An old film about 2 men & 1 woman who agreed to meet at the glider field on the fist sunday after the war.?

Anbody know of a film about two men & one woman who were at the gliding airfield at the outbreak of ww2 , they said that they should all meet at the airfield on the first sunday after the war ends. The womans boyfriend/ husband goes up for one last flight, as the other man helps strap him in, he stabs him in the chest & then signals to the winch man to take him up & he dissapears into the clouds. The remaining man who fancies the woman meets her on the first sunday after the war, & as they are sitting talking, the missing glider comes in to land, & as they get to it she sees the skeleton of the other man with a knife sticking out of the bones & realises what has happened.