Junkers F 13 variant
Junkers F 13 F 13ba, ca, da, fa (Junkers L2)
The group of sub-types sharing the Junkers L2 engine — the first in-house powerplant fitted to the F 13 — along with a set of structural changes. It includes the F 13fa, whose fuselage was about a metre longer.
- 4
- Passengers
History
An engine of its own
Until 1923 the F 13 depended on other people's engines: Mercedes first, then BMW. That year brought the Junkers L2, a water-cooled four-stroke inline six and the first engine the firm designed and series-built itself. The F 13da was the first production batch to carry it, and the ba, ca and fa sub-types followed on the same powerplant, each with its own mix of reinforcements and structural detail changes.
What it bought
The gain showed up in payload. The documentation credits an L2-engined F 13 with roughly 40 per cent more load than a Mercedes-powered aircraft and 25 per cent more than a BMW-powered one. Range paid for it, falling by some 250 km against the earlier versions. On the short, frequently staged European routes of the period that was a trade worth making.
The long fuselage
Within the group the F 13fa stands apart in the airframe rather than the engine: it was about a metre longer than the rest. That stretched fuselage became the basis of the f-lettered sub-types, among them the L5-powered F 13fe, the largest and fastest version of the type.
Where it fits
The L2 series marks the point at which the F 13 stopped being assembled around whatever engine was available and became an integrated Junkers product, airframe and powerplant from the same house. The pattern repeated in 1926 with the L5, which ended up as the type's principal engine.