Accident Beechcraft 56TC Baron N18LL,
ASN logo
ASN Wikibase Occurrence # 44179
 
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information. If you feel this information is incomplete or incorrect, you can submit corrected information.

Date:Friday 17 March 2006
Time:22:37
Type:Beechcraft 56TC Baron
Owner/operator:Private
Registration: N18LL
MSN: TG-65
Total airframe hrs:2766 hours
Engine model:Lycoming TIO-541-E1B4
Fatalities:Fatalities: 1 / Occupants: 1
Aircraft damage: Substantial
Category:Accident
Location:Winfield, WV -   United States of America
Phase: En route
Nature:Private
Departure airport:Glendive, MT (GDV)
Destination airport:St. Paul, MN (STP)
Investigating agency: NTSB
Confidence Rating: Accident investigation report completed and information captured
Narrative:
While on the last leg of a multiple day cross-country trip, all communications between the pilot of a non-pressurized, oxygen system equipped airplane, and air traffic control (ATC) were normal until the airplane was detected to have climbed 400 feet above its assigned altitude of FL240. After being notified of the deviation, the pilot responded that he was attempting to look at his contrails. Later in the flight, after leveling at FL270, the pilot queried ATC as to whether they had heard some of his previous calls. This was the last transmission received from the pilot, and attempts to reestablish contact were unsuccessful. After the pilot had not begun his descent for landing, nor joined the arrival course for his destination, ATC requested assistance from the North American Aerospace Defense Command (NORAD). After intercepting the airplane, the pilots of the fighter airplanes attempted to look into the cockpit, but were unable to see the pilot. Attempts to gain his attention were also unsuccessful. The airplane eventually descended and impacted terrain. A nasal cannula was connected to the airplane's installed oxygen system and was found near the pilot. An oxygen mask the pilot was wearing was connected to a portable oxygen bottle found on the floor next to him. Both systems were functional, their valves were open, and both were depleted of their contents. The portable bottle was manufactured for industrial use, and modified with an oxygen system fitting. The regulator was manufactured for the medical industry. A review of a journal kept by the pilot revealed that he flew at high altitudes for efficiency, and used an oximeter to monitor blood oxygen. He used a nasal cannula at altitudes exceeding 18,000 feet for comfort, and had used a "cannula and mask" up to 31,000 feet. Examination of his hangar revealed an aircraft oxygen tank and welding tank plumbed to an oxygen-service fitting. The airplane's oxygen system or portable bottle had not been serviced at the airports the airplane operated from during the trip. According to Advisory Circular (AC) 61-107A, "Operations of Aircraft At Altitudes Above 25,000 Feet MSL And/Or Mach Numbers (MMO) Greater Than .75", preflight inspections should include a thorough examination of aircraft oxygen equipment, "including available supply," and that "Oxygen systems should be checked periodically to ensure that there is an adequate supply of oxygen and that the system is functioning properly. This check should be performed frequently with increasing altitude. If supplemental oxygen is not available, an emergency descent to an altitude below 10,000 feet should be initiated." Additionally, it advised that when using continuous flow oxygen systems above 25,000 feet, "very careful attention to system capabilities is required."
Probable Cause: The pilot's inadequate preflight preparation to ensure an adequate supply of supplemental oxygen, and his inadequate in-flight planning and decision making, which resulted in exhaustion of his oxygen supply, and incapacitation from hypoxia during cruise flight.

Accident investigation:
cover
  
Investigating agency: NTSB
Report number: NYC06FA079
Status: Investigation completed
Duration:
Download report: Final report

Sources:

NTSB: https://www.ntsb.gov/_layouts/ntsb.aviation/brief.aspx?ev_id=20060331X00370&key=1

Location

Revision history:

Date/timeContributorUpdates
28-Oct-2008 00:45 ASN archive Added
21-Dec-2016 19:24 ASN Update Bot Updated [Time, Damage, Category, Investigating agency]
05-Dec-2017 09:03 ASN Update Bot Updated [Other fatalities, Source, Narrative]

Corrections or additions? ... Edit this accident description

The Aviation Safety Network is an exclusive service provided by:
Quick Links:

CONNECT WITH US: FSF on social media FSF Facebook FSF Twitter FSF Youtube FSF LinkedIn FSF Instagram

©2024 Flight Safety Foundation

1920 Ballenger Av, 4th Fl.
Alexandria, Virginia 22314
www.FlightSafety.org