Tag Archives: Bu. No. 37971

3 May 1948

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

20 August 1947

Douglas D-558-I Skystreak Bu. No. 37970 makes a pass over the 3 kilometer course on Muroc Dry Lake. (U.S. Navy)
Douglas D-558-I Skystreak, Bu. No. 37970, makes a pass over the 3-kilometer course at Muroc Dry Lake. (U.S. Navy)

20 August 1947: At Muroc Dry Lake in the high desert of southern California, Commander Turner Foster Caldwell, Jr., United States Navy, flew the first of three Douglas D-558-I Skystreaks, Bu. No. 37970, to a Fédération Aéronautique Internationale (FAI) World Record for Speed Over a 3 Kilometer Straight Course.¹

Four passes were made over the course at an altitude of 200 feet (61 meters) or lower. Two runs were made in each direction to compensate for any head or tail winds. The official speed for a record attempt was the average of the two fastest consecutive passes out of the four.

Commander Caldwell’s average speed was 1,031.178 kilometers per hour (640.744 miles per hour). He was awarded his second Distinguished Flying Cross for this flight.

Commander Turner F. Caldwell, jr., United States Navy with the number one Douglas D-558-I Skystreak, Bu. No. 37970, at Muroc dry Lake, 1947. (U.S. Naval Institute)
Commander Turner F. Caldwell, Jr., United States Navy, with the number one Douglas D-558-I Skystreak, Bu. No. 37970, at Muroc Dry Lake, 1947. (U.S. Naval Institute)

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.

Major Marion E. Carl, USMC, left, and Commander Turner F. Caldwell, Jr., USN, stand with the record-setting Douglas D-558-I Skystreak, Bu. No. 37970, on Muroc Dry Lake. (U.S. Navy)
Major Marion E. Carl, USMC, left, and Commander Turner F. Caldwell, Jr., USN, stand with the record-setting Douglas D-558-I Skystreak, Bu. No. 37970, on Muroc Dry Lake. (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.

This photograph shows two of the three D-558-I Skystreaks being inspected by U.S. navy officials at the Douglas Aircraft Company plant. In the foreground is the number two aircraft, Bu. No. 37971, with the sections o fte hfuselage separted for better viewing. The entire nose section, including teh cockpit, coul dbe jettisoned in an emergency. The second aircraft is Bu. No. 37970, th eSkystrak flown by CDR Caldwell for his speed record. In the background is another Douglas airplane, the famous AD Skyraider. (Douglas Aircraft Company)
This photograph shows two of the three D-558-I Skystreaks being inspected by U.S. Navy officers at the Douglas Aircraft Company plant. In the foreground is the number two aircraft, Bu. No. 37971, with the sections of the fuselage separated. The entire nose section, including the cockpit, could be jettisoned in an emergency. Just beyond that, two wing tip fuel tanks are displayed on a cart. The second aircraft is Bu. No. 37970. An Allison J35-A-11 jet engine is shown between that and the last airplane, another Douglas product, the famous AD Skyraider. (Douglas Aircraft Company)

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.

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 the dry lake at Muroc. (After 1949, this would be known as Edwards Air Force Base.) 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.

Gene May did reach Mach 1.0 in 37970, 29 September 1948, though he was in a 35° dive. This was the highest speed that had been reached up to that time by an airplane capable of taking off and landing under its own power.

The three D-558-I Skystreaks made a total of 229 flights and Bu. No. 37970 made 101 of them. After the Douglas test program was completed, -970 was turned over to NACA as NACA 140, but it was quickly grounded after the crash of the number two aircraft, and was used for spare parts for number three.

Today, 37970 is in the collection of the National Naval Aviation Museum at Naval Air Station Pensacola, Florida. The other surviving Skystreak, Bu. No. 37972, is at the Carolinas Aviation Museum, Charlotte-Douglas International Airport, Charlotte, North Carolina.

