摘要 |
A propellor attachment 10 comprises a collar 34 for engaging a propellor 36 located within a housing 22. The housing 22 is movable against resilient biassing means 30 when the propellor develops sufficient thrust. Motion of the housing 22, by means of a rod 32 contacting a flange 38 on the collar, effects rotation of the collar 34 thereby altering the pitch of the propellor. The force required to overcome the biassing means 30 is set approximately midway between the thrust required for climbing and the thrust required for cruising. The propellor therefore automatically takes up the required pitch for take off/climb conditions and cruising conditions. |