ACCIDENT INVESTIGATION REPORT ON 9N-AJU Cessna Grand Caravan (Charter Flight) OPERATED BY MAKALU AIR AT EKLABHUJ KHARKA, SOUTH OF SIMIKOT AIRPORT DISTRICT, NEPAL ON 16th MAY 2018 SUBMITTED BY AIRCRAFT ACCIDENT INVESTIGATION COMMISSION TO THE GOVERNMENT OF NEPAL MINISTRY OF CULTURE, TOURISM AND CIVIL AVIATION December, 2019 (Poush, 2076 B.S.) Accident Investigation Final Report of 9N-AJU FOREWORD This report on the accident of 9N-AJU, Cessna Grand Caravan (Charter flight) operated by Makalu Air, Nepal is based on the investigation carried out by the Accident Investigation Commission constituted by the Government of Nepal on 16th May 2018 (2nd Jestha 2075 B.S.) as per the provision of the Aircraft Accident Investigation Regulation 2014 (2071 B.S.) and article-26 of Chicago Convention. The main objective of the investigation is to find out the cause of the accident and suggest recommendations to prevent the recurrence of such kind of accident in the future. Thus, it is not the function of the Commission to apportion blame or determine civil or criminal liability since neither the investigation nor the reporting process has been undertaken for that purpose. The Commission adopted standard methodology and resources in compiling this report including technical information on the aircraft, relevant documents, existing rules and regulations, crash site examination, meteorological reports, and direct interviews with other flight crew, witnesses & other concerned personnel. The commission conducted detail study and analysis of all available information, evidences, records, and documents and took references of several previous reports prepared by different air accident investigation bodies/commissions. Composition of Commission: 1. Mr. Tri Ratna Manandhar (Former DG CAAN) ----- Chairman 2. Sr. Engineer Upendra Lal Shrestha (Buddha Air) --------- Member 3. Sr. Captain Gopal Singh Bist (Nepal Airlines) ------------ Member 4. Joint Secretary Buddhi Sagar Lamichhane (MoCTCA)-- Member Secretary Experts to the Commission: 1. Dr. Rajeev Deo (Aero Medical Expert) 2. Er. Yogesh Aryal. (MoCTCA) Note: The extracts may be published without specific permission provided that the source is duly acknowledged, the material is reproduced accurately and it is not used in a derogatory manner or in a misleading context. i Accident Investigation Final Report of 9N-AJU ACKNOWLEDGEMENTS The Commission would like to thank to the Government of Nepal, Prat & Whitney, TSB Canada and all those who spared out their valuable time and suggestions in course of investigation to prepare this report. ii Accident Investigation Final Report of 9N-AJU Abbreviations and Definitions AD Airworthiness Directives AGL Above Ground Level AIG Aircraft Accident and Incident Investigation AMSL Above Mean Sea Level AMT Aircraft Maintenance Technician ARP Aerodrome Reference Point ATF Aviation Turbine Fuel ATC Air Traffic Controller ATPL Airline Transport Pilot License ATZ Aerodrome Traffic Zone AUW All up weight B. S. Bikram Sambat C of A Certificate of Airworthiness CAAN Civil Aviation Authority of Nepal CFIT Controlled Flight Into Terrain CG Center of Gravity CPL Commercial Pilot License CTR Control Zone CVR Cockpit Voice Recorder DCP Designated Check Pilot DI Daily Inspection ELT Emergency Locator Transmitter ECTM Engine Condition Trend Monitoring F/O First Officer FAA Federal Aviation Administration FDR Flight Data Recorder FG Fog FOM Flight Operation Manual FOR Flight Operation Requirements GPWS Ground Proximity Warning System HF High Frequency HSI Horizontal Situation Indicator IFR Instrument Flight Rules IP Instructor Pilot ITT Inter Turbine Temperature Kg Kilogram KHz Kilo Hertz Kts Knots Lbs Pounds LCD Liquid Crystal Display LH Left Hand LST Local Standard Time iii Accident Investigation Final Report of 9N-AJU MEL Minimum Equipment List METAR Meteorological Report MHz Mega Hertz MoCTCA Ministry of Culture, Tourism and Civil Aviation MSA Minimum Safe Altitude Mtr Meter N/A Not Applicable NAC Nepal Airlines Corporation NM Nautical Mile NTSB National Transportation Safety Board OAT Outside Air Temperature OM Operations Manual PI Preflight Inspection PIC Pilot in Command POH Pilot„s Operating Handbook PPC Pilot Proficiency Check QNH Pressure Setting to Indicate Elevation RH Right Hand RTOW Regulated Take-Off Weight SB Service Bulletin SOP Standard Operating Procedure TAWS Terrain Awareness and Warning Systems TLP Technical Log Page TSB Transportation Safety Board of Canada UTC Universal Coordinated Time VFR Visual Flight Rules VHF Very High Frequency WX Weather iv Accident Investigation Final Report of 9N-AJU Definitions Aircraft Engine: An engine that is used or intended to be used for propelling aircraft. It includes turbo superchargers, appurtenances, and accessories