First Lieutenant Harold Ross Harris, Air Service, United States Army, 1922.
17 April 1923: At Wilbur Wright Field, Dayton, Ohio, First Lieutenant Harold Ross Harris set two Fédération Aéronautique Internationale (FAI) World Speed Records, flying a modified de Havilland XDH-4L powered by a Hall-Scott Liberty 375 engine. Lieutenant Harris averaged 184.03 kilometers per hour (114.35 miles per hour) over a 1,500 kilometer (932.1 miles) closed circuit,¹ and 183.82 kilometers per hour (114.22 miles per hour) over a 2,000 kilometer (1,242.7 mile) course. ²
Harold R. Harris was an important figure in the development of aircraft following World War I. He served as Engineering Officer for the U.S. Army at McCook Field and flew many experimental aircraft, setting records for speed and altitude, and worked on the development of airplanes, engines and other equipment. Harris was the first man to use a parachute to escape an airplane during an actual in-flight emergency.
In civil aviation, Harris was an executive with the company that would become Pan American World Airways. During World War II, he was chief of staff of the Air Transport Command, retiring with the rank of brigadier general, and then returning to commercial aviation as a vice president of Pan Am and later president of Northwest Airlines.
de Havilland XDH-4L A.S. 64593, FAI World Speed record holder. (FAI)
The XDH-4L was a variant of the Airco DH.4, designed by Geoffrey de Havilland. It was a two-place, single-engine biplane intended as a bomber, but the type served in virtually every capacity during World War I and the years following. At McCook Field, American-built DH-4s were commonly used as test beds for engines and other aeronautical equipment.
The standard Airco DH.4 had a crew of two. It was 30 feet, 8 inches (9.347 meters) long with a wingspan of 43 feet, 4 inches (13.208 meters) and height of 11 feet (3.353 meters). Empty weight was 2,387 pounds (1,085 kilograms) and loaded weight was 3,472 pounds (1,578 kilograms). British-built DH.4s were powered by a 1,240.54-cubic-inch-displacement (20.33 liter) liquid-cooled Rolls-Royce Eagle overhead cam 60° V-12 engine which produced 375 horsepower. A gear-reduction system kept propeller r.p.m. below engine speed for greater efficiency.
American-built DH.4 airplanes were produced by the Boeing Airplane Company, Dayton-Wright Airplane Company, Fisher Body Corporation, and Standard Aircraft Corporation. Most were powered by the Liberty L12 engine.
Major Henry H. Arnold standing beside the first Liberty 12 aircraft engine turned out for war use. “Hap” Arnold would later hold the 5-star rank of General of the Army and General of the Air Force. (U.S. Air Force)
The Liberty L12 aircraft engine was designed by Jesse G. Vincent of the Packard Motor Car Company and Elbert J. Hall of the Hall-Scott Motor Company. It was a water-cooled, normally-aspirated, 1,649.336-cubic-inch-displacement (27.028 liter) Liberty L-12 single overhead cam (SOHC) 45° V-12 engine with a compression ratio of 5.4:1. The Liberty produced 408 horsepower at 1,800 r.p.m. The L-12 as a right-hand tractor, direct-drive engine and it turned turned a two-bladed fixed-pitch wooden propeller. The Liberty 12 was 5 feet, 7.375 inches (1.711 meters) long, 2 feet, 3.0 inches (0.686 meters) wide, and 3 feet, 5.5 inches (1.054 meters) high. It weighed 844 pounds (383 kilograms). This engine was produced by Ford Motor Company, as well as the Buick and Cadillac Divisions of General Motors, The Lincoln Motor Company (which was formed by Henry Leland, the former manager of Cadillac, specifically to manufacture these aircraft engines), Marmon Motor Car Company and Packard. Hall-Scott was too small to produce engines in the numbers required.
Following World War I, many DH-4s were rebuilt by Boeing and Atlantic Aircraft. An improved version, the DH-4M, used a tubular steel framework instead of the usual wood construction. DH-4s remained in service with the United States Army as late as 1932.
De Havilland XDH-4L, U.S. Army Air Service serial number A.S. 64593, was used for engineering tests at McCook Field. It carried project number P193 painted on its rudder. At the time of the world speed records, it was powered by a Hall-Scott Liberty 375, a 375 horsepower version of the Liberty V-12 engine. The rear cockpit was faired over and a 185 gallon (700.3 liter) fuel tank installed for long range flights.
