Domk-mIc Cnllicritm !'!!- 'r,n Fort-Ism lntvl!iucncc Intorm.iiicm Ki port SUBJECT Atrial Observation of Ini Source of Light RfFERENCtS I)CD Case! X. An unusual incident was observed during a 10 September 1976 British European Airways (BEA) flight (number 831) from Moscow to London. Bctwe; 1800 and 1900 hours, the aircraft was cruising at an altitude of approxi- mately 33 thousand feet (9,900 meters), apparently inside the border of Lithuania, when a blinding, single source, constant intensity, and stationary light was' observed off the starboard flight path of the air- craft. The light's distance was estimated to be approximately 10 to 15 miles (16 to 24 kilometers) eif of the aircraft's path and approximately five to six thousand feet (1,500 te 1,300 rotters) below the aircraft,' somewhat above a lower cloud layer. The light, which resembled a sodium vapor lamp (yellowish in color), and which was too intense tc view directly for any period of time, completely lit the top of the lower cloi layer, giving it a glowing cast. 2. The light was of such interest that the BEA pilot cause onto the aircraft' inter cons network, stated that he was somewhat concerned over its presorsc* and said he had asked the Soviet authorities for an identification of its source. The Soviet authorities came tack with a negative identification response, suggesting that he should not ask questions. The light was observed foT approximately 10 to 15 minutes, until the aircraft had flowt past and left the light source behind.