NTSB Factual Report

HISTORY OF FLIGHT

On October 2, 1993, at 2329 Pacific daylight time, a Cessna 177RG, N45022, descended into rising terrain about three and one-half miles east-southeast of the Petaluma Municipal (uncontrolled) Airport, Petaluma, California. Instrument meteorological conditions prevailed in the vicinity of the accident site. The airplane was destroyed during the bright nighttime personal flight. Two private pilots (a female who owned the airplane, and a male) and two passengers were fatally injured. No evidence was found that either pilot had received a preflight weather briefing prior to taking off from the Reno Cannon International Airport, Reno, Nevada, or had received a weather briefing while en route to Petaluma. No flight plan was filed, and no instrument flight rules clearance was issued during the accident flight.

Based upon the National Transportation Safety Board's review of the Federal Administration Administration's air traffic communications tape, at 2208 the pilot with a male-sounding voice contacted the air traffic facility at the Reno Airport. The pilot indicated that he planned to fly to Petaluma. The pilot was issued a clearance to taxi for takeoff, and a few minutes later, at 2214, the airplane departed in visual flight conditions. During the airplane's initial climb, at 2219, Reno Departure Control identified the airplane on radar. FAA controllers did not experience any difficulty handling the airplane's flight. All radar services and communications were described as having been routine. All services with the airplane were terminated at 2224. No other FAA facility reported having contact with the airplane, and its en route flight path to Petaluma was not determined.

FAA quality assurance personnel at the Oakland Air Route Traffic Control Center (ARTCC) verbally reported to the Western-Pacific Systems Effectiveness supervisor and to the Safety Board that a search was performed for the presence of primary radar targets and Mode C transponder targets which approached the Petaluma Airport between 2300 on October 2, and 0100 on October 3, 1993. (The Safety Board estimated that based upon nominal cruise performance for the accident airplane, and no en route delays, the airplane could have been expected to arrive at Petaluma between 65 and 90 minutes after departing Reno.)

Only one target was found during the searched period, and that target was noted to be a Mode C-equipped aircraft. The aircraft descended while flying in a southwesterly direction until crossing the 276-degree radial of the Scaggs Island VORTAC (navigation aid) about 1,900 feet at 2327. The target then turned to a westerly heading and continued descending. At 2328, the target flew about 0.9 nautical miles to the left of the AFTIN Intersection. At this time, the target was descending through about 1,400 feet and was flying approximately parallel (but to the left of) the 276-degree radial from the Scaggs VORTAC.

The radar data shows the target continued to descend and it commenced a right turn. Between 2328:41 and 2328:53, during the last 12 seconds of the target's recorded flight, it descended from 1,000 feet to 700 feet, and traveled 0.37 nautical miles along a magnetic track of 300 degrees. The magnetic bearing between the target's last recorded radar position (at 2328:53) and the crash site was about 344 degrees.

PERSONNEL INFORMATION

First Pilot

FAA records indicated that the female pilot possessed a private pilot certificate and an airplane single-engine land rating. She was not instrument rated. On June 25, 1992, when the pilot applied for a Third-Class Aviation Medical Certificate, she indicated having 1,300 total hours of flight time. Also, she indicated having flown for 25 hours during the preceding six- month period.

Second Pilot

FAA records indicated that the male pilot possessed a private pilot certificate with an airplane single-engine land and an instrument rating. On September 25, 1992, when the pilot last applied for a Third-Class Aviation Medical Certificate, he indicated having 1,400 total hours of flight time. Also, he indicated having flown for 70 hours during the preceding six- month period.

The recency of instrument flight experience, currency, and compliance with the FAA's Biennial Flight Review requirements could not be established for either pilot. No flight records have been provided to the Safety Board.

AIRPLANE INFORMATION

The airplane was registered to the female pilot. The airplane was found equipped with dual flight controls, and its design allowed for piloting from either cockpit seat, although the flight instruments were grouped on the left side of the instrument panel.

The Mode C transponder and turbocharged airplane was found equipped for flight under instrument flight rules. Navigation equipment found in the wreckage included dual VORs, Loran, and a hand-held type of global positioning receiver (GPS).

From a review of ledger papers found scattered throughout the wreckage, on June 24, 1993, the airplane received a 100-hour inspection at 2,484.0 hours. No other inspection data was noted.

