History of Flight
On October 6, 2017, at 1329 central daylight time, a Bellanca 17-30A, N8234R, experienced a total loss of electrical power, followed about 18 minutes later by a total loss of engine power during cruise flight. The pilot performed a forced landing to a field near Sweetwater, Texas, where the airplane impacted trees and terrain. The pilot and passenger on board were not injured, and the airplane sustained substantial damage. The flight originated from Midland International Air and Space Port Airport (MAF), Midland, Texas, at 1230 and was destined for Abilene Regional Airport (ABI), Abilene, Texas, but diverted to Avenger Field Airport (SWW), Sweetwater, Texas, after the loss of engine power. Visual meteorological conditions prevailed, and the flight operated under Part 91 on a VFR flight plan.
The pilot reported no anomalies during preflight, taxi, runup, or departure climb. At departure, the left- and right-wing fuel tanks were half full, and the fuselage auxiliary tank was empty. About 18 minutes after departure, both communication radios flickered, followed by a loss of electrical power to the avionics; no circuit breakers were tripped. The pilot reset the alternator circuit breaker without restoring power. He diverted to SWW and entered a right downwind for runway 17 at 700 feet above pattern altitude. He attempted but could not extend flaps and did not receive a landing gear down and locked indication. He extended the downwind leg and slowed to 90 knots indicated airspeed to perform an emergency gear extension, pressing the emergency gear release lever several times without indication that the gear extended. He flew an extended final and, about 8 miles from runway 17, the airplane experienced total engine power loss. He located a field encircled by trees for a forced landing. During approach, he attempted twice to restart the engine unsuccessfully. He was unable to reach the field; the airplane impacted trees with the left wing, turned and yawed left, impacted the ground, and slid to a stop.
Aircraft Information
The airplane was equipped with left- and right-wing tanks, each of 19-gallon capacity (15 gallons usable), and left and right auxiliary wing tanks outboard, each of 17-gallon capacity (17 gallons usable). A fuselage auxiliary fuel tank had a total and usable capacity of 20 gallons. The airplane underwent annual inspections in 2012, 2016, and on June 17, 2017, at a total airframe time of 3,401.82 hours, engine time since overhaul of 970.82 hours, and tachometer time of 3,401.82 hours. Tachometer time at the accident was 3,407.2 hours.
Wreckage and Impact Information
Post-accident examination revealed flaps and landing gear retracted. The propeller was attached; all three blades exhibited chordwise scratches consistent with rotation and were able to be rotated by hand, consistent with broken pitch change links. Flight control continuity was confirmed. Fuel tanks were intact and not broken open; fuel caps were secure but showed corrosion at filler necks and caps. The cockpit fuel tank selector was OFF, and auxiliary fuel tank selector was RIGHT WING. The pilot did not report positions used during flight.
During salvage, the right-wing tank contained about 9 gallons of fuel, right-wing auxiliary tank empty, left-wing tank about 1 gallon, left-wing auxiliary tank about 8 gallons, and rear auxiliary tank empty. All fuel tank sending units were resistive type; they were examined and tested. All float arms moved freely, connections secure. Resistive test measurements were taken at bottom limit, mid-range, and upper limit positions, but specifications were unknown. There was no record of sender replacement since manufacture.
When electrical power was applied post-accident, communication and navigation radios powered up, and no circuit breakers tripped. Electrical continuity from battery to alternator was confirmed. The alternator was secure with normal belt tension; bench testing showed no anomalies. The loss of electrical power was not duplicated during examination.
Engine Examination
Fuel lines were attached and secure. Lines between fuel pump and metering unit contained no fuel; line between metering unit and manifold valve also contained no fuel. The manifold cap was removed; no fuel was present, and the screen was clean, diaphragm intact, plunger normal. Borescope of cylinders showed no mechanical anomalies. Engine drive and valve train continuity was confirmed during hand rotation. Top spark plugs displayed color consistent with a lean mixture; no fouling, electrodes normal worn. During crankshaft rotation, a repetitive sound consistent with magneto impulse coupling operation was heard. Neither magneto produced electrical spark; they were removed for bench testing.
Both magnetos (Slick 6310) were tested at 3,600 rpm; no spark was produced due to wear of magneto pick-up brushes. Coil and condenser testing showed no anomalies. Slick Service Bulletin SB3-08 for mandatory inspections on certain magnetos described premature carbon brush wear leading to possible loss of engine power, but the bulletin did not provide a terminating action. A review of aircraft and engine records showed the most recent magneto maintenance was installation of the right magneto on October 26, 2010, at tachometer time 2,944.04 hours. No subsequent overhaul/inspection records were found.
No probable cause was stated in the source.