DCA10CA061

NTSB accident investigation · Boeing 747 · Miami, FL · May 17, 2010

Accident · No injuriesData collectionFinal report
Date
May 17, 2010, 22:33 UTC
Place
Miami, FL
Injuries
3 uninjured
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N498MCBoeing 747
Defining event
Approach: Flight control sys malf/fail
Weather
Visual (VMC) · