Airship D-LZ129 Hindenburg moored at New Jersey at the end of a previous voyage.
6 May 1937: After a three-day Trans-Atlantic crossing from Frankfurt, Germany, the rigid airship Hindenburg (D-LZ129) arrived at Lakehurst, New Jersey, with 36 passengers and 61 crewmembers.
Airship LZ-129 Hindenburg burning, 1925 hours, 6 May 1937, at Lakehurst, New Jersey.
At 7:25 p.m., while the airship was being moored, it suddenly caught fire. The fabric covering burned first, but then the hydrogen gas contained in the buoyancy tanks exploded and burned. Hindenburg settled to the ground and was completely destroyed within 30 seconds.
Water ballast rains down as Hindenburg burns at the mooring mast 1925 hours, 6 May 1937, at Lakehurst, New Jersey. SFA003016395Hindenburg NY Daily NewsHindenburg settles to the ground. (Arthur Cofod, Jr./USAF 12293 A.C.)
Of those on board, 13 passengers and 22 crewmembers died. One member of the ground crew was also killed.
Surprisingly, though there were many survivors and witnesses—as well as newsreel footage of the accident—the cause has never been determined.
This dramatic accident ended the airship passenger industry.
Airship LZ-129 Hindenburg burning, 1925 hours, 6 May 1937, at Lakehurst, New Jersey.Hindenburg burning
Curtiss-Wright Model 75, X17Y. (Ray Wagner Collection, San Diego Air & Space Museum Archives)
6 May 1935: At Buffalo, New York, the prototype Curtiss-Wright Model 75, X17Y, serial number 11923, made its first flight.
Donovan Reese Berlin. (Niagara Aerospace Museum)
Designed by Donovan Reese Berlin, the airplane was a modern design of all metal construction, with fabric covered control surfaces. The Model 75 was a single-seat, single-engine low-wing monoplane with retractable landing gear.
Curtiss-Wright Model 75, X17Y. (Ray Wagner Collection, San Diego Air & Space Museum Archives)
In its original configuration, the Model 75 was powered by an air-cooled, supercharged 1,666.860 cubic inch displacement (27.315 liter) Wright Aeronautical Division GR1670A1 two-row 14-cylinder radial engine. The GR1670A1 was a developmental engine with a compression ratio of 6.75:1. It was rated at 775 horsepower at 2,400 r.p.m. at Sea Level, and 830 horsepower at 2,600 horsepower for takeoff, burning 87-octane gasoline. The engine was 3 feet, 9 inches (1.143 meters) in diameter, 4 feet, 4–25/32 inches (1.341 meters) long, and weighed 1,160 pounds (526 kilograms). The GR1670A1 drove a three-bladed Curtiss Electric constant-speed propeller through a 16:11 gear reduction.
The GR1670A1 was also used in the Seversky SEV-S1, NR18Y, a record-setting experimental variant of the rival Seversky P-35.
The United States Department of Commerce, Bureau of Air Commerce, registered X17Y to the Curtiss-Wright Corporation, Kenmore & Vulcan Street, Buffalo, New York, on issued 1 June 1936. This registration was cancelled 26 April 1937.
Curtiss-Wright Model 75, X17Y. (Ray Wagner Collection, San Diego Air & Space Museum Archives)Curtiss-Wright Model 75, X17Y. (Ray Wagner Collection, San Diego Air & Space Museum Archives)
The Curtiss-Wright Model 75 would be developed into the P-36 Hawk fighter for the U.S. Army Air Corps. France ordered it as the H75A-1, and in British service, it was known as the Mohawk Mk.I.
The tenth production P-36 was modified with a liquid-cooled Allison V-1710 V-12 engine to become the prototype XP-40.
