Nevada

The pilot landed with the landing gear in the retracted position, when both the main and auxiliary hydraulic systems failed to extend the gear. The airplane caught fire as it skidded down the runway. The left inboard main tire had blown on takeoff and a 30-inch section of tread was loose. Black marks were along the length of the landing gear strut and up into the wheel well directly above the left inboard wheel. The normal and emergency hydraulic systems both connect to a common valve body on the landing gear actuator. This valve body also had black marks on it. A gap of 0.035 inch was measured between the valve body and actuator. When either the normal or auxiliary hydraulic system was pressurized, red fluid leaked from this gap. Examination revealed that one of two bolts holding the hydraulic control valve in place had fractured and separated. The fractured bolt experienced a shear load that was oriented along the longitudinal axis of the actuator in a plane consistent with impact forces from the flapping tire tread section.. Separation of only one bolt allowed the control valve to twist about the remaining bolt in response to the load along the actuator's longitudinal axis. This led to a loss of clamping force on that side of the actuator. Hydraulic line pressure lifted the control valve, which resulted in rupture of an o-ring that sealed the hydraulic fluid passage. 14 CFR 25.739 describes the requirement for protection of equipment in wheel wheels from the effects of tire debris. The revision of this regulation in effect at the time the airplane's type design was approved by the FAA requires that equipment and systems essential to safe operation of the airplane that is located in wheel wells must be protected by shields or other means from the damaging effects of a loose tire tread, unless it is shown that a loose tire tread cannot cause damage. Examination of the airplane and the FAA approved production drawings disclosed that no shields were installed to protect the hydraulic system components in the wheel well.

The pilot had filed an instrument flight rules (IFR) flight plan for 25,000 feet mean sea level (MSL), and he amended it to 27,000 feet MSL en route. About 36 minutes after the altitude change to 27,000 feet, the pilot advised air traffic control (ATC) that he had lost cabin pressurization and needed an immediate descent. About 20 seconds later he was cleared to 25,000 feet, then 15 seconds later to 15,000 feet. Shortly after the pilot acknowledged the lower altitudes, the radio communications deteriorated to microphone clicks with no carrier. The aircraft started a shallow descent with slight heading changes, then was observed to make a rapid descent into desert terrain. About 10 months prior to the accident the aircraft had been inspected in accordance with the Piper Cheyenne Progressive Inspection 100-hour Cycle, event No. 1. According to the servicing agency, the aircraft inspection was completed and the aircraft was returned to service with a 12,500 feet MSL altitude restriction due to unresolved oxygen system issues. The last oxygen bottle hydrostatic check noted on the bottle was October 1989. The oxygen system was in need of required maintenance and the masks were in a rotted condition. The pilot failed to report his severe coronary artery disease condition, medications, and other conditions to his FAA medical examiner for the required flight physical.

After climbing to 18,400 feet msl, the pilot reported a turbocharger problem and reversed course. He said he 'may lose the left engine' and that he was unable to maintain altitude. He diverted to an alternate airport. During a right turn onto final approach, the airplane was observed to cross (overshoot) the extended centerline of the runway. It continued in a right turn back toward the centerline, and then entered a left turn to intercept the inbound course. The turn steepened, and then the airplane entered a spin and crashed 1/2 mile short of the runway. A warped flange and evidence of exhaust gas leakage were found on the Inconel exhaust system Wye collector, at the wastegate outlet of the left engine. Neither propeller was in a feather position. There was evidence that the left engine was providing low power during impact. A note on the pilot's clipboard indicated that the (left engine) fuel flow and cylinder head temperature went to zero, and the manifold pressure dropped to 10 inches. The note also indicated that the pilot switched the 'boost pump' to high, the fuel flow went to 260 psi, and manifold pressure increased to 18.5 inches. Calculations showed that the airplane's gross weight (GW) and center-of-gravity (CG) were 7,645 pounds and 158.32 inches. The maximum allowable GW and CG were 7,450 pounds and 158 inches. During impact, the flaps were fully extended. The 'Engine Inoperative Landing' procedure stated, 'Wing Flaps - DOWN when landing is assured.' Most of the pilot's flight time in the Cessna 421 was before 1985; no record was found of recurrent training in the airplane since 1984. Annual and turbocharger inspections were made at 78 and 120 flight hours, respectively, before the accident, but no logbook entries were made concerning maintenance or replacement parts for the exhaust system. All eight occupants were killed.

Approaching Reno, the pilot received an instrument clearance to perform a Localizer DME-1, Rwy 16R, approach, which the FAA had previously approved for the operator's use. The localizer centerline passed over a 6,161-foot msl mountain, which was depicted on the chart. The pilot was familiar with the area, having transported cargo from Sacramento to Reno for 5 days each week since December, 1994. IMC existed and light snow showers were present. ATC issued the pilot a series of instructions as he was radar vectored toward the final approach fix (FAF), which had a minimum crossing altitude of 6,700 feet msl. The pilot misstated four of the instructions during clearance readbacks and was corrected by ATC each time. Contact with the pilot was lost following issuance of his landing clearance. The airplane impacted the mountainside at an elevation of about 6,050 feet, while tracking inbound near the centerline of the localizer course, about 2.7 nautical miles before reaching the FAF. The airframe, engine, and avionics equipment were examined. No mechanical malfunctions were found.

The pilot was completing the first leg of an IFR flight in a multi-engine airplane. As the airplane was established on final approach, about 5 miles from the airport, the pilot encountered visual meteorological conditions and canceled his IFR flight plan. Moments later, the right engine began to sputter and then lost power. The pilot said that he switched the fuel selector valves to various positions and positioned the fuel boost pump to high-flow; however, during this time, the left engine also lost power. The pilot attempted to start both engines, but without success. During a forced landing, the airplane struck a pole, then crashed into a condominium. A fire erupted, but all 4 occupants survived the accident. Two occupants in the condominium received minor injuries. The pilot believed that he had moved the fuel selector valves to the auxiliary position for about 1 hour during flight; however, the passengers did not see him move the fuel selectors until after the engine(s) lost power. The right fuel selector handle was found between the right main tank and off positions. The left fuel selector was destroyed by post-impact fire.