Aerial Oddities # 1: Howell Miller’s MAC-1


In the early 1930s, the name Gee Bee became synonymous with speed as the bullet-shaped racers blazed a winning trail at Cleveland. Yet the beautiful planes, with their gleaming red and white finish, soon acquired the reputation as pilot killers. And so they were—in the 1930s.
The Granville Brothers—Zantford, Thomas, Robert, Edward, and Mark—used their wide range of skills to create a series of advanced biplanes, some good looking sport monoplanes and a single brilliant racing aircraft, the Gee Bee Model Z, the City of Springfield, to propel themselves from shade-tree mechanic status to a full fledged, highly respected aircraft manufacturing company. Led by Zantford (better known as “Granny”) the brothers combined design, flying, welding, woodworking and other skills to create beautiful, record setting airplanes.
But Granny was wise enough to know his own limitations, and he engaged the personable Bob Hall as his Chief Engineer. Hall, later to be a famous test pilot with Grumman, was the perfect complement to Granny. He could translate the elder Granville’s visionary ideas into rugged designs, and he also had many contacts in the industry. The two men decided that they would build an aircraft capable of winning the 1931 National Air Races, and fell to with a passion, creating the Gee Bee Model Z in just a few months.
The City of Springfield won all five races in which it was entered at Cleveland, including the prestigious Thompson Trophy Race at a record 236.239 mph, with Lowell Bayles flying. In a single racing meet, the Model Z put Granville Brothers Aircraft in the forefront of aviation.
Sadly, on December 5, 1931, Bayles was killed in an official attempt on the world’s land plane speed record. Newsreel cameramen were filming as he blazed though the speed trap, and they caught the City of Springfield as its right wing snapped off. The plane crashed into the ground, leaving a long trail of debris and burning gasoline. This snippet of celluloid, with the Gee Bee representing any number of aircraft, was subsequently used hundreds of times in dramatic films and television productions.
Bayles’ accident began a saga of fatal crashes which led the public to believe that all Gee Bees required super-human pilots such as Jimmy Doolittle to fly them and live. The inherently bad reputation was disproved forever when the great pilot Delmar Benjamin and his team created a perfect replica of the Gee Bee Super Sportster. From his first flight on December 23, 1991, Delmar demonstrated to everyone that the Gee Bee was not a killer aircraft but instead a superbly aerobatic airplane.
But sixty years earlier, the crash of the Model Z had devastated the Granvilles. Hall resigned, later building his own racer, the gull-wing Hall Bulldog. When Russell Boardman placed an order with Granville Brothers Aircraft for two new racers, Granny hired Howell W. “Pete” Miller to serve as Chief Engineer.
The swift but troubled Super Sportsters were essentially Granny’s design, fulfilling his vision that a tear drop was the ideal streamlined shape, a concept that Miller validated in wind tunnel tests. The Super Sportsters, with their famous numbers, 7 and 11, reached their peak in 1932, with Doolittle winning the Thompson Trophy and setting a world’s land speed record of 296.287 mph. Unfortunately in the following years Gee Bee crashes killed many famous pilots, including Granny himself, Russell Boardman, Florence Klingensmith, Cecil Allen and Francesco Sarabia.
The depression, the crashes and the generally limited market for racing aircraft forced Granville Brothers Aircraft out of business. Granny, Miller and Don DeLackner formed a consulting firm. Their first design was a lengthened Gee Bee. Called the “International Sportster,” it was used by the famous aviatrix (a term used at the time) in the 1934 “MacRobertson” race from London to Melbourne.
Disaster struck before it was built, when the thirty-two year old Granny was killed in a crash at Spartanburg, South Carolina, on February 12, 1934. Miller and the rest of the firm pressed on, and completed the R-6H, known as the Q.E.D. (Quod Erat Demonstrandum—for “So It is Proven). The aircraft, painted in “Lucky Strike Green” was flown by Lee Gehlbach in the 1934 Bendix, but encountered mechanical problems and did not finish. The aircraft was then shipped to Great Britain where Jacqueline Cochran (the “Lucky Strike Girl”) and her co-pilot, the far more experienced Wesley Smith, made it to Bucharest before calling it quits.
