ASN Aircraft accident Learjet 35A N47BA Aberdeen, SD

Home » Database » 1999

Status:	Accident investigation report completed and information captured
Date:	Monday 25 October 1999
Time:	12:13
Type:	Learjet 35A
Operator:	Sunjet Aviation
Registration:	N47BA
MSN:	35-060
First flight:	1976
Total airframe hrs:	10506
Engines:	2 Garrett TFE731-2-2B
Crew:	Fatalities: 2 / Occupants: 2
Passengers:	Fatalities: 4 / Occupants: 4
Total:	Fatalities: 6 / Occupants: 6
Aircraft damage:	Destroyed
Aircraft fate:	Written off (damaged beyond repair)
Location:	20 km (12.5 mls) W of Aberdeen, SD ( United States of America)
Phase:	En route (ENR)
Nature:	Executive
Departure airport:	Orlando International Airport, FL (MCO/KMCO), United States of America
Destination airport:	Dallas-Love Field, TX (DAL/KDAL), United States of America

Narrative:
A Learjet 35, N47BA, operated by Sunjet Aviation, crashed near Aberdeen, SD. The airplane departed Orlando, FL (MCO) for Dallas, TX (DAL) about 09:20 EDT. Radio contact with the flight was lost north of Gainesville, FL, after air traffic control (ATC) cleared the airplane to FL390. The airplane was intercepted by several U.S. Air Force (USAF) and Air National Guard (ANG) aircraft as it proceeded northwestbound. The military pilots in a position to observe the accident airplane at close range stated (in interviews or via radio transmissions) that the forward windshields of the Learjet seemed to be frosted or covered with condensation. The military pilots could not see into the cabin. They did not observe any structural anomaly or other unusual condition. The military pilots observed the airplane depart controlled flight and spiral to the ground, impacting an open field. All occupants on board the airplane (the captain, first officer, and four passengers) were killed, and the airplane was destroyed. Among the passengers was professional golfer Payne Stewart.

Probable Cause:

PROBABLE CAUSE: "Incapacitation of the flight crewmembers as a result of their failure to receive supplemental oxygen following a loss of cabin pressurization, for undetermined reasons. "

Accident investigation:

Investigating agency:	NTSB
Status:	Investigation completed
Duration:	1 year and 1 months
Accident number:	DCA00MA005
Download report:	Summary report

Classification:

Flightcrew incapacitation

Loss of control

Sources:

» NTSB-AAB-00-01

Follow-up / safety actions

NTSB issued 11 Safety Recommendations

Issued: 20-DEC-2000	To: FAA	A-00-109
(1) Revise existing guidance and information about high-altitude operations to accurately reflect the time of useful consciousness and rate of performance degradation following decompression and to highlight the effect of hypoxia on an individual\'s ability to perform complex tasks in a changing environment and (2) Incorporate this revised information into both the required general emergency training conducted under 14 CFR Parts 121 and 135 and training and flight manuals provided to all pilots operating pressurized aircraft. (Open - Unacceptable Response)
Issued: 20-DEC-2000	To: FAA	A-00-110
Convene a multidisciplinary panel of aeromedical and operational specialists to study and submit a report on whether mandatory hypoxia awareness training, such as altitude chamber training, for civilian pilots would benefit safety. The report should consider alternatives to altitude chamber training, clearly identify which pilots and/or flight operations would benefit most from such training, and determine the scope and periodicity of this training. If warranted, establish training requirements based on the findings of this panel. (Open - Acceptable Response)
Issued: 20-DEC-2000	To: FAA	A-00-111
Require that operators of all pressurized cabin aircraft provide guidance to pilots on the importance of a thorough functional preflight of the oxygen system, including, but not limited to, verification of supply pressure, regulator operation, oxygen flow, mask fit, and communications using mask microphones. (Closed - Acceptable Action)
Issued: 20-DEC-2000	To: FAA	A-00-112
Remove the reference to the donning of oxygen masks in the event of loss of pressurization as an example of an immediate action item that may be stated as a policy rather than as a checklist item as an acceptable use in FAA Order 8400.10, "Air Transportation Operations Inspectors Handbook," paragraph 2207c, and review the appropriateness of its position that immediate action items may be stated as policies rather than checklist items. (Closed - Acceptable Action)
Issued: 20-DEC-2000	To: FAA	A-00-113
Require that all pressurized aircraft certificated to operate above 25,000 feet have a clear and explicit emergency procedure associated with the onset of the cabin altitude warning that contains instructions for flight crews to don oxygen masks as a first and immediate action item, followed by instructions appropriate to diagnose, manage, and resolve the condition indicated by the warning. (Closed - Acceptable Action)
Issued: 20-DEC-2000	To: FAA	A-00-114
Issue guidance within 6 months directly to pilots operating pressurized aircraft regarding the need to don oxygen masks immediately following activation of the cabin altitude warning. (Closed - Acceptable Action)
Issued: 20-DEC-2000	To: FAA	A-00-115
Issue an airworthiness directive requiring Learjet, inc., to instruct operators of the Learjet model 35/36 (and other affected models) to modify the oxygen bottle regulator/shutoff valve assembly so that flight crews can clearly and accurately verify the position of the valve during preflight visual inspections. (Closed - Acceptable Alternate Action)
Issued: 20-DEC-2000	To: FAA	A-00-116
Evaluate the feasibility of requiring design changes to automate the existing emergency pressurization systems on Learjet model 35/36 airplanes (and other affected models) that do not have an automatic emergency pressurization system. If the automation of their existing systems is determined to be feasible, require such design changes. (Closed - Acceptable Action)
Issued: 20-DEC-2000	To: FAA	A-00-117
Evaluate all Part 25 aircraft that do not have automatic emergency pressurization systems to determine if automation of their existing systems is feasible and, if warranted, require changes to affected models as soon as possible. (Closed - Acceptable Action)
Issued: 20-DEC-2000	To: FAA	A-00-118
Increase the frequency of unannounced inspections of Part 135 operators to verify the accuracy and adequacy of pilot discrepancy and maintenance logbook record-keeping procedures and entries. (Closed - Acceptable Action)
Issued: 20-DEC-2000	To: FAA	A-00-119
Ensure that all transport-category airplanes, regardless of whether they are operated under 14 CFR Parts 91, 121, 125, or 135, are included in its review of aging transport aircraft systems and structures. (Closed - Acceptable Action)

Show all...

Photos

accident date: 25-10-1999
type: Learjet 35A
registration: N47BA

Map

This map shows the airport of departure and the intended destination of the flight. The line between the airports does not display the exact flight path.
Distance from Orlando International Airport, FL to Dallas-Love Field, TX as the crow flies is 1554 km (971 miles).
Accident location: Approximate; accuracy within a few kilometers.

This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.

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Learjet 35

738 built
45^th loss
35^th fatal accident
4^th worst accident (at the time)
7^th worst accident (currently)

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