Daily Archives: August 15, 2019

15 August 1962

An American Airlines Boeing 707-023B Astrojet (720B) at Los Angeles International Airport, 26 December 1962. (Photograph courtesy of Jon Proctor)
An American Airlines Boeing 707-023B Astrojet (720B) at Los Angeles International Airport, 26 December 1962. (Photograph courtesy of Jon Proctor)

15 August 1962: American Airlines’ Captain Eugene M. (“Gene”) Kruse set a National Aeronautic Association Class C-1 record for Speed Over a Commercial Air Route, East to West Transcontinental, when he flew a Boeing 720B Astrojet from New York to Los Angeles, 2,474 miles (3,981.5 kilometers), in 4 hours, 19 minutes, 15 seconds, at an average speed of 572.57 miles per hour (921.46 kilometers per hour). 56 years later, this record still stands.

Screen Shot 2015-01-02 at 12.22.27

The National Aeronautic Association has placed Captain Kruse’ record on its “Most Wanted” list: long-standing flight records that it would like to see challenged. Rules require that a new record exceed the old by at least a 1% margin. The performance needed to establish a new record would be 578.30 miles per hour (930.68 kilometers per hour).

The Boeing 720 was a variant of the Model 707, intended for short to medium range flights. It had 100 inches (2.54 meters) removed from the fuselage length and improvements to the wing, decreasing aerodynamic drag.

The Boeing 720 was operated by a flight crew of four and could carry up to 149 passengers. It was 136 feet, 2 inches (41.25 meters) long with a wingspan of 130 feet, 10 inches (39.90 meters) and overall height of 41 feet, 7 inches (12.65 meters). The airplane had an empty weight of 103,145 pounds (46,785 kilograms) and Maximum Takeoff Weight of 220,000 pounds (100,800 kilograms).

The Boeing 720 was powered by four Pratt & Whitney Turbo Wasp JT3C-7 turbojet engines, a civil variant of the military J57 series. The 720B was equipped with the more efficient P&W JT3D-1 turbofan engines. The JT3C-7 was a “two-spool” axial-flow engine with a 16-stage compressor (9 low- and 7 high-pressure stages), 8 combustion tubes, and a 3-stage turbine (1 high- and 2 low-pressure stages). It was rated at 12,030 pounds of thrust (53.512 kilonewtons) for takeoff. The JT3D-1 was a dual axial-flow turbofan engine, with a 2-stage fan section 13-stage compressor (6 low- and 7 high pressure stages), 8 combustion chambers and a 4-stage turbine (1 high- and 3 low-pressure stages). This engine was rated at 14,500 pounds of static thrust (64.499 kilonewtons) at Sea Level, and 17,000 pounds (75.620 kilonewtons), with water injection, for takeoff (2½ minute limit). Almost half of the engine’s thrust was produced by the fans. Maximum engine speed was 6,800 r.p.m. (N1) and 10,200 r.p.m. (N2). It was 11 feet, 4.64 inches (3.471 meters) long, 4 feet, 5.00 inches (1.346 meters) wide and 4 feet, 10.00 inches (1.422 meters) high. It weighed 4,165 pounds (1,889 kilograms). The JT3C could be converted to the JT3D configuration during overhaul.

The maximum cruise speed was 611 miles per hour (983 kilometers per hour) and maximum speed was 620 miles per hour (1,009 kilometers per hour). Range at at maximum payload was 4,370 miles (7,033 kilometers).

Boeing built 154 720 and 720B airliners from 1959 to 1967.

The last flight of a Boeing 720 was on 9 May 2012, when a 720B aircraft used by Pratt and Whitney Canada as a test aircraft was placed in the National Air Force Museum of Canada at Trenton, Ontario.

© 2018, Bryan R. Swopes

Facebooktwitterredditpinterestlinkedinmailby feather

15 August 1951

William Barton Bridgeman (TIME Magazine)
William Barton Bridgeman (Boris Artzybasheff/TIME Magazine)

15 August 1951: Just 8 days after he set an unofficial world speed record of  Mach 1.88 (1,245 miles per hour; 2,033.63 kilometers per hour) Douglas Aircraft Company test pilot William Barton (“Bill”) Bridgeman flew the rocket-powered United States Navy/National Advisory Committee on Aeronautics (NACA) Douglas D-558-II Skyrocket, Bu. No. 37974, to a world record altitude at Edwards Air Force Base in the high desert of Southern California.