1st Lieutenant Benjamin Scovill Kelsey in the cockpit of a Curtiss-Wright P-36A Hawk, circa 1938. (U.S. Air Force)1st Lieutenant Benjamin Scovill Kelsey, Air Corps, United States Army, with a Curtiss Wright P-36A Hawk, Air Corps serial number 38-2, at Wright Field, Ohio, circa 1938. (Ray Wagner Collection/San Diego Air & Space Museum Archives)Curtiss-Wright P-36B 38-020. (U.S. Air Force)Curtiss-Wright P-36B 38-020. (U.S. Air Force)Curtiss-Wright P-36C camouflage test, Maxwell Field, 1940. (Ray Wagner Collection, San Diego Air & Space Museum Archives)Curtiss-Wright P-40 Warhawk, 55th Pursuit Squadron, Oakland, CA, 1941 (IWM FRE11437)
Mercury-Redstone 3 lifts off from LC-5, 10:34:13 EDT, 5 May 1961. (NASA)Alan Bartlett Shepard Jr., Astronaut. (NASA)
At 10:34:13.48 a.m., Eastern Daylight Time ¹ (13:34:13.48 UTC), 5 May 1961, Mercury-Redstone 3 lifted off from Launch Complex 5 at the Cape Canaveral Air Force Station, Cape Canaveral, Florida. On board was a NASA Astronaut, Commander Alan Bartlett Shepard, Jr., United States Navy. Shepard had named his spacecraft Freedom 7.
This was the very first time that an American astronaut had been carried into space aboard a rocket and came 23 days after Soviet Union Cosmonaut Yuri Alekseyevich Gagarin had completed one orbit of the Earth.
During the launch, acceleration reached 6.3 gs. The Redstone’s engine shut down at T+02:21.3, with the rocket having reached a velocity of 7,388 feet per second (2,251.9 meters per second). 10 seconds later, the Mercury spacecraft separated from the Redstone booster. The spacecraft’s maximum speed was 5,134 miles per hour (8,262.4 kilometers per hour). For the next 5 minutes, 4 seconds, Alan Shepard was “weightless.” Freedom 7 reached a peak altitude of 101.2 nautical miles (116.46 statute miles/187.42 kilometers), 0.9 nautical miles (1.7 kilometers) higher than planned.
Alan B. Shepard, Jr., seated in the cockpit of Freedom 7 before launch, 5 May 1961. (NASA)
Alan Shepard’s flight was suborbital. The rocket launched the capsule on a ballistic trajectory. During the flight, Shepard demonstrated the use of manually controlled thrusters to orient the Mercury capsule in three axes.
Freedom 7 began reentry to the atmosphere at T+07:38. Deceleration forces reached 11.0 gs. Shepard manually controlled the vehicle’s attitude, and once correctly oriented for reentry, reverted to automatic control. With the blunt (bottom) end of the spacecraft forward, aerodynamic drag slowed the capsule. A spherical-segment ablative Beryllium heat shield protected the space ship and its passenger.
On reaching the lower atmosphere, the capsule’s speed was reduced by a 63-foot (19.2 meter) diameter ring-sail parachute, and a “landing bag” deployed from the base of the spacecraft to provide an impact cushion. The landing, or “splash down,” took place in the Atlantic Ocean, 263.1 nautical miles (302.8 statute miles/487.3 kilometers) down range, 6.8 nautical miles (7.8 miles/12.6 kilometers) farther than planned. (N. 75° 53′, W. 27° 13.7′)
The total duration of Alan Shepard’s flight was 15 minutes, 28 seconds. All mission objectives were accomplished and no malfunctions occurred.
Alan B. Shepard, Jr., being hoisted aboard the Sikorsky HUS-1 Seahorse helicopter, N. 75° 53′, W. 27° 13.7′, in the Atlantic Ocean, 5 May 1961. (NASA)
Eleven minutes after splash down, Commander Shepard was hoisted from the capsule to a hovering U.S. Marine Corps HUS-1 Sea Horse (Sikorsky S-58) helicopter of Marine Helicopter Transport Squadron (Light) 262 (HMR(L)-262).² The helicopter then lifted the Mercury capsule and flew to the nearby U.S. Navy Ticonderoga-class anti-submarine aircraft carrier, USS Lake Champlain (CVS-39). The Mercury capsule was returned to Cape Canaveral for inspection and found to be in excellent condition.
