[Elecraft] CW puzzle... From circa 1950

[73 de M3MPH]

Greetings all

This might be of interest to the CW ops, OM and aviation historians out
there who's experience and knowledge may shed some light on a mystery
that happened about 53 years ago....

An aircraft, a civilian adaption of a Lancaster bomber, with a British
crew, got lost and flew into a mountain in cloud. The reason is still
unknown but the last message it sent in CW was copied as; 

S T E N D E C <message ended>

Could this have been miscopied for another lesser known abbreviation?
Were there any competing or precursors to the
 "Q" codes that would have been known to probably ex military pilots,
crew, radio op?

Any suggestions, ideas or theories...