The Skyrocket was airdropped at 34,000 feet (10,363 meters) from a highly-modified U.S. Navy P2B-1S Superfortress, Bu. No. 84029. The mother ship was a U.S. Air Force Boeing B-29-95-BW Superfortress, 45-21787, transferred to the Navy and flown by another Douglas test pilot, George R. Jansen.

Douglas D-558-II Skyrocket, Bu. No., 37974, NACA 144, is dropped from the Boeing P2B-1S Superfortress, Bu. No. 84029, NACA 137. (NASA)
Douglas D-558-II Skyrocket, Bu. No., 37974, NACA 144, is dropped from the Boeing P2B-1S Superfortress, Bu. No. 84029, NACA 137. (NASA)

The flight plan was for Bridgeman to fire the rocket engine and allow the Skyrocket to accelerate to 0.85 Mach while climbing. The Skyrocket was powered by a Reaction Motors LR8-RM-6 engine, which produced 6,000 pounds of thrust. As the rocketplane continued to accelerate to Mach 1.12, the test pilot was to pull up, increasing the angle of climb while holding an acceleration rate of 1.2 Gs. This would result in a constantly increasing angle of climb. When it reached 50°, Bridgeman was to maintain that, climbing and accelerating, until the rocket engine ran out of fuel.

Initially, the plan was to continue climbing after engine shutdown until the D-558-II was approaching stall at the highest altitude it could reach while on a ballistic trajectory. There were differing expert opinions as to how it would behave in the ever thinner atmosphere. On the morning of the flight, Douglas’ Chief Engineer, Ed Heinemann, ordered that Bridgeman push over immediately when the engine stopped.

Bill Bridgeman stuck to the engineers’ flight plan. As the Skyrocket accelerated through 63,000 feet (19,200 meters), it started to roll to the left. He countered with aileron input, but control was diminishing in the thin air. The next time it began there was no response to the ailerons. Bridgeman found that he had to lower the Skyrocket’s nose until it responded, then he was able to increase the pitch angle again. At 70,000 feet (21,336 meters), travelling Mach 1.4, he decided he had to decrease the pitch angle or lose control. Finally at 76,000 feet (23,165 meters), the engine stopped. Following Heinemann’s order, Bridgeman pushed the nose down and the D-558-II went over the top of its arc at just 0.5 G.

Bill Bridgeman. (Unattributed)
Bill Bridgeman. (Unattributed)

“In the arc she picks up a couple of thousand feet. The altimeter stops its steady reeling and swings sickly around 80,000 feet. The altitude is too extreme for the instrument to function.

“Eighty thousand feet. It is intensely bright outside; the contrast of the dark shadows in the cockpit is extreme and strange. It is so dark lower in the cockpit that I cannot read the instruments sunk low on the panel. The dials on top, in the light, are vividly apparent. There seems to be no reflection. It is all black or white, apparent or non-apparent. No half-tones. It is a pure, immaculate world here.

“She levels off silently. I roll right and there it is. Out of the tiny windows slits there is the earth, wiped clean of civilization, a vast relief map with papier-mâché mountains and mirrored lakes and seas. . . .

“It is as if I am the only living thing connected to this totally strange, uninhabited planet 15 miles below me. The plane that carries me and I are one and alone.”

The Lonely Sky, William Bridgeman with Jacqueline Hazard, Castle and Company LTD, London, 1956, Chapter XXII at Page 268.

After the data was analyzed, it was determined that William Bridgeman and the Douglas Skyrocket had climbed to 79,494 feet (24,230 meters), higher than any man had gone before. This was the last flight that would be made with a Douglas test pilot. The rocketplane was turned over to NACA, which would assign it the number NACA 144.

A Douglas D-558-II Skyrocket, Bu. No. 37974. glides back toward Rogers Dry Lake at Edwards Air force Base. A North American Aviation F-86E-1-NA Sabre, 50-606, flies chase. Major Charles E. "Chuck" Yeager frequently flew as a chase pilot for both Bill Bridgeman and Scott Crossfield. (NASA)
A Douglas D-558-II Skyrocket, Bu. No. 37974, glides back toward Rogers Dry Lake at Edwards Air Force Base. A North American Aviation F-86E-1-NA Sabre, 50-606, flies chase. Lieutenant Colonel Frank K. “Pete” Everest and Major Charles E. “Chuck” Yeager frequently flew as chase pilots for both Bill Bridgeman and Scott Crossfield. (NASA)

Bill Bridgeman had been a Naval Aviator during World War II, flying the Consolidated PBY Catalina and PB4Y (B-24) Liberator long range bombers with Bombing Squadron 109 (VB-109), “The Reluctant Raiders.” Bridgeman stayed in the Navy for two years after the war, then he flew for Trans-Pacific Air Lines in the Hawaiian Islands and Southwest Airlines in San Francisco, before joining Douglas Aircraft Co. as a production test pilot, testing new AD Skyraiders as they came off the assembly line at El Segundo, California. He soon was asked to take over test flying the D-558-2 Skyrocket test program at Muroc Air Force Base.