Lieutenants Oakland G. Kelly and John A. Macready with the fuel drums for their duration flight in front of the Fokker T-2, A.S. 64233. (U.S. Air Force)
16–17 April 1923: At Wilbur Wright Field, Dayton, Ohio, U.S. Army Air Service pilots Lieutenant Oakland George Kelly and Lieutenant John Arthur Macready set six Fédération Aéronautique Internationale (FAI) World Records for speed, distance and duration, flying the Nederlandse Vliegtuigenfabriek Fokker T-2, serial number A.S. 64233, which they planned to fly non-stop across the United States of America.
They flew 2,500 kilometers (1,553.428 miles) at an average speed of 115.60 kilometers per hour (51.83 miles per hour);¹ 3,000 kilometers (1,864.114 miles) at 115.27 kilometers per hour (71.63 miles per hour);² 3,500 kilometers (2,174.799 miles) at 114.82 kilometers per hour (71.35 miles per hour);³ 4,000 kilometers (2,485.485 miles) at 113.93 kilometers per hour (70.79 miles per hour);⁴ flew a total distance of 4,050 kilometers (2,517 miles);⁵ and stayed aloft for 36 hours, 4 minutes, 34 seconds.⁶ Their overall average speed was 112.26 kilometers per hour (69.76 miles per hour).
Lieutenant Oakley George Kelly, U.S. Army Air Service. (FAI)Lieutenant John A. Macready, U.S. Army Air Service
The Fokker F.IV was built by Anthony Fokker’s Nederlandse Vliegtuigenfabriek at Veere, Netherlands in 1921. The Air Service purchased two and designated the type T-2, with serial numbers A.S. 64233 and A.S. 64234.
Several modifications were made to prepare for the transcontinental flight. Normally flown by a single pilot in an open cockpit, a second set of controls was installed so that the airplane could be controlled from inside while the two pilots changed positions. On this flight, it carried 735 gallons (2,782 liters) of gasoline in three fuel tanks.
For its time, the Fokker was a large airplane: 49 feet (14.9 meters) long, with a wing span of 82 feet (25 meters). The high-wing monoplane was powered by a 1,649.3-cubic-inch-displacement (27.028 liter) liquid-cooled Liberty L12 single overhead cam (SOHC) 45° V-12 engine producing 420 horsepower. The airplane was designed to carry 8–10 passengers in an enclosed cabin.
The second Fokker T-2, A.S. 64234, also designated A-2 (ambulance). (U.S. Air Force)
From 2–3 May 1923, MacReady and Kelly succeeded in their non-stop transcontinental flight, flying from Roosevelt-Hazelhurst Field, Long Island, New York, to Rockwell Field (now, NAS North Island), San Diego, California, 2,470 miles (3,975 kilometers) in 26 hours, 50 minutes, 38.8 seconds, for an average speed of 92 miles per hour (148 kilometers per hour).
The U.S. Army Air Service transferred A.S. 64223 to the Smithsonian Institution in January 1924. It is on display at the National Air and Space Museum.
This McDonnell RF-101C-60-MC Voodoo, 56-055, is the sister ship of the airplane flown by Captain Edwards to set a World Speed Record, 15 April 1959. (Hervé Cariou)
15 April 1959: Captain George A. Edwards, Jr., United States Air Force, assigned to the 432nd Tactical Reconnaissance Wing, Shaw Air Force Base, South Carolina, set a Fédération Aéronautique Internationale (FAI) World Record for Speed Over a Closed Circuit of 500 Kilometers (310.686 miles) Without Payload at Edwards Air Force Base, California. Captain Edwards flew a McDonnell RF-101C-60-MC Voodoo, serial number 56-054. His speed over the course averaged 1,313.677 kilometers per hour (816.281 miles per hour).¹
Captain Edwards told The Nashville Tennessean, “The flight was routine. The plane ran like a scalded dog.”
Nine days earlier, Colonel Edward H. Taylor flew another McDonnell RF-101C to a World Record for Speed Over a 1000 Kilometer Course of 1,126.62 kilometers per hour (700.05 miles per hour).²
The RF-101C Voodoo was an unarmed reconnaissance variant of the F-101C fighter. It was 69 feet, 4 inches (21.133 meters) long with a wingspan of 39 feet, 8 inches (12.090 meters). The height was 18 feet (5.486 meters). Empty weight for the RF-101C was 26,136 pounds (11,855 kilograms), with a maximum takeoff weight of 51,000 pounds (23,133 kilograms).
