Boeing 747-273C N470EV

Summary

On 19 May 1996 at about 11:40 local time, a Boeing 747-273C registered N470EV was involved in an incident near Los Angeles, California, 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

19 May 1996 at 11:40

Classification

Incident

Location

Los Angeles, California, United States

Coordinates

Not recorded

Aircraft

Boeing 747-273C

Registration

N470EV

Category

Airplane

Engines

4

Operator

Not recorded

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Unknown → Honolulu

Aircraft damage

Minor

Weather

VMC

Light

Night/Dark

NTSB number

LAX96IA199

Nobody was injured.

the operator's failure to adopt a manufacturer's stipulated ultrasonic inspection procedure, which led to the in-flight separation of the wing panel.

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

Read the full NTSB narrative

The crew felt a rumble as the aircraft was accelerating in the climb-to-cruise segment, and subsequently found that the right wing inboard wing panel had been partially torn away. The captain elected to return to the airport where a landing was made with the inboard flaps, which showed secondary damage, retracted. An inspection showed trailing edge portions of the composite right inboard wing panel had separated and damaged the fore and mid right inboard flaps. Maintenance records revealed that cracking was detected in the forward outboard corner during the last C check. The crack was repaired, inspected, and repainted. The previous C check also found disbonding and delamination in the right wing panel. Boeing has received a total of 245 operator reports involving disbonding of this panel, which has separated from the aircraft in flight in 95 instances. The wing flaps are susceptible to secondary damage as a result of the panel separations. A service bulletin with five revisions has been issued. Operators have been directed to replace the coin tap sound inspection with an ultrasound inspection of the panels to improve the detection likelihood of a disbonding that has occurred below the panel surface. Prior to this incident, the operator chose to retain the coin tap sound inspection method rather than adopt the ultrasonic inspection.

Quoted verbatim from the NTSB record.