TEST # THREE of 31-Dec’ 1938:
First Flight away from a runway.
Same crew as on test #1, except not Price.
T/O Gwt = 32,000 Lbs.
Planned test for directional stability on ground.
Time from brake release to airborne was 9 seconds,
flight then continued due to limited runway remaining.
Attempted to retract Landing Gear, but the Tail Wheel failed to retract.
Pilot's comments from his report,
"Good rolling moment due to yaw."
Test # FOUR done 4-Jan’ 1939:
Taxi testing focused on brake pressures and temperature.
Flt time = 1hr 48 minutes; logged engine time as 3 hrs.
Crew was Allen, Barr, Ferguson, West, Cram, Jewett, Anderson.
At T/O Gwt of 37,000 Lbs, T/O distance was 800 feet into a light SSE wind of 3 mph;
after tracking 2300 feet along and above runway the height was 100 feet, using 1100 hp.
Tested Rudder with asymmetric thrust, one engine "throttled", and recorded Beta.
Item H of pilot's report mentions that #1 and #2 Engines were "throttled",
states that pilot employed Rudder to keep Beta = 0,
— recording pedal-force of 40 Lbs needed at airspeed of 100 mph;
— and 100 Lbs of pedal-force needed at airspeed of 80 mph.
Pilot included comments about "flying qualities" in his report Item L.
Test # FIVE done 11-Jan' 1939, from 12 noon to 3:30 pm.
T/O Gwt = 40,000 Lbs.
Comments from pilot state that testing of Rudder with an engine failure at Takeoff,
the Rudder was inadequate at low speed.
Test # ONE accomplished on 30-Dec’ 1938:
Engine time recorded was 55 minutes, taxiing time was 30 minutes.
Comments from pilot's report, item C,
"Control was good except for the Rudder which has not yet been adequately tested."
Crew aboard: Eddie Allen, Ferguson, West, Barr, Price, Gaylord.
Test # TWO done on 31-Dec’ 1938:
Engine time logged as 45 minutes, taxi time was 35 minutes.
Much effort spent recording brake temperatures during taxi tests.
Three short intervals of flight above runway:
12.5 seconds, 18.5 s, and 13 seconds;
done at speeds of 70 - 80 mph.
Failure - Interactions
Lavelle, Mike . "Boeing Model 307 Stratoliner: A Culmination of the 1930s Commercial Aircraft Design, Engineering, and Manufacturing Progress." 47th AIAA Aerospace Sciences Meeting, HIS-1: Aerodynamics and Design History, Wednesday, 7 January 2009, 0900 hrs. [pdf, 55 pages, 2.2MB]
In-progress --- more later . . .
Best photo of a B307 original designed empennage.
Photo: #3 and #4 engine-propellers stopped.