The Q.E.D., despite its 260 mph cruise speed and 1,850 mile range, was unsuccessful in the 1938 Bendix, and was sold to Captain Sarabia, the “Mexican Lindbergh.” Finished in white and renamed “Conquistador del Cielo” Sarabia brought the R-6H its own success in a record setting flight from Mexico City to New York. Feted as a hero in the Big Apple and Washington, D.C., he was killed when a rag was sucked into his carburetor intake after takeoff from Washington. He crashed into the Potomac and was killed.
Undaunted, Miller and company went on to greater airplanes—and greater disappointments. One of the major figures of American aviation, an aging Frank Hawks, needed a fast new airplane to stay competitive. He turned to Miller, who created his masterpiece, the HM-1, the beautiful Time Flies.
Miller formed the New England Aircraft Company, with himself as president and Hawks as vice president. The firm functioned exactly as the old Granville Brothers firm, with many of the same personnel. Design work began on June 12, 1936.
The Gruen Watch Company—then perhaps the most prestigious watch company in the Untied States—bankrolled the effort to the tune of about $70,000, and the resulting aircraft had a performance equal to or greater than its more famous contemporary, the Hughes H-1 racer. In an interview with Miller, the author was told that the Time Flies was slightly faster than the Hughes racer, had a much better rate of climb and a slightly greater range.
Both aircraft used sleek plywood wings. The all-metal semi-monocoque fuselage of the Hughes aircraft was much more sophisticated than the steel tube fuselage of the Time Flies. Miller said that he planned from the start that there the production version of the Time Flies, would be all metal.
Miller created an exceptionally clean aircraft, forgoing the classic Gee Bee tear drop for a sleek streamlined fuselage, constructed of Summerill chrome-moly tubing, and faired to a perfectly circular section by wooden formers. It was covered with Haskelite plywood for a strong, smooth surface. Instead of a conventional enclosed cockpit, he used a modified automobile hydraulic jack to elevate the seat and windscreen for takeoff and landing. In flight, the windscreen retracted flush, and Hawks visibility was limited to tear-drop shaped side windows.
Miller, who was a courtly, courteous, pleasant man in all situations, had rapport with Hawks, who was bright, intelligent and had a good sense of humor. After all the difficulties of the past, most of the team that produced the Gee Bees still worked in harmony. Hawks (like many pilots) had previously had bad experience with carbon monoxide fumes while flying, so at his suggestion, Miller designed air intakes well out on the cantilever wings to funnel fresh air to the cockpit.
A Pratt & Whitney R-1830 engine, rated at 1,150 takeoff horsepower was mated to a three blade Hamilton Standard constant speed propeller. Miller stressed the aircraft to handle engines of up to 2,000 horsepower.
The undercarriage resembled a conventional fixed gear Gee Bee’s in terms of its construction and shock absorption, but it was designed to retract inward to nestle in the fuselage. The usually reliable retraction mechanism, powered by a Crosley automobile starter, had an Achilles heel, as will be seen.
On October 18th, 1936 (four months and six days after work began)
Frank Hawks flew the beautiful Time Flies for the first time. After taking off from the Springfield, Massachusetts factory (the same former dance hall where the Gee Bees were built) Hawks flew to Rentschler Field in Hartford, Connecticut, where both Pratt & Whitney and Hamilton Standard technicians were available for the brief but attenuated test program.
During the fourth test flight on January 6, 1937, Hawks pulled off his long fur gauntlets, a present from his wife, and put them in a whole in the instrument panel where the Sperry autopilot was due to be installed. When he extended the gear, the threaded gear mechanism grabbed the gauntlets, chewed them up—and jammed the gear half-way down. Hawks landed, and the gear did not collapse, but damage was done to the propeller tips and gear fairing.
Time Flies was quickly repaired, but Hawks was running out of time and money. Instead of attempting something that really would have gathered attention, such as an attempt to best the records Hughes had set, Hawks made a series of short flights. The most important of these was a record setting trip from East Hartford to Miami in four hours and fifty-five minutes. On the return flight, he ran into headwinds and elected to terminate at Newark, New Jersey, where his ultra-hard landing smashed the landing gear and broke the main wing spar. Hawks had many crashes in the past; he had one fatal one coming in the future.