U.S. Marine Corps HUS-1 Seahorse (Sikorsky S-58) Bu. No. 148767 of HMR(L)-262 hovers while hoisting Alan Shepard from Freedom 7 after his sub-orbital flight, 5 May 1961. The Mercury capsule will also be lifted from the ocean by the helicopter and carried to USS Lake Champlain (CVS-39). (NASA)USS Lake Champlain (CVS-39), 1 July 1960. (U.S. Navy)
Freedom 7 was the seventh of twenty Mercury capsules built by McDonnell Aircraft Corporation at St. Louis, Missouri, which would also build the follow-on, two-place Gemini spacecraft. It was delivered to Cape Canaveral 9 December 1960.
The space capsule was truncated cone with sides angled 20° from the longitudinal axis. It was 6 feet, 10 inches (2.083 meters) long and had a maximum diameter of 6 feet, 2.50 inches (1.892 meters). The total height of the spacecraft, from the tip of the aero spike to the booster adapter, was 26 feet, 1.26 inches (7.957 meters). At launch, Freedom 7 weighed 4,040.28 pounds (1,832.64 kilograms).
Project Mercury spacecraft under construction at McDonnell Aircraft Corporation, St. Louis, Missouri. (NASA)
During flight outside the atmosphere, the Mercury spacecraft could be controlled in its pitch, roll and yaw axes by hydrogen peroxide-fueled reaction control thrusters. Both manual and automatic attitude control were available. It could not accelerate or decelerate (except for reentry), so it could not change its orbit.
The spacecraft cabin was pressurized to 5.5 psi (0.38 Bar) with 100% oxygen. The astronaut wore a B.F. Goodrich Mark IV Model 3 Type I full-pressure suit and flight helmet for protection in the event that cabin pressure was lost.
Mercury-Redstone Launch Vehicle with dimensions. (NASA)
The Redstone MRLV rocket was a redesigned, “man rated” version of the Chrysler Corporation Missile Division-built United States Army M8 Redstone nuclear-armed medium range ballistic missile (MRBM). It was lengthened to provide greater fuel capacity, a pressurized instrumentation section was added, the control systems were simplified for greater reliability, and an inflight abort sensing system was installed. The rocket fuel was changed from hydrazine to ethyl alcohol.
The cylindrical booster was 59.00 feet (17.983 meters) long and 5 feet, 10 inches (1.778 meters) in diameter. The rocket had four guidance fins with rudders mounted at the tail section. (Interestingly, the Redstone stood freely on the launch pad. No hold-downs were used. The guidance fins supported the entire weight of the vehicle.)
Compare the U.S. Army M8 Redstone medium-range ballistic missile in this photograph to the Mercury-Redstone launch vehicle in the photograph above. This rocket, CC-1002, was the first Block 1 tactical rocket, photographed at Cape Canaveral Air Force Station, 16 May 1958. (NASA)
The Redstone MRLV was powered by a single liquid-fueled NAA 75-110-A7 rocket engine built by the Rocketdyne Division of North American Aviation, Inc., at Canoga Park, California. The MR-3 A7 produced 78,860 pounds of thrust (350.79 kilonewtons) at Sea Level, and approximately 89,000 pounds (395.89 kilonewtons) in vacuum, burning ethyl alcohol with liquid oxygen.
The total vehicle height of Mercury-Redstone 3, including the booster, adapter, capsule and escape tower, was 83.38 feet (25.414 meters). The total MR-3 vehicle launch weight was 66,098 pounds (29,982 kilograms).
Alan B. Shepard, Jr. is credited with two Fédération Aéronautique Internationale (FAI) World Records for this flight:
FAI Record File Num #9519 [Direct Link]
Status: ratified – current record
Region: World
Class: K (Space records)
Sub-Class: K-1 (Suborbital missions)
Category: Spacecraft with one astronaut
Group: General category
Type of record: Altitude
Performance: 186.307 km
Date: 1961-05-05
Course/Location: Cape Canaveral, FL (USA)
Claimant Alan B. Shepard, Jr (USA)
Spacecraft: NASA Mercury Redstone MR-7 / Capsule Mercury Spacecraft n°7
FAI Record File Num #9520 [Direct Link]
Status: ratified – current record
Region: World
Class: K (Space records)
Sub-Class: K-1 (Suborbital missions)
Category: Spacecraft with one astronaut
Group: General category
Type of record: Greatest mass lifted to altitude
Performance: 1 832.51 kg
Date: 1961-05-05
Course/Location: Cape Canaveral, FL (USA)
Claimant Alan B. Shepard, Jr (USA)
Spacecraft: NASA Mercury Redstone MR-7 / Capsule Mercury Spacecraft n°7
The flight of Freedom 7 was the first manned spaceflight in the 50-year history of the NASA program.³ Alan Shepard would later command Apollo 14, the third successful manned lunar landing mission, in 1971.
