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ASN Wikibase Occurrence # 38425
Last updated: 9 August 2019
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Date:05-JAN-1991
Time:20:43
Type:Silhouette image of generic C421 model; specific model in this crash may look slightly different
Cessna 421B
Owner/operator:Ronnie Ray Shanks
Registration: N421H
C/n / msn: 421B-0516
Fatalities:Fatalities: 6 / Occupants: 6
Other fatalities:0
Aircraft damage: Written off (damaged beyond repair)
Category:Accident
Location:1.5 nm from Muskagee Airport, Muskogee, Oklahoma -   United States of America
Phase: Take off
Nature:Private
Departure airport:Muskagee, Oklahoma (MKO/KMKO))
Destination airport:Albuquerque, New Mexico (ABQ/KABQ)
Investigating agency: NTSB
Narrative:
The aircraft took off at night in IMC. Shortly after takeoff, the aircraft crashed about 1.5 mi from the departure end of the runway. There was evidence that it impacted in an 85 deg right bank, nose down attitude at high speed. No pre impact failure was found during the investigation

However, during a pre-purchase inspection on 16/10/90, several discrepancies were noted. These included an inoperative flight director, an autopilot malfunction and a mis-rigged flight control system that allowed the control wheel to indicate a left turn when the aircraft was in level flight. There was no record of these being repaired.

Records showed the pitot-static system was last tested on 24/03/88. The pilot was taking Sine-Aid and Tylenol for a chronic sinus infection. Although tox checks indicated the presence of 50.7 ug/ml of Pseudoephedrine and 36.4
ug/ml of Acetaminophen in the pilot's urine, none was found in his blood. The sinus condition could have affected the pilot's balance and equilibrium.

The NTSB determined the cause to be: The pilot's failure to maintain control of the aircraft, due to spatial disorientation. Factors related to the accident were: darkness, adverse weather conditions, and the pilot's physical impairment from the chronic sinus infection.

Sources:

1. NTSB: https://www.ntsb.gov/ntsb/brief.asp?ev_id=20001212X16312
2. FAA: http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?omni=Home-N-Number&nNumberTxt=421H


Revision history:

Date/timeContributorUpdates
24-Oct-2008 10:30 ASN archive Added
18-Aug-2016 02:14 Dr.John Smith Updated [Time, Cn, Operator, Location, Departure airport, Destination airport, Source, Narrative]
21-Dec-2016 19:23 ASN Update Bot Updated [Time, Damage, Category, Investigating agency]

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