The D-558-II Skyrocket was Phase II of a planned three phase experimental flight program. It was designed to investigate flight in the transonic and supersonic range. It was 46 feet, 9 inches (14.249 meters) long with a 25 foot (7.62 meter) wing span. The wings were swept back to a 35° angle. The Skyrocket was powered by a Westinghouse J34-WE-40 11-stage axial-flow turbojet engine, producing 3,000 pounds of thrust, and a Reaction Motors LR8-RM-6 four-chamber rocket engine, which produced 6,000 pounds of thrust. The rocket engine burned alcohol and liquid oxygen.

There were three D-558-2 Skyrockets. Between 4 February 1948 and 28 August 1956, they made a total of 313 flights. Bill Bridgeman’s speed and altitude record-setting Skyrocket, Bu. No. 37974, NACA 144, is in the collection of the Smithsonian Institution National Air and Space Museum.

Douglas D-558-2 Skyrocket, Bu. No. 37974, NACA 144. (NASA)

© 2016, Bryan R. Swopes

Facebooktwitterredditpinterestlinkedinmailby feather

15 August 1939

Junkers Ju 87 B-1 Sturzkampfflugzeug (“Stuka”) photographed before World War II. Note the extended dive brake under the wing. (Unattributed)

15 August 1939: As Nazi Germany prepared for a war now just weeks away, the Luftwaffe gave a demonstration of its Junkers Ju 87 B-1 Stuka dive bombers for a group of generals at a test range near Neuhammer-am-Queis, Silesia :

“. . . scores of generals were assembled at the training area at Neuhammer to watch a dive-bombing demonstration. Already, said Rudolf Braun, who took part with his unit (I St. G 3) there was a feeling of war in the air.

Hauptmann Rudolf Braun, Knight’s Cross of the Iron Cross

“Normally the order of attack was the Kommandeur’s Stab Kette (Staff Flight) first, followed by Staffels 1, 2, and 3. For some unknown reason Staffel I, led by Oberleutnant Peltz, was this time ordered to attack last. It would save Rudolf Braun’s life.

“The Met. reported cloud from 6,000 feet down to 2,500 with clear visibility below. At 6.00 a.m. Hauptmann Sigel led his Gruppe into attack at 12,000 feet. Half-rolling his Ju. 87 he plunged nearly vertically earthwards, with Oberleutnants Eppen and Mueller on each side.

“On the ground below, the generals (including Wolfram von Richthofen, the Stuka’s chief) listened to the whining crescendo of the dive-bombers as they plummeted towards the ground. Horrified, they knew that nothing could avert disaster. The Met. report was wrong. Cloud base was at three hundred feet.

Hauptmann Sigel, yelling into his microphone, “Pull out!” managed to do so himself a few feet above the trees. But Eppen went in, Mueller went in, and both burst into flames. The nine Ju. 87s of Staffel 2 and two of Staffel 3 all went in.

“Rudolf Braun and his comrades of Staffel I had heard Sigel’s warning and remained circling above the cloud layer through which columns of black smoke were now rising from the wreckage of thirteen dive bombers. I St. G 3 lost twenty-six young aircrew that day.”

— Duel of Eagles, Group Captain Peter Wooldridge Townsend, C.V.O., D.S.O., D.F.C. and Bar, Royal Air Force. Castle Books, Edison, New Jersey, 2003, Chapter 14 at Pages 171–172.

Two Junkers Ju 87 Stuka dive bombers.

The Junkers Flugzeug-und-Motorenwerke AG Ju 87 B-1 Sturzkampfflugzeug (“diving combat aircraft”) was a two-place, single-engine, low-wing monoplane with fixed landing gear, designed as a dive bomber. The airplane, commonly known as the “Stuka,” has a blocky, unstreamlined appearance. Its most identifiable feature is its sharply-tapered, inverted “gull wing.” ¹

The Ju 87 made its first flight 17 September 1935. Among the tests pilots who flew it during pre-production testing were Hanna Reitsch and aeronautical engineer Gräfin Melitta Schenk von Stauffenberg.

The Stuka was used in the murderous attacks on the Spanish market town of Guernica, 26 April 1937, and Wieluń, Poland, 1 September 1939.