Alan Shepard’s Mercury spacecraft, Freedom 7, is on display at the John F. Kennedy Presidential Library and Museum, Boston, Massachusetts.
Alan Shepard’s Freedom 7 on display at the John F. Kennedy Presidential Library and Museum, Boston, Massachusetts.
¹ In 1961, Daylight Saving Time in the United States began on 30 April, just six days before Shepard’s flight. Contemporary newspaper articles about the flight frequently give the time of the launch in both standard time and daylight saving time.
² Sikorsky HUS-1 Sea Horse, Bu. No. 148767, modex ET-44. Sikorsky serial number 581318.
³ From the liftoff of Mercury-Redstone 3 until wheel stop of Space Shuttle Discovery (STS-135), the era of NASA’s Manned Spaceflight Programs lasted 50 years, 2 months, 15 days, 20 hours, 23 minutes, 41 seconds.
North American Aviation P-51B-1-NA Mustang 43-12093 (102-24541), the first production P-51B. (NASA Langley Research Center Vintage Photographs Collection)
5 May 1943: First flight of a production North American Aviation P-51B-1-NA Mustang, 43-12093 (NAA serial number 102-24541).
Compare the Merlin-powered P-51B, above, to this Allison-engined P-51A-1-NA Mustang, 43-6008 (99-22111). (NASA)
North American Aviation, Inc., located at Mines Field, Los Angeles, California (now, Los Angeles International Airport, or more commonly, LAX), contracted with the British Purchasing Commission to produce a new fighter designed around the liquid-cooled Allison Engineering Company V-1710-F3R V-12 engine. Just 117 days later, the first prototype, the NA-73X, was completed. The airplane made its first flight on 26 October 1940, with free-lance test pilot Vance Breese. The British ordered 320 fighters for the Royal Air Force, and named it the Mustang Mk.I. Soon after, a second order for 300 airplanes came through. On 23 April 1941, North American test pilot Louis Sanford Wait flew the first production airplane, RAF serial number AG345.
The first production Mustang Mk.I, AG345, first flight, 23 April 1941. (North American Aviation, Inc.)
The Mk.I was 30 miles per hour (48 kilometers per hour) faster than its contemporary, the Curtiss-Wright P-40 Warhawk, though both used the same engine and propeller. Below 15,000 feet (4,572 meters), the Mustang was also 30–35 m.p.h (48–56 kilometers per hour) faster than a Supermarine Spitfire, which had the more powerful Roll-Royce Merlin V-12.
The Mustang Mk.I was heavily armed with eight machine guns. Two Browning .50-caliber machine guns were positioned under the engine, synchronized to fire forward through the propeller arc. Two more .50s and four .303-caliber Browning Mark II machine guns were installed in the wings.
Two Mustang Mk.Is, the fourth and tenth production airplanes, were turned over to the United States Army Air Corps for testing at Wright Field, Dayton, Ohio. These were designated XP-51 by the Air Corps. Test pilot Robert Creed Chilton took the first XP-51, 41-038 (ex-RAF AG348) for its first flight, 20 May 1941. Both airplanes were also extensively tested by the National Advisory Committee for Aeronautics (NACA) at the Langley Memorial Aeronautical Laboratory, Hampton, Virginia.
North American Aviation XP-51 at Wright Field. (Charles M. Daniels Collection, San Diego Air & Space Museum Archives)
The Air Corps initially ordered the airplane as a dive bomber, designated A-36 Apache. With various changes from the British fighter, on 23 June 1942, the Air Corps ordered 1,200 fighters as the P-51A. Chilton flew the first production P-51A, 43-6003, on 3 February 1943.
