On September 12, 1943, a Fieseler Fi 156 C-5, bearing the factory registration SJ+LL, performed a high-risk extraction of the deposed Italian dictator Benito Mussolini from the Gran Sasso d'Italia massif. This mission, part of the German operation codenamed Eiche (Oak), remains one of the most historically significant demonstrations of the aircraft's short take-off and landing (STOL) capabilities under extreme conditions.

The operation was characterized by the following historical and technical details:

• The Landing: Hauptmann Heinrich Gerlach, the personal pilot of General Kurt Student, navigated the Storch to a landing on a narrow, debris-strewn plateau adjacent to the Campo Imperatore hotel, situated at an altitude of approximately 2,000 meters. The landing area was highly restricted, requiring Gerlach to navigate a steep approach and manage a touchdown on a surface covered in rocks and snow-melt gullies.
• The Weight Crisis: A significant complication arose when SS-Sturmbannführer Otto Skorzeny, the leader of the commando unit, insisted on boarding the aircraft alongside Mussolini. Gerlach initially protested, noting that the combined weight of the two men, in addition to the thin air at that altitude, severely compromised the safety of the takeoff. Despite these professional concerns, the pilot was compelled to accept both passengers, resulting in a dangerously overloaded airframe.
• The Takeoff: Utilizing a takeoff run of only 80 to 120 meters, Gerlach steered the aircraft toward the edge of a steep precipice. To achieve sufficient airspeed for flight, the Storch was essentially driven off the cliff's edge, plunging into the abyss to gain aerodynamic lift. During this maneuver, the aircraft's undercarriage reportedly struck a rock, causing a visible bend in one of the landing gear struts, though the machine remained airworthy.
• Mission Conclusion: Gerlach successfully stabilized the aircraft and transported his passengers to the Pratica di Mare airfield near Rome, where Mussolini was transferred to a Heinkel He 111 for further transport to Vienna.

The success of the SJ+LL mission at Gran Sasso solidified the Storch's reputation as a peerless utility aircraft, capable of operating from environments that were inaccessible to any other contemporary fixed-wing aircraft. In recognition of this feat, Hauptmann Gerlach was subsequently awarded the Knight's Cross of the Iron Cross.