In early 1941 the Stirling entered squadron service. During its use as a bomber pilots praised the type for its ability to out-turn enemy night fighters and its favourable handling characteristics whereas the altitude ceiling was often a subject of criticism. The Stirling had a relatively brief operational career as a bomber before being relegated to second line duties from late 1943. This was due to the increasing availability of the more capable Handley Page Halifax and Avro Lancaster, which took over the strategic bombing of Germany. Decisions by the Air Ministry on certain performance requirements (most significantly to restrict the wingspan of the aircraft to 100 feet) had played a role in limiting the Stirling's performance; the 100ft limit also affected earlier models of the Halifax (MkI & MkII) though the Lancaster never adhered to it.