Piper PA 28-140 accident near Brinnon, Washington, September 30, 2017

The NTSB's narrative final · quoted from the NTSB record

The flight instructor and student pilot were conducting the student's first night flight: a cross-country visual flight rules flight to two other airports which concluded with a return to their home airport. Review of the student's flight planning documents, which included the penciled flight route on a Sectional Aeronautical chart and a hand-filled paper flight planning form, revealed that the student had planned to conduct the entire flight at an altitude of 3,500 ft msl. The student's plotted course for the last leg of the flight, which was drawn directly from the departure airport to the destination, passed over a peak with a charted elevation of 3,440 ft. While in the airplane, and prior to engine start, the student and instructor reviewed the planned flight and current weather. The first leg was flown using air traffic control (ATC) flight following services. This northeast-bound leg was flown at 4,500 ft, an altitude that was contrary to the FAA hemispheric rule (easterly flights should be flown at odd-thousand ft altitudes and westerly flights should be flown at even-thousand ft altitudes); ATC did not assign or question this altitude selection. The second leg was westbound and did not use ATC flight-following; the leg was flown at 3,500 ft, again contrary to the FAA hemispheric rule. The final, southbound accident leg was also flown at 3,500 ft; this altitude selection was erroneous for two reasons. First, it was contrary to the hemispheric rule, but more significantly, the student pilot's plotted course line on the Sectional chart passed directly over a peak that was charted as having an elevation of 3,440 ft. The airplane impacted the terrain immediately prior to that peak at an elevation about 3,075 ft mean sea level (msl). Examination of the airplane and engine did not reveal any pre-impact mechanical deficiencies or failures that would have precluded continued normal operation. Review of flight track and data from onboard personal electronic devices (PEDs) was consistent with a controlled flight into terrain (CFIT) event. Further review of the flight planning form showed an airport listed as a waypoint for the accident leg; the airport was located just east of the direct route between the departure and destination. If the pilots had chosen to navigate first toward this airport then to the destination rather than flying direct, the flight would have avoided the mountainous terrain. Additionally, the student's planned altitudes did not comply with Federal Aviation Administration regulations regarding cruise flight altitudes. The investigation was unable to determine why neither the student nor the flight instructor detected the erroneous planned and flown altitude. Although the student's work schedule in the days leading up to the accident may have been conducive to the development of fatigue and, subsequently, his error in planning, there was insufficient evidence to determine the presence or role of fatigue. Further, as pilot-in-command, the instructor should have reviewed the flight planning documents and detected these errors. Both the student pilot and the flight instructor owned multiple portable electronic devices (PEDs) equipped with flight planning and operating software capable of displaying geo-referenced flight and terrain information. As part of his training regimen, the flight instructor did not let the student use any PEDs during flight; however, the student stated that the flight instructor would typically use his PEDs to monitor or augment the flight while they were airborne. Whether the flight instructor was using his PEDs during the accident flight could not be determined; however, he had sufficient time, tools, and knowledge to detect the flight's improper altitude and proximity to terrain with or without the use of PEDs, and why he failed to do so and instead allowed the flight to remain on that track at that altitude could not be determined.   CFIT prevention is primarily dependent on pilots' complete and accurate situational awareness, which can be aided by many safety tools and measures. Despite the fact that the flight instructor held the knowledge, tools, and responsibility to ensure proper and safe conduct of the flight, particularly with regard to appropriate altitude selection, the circumstances of the accident indicate that neither he nor the student possessed complete and accurate situational awareness, most critically for the accident leg, which resulted in the CFIT event.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.