In England, tests were made of the Mustang Mk.I with Rolls-Royce Merlin 61 and 65 V-12 engines installed in place of the Allison V-1710. Called the Mustang X, it proved to be a superior fighter, particularly at high altitude. The RAF ordered it as the Mustang Mk.III.
Identical to the Inglewood, California-built North American Aviation P-51B Mustang, this is a Dallas, Texas-built P-51C-1-NT, 42-103023. (North American Aviation, Inc.)
In the United States, the Packard Motor Car Company of Detroit, Michigan, had begun building Merlin engines under license from Rolls-Royce. These American engines were designated V-1650. North American modified two P-51As from the production line to install the Packard V-1650-3. These were designated XP-51B. Testing revealed that the new variant was so good that the Army Air Corps limited its order for P-51As to 310 airplanes and production was changed to the P-51B.
The P-51B and P-51C are virtually identical. The P-51Bs were built by North American Aviation, Inc., at Inglewood, California. P-51Cs were built at North American’s Dallas, Texas plant. They were 32 feet, 2.97 inches (9.829 meters) long, with a wingspan of 37 feet, 0.31-inch (11.282 meters) and overall height of 13 feet, 8 inches (4.167 meters) high. The fighter had an empty weight of 6,985 pounds (3,168 kilograms) and a maximum gross weight of 11,800 pounds (5,352 kilograms).
P-51Bs and Cs were powered by a right-hand tractor, liquid-cooled, supercharged, 1,649-cubic-inch-displacement (27.04-liter) Packard V-1650-3 or -7 Merlin single overhead cam (SOHC) 60° V-12 engine which produced 1,380 horsepower at Sea Level, turning 3,000 r.p.m at 60 inches of manifold pressure (V-1650-3) or 1,490 horsepower at Sea Level, turning 3,000 r.p.m. at 61 inches of manifold pressure (V-1650-7). (Military Power rating, 15 minute limit.) These were license-built versions of the Rolls-Royce Merlin 63 and 66. The engine drove a four-bladed Hamilton Standard Hydromatic constant-speed propeller with a diameter of 11 feet, 2 inches (3.404 meters) through a 0.479:1 gear reduction.
A Packard Motor Car Company V-1650-7 Merlin V-12 aircraft engine at the Smithsonian Institution National Air and Space Museum. This engine weighs 1,715 pounds (778 kilograms) and produces 1,490 horsepower at 3,000 r.p.m. Packard built 55,873 of the V-1650 series engines. Continental built another 897. The cost per engine ranged from $12,548 to $17,185. (NASM)
The P-51B/C had a cruise speed of 362 miles per hour (583 kilometers per hour) and the maximum speed was 439 miles per hour (707 kilometers per hour) at 25,000 feet (7,620 meters). The service ceiling was 41,900 feet (12,771 meters). With internal fuel, the combat range was 755 miles (1,215 kilometers).
In U.S. service, armament consisted of four air-cooled Browning AN-M2 .50-caliber machine guns, mounted two in each wing, with 350 rounds per gun for the inboard guns and 280 rounds per gun for the outboard.
1,988 P-51B Mustangs were built at North American’s Inglewood, California plant and another 1,750 P-51Cs were produced at Dallas, Texas. This was nearly 23% of the total P-51 production.
North American P-51B Mustang with identification stripes. (U.S. Air Force)
Colonel Robin Olds, United States Air Force, Wing Commander, 8th Tactical Fighter Wing, Ubon Rachitani RTAFB. (U.S. Air Force)
4 May 1967: Colonel Robin Olds, United States Air Force, commanding the 8th Tactical Fighter Wing based at Ubon RTAFB, shot down his second enemy airplane during the Vietnam War.
Colonel Olds had flown Lockheed P-38 Lightning and North American P-51 Mustang fighters during World War II. He is officially credited with shooting down 12 enemy airplanes over Europe and destroying 11.5 on the ground. On 2 January 1967, he had destroyed a MiG-21 near Hanoi, North Vietnam, while flying a McDonnell F-4C Phantom II. He was the first U.S. Air Force fighter ace to shoot down enemy aircraft during both World War II and the Vietnam War.
