Tag Archives: Muroc Air Force Base

5 June 1948

Aviation, , , , , , , , , , , , , , , , ,
Northrop YB-49 42-102368. (U.S. Air Force)

5 June 1948: Flying at 40,000 feet (12,192 meters), north of Muroc Air Force Base, California, the second Northrop YB-49 “flying wing,” serial number 42-102368, was undergoing stall recovery performance testing with a crew of five aboard. The pilot was Major Daniel A. Forbes, Jr., United States Air Force, and the co-pilot was Captain Glen W. Edwards.

The aircraft suffered a catastrophic structural failure with the outer wing panels tearing off. The experimental airplane crashed approximately 10 miles (16 kilometers) east of the small desert town of Mojave. The entire crew, which included 1st Lieutenant Edward L. Swindell, flight engineer, and civilian engineers Charles H. LaFountain and Clare C. Lesser, were killed.

Northrop YB-49. (U.S. Air Force)

The YB-49 was an experimental jet engine-powered bomber, modified from a propeller-driven Northrop XB-35. It was hoped that the all-wing design would result in a highly efficient airplane because of its very low drag characteristics. However, the design could be unstable under various flight conditions.

A few months after the crash, the first YB-49 was destroyed in a taxiing accident and the project cancelled. It would be 41 years before the concept would be successful with the Northrop B-2 Spirit.

Northrop YB-49 42-102367. (U.S. Air Force)

42-102367 had been converted from the second YB-35 pre-production test aircraft. The original Flying Wing’s four Pratt & Whitney Wasp Major (R-4360-21) radial engines were replaced by eight Allison J35-A-15 turbojet engines and several aerodynamic improvements were made. The change to jet power  increased the airplane’s speed by about 100 miles per hour (161 kilometers per hour) and significantly reduced the vibrations caused by the reciprocating engines, drive shafts and counter-rotating propellers.

The YB-49 was 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. Air intakes for the turbojet engines were placed in the leading edge of the wing. The exhaust nozzles were at the trailing edge. Four small vertical fins for improved yaw stability were also at the trailing edge.

The fins were likely too small. Test pilots complained about the airplane’s instability, which made it difficult to maintain course or altitude. A stability augmentation system was required.

Northrop YB-49 (U. S. Air Force)

The YB-49 had a length of 53 feet, 1 inch (16.180 meters), wingspan of 172 feet, 0 inches (52.426 meters) and overall height of 15 feet, 2 inches (4.623 meters). It weighed 88,442 pounds (40,117 kilograms) empty, and its maximum takeoff weight was 193,938 pounds (87,969 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, -4° at the wing tips, 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).

Northrop YB-49

The YB-49 was powered by eight General Electric-designed, Allison Engine Company-built J35-A-15 engines. The J35 was a single-spool, axial-flow turbojet engine with an 11-stage compressor section and single-stage turbine. The J35-A-15 was rated at 3,270 pounds of thrust (14.55 kilonewtons) at 7,400 r.p.m., Normal Power, and a Maximum (Military Power) rating of 3,750 pounds of thrust (16.68 kilonewtons) at 7,700 r.p.m. The engine was 14 feet, 0.0 inches (4.267 meters) long, 3 feet, 4.0 inches (1.016 meters) in diameter and weighed 2,400 pounds (1,089 kilograms).

Cruise speed for the YB-49 was 429 miles per hour (690 kilometers per hour). Its maximum speed 499 miles per hour (802 kilometers per hour) at 18,000 feet (5,486 meters) was restricted by Mach number. The airplane could climb from Sea Level to 30,000 feet (9,144 meters) in 21.0 minutes. It had a service ceiling of 49,700 feet (15,149 meters). The YB-49 had a combat radius of 1,611 miles (2,593 kilometers) at 420 miles per hour (676 kilometers per hour), carrying a 10,000 pound (4,536 kilogram) bomb load.

The YB-49 had no defensive armament. It could carry a maximum bomb load of 16,000 pounds (7,257 kilogram) in its internal bomb bay. (Turbulence resulting from open bomb bays significantly decreased bombing accuracy.)

Only two Northrop YB-49s were built. They were tested by Northrop and the Air Force for nearly two years. Although an additional nine YB-35s were ordered converted, the B-49 was not placed into production.