The Ju 87 B-1 was the first variant to be produced in large numbers and was in service at the beginning of World War II. The airplane is 11.000 meters (36.089 feet) long with a wingspan of 13.800 meters (45.276 feet) and height of 3.770 meters (12.369 feet). The total wing area is 31.9 square meters (343.4 square feet). The B-1 variant had an empty weight of 2,745 kilograms (6,052 pounds), and gross weight of 4,235 kilograms (9,337 pounds).

Two-view illustration of the Junkers Ju 87 B-1, with dimensions in millimeters. (Junkers Ju 87 B-1 Betriebsanleitung, at Page 0 05)

The Ju 87 B-1 was powered by a liquid-cooled, supercharged 34.989 liter (2,135.190 cubic-inch-displacement) Junkers Jumo 211 A inverted 60° V-12 engine. The 211 A had direct fuel-injected and the cylinder heads were machine for four spark plugs per cylinder. The compression ratio was 6.57:1, requiring 88-octane gasoline. It was rated at a maximum 900 Pferdestärke at 2,200 r.p.m. at 5,500 meters (18,045 feet). The engine turned a three-blade Junkers-Verstelluftschraube propeller with a diameter of 3.4 meters (11.2 feet) through a 1.55:1 gear reduction. The Jumo 211 A weighed 660 kilograms (1,455 pounds).

The Stuka B-1 had a maximum dive speed of 600 kilometers per hour (373 miles per hour). The Ju 87 B-1 had a service ceiling of 8,000 meters (26,247 feet), and range of 550 kilometers (342 miles).

The B-1 was armed with two fixed 7.92 mm Rheinmetall-Borsig MG17 machine guns with 1,000 rounds of ammunition per gun, and one MG 15 machine gun on a flexible mount with 900 rounds of ammunition. It could carry a single 500 kilogram (1,102 pound) bomb under the fuselage.

An interesting feature the the Stuka was its automatic pull-out system. Once the bomb had been dropped, the airplane automatically began a 5–6 g recovery. This could save the airplane if the pilot became target-fixated, or blacked out.

The Ju 87 was equipped with a Zeiss gyro-stabilized bomb sight. According to an article in Air Force Times, the Stuka was a very accurate dive bomber. “. . . even the worst drops typically landed within 100 feet [30.5 meters] of the target. Good hits were either on target or no more than 15 feet [4.6 meters] off-center.”

In the same article, the legendary Royal Navy test pilot, Captain Eric Melrose Brown, C.B.E., D.S.C., A.F.C., K.C.V.S.A., Ph.D., Hon. F.R.Ae.S., R.N., is quoted:

A dive angle of 90 degrees is a pretty palpitating experience, for it always feels as if the aircraft is over the vertical and is bunting, and all this while terra firma is rushing closer with apparent suicidal rapidity. In fact I have rarely seen a specialist dive bomber put over 70 degrees in a dive, but the Ju 87 was a genuine 90-degree screamer. . . the Ju 87 felt right standing on its nose, and the acceleration to 335 mph [539 km/h] was reached in about 4,500 feet [1,372 meters], speed thereafter creeping up to the absolute permitted limit of 375 mph [604 km/h], so that the feeling of being on a runaway roller coaster experienced with most dive bombers was missing. I must confess that I had a more enjoyable hour’s dive-bombing practice than I had ever experienced with any other aircraft of this specialist type. Somehow the Ju 87D did not appear to find its natural element until it was diving steeply. Obviously the fixed undercarriage and large-span dive brakes of the Junkers were a highly effective drag combination.”

Only two Stukas still exist, one, a Ju 87 G-2, at the RAF Museum at Hendon, and the other, a Ju 87 R-2, is at the Museum of Science and Industry, Chicago, Illinois.

¹ TDiA has not found any source that provides the details of the Ju 87’s most characteristic feature: the angles of anhedral and dihedral of its wings. TDiA estimates that the wings’ inner section has -12° anhedral, while the outer wing panels have approximately 8° dihedral.

© 2018, Bryan R. Swopes

Facebooktwitterredditpinterestlinkedinmailby feather

15 August 1935

Will Rogers and Wiley Post with the Lockheed Model 9E Orion hybrid at Renton, Washington. The pontoons have just been installed on the airplane in place of its fixed landing gear. (Unattributed)
Will Rogers and Wiley Post with the Lockheed Model 9E Orion hybrid at Renton, Washington. The pontoons have just been installed on the airplane in place of its fixed landing gear. (Seattle Post Intelligencer Collection/Museum of History & Industry)

15 August 1935: Two of the most famous men of their time, Wiley Hardeman Post and William Penn Adair (“Will”) Rogers, were killed in an airplane crash near Point Barrow, Alaska.

