 miles per hour) over a 3 kilometer straight course at Cleveland, Ohio, ² and on 6 May, to 197.54 kilometers per hour (122.75 miles per hour) over a 100-kilometer course between Milford and Westbrook, Connecticut. ³

Sikorsky S-52-1 NX92824 (FAI)
Sikorsky S-52-1 NX92824 (FAI)
Hubert Gaddis. (Tom Tom 1938)

Hubert Dale Gaddis was born in Jasper County, Missouri, 9 September 1920, the first of two children of Hubert E. Gaddis, a utility company purchasing agent, and Beatrice Mae Cook Gaddis.

The family relocated to Tulsa, Oklahoma, where Hubert attended Central High School. While there, he developed an interest in radio. Gaddis graduated in 1938.

Gaddis married Martha Tucker in 1950. They would have three children, Cheryl, Sandra and Dale.

Captain Hubert D. Gaddis, Artillery, United States Army. (FAI)

Gaddis enlisted in the United States Army in Oklahoma, 24 September 1942. He had brown hair and hazel eyes, was 5 feet, 6 inches (1.68 meters) tall and weighed 133 pounds (60.3 kilograms).

Gaddis was commissioned a second lieutenant, Army of the United States (AUS), 18 February 1944. He remained in the Army following World War II as an officer in the Field Artillery (Regular Army). In 1956, he graduated of the Army Command and General Staff College.

On September 8 1966, Gaddis was promoted to the rank of colonel (temporary). The rank became permanent 1 July 1971. He was released from military service 28 February 1974. During his career, Colonel Gaddis had been awarded the Distinguished Flying Cross, the Bronze Star Medal, and the Air Medal with 14 oak leaf clusters (15 awards).

Colonel Hubert Dale Gaddis, United States Army (Retired) died 24 February 1976 at the age of 55 years. He was buried at Woodlawn Memorial Gardens, Ozark, Alabama.

¹ FAI Record File Number 2181

² FAI Record File Number 13097

³ FAI Record File Number 13146

© 2019, Bryan R. Swopes

21 May 1937

Amelia Earhart prepares to leave Burbank, California, 21 May 1937.
Amelia Earhart prepares to leave Burbank, California, 21 May 1937.

21 May 1937: Day 2 of Amelia Earhart’s second attempt to fly around the world aboard her Lockheed Electra 10E, NR16020. She and her navigator, Fred Noonan, fly from Union Air Terminal, Burbank, California, to Tucson, Arizona, where they stopped to refuel. Earhart’s husband, George Palmer Putnam, and aircraft mechanic Ruckins D. “Bo” McKneely were also aboard. ¹

When Earhart attempted to restart the left engine at Tucson, it caught fire. An unplanned overnight stay was required while the damage was repaired.

“Accompanying me on this hop across the continent was Fred Noonan. “Bo” McKneely my mechanic, and Mr. Putnam. A leisurely afternoon’s flight ended at Tucson, Arizona. The weather was sailing hot as Arizona can be in summertime. After landing and checking in, when I started my motors again to taxi to the filling pit the left one back-fired and burst into flames. For a few seconds it was nip-and-tuck whether the fire would get away from us. There weren’t adequate extinguishers ready on the ground but fortunately the Lux apparatus built in the engine killed the fire. The damage was trivial, mostly some pungently cooked rubber fittings a deal of dirty grime. The engine required a good cleaning and the ship a face-washing.”

—Amelia Earhart

¹ Although the standard Lockheed Electra 10E was certified to carry up to 10 passengers, the Restricted certification of NR16020 limited it to, “Only bona fide members of the crew to be carried.” The presence of Putnam and McKneely violated this restriction.

Great Circle route from the location of the former Union Air Terminal (now, Hollywood-Burbank Airport) to Davis-Monthan AFB, Tucson, Arizona: 396 nautical miles (455 statute miles/733 kilometers). (Great Circle Mapper)

© 2018, Bryan R. Swopes

21 May 1927

The Spirit of St. Louis arrives at Le Bourget Aerodrome, 21 May 1927. (San Diego Air and Space Museum Archives)

After a flight of 33 hours, 30 minutes, 30 seconds, from Roosevelt Field, Long Island, New York, United States of America, Charles A. Lindbergh lands his Spirit of St. Louis at Le Bourget Aerodrome, Paris, France, at 10:22 p.m. (20:22 G.M.T.), 21 May 1927. He is the first pilot to fly solo, non-stop, across the Atlantic Ocean.

“I circle. Yes, it’s definitely an airport. . . It must be Le Bourget. . . I shift fuel valves to the center wing-tank, sweep my flashlight over the instrument board in a final check, fasten my safety belt, and nose the Spirit of St. Louis down into a gradually descending spiral. . .

“I straighten out my wings and let the throttled engine drag me on beyond the leeward border. Now the steep bank into the wind, and the dive toward the ground. But how strange it is, this descent. I’m wide awake, but the feel of my plane has not returned. . . My movements are mechanical, uncoordinated, as though I were coming down at the end of my first solo. . .

“It’s only a hundred yards to the hangars now — solid forms emerging from the night. I’m too high — too fast. Drop wing — left rudder — sideslip — — — Careful — mustn’t get anywhere near the stall — — — I’ve never landed the Spirit of St. Louis at night before. . . Below the hangar roofs now — — — straighten out — — — A short burst of the engine — — — Over the lighted area — — — Sod coming up to meet me. . . Still too fast — — — Tail too high — — — The wheels touch gently — off again — No, I’ll keep contact — Ease the stick forward — — — Back on the ground — Off — Back — the tail skid too — — — Not a bad landing. . . .”

The Spirit of St. Louis, by Charles A. Lindbergh, Charles Scribner’s Sons, 1953, Pages 489–492.

Lindbergh established a Fédération Aéronautique Internationale (FAI) World Record for Distance in a Straight Line Without Landing of 5,809 kilometers (3,310 miles). ¹

Over 100,000 people have come to Le Bourget to greet Lindbergh. He has flown the Spirit of St. Louis into history.

Crowds approach Charles Lindbergh an dteh Spirit of St. Louis at Le Bourget, shortly after landing, 21 May 1927.(Keystone-France/Gamma-Keystone/Getty Images)
Crowds mob Spirit of St. Louis at Le Bourget Aerodrome, shortly after Charles A. Lindbergh’s  arrival from New York, 21 May 1927. The crowd soon swelled to over 100,000 people. (Keystone-France/Gamma-Keystone/Getty Images)

¹ FAI Record File Number 14842

Great Circle route from the location of the former Roosevelt Field to Le Bourget, Paris: 3,145 nautical miles (3,619 statute miles/5,825 kilometers). (Great Circle Mapper)

© 2019, Bryan R. Swopes