Northrop YB-49.
Daniel H, Forbes, Jr., 1940

Daniel Hugh Forbes, Jr., was born at Carbondale, Kansas, 20 June 1920. He was the son of Daniel Hugh Forbes, a farmer, and Hattie Rundle Forbes. He attended North High School in Wichita Kansas, and then the Kansas State College at Manhattan, Kansas,

Maj. Daniel Forbes, Jr., USAF

Daniel Forbes enlisted in the United States Army as an aviation cadet at Fort Riley, Kansas, 23 May 1941. On 9 January 1942, he was commissioned a second lieutenant, Air Reserve. Forbes was promoted to the rank of 1st lieutenant, Army of the United States, 25 August 1942, and to captain, A.U.S., 15 August 1944. On 4 October 1945, he was promoted to major, A.U.S.

Major Forbes married Mrs. Edward C. Winkle (née Hazel Marie Moog), 11 March 1948. Her first husband, a 1st lieutenant assigned to the 314th Infantry Regiment, 79th Infantry Division, was killed in action in France, 1 October 1944. Less than three months later, Mrs. Hughes was a widow again.

Major Daniel Hugh Forbes, Jr., Air Corps, United States Army.

Glen Walter Edwards was born at Medicine Hat, Alberta, Canada, 5 March 1916, the second son of Claude Gustin Edwards, a real estate salesman, and Mary Elizabeth Briggeman Edwards. The family immigrated to the United States in August 1923 and settled near Lincoln, California. He attended Lincoln High School, where he was a member of the Spanish Club and worked on the school newspaper, “El Eco.” He graduated in 1936.

Lt. Glen W. Edwards

Edwards attended Placer Junior College, Auburn, California, before transferring to the University of California, Berkeley. He graduated in 1941 with a Bachelor of Arts (A.B.) degree, and then enlisted in the United States Army as an aviation cadet, 16 July 1941.

Following pilot training, Edwards was commissioned as a second lieutenant, Air Reserve, 6 February 1942. He was promoted to 1st lieutenant, Army of the United States, 16 September 1942. Lieutenant Edwards flew 50 combat missions in the Douglas A-20 Havoc light bomber with the 86th Bombardment Squadron (Light), 47th Bomb Group, in North Africa and fought at the Battle of the Kasserine Pass, 19–24 February 1943. He was next promoted to captain, 28 April 1943. He also flew during the invasion of Sicily, in late 1943.

Two U.S. Army Air Force Douglas A-20B-DL Havoc light bombers, 41-3014 and 41-3134, in Tunisia, 1943. (U.S. Air Force)

Edwards returned to the United States and was assigned to the Pilot Standardization Board, but was then sent to train as a test pilot at Wright Field. Captain Edwards was assigned as a test pilot in 1944 and tested the Northrop XB-35 and Convair XB-36.After World War II came to an end the U.S. Army and Air Corps were demobilized to 1/16 of their peak levels (from 8,200,000 to 554,000). Edwards was retained but reverted to the rank of 1st lieutenant. He had been awarded the Distinguished Flying Cross and the Air Medal with three oak leaf clusters (four awards). He was transferred to the United States Air Force after it was established as a separate service, 18 September 1947.

Glen Edwards was recommended to fly the Bell X-1 rocket plane, but when that assignment went to Chuck Yeager, Edwards was sent to Princeton University, Princeton, New Jersey, to study aeronautical engineering. He earned a masters degree in engineering (M.S.E.) in 1947.

Captain Glen Walter Edwards, Air Corps, United States Army.

Following the crash of the YB-49, Topeka Air Force Base in Kansas was renamed Forbes Air Force Base. Muroc Air Force Base was renamed Edwards Air Force Base in honor of Captain Edwards.

Captains Edwards’ remains were buried at the Lincoln Cemetery, Lincoln, California.

Edwards Air Force Base, California, looking northeast, photographed in 2007. (U.S. Air Force)

Edward Lee Swindell was born at Currituck, North Carolina, 22 April 1916. He was the son of Rudolph Bridgman Swindell, a machinist’s helper at the Portsmouth Navy Yard, and Eula Belle Williams Swindell.

Edward L. Swindell married Miss Edna Irene Hayman, 2 January 1942 at South Mills, North Carolina.

Swindell enlisted in the U.S. Army at Camp Lee, Virginia, 17 March 1942. He was 5 feet, 9 inches (1.75 meters) tall and weighed 156 pounds (70.7 kilograms).

