Janus CM engine malfunction leads to field landing near Sheffield
On October 14, 1996, a Schempp-Hirth Janus CM motor glider experienced an engine malfunction near South West Sheffield, UK. The pilot was unable to fully extend and lock the engine, which increased the aircraft's drag. After ridge-soaring for some time, the pilot attempted a field landing to avoid power cables but stalled, resulting in a 20-foot fall. The aircraft sustained significant damage, but both the pilot and passenger were unharmed. An inspection revealed a missing roll-pin in the engine mechanism, which prevented proper engine extension.
- Ridge-soaring flight: After a weather-related diversion from Longmynd to the Camphill area, the pilot spent about one and a half hours ridge-soaring before intending to use the engine.
- Engine fails to extend: When the pilot attempted to raise the engine, it would not fully extend and lock into position, and then became jammed in a partially extended, unusable state that increased drag.
- Mechanical roll-pin loss: A roll-pin securing the upper end of the engine extension/retraction spindle had fallen out, allowing the upper spindle pivot to unwind and preventing full engine extension and locking.
- Continued ridge-soaring, field selection: The pilot continued ridge-soaring while searching for and selecting a suitable upslope field across a valley for an outlanding.
- Approach over power cables: On approach to the chosen field, the pilot noticed a line of power cables late and decided to fly over them rather than adjust the approach path.
- Stall avoiding cables: During the manoeuvre to clear the power cables, the aircraft was stalled and dropped approximately twenty feet into the field.
- Outlanding - damage: The aircraft impacted the field heavily, causing minor nose damage and complete disruption of the tail, but the pilot and passenger were uninjured.