Accident Narrative
On July 9, 2017, at about 1220 Alaska daylight time, a float-equipped Cessna 180, registration N2429C, was substantially damaged in an accident in Anchorage, Alaska. The pilot sustained minor injuries. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
The pilot reported that the airplane's annual inspection had been completed the previous week, and the accident flight was the first flight after return to service. He had not flown the airplane in approximately nine months. The purpose of the flight was to perform takeoffs and landings at a nearby lake. Before departure, he fueled the airplane to capacity and checked the fuel for contaminants, noting no abnormalities.
After takeoff from the north water lane at Lake Hood Seaplane Base (LHD), during climb out, the pilot was unable to move the flap handle to retract the wing flaps. He maneuvered the airplane to a right downwind to return for landing. At an altitude of about 600 ft and airspeed of 70 knots, the engine experienced a total loss of power. The pilot lowered the nose to attain glide speed and initiated a forced landing toward an open field. When he realized the airplane would not reach the intended site, he aimed for an adjacent residential road. The airplane collided with a 40-ft-tall tree, a light pole, two houses, and a vehicle before impacting the road.
A witness reported hearing the engine change from normal rpm to silence, followed by a loud ground impact.
Postaccident Examination
The airplane came to rest upright with both floats bent under and to the left of the fuselage. The right wing leading edge exhibited a large impact indentation corresponding to the fallen light pole. The wings, fuselage, engine firewall, and empennage sustained substantial damage. Fuel spillage was evident at the site from ruptured fuel lines at the wing roots. A fuel sample was clear and blue, free of contaminants.
All major components were located at the scene. Flight control continuity was established from the cockpit to the control surfaces. The aileron interconnect balance cable was fractured near the right door post with broomstraw signatures. The flap handle was in the 20° detent and could be easily moved through all detents with corresponding cable movement. The right wing flap cable was separated at the wing root with broomstraw overload signatures. A headset cord from the right seat was wrapped around the flap handle base.
Engine and Fuel System Tests
Fuel was present in the header tank and gascolator. The fuel selector valve was functionally tested in all positions, and fuel lines from the wing roots to the gascolator were clear of obstructions. The fuel line from the fuel flow transducer to the fuel manifold valve contained no fuel, and the manifold contained only residual fuel.
The engine was test run at various power settings, with the throttle rapidly moved from idle to full power multiple times. No discrepancies were noted.
Maintenance History
Review of the maintenance logbooks revealed that the last documented annual inspection was in 2013. The pilot and a mechanic stated that the inspection completed the week before the accident was not yet annotated in the logbooks.
Postaccident examinations of the airframe and engine found no evidence of mechanical malfunctions or failures that would have precluded normal operation.