RF-101 on ramp with cameras. (United States Air Force 140114-F-DW547-001)
Two Pratt & Whitney J57-P-13 turbojet engines. The J57 was a two-spool axial-flow turbojet which had a 16-stage compressor (9 low- and 7 high-pressure stages), 8 combustors and a 3-stage turbine (1 high- and 2 low-pressure stages). The J57-P-13 was rated at 10,200 pounds of thrust (45.37 kilonewtons), and 15,800 pounds (70.28 kilonewtons) with afterburner.
The aircraft had a maximum speed of 1,012 miles per hour (1,629 kilometers per hour) at 35,000 feet (10,668 meters). The service ceiling was 55,300 feet (16,855 meters). The Voodoo could carry up to three drop tanks, giving a total fuel capacity of 3,150 gallons (11,294 liters) and a maximum range of 2,145 miles (3,452 kilometers).
The RF-101C carried six cameras in its nose. Two Fairchild KA-1s were aimed downward, with four KA-2s facing forward, down and to each side.
Beginning in 1954, McDonnell Aircraft Corporation built 807 F-101 Voodoos. 166 of these were the RF-101C variant. This was the only F-101 Voodoo variant to be used in combat during the Vietnam War. The RF-101C remained in service with the U.S. Air Force until 1979.
This McDonnell RF-101C-45-Voodoo, 56-0183, of the 20th Tactical Reconnaissance Squadron, 432nd Tactical Reconnaissance Wing, is similar in appearance to the Voodoo flown by Captain Edwards, 15 April 1959. (Unattributed)Captain George A. Edwards, Jr., in the cockpit of his McDonnell RF-101C Voodoo, after setting an FAI World Record for Speed. (U.S. Air Force)
George Allie Edwards, Jr., was born in Nashville, Tennessee in 1929, the son of George Allie Edwards, an automobile agent, and Veriar (“Vera”) Lenier Edwards. When his father died, his mother, younger sister Jane, and George went to live with Mrs. Edwards’ parents at Crossville, Tennessee. He attended Cumberland High School and studied at the University of Tennessee at Knoxville. He took flight lessons at the age of 15 and accumulated more than 2,000 flight hours over the next six years.
In 1951, during the Korean War, Edwards entered the United States Air Force as an aviation cadet. He graduated from flight school at Vance Air Force Base, Oklahoma, and was commissioned a second lieutenant. He was assigned to the 67th Tactical Reconnaissance Wing at Kimpo Air Base, South Korea. As a pilot of North American RF-51D Mustang and Lockheed RF-80 Shooting Star photographic reconnaissance airplanes, he flew 101 combat missions.
His next assignment was as a jet instructor at Bryan Air Force Base, Texas, and then an F-100 pilot with the 354th Tactical fighter Wing. he next served as chief of safety and standardization for the 432nd Tactical Reconnaissance Wing. It was during this assignment that he set the world record.
From 1959 to 1962, Edwards was an advisor to the West German Air Force. In recognition for his service, the chief of staff awarded him Luftwaffe pilot’s wings. For the next several years, he rotated through a series of training assignments, education and staff assignments.
Major George A. Edwards climbs to the cockpit of a McDonnell RF-4C Phantom II. (Lake Travis View)
During the Vietnam War, Lieutenant Colonel Edwards commanded the 19th Tactical Reconnaissance Squadron which was equipped with the McDonnell RF-4C Phantom II reconnaissance variant. He also commanded a detachment of the 460th Tactical Reconnaissance Wing, and flew the Martin RB-57 Canberra. Edwards flew another 213 combat missions.
Colonel Edwards went on to command the 67th Tactical Reconnaissance Wing, (which he had previously served with during the Korean War), Bergstom Air Force Base, Texas; as a brigadier general, was vice commander of 12th Air Force; commander 314th Air Division, Osan Air Base, Republic of Korea, and also commanded the Korean Air Defense Sector. Edwards was promoted to Major General 1 August 1976, with an effective date of rank of 1 July 1973.
Major General George A. Edwards, Jr., United States Air Force.
During his career in the United States Air Force, Major General George A. Edwards, Jr., was awarded the Distinguished Service Medal, Legion of Merit, Distinguished Flying Cross with four oak leaf clusters (5 awards), the Bronze Star, Air Medal with 19 oak leaf clusters (20 awards), Joint Service Commendation Medal, Air Force Commendation Medal, Presidential Unit Citation emblem, Air Force Outstanding Unit Award ribbon with four oak leaf clusters (5 awards).
General Edwards retired from the Air Force 1 March 1984 after 33 years of service. As of 2015, the General and Mrs. Edwards live near Austin, Texas.