Rear Admiral Turner F. Caldwell, Jr., USN, circa 1960. (U.S. Navy)
Rear Admiral Turner F. Caldwell, Jr., United States Navy, circa 1960. (U.S. Navy)
Midshipman Turner F. Caldwell, jr., 1935. (U.S. Navy)

Turner Foster Caldwell, Jr., was born 17 November 1913 at Narbeth, Pennsylvania. He was the first of four children of Lieutenant Turner Foster Caldwell and Eleanor Polk Owings Caldwell. The senior Caldwell was a graduate of Yale University, New Haven, Connecticut, and was commissioned as an ensign, United States Navy, through the Reserve Officers Training Corps (R.O.T.C). Commander Caldwell was assigned to the U.S. Naval Academy, Annapolis, Maryland, 1 September 1930, and was promoted to the rank of captain, 1 October 1930. He retired from the Navy 1 August 1940.

Turner Foster Caldwell, Jr., entered the United States Naval Academy as a midshipman, 12 June 1931. He graduated and was commissioned an Ensign, United States Navy, 6 June 1935.

Ensign Caldwell was promoted to the rank of Lieutenant (Junior Grade), with date of rank 6 June 1938. He was assigned as a flight instructor at NAS Pensacola, Florida. On that same day, Lieutenant (j.g.) Caldwell married Miss Helen Adele Glidden of Coronado, California, at Yuma, Arizona. They would have four children.

By 1940, Lieutenant (j.g.) Caldwell was assigned to Scouting Squadron Five (VS-5). On 7 December 1941, VS-5 was aboard USS Yorktown (CV-5) at Norfolk Virginia.

Caldwell was promoted to Lieutenant, 1 January 1942. He was a Douglas SBD-3 Dauntless scout bomber bomber pilot with Scouting Squadron Five (VS-5) aboard U.S.S. Yorktown (CV-5) and commanded the squadron with its 18 SBD-3s aboard U.S.S. Enterprise (CV-6) during the occupation of Guadalcanal and the Battle of the Eastern Solomons.

Two Douglas SBD-3 Dauntless dive bombers from VB-5, USS Yorktown, 1942. (U.S. Navy)

Between March and September 1942 he was three times awarded the Navy Cross, the U.S. Navy’s second-highest award for valor after the Medal of Honor. He was promoted to lieutenant commander (temporary) 1 May 1943, and to commander, 1 March 1944. (He retained the permanent rank of lieutenant until after the war.)

Later he commanded a night fighter group of F6F Hellcats and TBM Avengers, CVLG(N)-41, assigned to USS Enterprise (CV(N)-6). For his actions during that period he was awarded his first Distinguished Flying Cross and the Legion of Merit.

After the war, Caldwell commanded Carrier Air Group 4 (CVG-4) aboard USS Franklin D. Roosevelt (CVB-42). He was promoted to the rank of captain, 1 July 1954. Captain Caldwell commanded the “long-hull” Essex-class aircraft carrier USS Ticonderoga (CVA-14), from 5 September 1959 to 24 August 1960.

USS Ticonderoga (CVA-14) underway off the Philippines, 24 May 1960. (San Diego Air and Space Museum Archives)

Captain Caldwell was promoted to the rank of rear admiral, 1 April 1963. He rose to the rank of Vice Admiral, 1 November 1967, and served as Director of Anti-Submarine Warfare Plans. Admiral Caldwell retired from the Navy in May 1971. He died at Kilmarnock Hospital, Rappahannock, Virginia, 12 October 1991.

Douglas D-558-I Skystreak, Bu. No. 37970, at the National Naval Aviation Museum, Naval Air Station Pensacola, Florida. (U.S. Navy)
Douglas D-558-I Skystreak, Bu. No. 37970, at the National Naval Aviation Museum, Naval Air Station Pensacola, Florida. (U.S. Navy)

¹ FAI Record File Number 9864

© 2017, Bryan R. Swopes