Lieutenant Swindell’s remains were buried at the Forest Lawn Cemetery, Norfolk, Virginia.

Charles H. LaFountain was born 12 June 1925 in New York. He was the son of Leo L. LaFountain and Gladys Ethel Taylor LaFountain. He had served in the United States Navy and was a civilian employee of the Air Force. His remains were buried at the Lake Luzerne Cemetery, Lake Luzerne, New York.

Clare C. Lesser was born 27 June 1925 at Joliet, Illinois. He was the fifth of five children of Henry J. Leser, a worker at a wire mile, and Alvina Leser. Leser served as an ensign in the United States Naval Reserve. Like LaFountain, he was also a civilian employee of the Air Force. His remains were buried at St. John’s Cemetery, Joliet, Illinois.

© 2018, Bryan R. Swopes

3 May 1948

Aviation, , , , , , , , , , , ,
One of the three Douglas D-558-I Skystreaks. (Smithsonian Institution National Air and Space Museum, NASM A4958D)

3 May 1948: At Muroc Air Force Base in the high desert of southern California (after 1949, known as Edwards AFB), NACA 141, the second of three Douglas D-558-I Skystreak research aircraft, took off on a test flight to study stability at transonic speeds. In the cockpit was National Advisory Committee for Aeronautics Engineering Test Pilot Howard Clifton (“Tick”) Lilly. It was his twentieth flight in the Skystreak.

As Lilly climbed through 200 feet (61 meters), the Skystreak’s J35 turbojet engine suffered a catastrophic compressor failure. Fragments of the compressor cut through the airplane’s flight controls. With Lilly unable to control the airplane, it yawed to the left, then rolled over, and at 3:04 p.m., Pacific Daylight Saving Time (22:04 UTC), crashed onto Rogers Dry Lake. Lilly was decapitated in the crash.

Howard C. Lilly was the first NACA test pilot to be killed during a test flight since the commission had been established in 1915.

NACA Engineering Test Pilot Howard Clifton Lilly.
Howard C. Lilly

Howard Clifton Lilly was born 27 August 1916 at Crow, West Virginia. He was the fourth of five children of Ova Ashton Lilly, a locomotive engineer, and Amanda Elmira Bragg Lilly.

Lilly was given the nickname, “Tickie,” by a friend who, as a child, had been unable to pronounce his middle name, Clifton.

Lilly attended Beaver Elementary School. He graduated from Shady Spring High School, and then attended Beckley College (now, the West Virginia University Institute of Technology), both in Beckley, West Virginia. He also studied at the Concord State Teachers College at Athens, WV (now, Concord University).

Lilly began flying at Mount Hope Airport in Beckley as a member of the Civilian Pilot Training Program. His flight instructor was Karl Williams.

Howard C. Lilly registered for Selective Service (conscription) on 16 October 1940. He was described as having a ruddy complexion with brown hair and blue eyes. Lilly was 5 feet, 10½ inches (179.1 centimeters) tall and weighed 150 pounds (68 kilograms). He was employed as a pressman for the Beckley Newspaper Corporation, and later in the stereotyping department of the Charleston Gazette.

Aviation Cadet Howard C. Lilly, USNR. (Tooley-Myron Studios)

Howard C. Lilly enlisted in the United States Navy as a seaman second class, 11 September 1941, at Washington, D.C. As part of the Navy’s V-5 Program, Seaman Lilly was assigned to U.S. Naval Reserve Aviation Base at Anacostia, D.C., for Elimination Flight Training. He was then transferred to the Naval Reserve Air Base, New Orleans, Louisiana. Although Lilly had hoped to fly fighters, he was assigned to fly seaplanes.

Aviation Cadet Lilly requested to be discharged from the Navy. His request was approved and he was discharged 18 September 1942.

Lilly joined the National Advisory Committee for Aeronautics (NACA) as a test pilot at the Langley Memorial Aeronautical Laboratory, Hampton, Virginia, in October 1942. He was then assigned to the Lewis Flight Propulsion Laboratory, Cleveland, Ohio, in May 1943.

Mrs. H. Clifton Lilly (Raleigh Register)

Howard C. Lilly married Miss Arline Eveyn Grentzer, 20 July 1945, at the St. James Rectory in Cleveland. The ceremony was officiated by Rev. George R. Betting. Following their wedding, the couple resided at the Westlake Hotel in Cleveland. They divorced in 1947.

