Lockheed 10 Electra
Lockheed’s first all-metal aircraft, the Electra was conceived as a fast, ten-passenger airliner for use on routes too small to allow economic operation of the Boeing 247D or Douglas DC-2. The twin fin and rudder design, which was to become something of a Lockheed trademark, is owed to Clarence “Kelly” Johnson, then working at the University of Michigan on wind-tunnel testing of the original, single-fin Electra concept. Of the total production, 115 were delivered as airliners, 25 as private aircraft and the balance of nine to military customers. One of the private customers was the Purdue Research Foundation, which acquired an Electra for Amelia Earhart. Fitted with fuselage fuel tanks and additional navigation equipment, NR16020 left Oakland on 17 March 1937 on a attempted westbound round-the-world flight, but ground-looped on take-off from Pearl Harbor three days later. The aircraft was repaired at Oakland and, on 20 May, departed once again this time heading eastbound; but the aircraft was lost on 2 July in the vicinity of Howland Island in the central Pacific. The FAA now permanently assigns the registration N16020 in Earhart’s memory.
Survivor numbers have remained extremely stable for the last 20 years, doubtless in part due to the Earhart connection.
First flight: 28 Feb 34 (c/n 1001, X2334)
Production: 149, at Burbank, CA.
First delivery: 4 Aug 34, to Northwest Airlines (c/n 1002, NC14243)
Last delivery: 18 Jul 41, to LAN Chile (c/ns 1146, 1147 and 1148, respectively CC-227, CC-228 and CC-229)
Variants: 10 - prototype all-metal airliner powered by 2 Pratt & Whitney Wasp SB Jr. radials, with seating for 10 passengers (1 built);
10-A - initial production version, with minimal changes (101 built);
10-B - 10-A powered by Wright R-975-E3 Whirlwind radials (18 built);
10-C - 10-A powered by Wasp SC1s for Pan American (8 built);
10-E - 10-A powered by high performance Wasp S3H1s (15 built);
XR2O-1 - staff transport for the Secretary of the Navy, powered by R-985-48 Wasp Jrs (1 built);
XR3O-1 - 10-B for Coast Guard as staff transport for the Secretary of the Treasury (1 built);
XC-35 - pressurised version for high altitude research, powered by XR-1340-43 Wasps (1built);
Y1C-37 - staff transport for National Guard Bureau, powered by R-985-13 Wasp Jrs (1 built).
War-time impressments of 10-A, 10-E and 10-B were made under the designations C-36A, C-36B and C-36C respectively, these becoming UC-36A etc in Jan43.