The Junkers J 9 was the world's first all metal fighter. The type first flew late in 1917 and only one original survives in the Musee de l'Air at Le Bourget. Manfred Pflumm, the Director of this museum, was well known for building replica aircraft which are featured in museums across Germany. This example was either nearing completion or dismantled and it may be the example that I saw at Gatow in 2006. That was removed from display in 2016 when it was acquired by the Luftfahrttechnisches Museum in Rechlin and where it went on display in 2017.

As early as 1915, Hugo Junkers was working on an all-metal low-wing aircraft. This innovative concept was rejected by the Luftstreitkräfte despite the duralumin structure that offered pilots relatively greater safety. Finally, the J.9 design was approved, designated D-I but only arrived to front line pilots in the last months of the war. Despite the qualities of speed and maneuverability, only 41 copies were built, in particular due to a difficult construction. This plane is the only extant example that survives today.

All-metal, except the propeller! Fighter pilots did not like it, but the D.I was the harbinger of a lineage of Junkers airliners.

This exhibit at the Musee de l'Air first flew in 1918. It is the sole surviving example of the type.

The Junkers J 9 was the world's first all metal fighter and this replica is in the Luftwaffenmuseum at Gatow. The type first flew late in 1917 and only one original survives in the Musee de l'Air at Le Bourget

1918 fighter employing the Junkers corrugated metal construction.