On 1 September 1946, Lilly flew a Bell P-63A Kingcobra, 42-69063, in the Thompson Trophy Race at Cleveland. His airplane, with civil registration NX69901 and carrying race number 64, had qualified for the race in eighth place with an average speed of 346.155 miles per hour (557.083 kilometers per hour). He finished in ninth place at an average speed of 328.154 miles per hour (528.113 kilometers per hour). Bell Aircraft test pilot Tex Johnston won the race in his Bell P-39Q Airacobra with an average speed of 373.908 mph (601.746 kilometers per hour).

Howard Clifton Lilly, NACA engineering test pilot, with his 1946 Thompson Trophy racer, Bell P-63A NX69901. (NASA E-49-0091)

In August 1947, Lilly was assigned to NACA’s Muroc Flight Test Unit at Muroc Air Force Base as the commission’s first permanently assigned engineering test pilot there. He first flew the Bell XS-1 rocketplane on 9 January 1948. On 31 March 1948, Lilly flew the XS-1 to Mach 1.10, becoming just the third pilot to break sound barrier. Lilly made six test flight in the XS-1, all in the number two aircraft, 46-063.

Bell X-1 46-063. (NASA E49-001)

On 29 April 1948, Lilly flew the D-558-I to 0.88 Mach at 36,000 feet (10,973 meters). This was the highest speed that a Skystreak had reached up to that time.

Howard Clifton Lilly’s remains were interred at the Arlington National Cemetery. Lilly Avenue at Edwards AFB was named in his honor.

In May 1950, Lilly was posthumously awarded the Air Medal.

One the the three Douglas D-558-I Skystreaks in flight near Muroc Air Force Base. (Naval Aviation Museum)

NACA 141 (U.S. Navy Bureau of Aeronautics serial number 37971) was the second of three Douglas D-558-I Skystreak transonic research aircraft.

The D-558 Program was intended as a three-phase test program for the U.S. Navy and the National Advisory Committee on Aeronautics (NACA) to investigate transonic and supersonic flight using straight and swept wing aircraft powered by turbojet and/or rocket engines.

The Douglas Aircraft Company designed and built three D-558-I Skystreaks and three D-558-II Skyrockets. The Phase I aircraft were flown by Douglas test pilot Gene May and the Navy’s project officer, Commander Turner Caldwell.

Cutaway illustration of the Douglas D-558-I Skystreak. (U.S. Navy)

The D-558-I Skystreak was a single-engine, turbojet-powered airplane. It was built of magnesium and aluminum for light weight, but was designed to withstand very high acceleration loads. It was 35 feet, 8 inches (10.871 meters) long with a wingspan of 25 feet (7.62 meters) and overall height of 12 feet, 1¾ inches (3.702 meters). The airplane had retractable tricycle landing gear. Its empty weight was approximately 7,500 pounds (3,400 kilograms), landing weight at the conclusion of a flight test was 7,711 pounds (3,498 kilograms). The maximum takeoff weight was 10,105 pounds (4,583.6 kilograms). The aircraft fuel load was 230 gallons (870.7 liters) of kerosene.

The D-558-I was powered by a single Allison J35-A-11 turbojet engine. The J35 was a single-spool, axial-flow turbojet with an 11-stage compressor section, 8 combustion chambers and single-stage turbine. The J35-A-11 was rated at 5,000 pounds of thrust (22.24 kilonewtons). The engine was 12 feet, 1.0 inches (3.683 meters) long, 3 feet, 4.0 inches (1.016 meters) in diameter and weighed 2,455 pounds (1,114 kilograms). The J35-A-11 was a production version of the General Electric TG-180, initially produced by Chevrolet as the J35-C-3. It was the first widely-used American jet engine.

Cutaway illustration of J35 turbojet engine. (General Electric)

The D-558-I had a designed service ceiling of 45,700 feet (13,930 meters). Intended for experimental flights of short duration, it had a very short range and took off and landed from Rogers Dry Lake at Muroc. The experimental airplane was not as fast as the more widely known Bell X-1 rocketplane, but rendered valuable research time in the high transonic range.

The three D-558-I Skystreaks made a total of 229 flights.

Douglas test pilot Gene May (left) and Howard C. Lilly with the number two Douglas D-558-I Skystreak, Bu. No. 37971, at Muroc, circa 1948. (NASA E95-43116-8)

© 2023, Bryan R. Swopes