History of Flight
On May 21, 2014, at 0810 eastern daylight time, a Cessna 182S, registration N182PJ, was substantially damaged during a runway overrun at Cecil County Airport (58M), Elkton, Maryland. The airline transport pilot and two passengers were not injured. Instrument meteorological conditions prevailed, and an instrument flight plan had been filed for the personal flight from Penn Valley Airport (SEG), Selinsgrove, Pennsylvania, to Albert Ellis Airport (OAJ), Jacksonville, North Carolina, conducted under 14 CFR Part 91.
According to the pilot's written statement, while climbing to 8,000 feet msl, he encountered light turbulence and light to moderate rain for the first 30 minutes in continuous IMC. Shortly after crossing the Pennsylvania/Maryland border, he requested and received ATC approval for a different routing due to heavy rain showers.
Once level at 8,000 feet, the pilot leaned the mixture, closed cowl flaps, and set cruise power. He noted the exhaust gas temperature gauge malfunctioning, but fuel flow and other gauges were normal. The autopilot could not hold NAV mode and rocked in HDG mode. Later, he could barely hear his own voice in the headset after lowering volume, then increased it.
ATC advised a 160-degree heading to avoid traffic. Shortly after, the instrument panel blinked rapidly and a total electrical failure occurred. The transponder, radios, GPS, weather display, ADF, attitude indicator, autopilot, and all electrically driven equipment stopped functioning. The pilot focused on hand-flying in IMC.
Unable to contact ATC and lacking a handheld radio or cell service at altitude, the pilot used an iPad app to identify the nearest paved runway airport, 58M, about 8 miles northeast. He diverted and saw the ground at about 3,000 feet with scattered clouds and haze. A passenger called ATC via cell phone to report the situation.
The pilot identified the airport from 2 miles out and entered the traffic pattern for Runway 13. Due to the electrical failure, flaps could not be extended. He flew an extended downwind leg and attempted a no-flap landing. He was confident he could land on the nearly 3,000-foot runway, having done so before, and did not want to risk continued IMC flight with a complete electrical failure.
He conducted an elongated shallow approach at 75 knots. Upon reaching the runway, he immediately put the main wheels aggressively on the runway and applied full brakes, but there was no reaction. The airplane did not skid or slow. He pushed forward on the control wheel to add weight, and he and a passenger pressed hard on the brakes, but the airplane continued without decelerating halfway down the runway. He opted not to go around due to trees, power lines, IMC, fuel, and passengers. He pulled the emergency brake handle and intentionally deviated left onto an airport access road. The airplane struck a fence and other obstacles, coming to rest about 10 feet off a road shoulder.
The pilot stated he was unaware that the runway had a significant downhill gradient and was sealed with weather sealant.
Aircraft and Electrical System
The airplane was a four-place, high-wing, single-engine Cessna 182S with tricycle landing gear and electrically controlled wing flaps. It was manufactured in 1998 and had its most recent annual inspection on June 1, 2013, with about 1,103 total hours.
The electrical system was 28-volt DC, powered by a belt-driven 60-amp alternator and a 24-volt battery in the tailcone. Power distribution used a J-Box on the firewall containing relays, the alternator control unit (ACU), and external power connector. The system had two primary buses and an essential bus, plus two avionics buses controlled by a master switch. The ammeter/vacuum gauge indicated charging or discharge. An annunciator panel included a low voltage warning light that activated below 24.5 volts.
The wing flap system drew power from Electrical Bus No.2 via a 10-amp circuit breaker. Flaps could be set to 10, 20, or 30 degrees.
Meteorological Conditions
The 0800 surface analysis showed a stationary front over the area, with the accident site north of the front and a small high-pressure system. Station models indicated light winds, overcast skies, rain, fog, and mist. Radar at 0810 showed extensive weather echoes along the flight track. Cecil County Airport had no weather reporting; the nearest was Phillips Army Airfield, about 11 miles southwest, which reported at 0754: calm wind, 6 miles visibility in mist, broken clouds at 6,000 feet, overcast at 11,000 feet, temperature 16°C, dew point 18°C, altimeter 30.00 inHg. At 0856: winds 360° at 4 knots, 5 miles visibility in light rain and mist, similar cloud layers, temperature 16°C, dew point 13°C, altimeter 30.01 inHg.
Airport Information
Cecil County Airport (58M) is located in Elkton, Maryland. The accident runway was 13, which had no displaced threshold. The pilot noted a significant downhill gradient and a weather sealant on the runway surface.
Wreckage and Impact Information
Examination by an FAA inspector revealed damage to the propeller, engine, engine mount, firewall, nose landing gear, engine cowlings, fuselage, left wing, empennage, horizontal stabilizer, and vertical fin. The battery was discharged; there was no evidence of lightning strike. Brakes were functional.
The J-Box components, including relays, fuses, and ACU, showed no signs of failure. Relay coil resistances were normal; bus fuses were intact. The ACU low voltage function provided a discrete signal when bus voltage dropped below 24.5 volts.
Testing of the alternator revealed no output; system voltage was at battery level. The field voltage from the ACU was at full field, indicating a possible alternator problem. Field resistance between the field terminal and ground was open circuit. Upon disassembly, the negative (ground) field brush was completely worn down to its braided lead, with evidence that the lead had ridden on the slip ring and worn through. A deep groove was worn into the slip ring. The positive brush had about 40 percent remaining. Brush springs were defect-free. Rotor winding resistance was normal at 12.2 ohms.
Additional Information
No-flap landing: According to the Airplane Flying Handbook, a no-flap landing requires substantially more runway (up to 50% increase). Without flaps, the airplane tends to float more during roundout. The pilot flew the approach at 75 knots; the Cessna 182S manual shows a stall speed with flaps up of 40 knots. The FAA recommends 1.3 times the power-off stall speed (52 knots for this airplane).
Dynamic hydroplaning: For a Cessna 182S with main tire pressure of 32 psi, the calculated minimum hydroplaning speed is about 49 knots. Once started, hydroplaning can persist at slower speeds.