He tried to salvage something from his efforts and sold the plane to Tri-American Aviation, which had primarily South American interests. Headed by Edward Connerton and Leigh Wade, a test pilot in France in World War I and pilot of the Douglas World Cruiser Boston, Tri-American wanted to convert the aircraft into a fast two-seat fighter/attack plane for South American air forces.
Wade, Connerton and Miller formed the Miller Aircraft Corporation in 1938 to convert the damaged Time Flies. The modification was initially called the HM-2, and then the MAC-1. Changes were kept to a minimum, with a fuel tank removed to allow two seats and the retractable canopy replaced by a conventional sliding canopy positioned well aft on the fuselage. Dual controls were fitted and the wings were modified to accept a single .50 caliber machinegun on each side. A flexible gun was installed for the back seater. (Only dummy guns were ever fitted.) The paint job was changed to a military blue fuselage with orange wings and horizontal stabilizer, and a 900 horsepower Twin Wasp engine was installed.
Leigh Wade made the first flight of the MAC-1 on August 23, 1937—ironically the same day that Hawks was killed in the crash of the weird-looking Gwinn Air Car. Hawks had followed the conversion of the Time Flies with interest, and spoke to Miller about it on the day of its first flight—and his last.
The MAC-1 was entered in the 1938 Thompson, and Wade flew the airplane despite the fact that there had been little time for testing, and he had no idea of what the fuel consumption would be. He flew a conservative race to insure his finishing, and did so in fourth place at 248.42 mph. When he touched down, the engine quit from lack of fuel, so he had eyeballed the race quite accurately.
Earl Ortman ( who had finished second behind Roscoe Turner in the Thompson, flying the Marcoux Bromberg Special) continued the test program when Wade had to go to South America on business. The first test was over a measured twenty-five mile course near Rentschler Field, and Ortman averaged an amazing 369 mph.
The next test was to measure time to climb, and Ortman achieved a blistering initial climb rate of 6,000 feet per minute. (The Air Corp’s current first line fighter, the Seversky P-35, had a top speed of about 285 mph and an initial climb rate of about 2,000 feet per minute.
During the climb tests, however, the center of gravity moved back as fuel was burned, and in a 425 mph dive back to altitude, Ortman felt the stick jerk out of his hand in a series of oscillations of increasing amplitude. He hit the canopy quick release and was hurled out of the airplane just as it began to break up in the air, the tail separating. He landed safely by parachute, and that was the end of the Time Flies/MAC-1.
Miller went on to a profitable career designing many smaller aircraft, but he always regretted that the HM-1 was not given a chance to show its full potential as a production, all-metal aircraft.

3 responses to “Aerial Oddities # 1: Howell Miller’s MAC-1

  1. Delmar Benjamin used a much more benign airfoil on his replica than Zantford Granville chose for the original. I agree that the reputation of the Gee Bee Rs is exaggerated but they did kill pilots, or perhaps more correctly, pilots killed them. The airfoil used was selected for its drag coefficient and Cp travel, not it’s stall characteristics. Boardman stalled taking off fully fueled. Allen installed extra fuel tanks which pushed the CG to, perhaps beyond, the aft limit.

    Steve Wolf and Delmar Benjamin appear to have been well aware of the stall characteristics and changed the airfoil. Granville had used a modified M-6 (65%). The reason for that was to achieve minimum profile drag. One of his considerations was the small travel of the Cp with angle of attack shifts, an important factor given the tight turns and straight stretches the pilot would have to deal with. His goal was an airplane which would require no use of the trim during a race. Stall characteristics were not a major concern compared to low drag and small Cp travel with a frequently shifting angle of attack.

    Zantford Granville was designing a racing plane not a sport airplane. I bet he did not choose a M series airfoil for his never completed C-8 transport design.

  2. What an exceptional read. I look forward to the rest of your articles!

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