Accident Cessna 500 Citation I N113SH,

ASN Wikibase Occurrence # 321762

Date:	Tuesday 4 March 2008
Time:	15:15
Type:	Cessna 500 Citation I
Owner/operator:	Interstate Helicopters
Registration:	N113SH
MSN:	500-0285
Year of manufacture:	1975
Total airframe hrs:	6487 hours
Engine model:	Pratt & Whitney Canada JT15D-1A
Fatalities:	Fatalities: 5 / Occupants: 5
Aircraft damage:	Destroyed, written off
Category:	Accident
Location:	6,5 km SW of Oklahoma City-Wiley Post Airport, OK (PWA) - United States of America
Phase:	En route
Nature:	Executive
Departure airport:	Oklahoma City-Wiley Post Airport, OK (PWA/KPWA)
Destination airport:	Mankato Municipal Airport, MN (MKT/KMKT)
Investigating agency:	NTSB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
A twin-engine Cessna 500 airplane, N113SH, was destroyed upon impact with terrain following a loss of control shortly after takeoff from runway 17L at the Wiley Post Airport (PWA), in Oklahoma City, Oklahoma. The airplane was registered to the Southwest Orthopedic and Sports Medicine Clinic and operated by Interstate Helicopters.
At the time of the accident, Interstate Helicopters was operating the accident airplane in commercial service contrary to its Federal Aviation Administration-issued 14 Code of Federal Regulations Part 135 operating certificate, which, at the time, did not authorize operation of the accident airplane or any other fixed-wing aircraft.
The Cessna Citation took off from Wiley Post Airport, OK at 15:13 and climbed to an altitude of 3,100 feet while on a southwesterly heading. While in the
airspace near the Lake Overholser dam the airplane started a steep descent. The airplane impacted wooded terrain approximately one mile south of the dam. There were no reported radio calls of distress from the flight crew.
Investigation revealed that departure from controlled flight likely resulted from wing structure damage sustained during an in-flight collision with a flock of American white pelicans, which far exceeded the airframes design certification limit. Also, the right engine failed as a result of the collision with these birds.

PROBABLE CAUSE: "The National Transportation Safety Board determines that the probable cause of this accident was airplane wing-structure damage sustained during impact with one or more large birds (American white pelicans), which resulted in a loss of control of the airplane."

Accident investigation: