# NTSB CHI94LA026: Beech F33A, N6333Y, Saint Paul, MN, October 27, 1993 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: October 27, 1993, 18:45 local (23:45 UTC) - Place: Saint Paul, MN - Coordinates: 44.950527, -93.089439 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.9505&lon=-93.0894&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor, 2 uninjured - Status: Completed, report October 20, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 9422 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI94LA026 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9422/pdf - Page: https://openairdocs.org/ntsb/CHI94LA026 ## Probable cause other maintenance personnel's improper maintenance installation and fuel system line fitting undertorqued. Factors related to the accident were the dark night, along with the fence and posts which were contacted. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, cruise - fuel system,line fitting - undertorqued (cause) - maintenance,installation - improper, other maintenance personnel (cause) - Forced landing, descent - emergency - In flight collision with object, descent - emergency - light condition - dark night (contributing factor) - unsuitable terrain or takeoff/landing/taxi area - encountered, pilot in command - object - fence (contributing factor) - object - pole (contributing factor) ## Analysis PRIOR TO THE ACCIDENT FLIGHT THE MECHANICAL FUEL PUMP WAS REMOVED AND REPLACED TO COMPLY WITH AN AIRWORTHINESS DIRECTIVE. THE ACCIDENT FLIGHT WAS THE FIRST FLIGHT AFTER THE MAINTENANCE. WHILE IN CRUISE FLIGHT THE PILOT NOTICED A LOSS IN FUEL PRESSURE. THE PRESSURE LOSS CONTINUED UNTIL THE PILOT WAS REQUIRED TO MAKE A FORCED LANDING AT NIGHT. THE AIRPLANE CONTACTED A FENCE AND GUARD RAIL POSTS DURING THE LANDING. SUBSEQUENT EXAMINATION REVEALED THAT A 'B' NUT ATTACHING THE FUEL LINE TO THE MECHANICAL FUEL PUMP HAD BACKED OFF. NO OTHER DISCREPANCIES WERE NOTED. ## Factual narrative On October 27, 1993, at 1845 central daylight time, a Beech F33A, N6333Y, registered to James B. Griebel Farms of Fridley, Minnesota, and operated by an instrument rated private pilot, experienced a loss of engine power. A night forced landing was initiated and on landing the airplane impacted a fence and guard rail posts alongside a highway. The airplane sustained substantial damage. The pilot and one passenger reported no injuries. A second passenger reported minor injuries. The business 14 CFR Part 91 flight was operating in visual meteorological conditions. An IFR flight plan was on file with the intended destination of Saint Louis, Missouri. The flight departed Anoka, Minnesota, at 1820. Prior to departure the mechanical fuel pump had been removed and replaced to comply with an Airworthiness Directive. The accident flight was the first flight after the maintenance. The pilot stated that while the airplane was in cruise flight he noticed a drop in fuel pressure. The pressure drop continued until power was lost and it became necessary for him to make a forced landing. On examination it was found that the fuel line "B" nut had backed all the way off the flare nut fitting at the mechanical fuel pump. During the examination the nut was hand threaded onto the fitting and no other discrepancies were noted. ## Aircraft - Registration: [N6333Y](https://openairdocs.org/deregistered/N6333Y-1995-04-07), registration cancelled 1995-04-07, S/N CE991 (OpenAirDocs) - Reported make and model: BEECH F33A - Registry model: [Beech F33A](https://openairdocs.org/model/beech-f33a) (registry code 1151425) (OpenAirDocs) - Category: Airplane - Serial number: CE991 - Engines: CONTINENTAL IO-520-BB 285 horsepower reciprocating - Damage: Substantial damage - Flight: Business, Part 91 - Registered owner: James B. Gribel Farms - Airworthiness certificate: Standard, Utility - Departed: ANE, ANOKA, MN - Destination: SUS, SAINT LOUIS, MO - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 1,725 total, 1,633 in this make and model, 1,622 as pilot in command, 69 in the last 90 days, 10 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night/dark - Wind: 190° at 6 knots - Visibility: 15 statute miles - Lowest ceiling: 11,000 ft broken - Temperature: 45 °F, dew point 25 °F - Altimeter: 29.00 inHg - Observed at: STP, 7 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 19931027040799A](https://openairdocs.org/incident/19931027040799A), Oct 27, 1993: Beech F33A, St Paul, MN, Substantial damage. Fuel pump replaced prior to this flight. Lost fuel pressure at cruise. Hit fence landing. Loose fuel line b nut. 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.