sentences:  It acquired the nickname 'Trusty' for their excellent ability to make a quick and effective recovery from a spin.Easy to fly, the Trusty made some students overconfident, and they received a shock when they advanced to faster airplanes with more difficult handling characteristics.The 'Trusty' was commonly flown without its cowlings in an effort to prevent overheating
  
  Whereas the TW-3 had supplemented the JN-4D, the PT-1 supplanted this wholly obsolescent type and was responsible for a radical improvement in the safety record of US Army pilot training.