The world record-setting Sikorsky S-76 Mark II, N1545X. The helicopter’s paint scheme has been updated since the world record flights in 1985. (MyFlightbook)
9–14 April 1985: Allison Gas Turbine Chief Test Pilot Frederick Jack Schweibold, along with company pilots Harry B. Sutton and R. Frederick (“Fritz”) Harvey, set a series of thirteen Fédération Aéronautique Internationale (FAI) world records for speed and distance, flying a Sikorsky S-76 Mark II, N1545X, which had been leased from Petroleum Helicopters, Inc., of Lafayette, Louisiana.
Contemporary news reports were that Schweibold and his crew, in addition to several PHI pilots, had actually set 15 speed, distance, and altitude records, but only thirteen world records are shown in the FAI’s online records database. The additional records may have been U.S. national records, but This Day in Aviation has been unable to confirm this with the National Aeronautic Association.
The Indianapolis Star reported:
(Frank Espich, The Indianapolis Star, 16 April 1985, Page 1, Columns 1–3)
Local Pilots set 15 world records in helicopter with Allison engine.
By Patricia Hagen
STAR STAFF WRITER
Three local pilots set 15 world records in a commercial helicopter in two days, stopping only to refuel while flying more than 7,000 miles over the United States and Canada.
The team from Allison Gas Turbine Division of General Motors Corp. started the marathon trip Friday evening in Lafayette, La. They set coast-to-coast, non-stop, altitude and speed records before inclement weather forced an early landing Sunday night in St. Louis.
The trio was tired but excited when they finished the trip Monday afternoon at the Indianapolis Heliport in the Sikorsky S-76 Mark II helicopter powered by an Allison engine.
The trip in the yellow and black craft was flawless, except for the early landing, said Jack Schweibold, Allison’s chief test pilot, who was dressed in tan coveralls and a company baseball cap.
His teammates in the 35-foot helicopter were R. Frederick “Fritz” Harvey of Indianapolis, director of small-engine programs, and Harry B. Sutton of Pittsboro, staff pilot. The men have been involved in other record-setting flights in small airplanes and helicopters.
The records set on this trip were for the heavy weight class of helicopters. The Allison team averaged 150 mph between Dallas and Montreal, Quebec, shattering the old record of 104 mph.
On the way to Canada, they flew a record 950 miles non-stop before refueling in Toledo, Ohio.
Then they cut several hours off the East Coast-to-West Coast record for this class of helicopters, going from New York City to Los Angeles in 19 hours, which included three stops for fuel.
They also established speed records for climbs to 10,000 feet an 15,600 feet, said Schweibold, the official recorder on the flight.
The records must be verified by the National Aeronautic Association in conjunction with the French aeronautics federation, the bodies that oversee challenges to air and space records. The pilots will receive awards at the Paris Air Show in June.
The pilots managed only a few hours of sleep between turns at the controls of the helicopter, which could seat 14 passengers on a typical commercial flight.
The only alteration to the $2.3 million helicopter for the weekend trip was a modified fuel tank, which added 200 gallons to the original 300 gallon capacity. About 4,100 gallons of aircraft fuel were burned in the 46 hours of flying time, the pilots estimated.
The point of the record-setting blitz was to show the versatility of the Allison engine.
“You can take a standard, stock Allison engine and expect to get championship performance,” Schweibold said.”We treated it like a stock Chevrolet.”
The Allison model 250 engine is about the size of a car engine but develops 650 horsepower. The flight showed that it performs safely and with little maintenance even when used to challenge world records, Harvey said.
“We’re bringing world-class aviation records to Indianapolis,” Harvey said. The Allison turbine engine division is proud of its reputation as a leader in engineering power plants for helicopters and turbo prop aircraft, he added.
The trio of pilots plan to try for two other records before returning the aircraft, which they borrowed from Petroleum Helicopters Inc. in Lafayette, La., Harvey said.
Over a 100-mile diameter circuit in Indianapolis,they will attempt an air speed record over 650 miles. They will also try to set a distance record on the course, which will entail going about 900 miles without stopping, Schweibold said.
—The Indianapolis Star, Tuesday, 16 April 1985, Page 6, Columns, 1–3
The Indianapolis News,16 April 1985 at Page 26
In his own Internet blog, Jack Schweibold wrote that he picked up Harvey and Sutton in New York City before proceeding west to Los Angeles, with fuel stops at Indianapolis (8A4), Wichita (ICT), and Albuquerque (ABQ). The fuel stops took only about ten minutes each. They flew at 12,000 feet (3,658 meters) when crossing over the San Jacinto Mountains, east of Los Angeles, then passed overhead of the Seal Beach VORTAC (SLI) on the coastline south of Los Angeles.
