# NTSB CHI91FA259: Piper PA-24-250, N5145P, Guide Rock, NE, August 12, 1991 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: August 12, 1991, 12:41 local (17:41 UTC) - Place: Guide Rock, NE - Coordinates: 40.070598, -98.320777 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.0706&lon=-98.3208&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 2 fatal - Status: Completed, report April 8, 1993 - Report: Approved by Office Director - NTSB case key (mKey): 14915 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI91FA259 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/14915/pdf - Page: https://openairdocs.org/ntsb/CHI91FA259 ## Probable cause SPATIAL DISORIENTATION, AND EXCEEDING THE DESIGN LIMITS OF THE AIRCRAFT. FACTORS RELATED TO THE ACCIDENT ARE INADEQUATE PREFLIGHT PLANNING, VFR FLIGHT INTO IMC, FLIGHT WEATHER AVOIDANCE ASSISTANCE NOT FOLLOWED, EXCESSIVE ALTITUDE, PHYSICAL IMPAIRMENT (ANOXIA/HYPOXIA), AND LACK OF TOTAL INSTRUMENT TIME. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, maneuvering - oxygen system - not installed - preflight planning/preparation - inadequate, pilot in command (contributing factor) - physical impairment(anoxia/hypoxia), pilot in command (contributing factor) - lack of total instrument time, pilot in command (contributing factor) - in flight weather avoidance assistance - not followed, pilot in command (contributing factor) - spatial disorientation, pilot in command (cause) - vfr flight into imc - encountered, pilot in command (contributing factor) - altitude - excessive, pilot in command (contributing factor) - Airframe/component/system failure/malfunction, descent - uncontrolled - wing - failure,total - design stress limits of aircraft - exceeded, pilot in command (cause) - In flight collision with terrain/water, descent - uncontrolled - terrain condition - crop ## Analysis THE PILOT WHO WAS NOT INSTRUMENT RATED WAS TRYING TO REMAIN VFR ON TOP WHEN HE ENCOUNTERED IMC AT 17,500 FEET. AIRCRAFT ENTERED AN UNCONTROLLED DESCENT AFTER THE PILOT TRIED TO MANEUVER TO REMAIN IN VMC. THE RIGHT WING SEPARATED FROM THE AIRCRAFT DURING DESCENT. THE PILOT WAS ABOVE 14,000 FEET FOR ONE HOUR. THE AIRCRAFT WAS NOT OXYGEN EQUIPPED, AND NO EVIDENCE OF PORTABLE OXYGEN WAS FOUND. THERE WAS NO RECORD OF A PRELFIGHT WEATHER BRIEFING. THE PILOT GOT AN INFLIGHT WEATHER BRIEFING 1.5 HOURS BEFORE THE CRASH IN WHICH VFR WAS NOT RECOMMENDED, AND A ROUTE OF FLIGHT TO AVOID THE WEATHER WAS SUGGESTED. A SECOND INFLIGHT WEATHER BRIEFING WAS OBSTAINED 20 MINUTES BEORE THE CRASH IN WHICH A ROUTE OF FLIGHT TO AVOID THE WEATHER WAS AGAIN SUGGESTED. PILOT CONTINUED UNTIL HE WAS IMC. ## Aircraft - Registration: [N5145P](https://openairdocs.org/deregistered/N5145P-1991-09-16), registration cancelled 1991-09-16, S/N 24161 (OpenAirDocs) - Reported make and model: PIPER PA-24-250 - Registry model: [Piper PA-24](https://openairdocs.org/model/piper-pa-24) (registry code 7102402) (OpenAirDocs) - Category: Airplane - Serial number: 24-161 - Airframe hours: 2441 - Engines: LYCOMING O-540-A1C5 250 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Operator: Thomas K. Phelps - Registered owner: Thomas K. Phelps - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 20, 1991, 20 hours before - Departed: SPF, SPEARFISH, SD - Destination: FYV, FAYETTEVILLE, AR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 817 total, 172 in this make and model, 756 as pilot in command, 18 in the last 90 days, 3 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 190° at 4 knots - Visibility: 5 statute miles - Lowest ceiling: 4,000 ft overcast - Temperature: 64 °F, dew point 63 °F - Altimeter: 30.00 inHg - Observed at: HSI, 30 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19910812033709A](https://openairdocs.org/incident/19910812033709A), Aug 12, 1991: Piper PA24250, Guide Rock, NE, Destroyed, 2 fatal. VFR on top FL 175 became IFR,not IFR rated. Apparently lost control. Went into dive,in flight breakup,vertical impact ## Other investigations on N5145P (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB UNK64X1885](https://openairdocs.org/ntsb/UNK64X1885), May 22, 1964: Piper PA24 (N5145P), Lexington, KY, substantial damage From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.