History of Flight
On January 28, 2016, about 1857 Pacific standard time, a Piper PA-24-260C, registration N9362P, impacted terrain during an instrument landing system (ILS) approach to Charles M. Schulz Airport – Sonoma County Airport (STS), Santa Rosa, California. The commercial pilot and passenger were fatally injured. The airplane was registered to and operated by Tango Charlie Aviation LLC as a 14 Code of Federal Regulations Part 91 flight. Night instrument meteorological conditions prevailed, and a visual flight rules (VFR) flight plan had been filed for the cross-country flight. The personal flight departed Palm Springs International Airport (PSP), Palm Springs, California, at 1535.
Witnesses reported that the pilot and passenger flew from STS to PSP the day before for an overnight stay. A fixed base operator filled the fuel tanks to capacity as instructed by the pilot, who anticipated an afternoon departure. On the accident day, the pilot filed a VFR flight plan and departed for STS with VFR flight following. He obtained an instrument flight rules (IFR) clearance about 46 nautical miles (nm) from STS and was cleared to an approach fix on the ILS approach to runway 32.
The airplane's final movements were recorded by ATC audio and an onboard Appareo Stratus 2 unit that captured GPS and attitude heading reference system data. At 1833, the pilot contacted Oakland Air Route Traffic Control Center (ARTCC) and reported VFR at 6,500 ft mean sea level (msl). After receiving the STS altimeter setting, he asked about approaches and was informed that STS was using the runway 32 ILS approach. Two minutes later, he requested IFR clearance. The airplane crossed Scaggs Island VOR at 1837 and turned to LUSEE intersection, an intermediate fix 12.2 nm from STS.
During cruise, the airplane flew directly to assigned waypoints with minimal course variation, consistent with autopilot use. Course variation became erratic after passing DACER intersection. At 1840, the controller cleared the pilot via radar vectors, instructing a left turn and descent to 5,000 ft msl. The pilot complied. The controller vectored him back toward the localizer and cleared him to LUSEE at 4,500 ft msl. At 1850, he was cleared for the ILS approach and instructed to cross LUSEE at or above 4,200 ft msl. He acknowledged and began descent.
At 1851:25, the pilot reported missing the localizer but correcting. The controller advised the STS tower controller that the airplane was arriving late due to trouble flying the localizer. GPS data showed the airplane crossed the final approach fix about 1,000 ft above the glideslope intercept altitude. At 1856:06, about 3.3 nm from the airport, the pilot notified the tower he was inbound and acknowledged a clearance to land. About 40 seconds later, the tower notified him he was "drifting right of course" and then "well right of course." ATC radar data matched GPS data, showing the airplane intercept LUSEE and maintain a course right of the localizer. After crossing PIGPN, the airplane passed left of the localizer, then turned right about 60° and crossed through it, during which the descent rate increased from 600 fpm to 1,200 fpm. Final GPS data points showed a left turn with a 35° nose-down attitude on a heading of 302° magnetic. The accident site was about 0.14 nm from the last GPS point.
Personnel Information
The pilot held a commercial pilot certificate with ratings for airplane single-engine land and instrument airplane. He held a second-class medical certificate issued October 22, 2015, with the restriction "must have available glasses for near vision." He reported 1,278 total flight hours, 50 hours in the previous 6 months. A spreadsheet from the pilot's friend showed his last instrument proficiency check (IPC) was completed in 1.3 hours on November 6, 2015. The IPC instructor reported good aeronautical decision-making during weather planning discussions but noted the pilot kept airspeed too high during approaches, resulting in steeper turns. The spreadsheet showed 93.6 hours of actual instrument experience. Before the IPC, he had 4 hours actual and 3.4 hours simulated instrument experience in the previous year, mostly in May 2015. No instrument experience was recorded between November 6, 2015, and January 2, 2016. The spreadsheet indicated 0.5 total hours of night flight experience in the preceding 2 years, with a November 2015 entry noted as "Night Current." His most recent night instrument meteorological conditions experience was documented on March 27, 2013. The most recent biennial flight review (BFR) was completed May 15, 2015; the BFR instructor stated the pilot demonstrated competency.
Aircraft Information
The airplane was manufactured in 1969 and registered to the pilot on September 9, 2015. It was powered by a Lycoming IO-540-N1A5, a normally-aspirated, direct-drive, air-cooled, 260-horsepower engine. The most recent annual inspection was completed August 20, 2015, at 5,284.2 flight hours. The tachometer at the accident site indicated 245.1 hours, corresponding to 5,315.1 total flight hours. The manufacturer originally equipped the airplane with a Piper Auto Control III autopilot; the logbook did not indicate upgrades or replacements. The BFR instructor reported two-axis autopilot in 2015.