While making a rapid descent to refuel at Riverside Airport (RAL), passing through 7,000 feet (2,134 meters), they heard two booms from the rear compartment. They checked the helicopter while refueling and everything seemed to be fine. They only filled the auxiliary tanks part way at Riverside, as they expected tail winds on the eastward leg.
The next fuel stop was at Saint Louis, Missouri. (Jack wrote that they didn’t land at Lambert Field (STL) because of adverse weather conditions, but did not specify where in St. Louis they did refuel.) They delayed their takeoff for New York waiting for improved weather conditions. When they finally went out to the helicopter, they found the S-76 surrounded by a pool of jet fuel about 200 feet (61 meters) across.
The two “booms” that the crew heard while descending in to RAL were caused by the auxiliary fuel tanks rupturing. They hadn’t leaked during the subsequent flight because the fuel level was kept below the fractures.
Jack’s full article can be found at: https://jetav.com/15-s76-records-set-in-week/
The records set by Schweibold, Harvey and Sutton were in the FAI’s Class E Rotorcraft, Sub-Class E-1 Helicopters, segments.
9 April 1985:
Speed Over A 3 Kilometer Course: 312,15 kilometers per hour (193.96 miles per hour), Lafayette, Louisiana. Leslie E. White, F. J. Schweibold, Arthur S. Chadbourne III. FAI Record File Number 1838
Speed Over A Straight 15-to-25 Kilometer Course: 304,73 kilometers per hour (189.35 miles per hour), Lafayette, Louisiana. Vernon E. Albert, F.J. Schweibold. FAI Record File Number 1839
Time To Climb To A Height of 3 000 Meters (9,843 feet): 6 minutes, 16 seconds, Lafayette, Louisiana. Joseph R. Bolen, Harry B. Sutton, Bruce A. Schneider. FAI Record File Number 1851
12 April 1985:
Speed Over A recognized Course, Dallas, Texas, to Indianapolis, Indiana. 268,56 kilometers per hour (166.88 miles per hour). F.J. Schweibold. FAI Record File Number 2067
Distance Without Landing, Dallas, to Toledo, Ohio. 1 508,91 kilometers (937.59 statute miles). F.J. Schweibold. FAI Record File Number 1823
13 April:
Speed Over a Recognized Course, Dallas to Montreal, Quebec, Canada. 255,96 km/h (159.05 m.p.h.) F.J. Schweibold. FAI Record File Number 2068
Speed Over a Recognized Course, Indianapolis to Montreal. 244,44 km/h (151.89 m.p.h.). F.J. Schweibold. FAI Record File Number 2069
Speed Over a Recognized Course, New York, New York, to Indianapolis. 261,36 km/h (162.40 m.p.h.). F.J. Schweibold. FAI Record File Number 2070
14 April:
Speed Over a Recognized Course, Indianapolis to Wichita, Kansas. 254,88 km/h (158.38 m.p.h.) F.J. Schweibold. FAI Record File Number 2071
Speed Over a Recognized Course, Indianapolis to Albuquerque, New Mexico. 225,36 km/h (140.03 m.p.h.) F.J. Schweibold. FAI Record File Number 2072
Speed Over a Recognized Course, Indianapolis to Los Angeles, California. 202,68 km/h (125.94 m.p.h.) F.J. Schweibold. FAI Record File Number 2073
Speed Over a Recognized Course, Wichita to Los Angeles. 197,28 km/h (122.58 m.p.h.) F.J. Schweibold. FAI Record File Number 2074
Speed Over a Recognized Course, New York to Los Angeles. 209,52 km/h (130.19 m.p.h.) F.J. Schweibold. FAI Record File Number 2075
A 1984 advertisement for the Sikorsky S-76 Mark II. (Sikorsky Aircraft)
N5145X (s/n 760050) was a Sikorsky S-76 Mark II, an improved version of the original S-76A. There were more than 40 modifications to improve reliability and maintainability. In addition to new helicopters, the Mark II modifications were available as kits to update earlier S-76As.
The Mark II is a twin-engine intermediate class helicopter that can be configured to carry 6 to 12 passengers. It is used as an executive transport, a scheduled passenger airliner, utility transport, search and rescue aircraft and air ambulance. The helicopter is certified for instrument flight and has retractable tricycle landing gear.