In the wreckage, the recording engine tachometer was observed at 2,513.0 hours. (The airplane inspection information listed in this Safety Board form was based upon the hours recorded in the ledger pages.)

METEOROLOGICAL AND MOON ILLUMINATION INFORMATION

The closest operative weather observation station to the accident site was at the Sonoma County Airport, elevation 125 feet msl. Sonoma is located about 21 nautical miles northwest of the crash site. Between 2200 on October 2, and 0120 on October 3, 1993, Sonoma reported a 400-foot overcast ceiling, visibility at least 10 miles, and temperature/dew point of 53/51 degrees Fahrenheit, respectively.

The Petaluma Airport manager verbally reported that on October 2, 1993, visual flight conditions existed in the airport area until about 1800. By 2000, a low altitude cloud layer moved over the airport creating an overcast sky condition. The clouds did not dissipate until after sunrise the following morning.

A commercial pilot, who provided student flight instruction from his Petaluma Airport office base of operations, verbally reported that during the early evening of October 2, 1993, the sky was overcast with cloud bases between 300 and 400 feet above ground level (agl). The visibility was about 5 miles. The following morning, the clouds were still present and had bases of about 400 feet agl.

At 2330, the moon was positioned approximately 43 degrees above the earth's horizon, and its magnetic azimuth was 89 degrees. Its illumination was 94 percent.

AIDS TO NAVIGATION

According to the FAA coordinator, all electronic aids to navigation associated with the VOR runway 29 approach procedure to the Petaluma Airport were functional at the time of the accident.

COMMUNICATION

A review of the FAA's air traffic voice tape, in conjunction with recorded radar track data, indicated that a male-sounding voice made broadcasts from the Mode C transponder equipped accident airplane to the FAA while departing from Reno. No female- sounding voice was heard during any of the communications.

AERODROME AND GROUND FACILITIES

The Petaluma Airport is located at 38 degrees, 15.28 minutes north latitude, by 122 degrees, 36.19 minutes west latitude. Its elevation is 87 feet msl.

The airport's manager verbally reported that the airport's rotating beacon had operated normally between the evening of October 2, and the morning of October 3, 1993.

WRECKAGE AND IMPACT INFORMATION

From an examination of the accident site and airplane wreckage, the airplane was found to have descended into the south slope of a hill located about 38 degrees, 13.39 minutes north latitude by 122 degrees, 32.64 minutes west longitude. Although the airplane's structure fragmented upon impact, all of the airplane's flight control surfaces and all major components were accounted for at the accident site. Based upon an examination of radar data in concert with the initial point of impact (IPI) ground scar, the structural fragmentation pattern, and related airframe wing crush damage, the airplane's initial ground contact occurred in a wings level or near wings level attitude.

Wreckage was found scattered over an estimated 100-yard-long path in the hard packed dirt hillside at elevations between 300 feet mean sea level (at the initial point of impact) and 400 feet msl.

The principal axis of wreckage distribution was measured along a magnetic course (ground track) of 340 degrees.

One of the airplane's two propeller blades was found at the IPI ground crater. The blade was observed torsionally deformed and was scratched in a chordwise direction.

The IPI crater measured approximately 5 feet wide, by 7 feet long, and 3 to 6 inches deep. A fragment from a metal seat track (rail) was observed about 15 feet to the north (340 degrees) of the IPI.

Near the middle of the wreckage distribution path, several pieces of engine compartment material were found, including the turbocharger and an exhaust stack (tail pipe). A 2-foot-long oval shaped area of native brush was observed burned adjacent to the turbocharger. A Royalite interior panel was found separated from the remainder of the fragmented airframe. The tail pipe was found on top of the Royalite panel and had melted it.

The aft portion of the empennage was found about 170 feet north of the IPI. The wings and the engine were found between 260 and 270 feet north of the IPI. An estimated 4 and 5 gallons, respectively, of blue-colored fuel was observed in the left and right wing tanks.

The second propeller blade was found attached to the engine. Its torsionally deformed and scratched appearance was similar to that observed on the separated blade.

The continuity of the cable control system was established between the ailerons and the crushed cockpit area. Also, cable continuity was confirmed between the rudder and stabilator surfaces and the forward cabin floor.

Circumferential score marks were noted on the directional gyroscope's rotor. Corresponding score marks were observed on the inside of the case. The heading bug was observed positioned at 344 degrees.

