ALCOR - A HIGH ALTITUDE PRESSURIZED SAILPLANE

Abstract

Alcor is a research sailplane which has utilized unusual design conncepts and manufacturing techniques to enable comfortable and safe flying at high altitude. The deslgn philosophy has placed emphasis on practicability and cost control without seriously compromising safety and performance. This new sailplane has a 20-meter wing span with an aspect ratio of 28. The performance capability has placed emphasis on a low sink rate. For this reason, weight saving has been an important guideline in both design and fabrication. The requirenent for low weight with flutter resistance has required the use of new materials and layup techniques. All critical assemblies are of the sandwich type assembIy with the cross sectionai-dimension adjusted to give, where necessary, an improvenent in the structural stiiffness. Physiological problems, presented in the high altitude environment, are solved in part through cabin temperature and pressure control. The oxygen system and pilot mask are non-conventional in both design and operation. The system permits  hight level of oxygen partial pressure at altitude and allows direct breathing from the cabin environnent, with all exhaled gases golng directly to the cabin pressure-regulator and discharged overboard. The initial flight testlng of Alcor is about complete and at present with Boeing staff assistance and comprehensive flutter analysis utilizing computer technology is being finalized. Only preliminary checks of the cabin sealing system have been completed. During 1974 it is hoped that alI qualitatlve flight tests will be completed and some high altitude flying will be accompllshed.