The prototype was rolled out at Stratford, Connecticut, on 11 January 1977 and the first flight took place on 13 March. It was certified in 1978 and the first production aircraft was delivered to Air Logistics, 27 February 1979.
Cutaway illustration of a Sikorsky S-76A. (Sikorsky Archives)
The S-76A is 52 feet, 6 inches (16.00 meters) long with rotors turning. The fuselage has a length of 43 feet, 4.43 inches (13.219 meters) and a width of 8 feet (2.44 meters). The helicopter’s overall height is 14 feet, 5.8 inches (4.414 meters). The four bladed composite main rotor is 44 feet (13.41 meters) in diameter. The blades are attached to a one-piece forged aluminum hub and use elastomeric bearings. As is customary with American helicopters, the main rotor turns counter-clockwise as seen from above. (The advancing blade is on the right.) The four-bladed tail rotor has a diameter of 8 feet (2.438 meters) and turns clockwise as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.) It is mounted in a pusher configuration on the left side of the tailboom. The tail rotor is constructed of composite airfoils mounted to graphite spars.
The S-76 Mark II was equipped with two Allison 250-C30S turboshaft engines. The -C30S was capable of producing 650 shaft horsepower, but was derated to 557 shaft horsepower when installed in the S-76. Subsequent S-76 variants have been built with Turbomeca Arriel 1S and 2S engines, as well as Pratt & Whitney PT6B-3A and PW210S engines.
The S-76 has an empty weight of 7,007 pounds (3,178 kilograms). The S-76A maximum gross weight was 10,500 pounds (4,763 kilograms). Beginning with the S-76B, this was increased to 11,700 pounds (5,307 kilograms).
The Sikorsky S-76 has a maximum cruise speed of 155 knots (287 kilometers per hour). It can hover in ground effect (HIGE) at 7,050 feet (2,149 meters) or out of ground effect (HOGE) at 3,300 feet (1,006 meters). The service ceiling is 13,800 feet (4,206 meters).
The helicopter was designed with offshore oil support as a major consideration. It was intended to carry 2 pilots and 12 passengers 400 nautical miles (460 statute miles, or 741 kilometers). Maximum range with no reserve is 411 nautical miles (473 statute miles/762 kilometers).
Sikorsky built 307 S-76As. More than 850 of all variants have been built. The current production model is the S-76D.
N1545X’s FAA registration was cancelled 7 December 2016. The current status of the helicopter is not known. (TDiA did inquire with PHI, but the company did not respond.)
Petroleum Helicopters’ Sikorsky S-76 Mark II, N1545X. (Charlie Mauzé. Image used with permission.)
Jack Schweibold is currently credited with 29 FAI world flight records in both airplanes and helicopters.
Frederick Jack Schweibold was born at Toledo, Ohio, 8 November 1935, the son of Henry E. (a fire extinguisher salesman) and Jeanette Schweibold. He attended Thomas A. De Vilbiss High School, then Ohio State University where he majored in engineering. He had enlisted in the United States Naval Reserve in 1952 and then joined the United States Air Force as an Aviation Cadet in 1954.
Jack Schweibold with a North American Aviation T-28A Trojan.
Schweibold went through pilot training at Randolph Air Force Base, San Antonio, Texas, flying the T-34 and T-28. He went on to train in the B-25 at Reese Air Force Base, Lubbock, Texas. He was commissioned as a second lieutenant and received his pilot’s wings in July 1957. In a momentary decision, he selected helicopter training.
Frederick Jack Schweibold married Miss Sharon Crouse at Toledo, Ohio, 27 December 1957.
Lieutenant Schweibold flew the Sikorsky H-19B for the U.S.A.F. Air Rescue Service, assigned to Oxnard Air Force Base, California (now Camarillo Airport, CMA).
Air Rescue Service Sikorsky H-19A Chicasaw 51-3850. (AR.1999.026)
After leaving the Air Force, Jack flew Sikorsky S-55s for Chicago Helicopter Service, then Bell 47s for Butler Aviation. In 1960, he was hired by the Allison Division of General Motors as a test pilot and engineer for the new 250-series turboshaft engine.
A Chicago Helicopter Airways Sikorsky S-55.
Jack Schweibold is the author of In The Safety Of His Wings: A Test Pilot’s Adventure, published in 2005.
Jack was inducted into the Indiana Aviation Hall of Fame in 2022.