During the engine examination, the propeller was rotated and thumb compression was obtained in all cylinders, and spark was noted at all eight terminal leads. The valve and gear train continuity was established. A drop of fuel was observed in the flow divider. The Lycoming engine party representative reported finding no evidence of any preimpact failures or engine malfunctions.

MEDICAL AND PATHOLOGICAL INFORMATION

On October 4, 1993, an autopsy on both pilots was performed by the Sonoma County Coroner's office, in Santa Rosa, California. Neither autopsy disclosed any evidence of either pilot having experienced a physical incapacitation or impairment that would have adversely affected their ability to operate the airplane. Toxicology tests on the first pilot were performed for the FAA by the Armed Forces Institute of Pathology (AFIP), Washington, D.C., and by laboratories under contract with the Sonoma County Coroner's office. All test results were reported as negative for

ethanol and all screened drugs. The coroner's contract laboratory reported that the carboxyhemoglobin saturation in the blood was less than 2 percent.

Toxicology tests performed by the AFIP on the second pilot were reported as negative for ethanol and all screened drugs. The carboxyhemoglobin saturation in the blood was 17 percent. The coroner's contract laboratory (verbally) reported a positive finding of ethanol in his blood at the level of 0.026 percent, and it provided a written report indicating the State of California reportable value of 0.02 percent. The laboratory reported carboxyhemoglobin saturation in the blood was 6 percent.

Regarding the passengers, the coroner's contract laboratory reported no evidence of drugs or ethanol. Carboxyhemoglobin saturation in their blood was reported for the male and female as less than 2 percent and 3 percent, respectively.

TESTS AND RESEARCH

Several Pacific Gas & Electric Company power lines were observed suspended from towers within one-half mile south of the crash site. According to PG & E representatives, following the accident the lines were inspected for damage. No evidence of a line strike or of airplane debris beneath the lines was found. Also, no power outage, current spikes, or customer complaints occurred during the evening of October 2, or on the morning of October 3, 1993.

An impact damaged portable (hand-held) type of global positioning receiver (GPS) was found in the wreckage. The unit's antenna cable was found pulled out of the receiver, and the battery compartment case was broken open. No present position or "On/Off" status information could be extracted from the receiver.

An impact damaged II Morrow Loran receiver, model 618, was examined at the Safety Board's request by its manufacturer. An FAA representative monitored the examination for the Safety Board. According to the manufacturer, the Loran's "On/Off" position switch was found in the "On" position. The internal battery was not found inside the unit. No present position information could be obtained. The unit appeared to have been in an operational condition prior to the accident.

The Safety Board's Metallurgical Laboratory, Washington, D.C., examined the face plate of an altimeter which was found in the wreckage. The hands (needles) which indicated elevation were observed missing. The laboratory's microscopic examination revealed evidence of "...an object such as a needle pointer impacting the face plate." The "needle" slap mark position corresponded to an indicated altitude of about 475 feet.

ADDITIONAL INFORMATION

The identification of the "First Pilot" and "Second Pilot" as noted in the Safety Board's forms was made in fulfillment of computer entry requirements and not as a statement of who was responsible for the flight. Also, the identification of the "First Pilot" was based upon the FAA's aircraft registration ownership records.

Based on the amount of damage to the airplane, the Safety Board was not able to establish the pilots' respective locations inside the airplane, or establish who was handling the flight controls at the time of the crash.

Family members of the passengers reported that neither passenger had taken flying lessons. The family members reported that it was their understanding the purpose of the flight was to fly to Reno for dinner, and then fly to Petaluma.

On October 4, 1993, the main airplane wreckage was verbally released, in person, to the owner's assigned insurance adjuster from AIG Aviation while the adjuster was at the accident site. The airplane's Loran, altimeter face plate, nose wheel and assembly, and assorted airplane papers which had been recovered from the crash site, were released to AIG on June 1, 1994. No parts or records have been retained by the Safety Board.

NTSB Probable Cause

VFR FLIGHT BY THE PILOT(S) INTO INSTRUMENT METEOROLOGICAL CONDITIONS (IMC), AND FAILURE TO MAINTAIN A PROPER ALTITUDE AND/OR CLEARANCE FROM TERRAIN, WHILE APPROACHING THE DESTINATION AIRPORT. FACTORS RELATED TO THE ACCIDENT WERE: THE LOW CEILING AND TERRAIN.