In reply to drmarten:
It is indeed the Dukes path,the upper part quite visible when clear of snow,the lower part now indistinct.Follow the burn up from nn973997 Larig Ghru and you should pick up the remains of the zigzags about nh966000 Coire Ruadh.You will probably see the remains of two different aircraft that crashed hereabout in the 1940s.