I have had the good fortune to know Jack Schweibold. I first met him through his involvement in the Helicopter Association International’s biennial flight instructor re-certification seminars, held during the HAI’s annual conventions. He kept the seminar classes on track, and in between, was always available for questions. Jack was the authority on Allison’s 250-series turboshaft engines, and over the years I have often called him for technical information and operational advice. On top of that, Jack Schweibold is just an all-around nice guy. It has been a pleasure to know him.
14 April 1953: Dmitry Konstantinovich Efremov, chief test pilot for the Kamov Design Bureau, made the first flight of the prototype Kamov Ka-15 helicopter.
The Ka-15 was a single-engine, two-place, light helicopter, flown by a single pilot. It used two fully-articulated, three-bladed, contra-rotating coaxial rotors. The helicopter had two vertical fins mounted at the ends of a horizontal stabilizer, and four-wheeled fixed landing gear.
The fuselage of the Ka-15 was 6.26 meters (20 feet, 6.5 inches) long. The main rotors’ diameter was 9.96 meters (32 feet, 8.1 inches), and the overall height of the the helicopter was 3.35 meters (10 feet, 11.9 inches). The span of the horizontal stabilizer and vertical fins were 2.85 meters (9 feet, 4.2 inches). The Ka-15 had an empty weight of 996 kilograms (2,196 pounds), normal takeoff weight of 1,360 kilograms (2,998 pounds), and maximum takeoff weight (MTOW) of 1,460 kilograms (3,219 pounds).
The rotors turn at 333 r.p.m. The upper rotor turned clockwise, as seen from above. (The advancing blade is on the left), and the lower blades turn counter-clockwise (their advancing blades are on the right). The area of the main rotor disc was 155.83 square meters (1,677.29 square feet) with a solidity ratio of 3% per rotor. (This is the lowest coefficient of disc area of any helicopter.) Each main rotor blade was trapezoidal, with a theoretical chord at the axis of rotation of 300 millimeters (11.8 inches), narrowing to 100 millimeters (3.9 inches) at the blade tip. The blades incorporated 12° of negative twist.
The Ka-15 was powered by a single air-cooled, supercharged 10.131 liter (618.234 cubic inches) Ivchenko AI-14V nine-cylinder radial engine with a compression ratio of 5.9:1. The engine was rated at 188 kilowatts (252 horsepower). It weighed approximately 200 kilograms (441 pounds).
The helicopter could carry a single passenger or 364 kilograms (802 pounds) of cargo. (Interestingly, the contemporary single main rotor/tail rotor Mil Mi-1 helicopter required 575 horsepower to lift the same payload as the Ka-15.)
The Ka-15 had a cruise speed 120 kilometers per hour (75 miles per hour) and maximum speed 155 kilometers per hour (96 miles per hour). The service ceiling was 3,500 meters (11,483 feet). It could hover out of ground effect (HOGE) at 600 meters (1,969 feet). The helicopter had a normal range of 278 kilometers (173 miles) and maximum range of 520 kilometers (323 miles).
The performance of the Ka-15 was better than had been predicted. After several years of testing, the Ka-15 entered production in 1956. It was the first mass-produced coaxial helicopter, with approximately 375 being built by Aircraft Factory No. 99 at Ulan-Ude, the capitol city of the Buryat-Mongolian Autonomous Soviet Socialist Republic.
A Kamov Ka-15, circa 1953.Nikolai Ilich Kamov
In a coaxial rotor system, one rotor is placed above the other, with the drive shaft for the upper rotor inside the hollow drive shaft of the lower. As in tandem rotor helicopters, each contra-rotating rotor counteracts the torque effect of the other. There is no anti-torque rotor (tail rotor) required. In helicopters using a tail rotor, as much as 30% of engine power is required to drive the tail rotor. With contra-rotating rotors, all of the engine’s power can be used to provide lift and thrust.
A second benefit of a coaxial rotor is that the dissymetry of lift of each rotor is also canceled out. There is no translating tendency while in a hover, and higher forward speeds are possible because the effect of retreating blade stall is reduced. A helicopter with coaxial rotors is more compact than a similar helicopter with tandem rotors. This makes it useful for operations in confined areas or aboard ships.
Nikolai Ilich Kamov was previously known for his autogyro designs, which were first produced in 1929. These included the Tsentralniy Aerogidrodinamicheskiy Institut (Central Aero-Hydrodynamic Institute) TsAGI A-7, which was the first armed autogyro. The Kamov Design Bureau was established 7 October 1948 at Lyubertsy, near Moscow, Russia.
The Kamov-designed TsAGI A-7 autogyro was armed with two 7.62 mm machine guns and could carry four 100 kilogram (220 pound) bombs or six RS-82 rockets under the fuselage.Ефремов Дмитрий Константинович (Dmitry Konstantinovich Efremov).
