The World War II Photo of the Week
for 17 January 2005
|The Flying Vibrators ...|
The flightline at Randolph Field, Texas is filled with Vultee Valiant BT-13 trainers. In the foreground, a group of air cadets are lectured on the BT-13's virtues as a training craft. The Valiant was the basic trainer most widely used by the USAAF during WW II. It represented the second of the three stages of pilot training primary, basic, and advanced. Its main use was to transition pilots from a less powerful primary trainer, such as the Piper Cub or the PT-17 Stearman, to the more powerful and complex advanced trainer, the SNJ or Texan. Compared with the primary trainers in use at the time, it was considerably more complex. The BT-13 not only had a more powerful engine, it was also faster and heavier. In addition, it required the student pilot to use two-way radio communications with the ground, operate landing flaps, and featured a two-position variable pitch propeller. Nicknamed the "Vibrator" by the pilots who flew it, the BT-13 was powered by a Pratt and Whitney R-985 engine. The origins of the nickname are unclear, but three reasons are often cited as the source for the moniker: when approaching a stall, the airplane shuddered noticeably; during more daring maneuvers, the canopy was prone to rattling; the powerful radial engine and fixed-pitch prop caused all the windows of nearby buildings to vibrate whenever a BT-13 took off.