Douglas C 118A N351CE

Summary

On 25 February 2014 at about 01:42 local time, a Douglas C 118A registered N351CE, operated by Tatonduk Outfitters Limited DBA, was involved in an incident near Emmonak, Alaska, United States. 3 people were on board and nobody was injured. The aircraft was slightly damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

25 February 2014 at 01:42

Classification

Incident

Location

Emmonak, Alaska, United States

Nearest airport

Emmonak (ENM)

Coordinates

62.7914, -164.5042

Aircraft

Douglas C 118A

Registration

N351CE

Category

Airplane

Year built

1954

Engines

4

Operator

Tatonduk Outfitters Limited DBA

Operating rule

Part 121: Air Carrier

Phase of flight

Not recorded

Route

Anchorage → Emmonak

Aircraft damage

Minor

Weather

VMC

Light

Day

NTSB number

ENG14IA016

Nobody was injured.

The fatigue failure of the lower wing skin due to aging mechanisms. Contributing to the failure were lower wing skin inspection procedures insufficient to identify the crack.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The airplane suffered a crack in the left wing lower skin just inside the left inboard engine nacelle. The crack was discovered by the flight crew during a post flight inspection when they saw fuel streaming from the nacelle area. The incident airplane was manufactured in 1954 and had accrued almost 36,900 flight hours. Examination of the lower wing skin revealed a crack with a total length about 15.5 inches. Two separate regions of pre-exiting progressive fracture were found that totaled about 4.12 inches in length. Fatigue cracking initiated and progressed from two separate rivet holes where a stringer was attached to the wing skin. There were no material discrepancies or other anomalies noted at the fatigue initiation sites. The remainder of the fracture was due to overstress separation. The fractured area of lower wing skin was inspected by x-ray in accordance with an existing Airworthiness Directive 611.7 hours prior to the discovery of the crack. No discrepancies were reported from this inspection. Post incident examination of the x-ray films showed the crack was present but very difficult to detect without close scrutiny, optimal lighting and a known crack location. The manufacturer released a Service Bulletin based on the findings of the investigation to provide more detailed instructions and additional methods to detect cracking of the lower wing skin at the inboard nacelle area.

Quoted verbatim from the NTSB record.