Crash of an IAI 1124A Westwind in Redwater: 7 killed
Date & Time:
Apr 4, 1986 at 1922 LT
Registration:
N50SK
Survivors:
No
Schedule:
Dallas - Teterboro
MSN:
309
YOM:
1980
Crew on board:
2
Crew fatalities:
Pax on board:
5
Pax fatalities:
Other fatalities:
Total fatalities:
7
Captain / Total hours on type:
657.00
Aircraft flight hours:
2745
Circumstances:
Airplane crashed during a uncontrolled descent, following a turbulence upset at FL370. The upset occurred as a result of clear air turbulences associated with a vip level 6 thunderstorm located within 7 miles of the last position of the airplane. After the upset, the airplane penetrated and descended thru the cell which contained lightning, extreme turbulences and severe icing. During the upset/descent both engines flamed out and the crew's attempts to recover the airplane were unsuccessful due to conditions in the cell. Crew received an improper briefing from FSS and reported their radar was malfunctioning to the deputy controller. Sigmet and AWW info was not given during the briefing. As the airplane came out of the bottom of the cell at 4,000 feet, the crew overstressed the airplane causing the left main landing door to separate and hit the left horizontal stab which subsequently separated in overload. Impact was 82° nose down. Nature of the airplane radar malfunction could not be determined. All seven occupants were killed.
Probable cause:
Occurrence #1: airframe/component/system failure/malfunction
Phase of operation: climb - to cruise
Findings
1. (c) flight/nav instruments, weather radar system - failure, partial
2. (f) operation with known deficiencies in equipment - continued - pilot in command
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Occurrence #2: in flight encounter with weather
Phase of operation: cruise - normal
Findings
3. (c) weather condition - thunderstorm
4. (c) weather condition - turbulence, clear air
5. (c) weather condition - gusts
6. (c) weather condition - downdraft
7. (f) light condition - dark night
8. (c) preflight briefing service - improper - atc personnel (fss)
9. (c) hazardous weather advisory - not issued - atc personnel (fss)
----------
Occurrence #3: in flight encounter with weather
Phase of operation: cruise - normal
Findings
10. (c) in-flight weather advisories - not issued - atc personnel (fss)
11. (c) information unclear - atc personnel (fss)
----------
Occurrence #4: loss of control - in flight
Phase of operation: cruise - normal
Findings
12. Remedial action - attempted - pilot in command
13. (f) excessive workload (task overload) - pilot in command
14. (f) excessive workload (task overload) - copilot/second pilot
----------
Occurrence #5: loss of engine power (total) - nonmechanical
Phase of operation: descent - uncontrolled
----------
Occurrence #6: in flight collision with terrain/water
Phase of operation: descent - uncontrolled
Phase of operation: climb - to cruise
Findings
1. (c) flight/nav instruments, weather radar system - failure, partial
2. (f) operation with known deficiencies in equipment - continued - pilot in command
----------
Occurrence #2: in flight encounter with weather
Phase of operation: cruise - normal
Findings
3. (c) weather condition - thunderstorm
4. (c) weather condition - turbulence, clear air
5. (c) weather condition - gusts
6. (c) weather condition - downdraft
7. (f) light condition - dark night
8. (c) preflight briefing service - improper - atc personnel (fss)
9. (c) hazardous weather advisory - not issued - atc personnel (fss)
----------
Occurrence #3: in flight encounter with weather
Phase of operation: cruise - normal
Findings
10. (c) in-flight weather advisories - not issued - atc personnel (fss)
11. (c) information unclear - atc personnel (fss)
----------
Occurrence #4: loss of control - in flight
Phase of operation: cruise - normal
Findings
12. Remedial action - attempted - pilot in command
13. (f) excessive workload (task overload) - pilot in command
14. (f) excessive workload (task overload) - copilot/second pilot
----------
Occurrence #5: loss of engine power (total) - nonmechanical
Phase of operation: descent - uncontrolled
----------
Occurrence #6: in flight collision with terrain/water
Phase of operation: descent - uncontrolled
Final Report:
