Jet-powered V/STOL aircraft - Lessons learned

Over the years a variety of jet-powered V/STOL aircraft were studied in test facilities and flight. The tests disclosed several fundamental limitations: (1) lack of design features conducive to good STOL performance, (2) inadequate performance margins and poor handling qualities, (3) performance and handling qualities degradation due to propulsion system induced flow and ground effect, and (4) inadequate integration of flight control and propulsion systems. The purpose of this paper is to review the lessons learned from tests of jet V/STOL aircraft in key technology areas including: (1) aerodynamic/performance tradeoffs, (2) unique propulsion requirements and induced flow effects, (3) handling qualities, and (4) operating procedures. The sensitivity of current ASTOVL designs to meet requirements in these critical technology area is examined.