Colonel Robin Olds and 1st Lieutenant William D. Lefever (standing, left and center) with other pilots of the 555th Tactical Fighter Squadron, 8th Tactical Fighter Wing, Ubon Rachitani RTAFB, 4 May 1967. (U.S. Air Force via Jet Pilot Overseas)
A description of the air battle follows:
On 4 May, the 8th TFW provided two flights of Phantoms for MiGCAP for five F-105 flights of the 355th TFW which were on a strike mission. Col. Olds, 8th Wing commander, led the rear flight, flying with 1st Lt. William D. Lafever. The other F-4 flight was sandwiched midway in the strike force. MiG warnings crackled on Olds’ radio just before his wingman sighted two MiG-21s at 11 o’clock, attacking the last of the Thunderchief flights. Colonel Olds’ account picks up the encounter at this point:
“The MiGs were at my 10 o’clock position and closing on Drill [the F-105 flight] from their 7:30 position. I broke the rear flight into the MiGs, called the F-105s to break, and maneuvered to obtain a missile firing position on one of the MiG-21s. I obtained a boresight lock-on, interlocks in, went full system, kept the pipper on the MiG, and fired two AIM-7s in a ripple. One AIM-7 went ballistic. The other guided but passed behind the MiG and did not detonate. Knowing I was too close for further AIM-7 firing, I maneuvered to obtain AIM-9 firing parameters. The MiG-21 was maneuvering violently and firing position was difficult to achieve. I snapped two AIM-9s at the MiG and did not observe either missile. The MiG then reversed and presented the best parameter yet. I achieved a loud growl, tracked, and fired one AIM-9. From the moment of launch it was obvious that the missile was locked on. It guided straight for the MiG and exploded about 5–10 feet beneath his tailpipe.
Mikoyan Gurevich MiG-21 in markings of the Vietnam People’s Air Force at the National Museum of the United States Air Force. (U.S. Air Force)
“The MiG then went into a series of frantic turns, some of them so violent that the aircraft snap-rolled in the opposite direction. Fire was coming from the tailpipe, but I was not sure whether it was normal afterburner or damage-induced. I fired the remaining AIM-9 at one point, but the shot was down toward the ground and did not discriminate. I followed the MiG as he turned southeast and headed for Phuc Yen. The aircraft ceased maneuvering and went in a straight slant for the airfield. I stayed 2,500 feet behind him and observed brilliant white fire streaming from the left side of his fuselage. It looked like magnesium burning with particles flaking off. I had to break off to the right as I neared Phuc Yen runway at about 2,000 feet, due to heavy, accurate, 85-mm barrage. I lost sight of the MiG at that point. Our number 3 saw the MiG continue in a straight gentle dive and impact approximately 100 yards south of the runway.”
Colonel Olds then took his flight to the target area and covered the last of the 355th TFW strike aircraft as they came off the target. Leading his flight to Hoa Lac airfield and dodging two SAMs on the way, he found five MiG-17s over that airfield.
“We went around with them at altitudes ranging from 1,500 to 6,000 feet, right over the aerodrome,” Olds reported. The F-4s ran low on fuel before any real engagements occurred, however, and were forced to break off the encounter.
— Aces and Aerial Victories: The United States Air Force in Southeast Asia 1965–1973, by R. Frank Futrell, William H. Greenhalgh, Carl Grubb, Gerard E. Hasselwander, Robert F. Jakob and Charles A. Ravenstein, Office of Air Force History, Headquarters USAF, 1976, Chapter II at Pages 51–53.
During this mission, Colonel Olds and Lieutenant Lefever flew McDonnell F-4C-21-MC Phantom II serial number 63-7668.
Colonel Robin Olds shot down a MiG-21 with this McDonnell F-4C-21-MC Phantom II, 63-7668, 4 May 1967. (U.S. Air Force)
6 May 1937: After a three-day Trans-Atlantic crossing from Frankfurt, Germany, the rigid airship Hindenburg (D-LZ129) arrived at Lakehurst, New Jersey, with 36 passengers and 61 crewmembers.
