Keith Rider R-3/Marcoux-Bromberg Special

The Marcoux-Bromberg Special started life in 1933, when Keith Rider built it as the R-3. Mrs. Edith Clark of Santa Monica and WH Marcoux financed the airplane which was originally designed for the MacRobertson Race. It was constructed in Santa Monica in an abandoned casket factory. Jim Granger a pilot with little if any high performance experience, took it up for it's first flight in 1934, he landed with too much speed and applied too much brake and the airplane nosed over, damaging the vertical tail and crushing the cockpit and killing the pilot. Once repaired Vance Breese made a record flight from San Francisco to Los Angeles, after which the airplane was put in storage for a time.

Earl Ortman was hired to fly the airplane in 1935. On July 3, 2020, Ortman took off from Vancouver, Canada and flew to Agua Caliente, Mexico in 5 hours, 27 min, 48 seconds; setting a record that stood for 2 years. A larger engine was installed for the 1935 Bendix, an installation which was completed shortly before the race. On it's test hop the day before the race the cowl pulled forward into the prop. Hasty repairs were carried out, and the airplane departed on time for Cleveland. It made it as far as Kansas City where it landed with a split fuel tank, chewed up cowl and damaged propeller. After further repairs it proceeded to Cleveland where the contest committee ruled in un-airworthy for the Thompson. The airplane was repaired and flown back to California where it was tied up due to labour liens against the Rider-Clark Airplane Company.

In early 1936 the title was transferred to Hal Marcoux. Hal was employed at Douglas Aircraft where he enlisted the help of Jack Bromberg who at that time was an engineer for Douglas. The Marcoux-Bromberg team proceeded to rebuild the ship, making major changes in the process and renaming the ship the Marcoux-Bromberg Special. The airplane placed second in the 1936 Thompson with an average race speed of 248 mph.

The airplane was reworked once more for the 1937 races. In the 1937 Bendix, Ortman encountered foul weather. Attempting to stay out of it he climbed too high, and lacking oxygen became light headed and drifted far off course. Eventually winding up over Lake Michigan, despite this the racer arrived in time to take second place with a time of 9 hours 48 minutes. It also took second in the 37 Thompson with an average race speed of 256 mph despite encountering problems with spark plugs that did not stand up to the high boost in use. On the way back to California he experienced a fuel leak. The source of the leak was a stand pipe vent that runs from the top of the tank downward where it protrudes from the lower forward end of the main tank. The location of the hole was such that fuel in the top 40 gallons of the tank would pour out. This leak was never repaired due to the expense.

Later in the year the airplane was flown for the MGM movie "Test Pilot" starting Clark Gable. Early in 1938 it was raced at the Golden Gate Classic where it won, setting a closed course record of 266 mph. In June 1938 it set a record from Oakland to San Diego of 1 hour and 48 minutes. In the 1938 Thompson the oil coolers were unexplainably wired closed, resulting in extremely high oil temperatures. An oil leak developed and the last several laps were flown with no il pressure, the engine freezing up just as it passed the finish line. Despite this it placed 2nd with an average speed of 268 mph. A new and more powerful engine was installed for the trip home. Upon landing in Kansas City for fuel, with ice on the brakes and no flaps, the airplane ran off the runway and nosed over. The ship was rebuilt in Kansas City with a new propeller and larger tail surfaces. It stayed in Kansas City until shortly before the 1939 Thompson. During the 1939 Thompson the engine quit three times. Despite this it managed to finish in the money at 3rd Place with an average speed of 254 mph. The airplane was retired after the 1939 Thompson.

Marcoux-Bromberg Special New England Air Museum

Original (1933) Configuration

Wing Span 25 ft
Airfoil NACA 23015
Length 21 ft 8 in

Powerplant: P&W Wasp Jr (500 hp)
Fuel Capacity: 170 gal
Top Speed 270 mph

First Flight: 1934
Total Built: 1
Registration: NX14215/NR14215

Spar Material - Laminated Black Walnut.

1935 Bendix Configuration

Powerplant P&W S1D1 direct drive Wasp (550 hp)

1936 Rebuild (Marcoux-Bromberg)

Wing Span 22 ft 3 in
Airfoil: Modified 23012 (thicker section, blunt leading edge.)

Length 22 ft 3 in
Fuselage Diameter 40 in
Cowl Diameter 46 in

Registration: NX14215

- New Cowling
- New fuel tanks
- Wing skin thickened to 1/8 inch
- Wing airfoil modified from 23012 to a thicker section with a blunt leading edge.
- Fuselage skin stiffened locally.
- Changed to an open cockpit as a quick fix due to excessive heat and lack of ventilation.

Speed (Test Hop): 312 mph, SL, 2425 rpm, 48 inches MAP.
Speed (1936 Thompson Qualification): 258.9 mph
Speed (1936 Thompson): 258.9 mph, with one lap at 278 mph

Modifications for the 1937 Races

- Added heavy longitudinal members to forward fuselage.
- Replaced all fuselage skin from the aft edge of the cockpit forward.
- New fuel system with larger tanks.
- Landing gear modifications
- Changed Powerplant to R-1340-S1A5-G Twin Wasp Jr (825 hp)
- Installed a 3 bladed prop.
- Enclosed Cockpit

Ortman noted the following:
- Great increase in wing loading.
- Tendency to mush at anything less than 80% power.
- some directional instability
- longitudinal stability very poor
- elevator control too soft at low speed.

Vtop: 340 mph at SL
1937 Thompson Qualification speed: 263 mph

Modifications for the 1938 Races

- Increased fuselage diameter to conform with the 46 inch diameter cowl.
- Added an additional oil cooler
- installed a two gallon oil tank in the extreme rear fuselage. The tank was controlled by a valve
and was intended to be filled to shift the CG aft for landing and taxi.

1938 Thompson Qualification: 270 mph.
1938 Thompson Average speed: 268 mph.

1938 Post Race Modifications

-Larger Twin Wasp Jr X8B4 installed.
-After a nose over the tail was rebuilt with larger surfaces.
-A prop with more blade area was installed.

1939 Thompson Qualification: 244 mph
Later Thompson Qualification run of: 307 mph
Thompson 1939: 254 mph avg speed.