necessary for its functioning, but does not include propellers. Airframe: The fuselage, booms, nacelles, cowlings, fairings, airfoil surfaces (including rotors but excluding propellers and rotating airfoils of engines), and landing gear of an aircraft and their accessories and controls. Airplane: An engine-driven fixed-wing aircraft heavier than air, that is supported in flight by the dynamic reaction of the air against its wings. Approved: Unless used with reference to another person, means approved by the Administrator. Approved Design Data: Applicable design data that has been granted an approval (for example: type certificate, supplemental type certificate, technical standard order authorization, parts manufacturer approval, or equivalent) by the relevant civil aviation authority. Authorized Instructor: A person who holds a valid ground instructor certificate or a person who holds a current flight instructor certificate issued by CAAN. Authorized Representative: Any individual within an organizational delegation that is authorized in the procedure manual to make findings of compliance, and determinations of conformity and/or airworthiness on behalf of the CAAN. Airworthy: An aircraft that meets its type design and is in a condition for safe operation. Crew Decision Making: Decision making is the cognitive process of selecting a course of action from among multiple alternatives. The decision-making process produces a choice of action or an opinion that determines the decision maker's behavior and therefore has a profound influence on task performance. Crew Member: A person assigned to perform duty in an aircraft during flight time. Crew Resource Management: Crew resource management or Cockpit Resource Management (CRM) is a set of training procedures for use in environments where human error can have devastating effects. Used primarily for improving air safety, CRM focuses on interpersonal communication, leadership, and decision making in the cockpit. Delegated Function: For DERs, a delegated function applies to the technical areas involved in determining compliance with applicable airworthiness regulations. v Accident Investigation Final Report of 9N-AJU Exception: A case in which a rule, general principle, etc., does not apply. Exemption: Approval to be freed from current regulations in NCAR. Export: When a product or article is found to be airworthy, meets the special conditions of the importing country/jurisdiction, and is transferred from one civil aviation authority (CAA) regulatory authority to another CAA‟s regulatory authority. Flight crew Member: A pilot, flight engineer, or flight navigator assigned to duty in an aircraft during flight time. Human Factors: Human factors is the discipline concerned with optimizing the relationships between people and their activities through the systematic application of the human sciences, integrated within the framework of system engineering. Load factor: The ratio of a specified load to the total weight of the aircraft. The specified load is expressed in terms of any of the following: aerodynamic forces, inertia forces, or ground or water reactions. Maintenance: Inspection, overhaul, repair, preservation, and the replacement of parts, but excludes preventive maintenance. Operate: With respect to aircraft, means use, cause to use or authorize to use aircraft, for air navigation including the piloting of aircraft, with or without the right of legal control (as owner, lessee, or otherwise). Over Confidence: The overconfidence effect is a well-established bias in which a person's subjective confidence in his or her judgments is reliably greater than the objective accuracy of those judgments, especially when confidence is relatively high. Preventive Maintenance: Simple or minor preservation operations and the replacement of small standard parts not involving complex assembly operations. Propeller: A device for propelling an aircraft that has blades on an engine-driven shaft and that, when rotated, produces by its action on the air, a thrust approximately perpendicular to its plane of rotation. It includes control components normally supplied by its manufacturer, but does not include main and auxiliary rotors or rotating airfoils of engines. Statement of Compliance: A statement of compliance (SOC) is a signed statement made by the aircraft manufacturer stating that the aircraft (specific by serial number) was designed, manufactured, and is supported with a monitoring and correction of safety-of-flight within a continued airworthiness system, in accordance with the appropriate consensus standards. vi Accident Investigation Final Report of 9N-AJU Situational Awareness: Situational Awareness (S.A.) means having a mental picture of the existing inter-relationship of location,