Meteorological Information
STS had an automated surface observation system. Observations showed VFR conditions early afternoon, deteriorating to IFR from departure to accident time, and then low IFR (LIFR) about 4 minutes after the accident. LIFR is ceiling less than 500 ft and/or visibility 1/2 mile or less. The final special report before the accident (1853) indicated calm winds, 2 1/2 miles visibility, mist, scattered clouds at 400 ft, overcast ceiling at 900 ft, temperature/dewpoint 12°C. A special METAR about 4 minutes after the accident reported calm winds, visibility 2 1/2 miles, mist, overcast at 400 ft, temperature/dewpoint 12°C. The area forecast included broken clouds at 2,000 ft msl with tops to 6,000 ft msl and isolated rain showers, outlook of IFR ceilings. AIRMETs covered the accident area for mountain obscuration and near a border for IFR conditions. A terminal area forecast (TAF) issued that morning indicated deteriorating weather but not IFR at the estimated arrival time; at departure, the TAF reported marginal VFR to IFR for later hours. The pilot retrieved weather from ForeFlight.com about 24 hours before departure. Lockheed Martin Flight Services provided TAFs, AIRMETs, area forecasts, METARs, and NOTAMs. The area forecast for Northern California valid until morning indicated VFR. The TAF for STS valid to midnight showed deteriorating conditions with low ceilings and visibility. The moon phase was waning gibbous with 79% illumination; moonset at 0948, moonrise at 2215.
Wreckage and Impact Information
The airplane impacted a grass field about 1.5 nm south of STS. All major components were accounted for. An initial impact point about 2 ft long was identified by left wing fragments and the red position light. The main wreckage was about 133 ft from the initial point beyond an intermediate impact crater. Portions of the left wing, including two breached fuel tanks, were about 40 ft south. The empennage was inverted but intact with deformation to the vertical stabilizer, rudder, and stabilator. The main wreckage comprised the cockpit, right wing, a portion of the left wing, and engine. Rudder, aileron, and stabilator cables were traced. The flap jackscrew displayed 17 threads, consistent with 10° flap setting. The stabilator pitch trim jackscrew extension was about 0.35 inches, consistent with neutral pitch. Both left main and auxiliary fuel tanks were breached and void of fuel. The right main tank was intact but its fuel line was open. The right auxiliary tank contained about 8 gallons of liquid consistent with 100LL aviation gasoline. The fuel selector was positioned on the left main tank and rotated to each of the four ports without obstruction. Main landing gear were attached to their respective wings; nose gear came to rest about 100 ft forward of the engine. Main landing gear control cables were impact damaged and extended about 8 inches, consistent with gear extended position. Two attitude indicators and a heading indicator showed light scoring on pendulous vane housings and vanes. The vacuum pump functioned normally when hand-rotated; vanes and carbon rotor were intact. The autopilot mode selector was in the HDG position. The engine displayed a crack in the case between cylinders No. 1 and No. 3 and around No. 2. All six cylinders remained attached. Fuel injection servo and air intake screen separated; left magneto and oil filter partially separated. Rotational continuity was established; thumb compression and suction on all cylinders. Borescope examination showed no foreign object ingestion or detonation; combustion chambers normal. Rocker arms showed no unusual wear. Spark plugs showed normal wear. Oil filter had impact damage and partial separation; oil sump pick-up screen was clear. Engine-driven fuel pump partially separated but produced suction and pressure, dispensing water and mud. Fuel flow divider contained about 1 tablespoon of residual fuel; all six fuel nozzles were unobstructed. Fuel injection servo had impact damage at throttle body; fuel inlet screen clear. Mixture control arm and throttle plate moved stop to stop. Left magneto produced spark on two of six terminals; case depressed onto distributor gear inhibited full rotation. Right magneto produced spark on all six terminals. Propeller remained attached; one blade had "S" bending and twist opposite rotation with chordwise scratching; the other blade had chordwise scratching and a bend about 6 inches from the hub opposite rotation.
Additional Information
48-Hour History: Two days before the accident, the pilot contacted a friend in Palm Springs and planned to fly to PSP for an overnight trip with his wife. The friend picked them up about 2015 on January 27 and heard the pilot instruct the FBO to fill all four fuel tanks. They spent the night; the pilot and wife awoke at 0800 and 0700, respectively, appearing rested. After errands and lunch, the friend took them to the airport. The friend offered his home for another night, but the pilot was anxious to return for work and his daughter who had a broken leg scheduled for surgery. They did not discuss weather beyond forecasted rainfall at the home airport.
ATC Communication: Review of communications revealed that the Oakland ARTCC controller did not issue current destination weather as required by FAA Order JO 7110.65 (conditions below 1,000 ft ceiling or highest circling minimum, or less than 3 miles visibility). Additionally, the controller had not been disseminating pilot reports (PIREPs). The STS tower controller received a PIREP from a landing aircraft that reported weather "right at minimums" but did not enter it into the national airspace system or report it to the accident airplane as required by the order.
Medical and Pathological Information: An autopsy performed by the Sonoma County Coroner indicated the cause of death as "total body trauma." Toxicological tests were negative for ethanol and carbon monoxide, but positive for atenolol and chlorthalidone. Both medications had been reported on previous medical examinations. Atenolol is FAA-approved; chlorthalidone is not considered impairing.
Tests and Research: Engine analyzer data from a JPI EDM-800 showed no anomalies during the flight. In the final 20 seconds, fuel flow increased from 7 to 14 gallons per hour, manifold pressure from 10 to 19 inches of mercury, and rpm from 2,100 to 2,480.
Aids to Navigation: The ILS runway 32 approach had a final approach course of 321° magnetic, decision height 377 ft msl (249 ft agl). The pilot was vectored to LUSEE, an intermediate fix 12.2 nm from the airport. PIGPN was the final approach fix at 2,000 ft msl intercept altitude. Published landing minimums required a runway visual range of 2,400 ft.