FTW93IA125

NTSB incident investigation · Boeing 747-269BC · Alexandria, LA · April 12, 1993

Incident · No injuriesIncident investigationFinal report
Date
April 12, 1993, 09:54 local (14:54 UTC)
Place
Alexandria, LA
Injuries
40 uninjured
Damage
Minor damage
Phase of flight
Enroute
Aircraft
9KADDBoeing 747-269BC
Weather
Visual (VMC) · Day
Status
Completed · report September 26, 1994
Report
Approved by Office Director
Case key
18847

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the incident.

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Probable cause

The inflight delamination of the wing panel skin. Factors were the water contamination of the honeycomb panel.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Airframe/component/system failure/malfunctionClimb - to cruise
Wing,skin - delaminationCause
Wing,skin - separation
Precautionary landing - performedPilot in command
Wing,skin - contaminationFactor

Analysis

A slight vibration was felt as the airplane was climbing through FL310 for an assigned altitude of FL390 during a domestic IFR cross country flight. A passenger seated on the left side of the airplane observed portions of the skin on a non-structural wing panel on the left wing peeling off and separating from the wing and informed a crewmenber of the condition. A precautinary landing was made without further incident. Examination of the airplane revealed that a section, 48 inches wide by 31 inches long, had separated from the trailing edge of the fixed trailing edge upper panel on the left wing. Additionally, a three inch portion of the trailing edge on the left fore flap panel was also damaged, and separated from the airplane. According to maintenance personnel contracted by the operator, the delamination of the honycomb panel was the result of water contamination.

Factual narrative

On April 12, 1993, at approximately 0954 central daylight time, a Boeing 747-269BC, Kuwait registration 9KADD, operating as Kuwait Airlines Flight 091, sustained minor damage when a non structural panel on the left wing became delaminated while the airplane was climbing through FL 310, approximately 25 miles south of Alexandria, Louisiana.

There were no injuries to the 24 passengers, 6 flight crewmenbers, and 10 flight attendants aboard. The airplane departed Ellington Field (EFD) near Houston, Texas, at approximately 0921, enroute to Andrews Air Force Base, Maryland. A passenger seated on the left side of the airplane observed portions of the skin on a wing panel on the left wing peeling off and informed a crewmember of the condition.

The airplane was diverted to the Houston Intercontinental Airport (IAH), in Houston, Texas, where a uneventful landing was made at 1028, with airport emergency equipment standing by.

According to the operator, a slight vibration was felt on the left side of the airplane after part of the skin departed the airplane. Physical examination of the airplane revealed that a section (48 inches wide by 31 inches long), separated from the trailing edge of the fixed trailing edge upper panel (part number 65B22845 33) on the left wing. There was evidence of delamination, working rivets, and rows of rivets pulled through the skin on the remaining fiberglass laminated honeycomb panel. Additionally, a 3 inch portion of the trailing edge on the left wing fore flap panel, was also damaged and separated from the aircraft. There was no other damage to the airplane.

According to maintenance personnel returning the airplane to service, the delamination of the honeycomb panel was the result of water contamination.

Aircraft

Registration
9KADD
Reported as
Boeing 747-269BC
Category
Airplane
Engine
P&W JT9D-7A, turbo jet
Damage
Minor damage
Flight
Part 129
Registered owner
Kuwait Airways Corp.
Airworthiness certificate
Standard, Transport
Departed
EFD · Houston, TX
Destination
ADW · Camp Springs, MD
Flight plan
IFR

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Certificate
Airline transport
Airplane ratings
Multi-engine land
Instrument ratings
Airplane
Medical
Expired
Seat
Left
Flight hours
10,000 total · 9,000 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
190° at 5 knots
Visibility
20 statute miles
Lowest ceiling
None
Temperature
70 °F, dew point 54 °F
Altimeter
29.00 inHg