Post, a pioneering aviator who had twice flown around the world—once, solo—and helped develop the pressure suit for high altitude flight, was exploring a possible air mail route from the United States to Russia. His friend, world famous humorist Will Rogers, was along for the trip.

Transcontinental and Western Airlines' Lockheed Model 9E special, NC12283. This airplane would be modified by Pacific Airmotive, Burbank, California, for Wiley Hardeman post. (Ed Coates Collection)
Transcontinental & Western Air Incorporated’s Lockheed Model 9E Special, NC12283. This airplane would be modified by Pacific Airmotive, Burbank, California, for Wiley Hardeman Post. (Ed Coates Collection)

Post’s airplane was a hybrid, built from the fuselage of a former Transcontinental & Western Air, Inc., Lockheed Model 9E Orion Special, NC12283, combined with a wing from a Lockheed Model 7 Explorer. T&WA operated the Orion for two years before selling it to Charles Babb, Glendale, California. Babb installed the salvaged wing from a modified Lockheed Model 7 Explorer, Blue Flash, NR101W, which had crashed in Panama in 1930.

The Orion’s standard 450 horsepower Pratt & Whitney Wasp SC1 engine was replaced with an air-cooled, supercharged, 1,343.8-cubic-inch-displacement (22.021 liter) Pratt & Whitney Wasp S3H1 nine-cylinder radial engine (serial number 5778), rated at 550 horsepower at 2,200 r.p.m. to 5,000 feet (1,524 meters), and 600 horsepower at 2,250 r.p.m. for takeoff. A three-bladed Hamilton Standard variable-pitch propeller was used. Both the SC1 and S3H1 were direct drive engines. The S3H1 was 3 feet, 7.01 inches (1.093 meters) long and 4 feet, 3.60 inches (1.311 meters) in diameter. It weighed 865 pounds (392 kilograms).

Post also wanted to replace the retractable landing gear with pontoons for water landings.

Lockheed engineers were of the opinion that the hybrid aircraft and the other modifications which were requested by Post were dangerous and refused to do the work. Pacific Airmotive, also located in Burbank, California, however, agreed to modify the airplane. Several names were used to describe the hybrid airplane, such as “Lockheed Aurora,” as well as others perhaps less polite. It was given the restricted registration NR12283.

NR12283 was 27 feet, 6 inches (8.382 meters) long with a wingspan of 48 feet, 6 inches (14.783 meters). The wing area was 313 square feet (29.079 square meters).

Wiley Post’s red Lockheed Orion/Explorer hybrid, NR12283, at Renton, Washington.

Post had the pontoons installed at Renton, Washington. The floats that he had ordered did not arrive on time so he installed a larger set intended for another aircraft.

NR12283, Wiley Post's hybrid Lockheed Orion/Explorer float plane, at Fairbanks, Alaska. (PBS)
NR12283, Wiley Post’s red hybrid Lockheed Orion/Explorer float plane, at Fairbanks, Alaska. (PBS)

After several days of flying from Seattle and through Alaska, Post and Rogers were nearing Point Barrow on the northern coast of the continent. They encountered dense fog and landed on Walakpa Bay, about 13 miles (21 kilometers) southwest of the village of Barrow.

“August 15, 1935 2:00 p.m. — Harding Lake, Alaska. Wiley Post and Will Rogers taxi for take-off. Last photo before their 6:30 p.m. crash near Barrow. Patton Collection #13 ” (Harding Lake Association)

After talking with a local resident, Clair Okpheah, they taxied back on the lagoon and took off to the north. Post banked to the right, but at about 50 feet (15 meters) the engine stopped. NR12283 pitched down, rolled to the right, and then its right wing struck the mud. The right wing and pontoon were torn off and the airplane crashed upside down. Post and Rogers died.

Clair Okpheah ran to Barrow for help. When a rescue party arrived 16 hours after the crash, the men recovered the bodies of Post and Rogers. It was noted that Wiley Post’s wristwatch had stopped at 8:18 p.m.

Wiley Post's hybrid airplane, NR12283, after the crash, 15 August 1935. (UPI)
The wreckage of Wiley Post’s Lockheed Model 9E Orion hybrid airplane, NR12283, after the crash at Walakpa Lagoon, Alaska, 15 August 1935. (UPI)

© 2018, Bryan R. Swopes

Facebooktwitterredditpinterestlinkedinmailby feather