Ефремов Дмитрий Константинович (Dmitry Konstantinovich Efremov) was born at Moscow, in the Russian Socialist Federative Soviet Republic, 30 October 1920.
In 1941, Efremov was a cadet at the Bauman Aero Club. He entered the Red Army the same year and was sent to the Saratov Military Aviation Gliding School, at Samara, Kuybyshev, Russia, U.S.S.R., for training as a military glider pilot. During the Great Patriotic War, Efremov flew gliders behind enemy lines. He was next assigned to an experimental test squadron of of the Airborne Forces, and then as a pilot instructor at the aviation school of the Airborne Forces in Slavogorod, Altai Krai, Russia, U.S.S.R.
Efremov contracted tuberculosis and in January 1948, was discharged from the Red Army. He was employed as a senior technician at TsAGI, and in November of that year went to work as a mechanic at Kamov OKB. He made the first flight of the Kamov Ka-10, and was then sent to test pilot school.
D.K. Efremov with a float-equipped Kamov Ka-10M. (авиару.рф)
Efremov returned to Kamov OKB after completing test pilot school and was soon promoted the the design bureau’s chief pilot. He made the first flights of the Ka-15, Ka-18 and Ka-25 helicopters.
After transitioning to the Antonov An-8 and Ilyushin Il-18 turboprop transports to gain flight experience in larger transport airplanes, Efremov made the first flight of the Kamov Ka-22 gyrodyne prototype, 15 August 1959. On 7 October 1961, with V. V. Gromov, he flew the Ka-22 to a Fédération Aéronautique Internationale (FAI) World Record for Speed Over a 15km/25km Straight Course of 356.3 kilometers per hour (221.4 miles per hour),¹ and on 24 November 1961, set seven world records for payload to altitude.²
On 28 February 1962, Efremov and a flight test crew were conducting a long-distance test flight of a Kamov Ka-22M gyrodyne prototype, 01-01, 63972, from Tashkent, Uzbekistan, to Kzyl-Orda, Kazakhstan. During an intermediate refueling stop in Turkestan, mechanics found a loose or missing retaining nut for the left support of the synchronizing shaft. The problem was repaired and the flight continued.
While on approach to the main runway at the Dzhusaly airport, the gyrodyne suddenly banked left, entered a left spiraling turn, and, in an inverted dive, crashed on the runway. The Ka-22 exploded and burned. Dmitry Konstantinovich Efremov and seven men of his flight test crew were killed.
Kamov Ka-22 turboprop gyrodyne.
TDiA would like to thank regular reader Mike for suggesting this topic.
¹ FAI Record File Number 13226
² FAI Record File Numbers 13221, 13222, 13223, 13224, 13227 and 13228
17 April 1923: At Wilbur Wright Field, Dayton, Ohio, First Lieutenant Harold Ross Harris set two Fédération Aéronautique Internationale (FAI) World Speed Records, flying a modified de Havilland XDH-4L powered by a Hall-Scott Liberty 375 engine. Lieutenant Harris averaged 184.03 kilometers per hour (114.35 miles per hour) over a 1,500 kilometer (932.1 miles) closed circuit,¹ and 183.82 kilometers per hour (114.22 miles per hour) over a 2,000 kilometer (1,242.7 mile) course. ²
The Liberty L12 aircraft engine was designed by Jesse G. Vincent of the Packard Motor Car Company and Elbert J. Hall of the Hall-Scott Motor Company. It was a water-cooled, normally-aspirated, 1,649.336-cubic-inch-displacement (27.028 liter) Liberty L-12 single overhead cam (SOHC) 45° V-12 engine with a compression ratio of 5.4:1. The Liberty produced 408 horsepower at 1,800 r.p.m. The L-12 as a right-hand tractor, direct-drive engine and it turned turned a two-bladed fixed-pitch wooden propeller. The Liberty 12 was 5 feet, 7.375 inches (1.711 meters) long, 2 feet, 3.0 inches (0.686 meters) wide, and 3 feet, 5.5 inches (1.054 meters) high. It weighed 844 pounds (383 kilograms). This engine was produced by Ford Motor Company, as well as the Buick and Cadillac Divisions of General Motors, The Lincoln Motor Company (which was formed by Henry Leland, the former manager of Cadillac, specifically to manufacture these aircraft engines), Marmon Motor Car Company and Packard. Hall-Scott was too small to produce engines in the numbers required.
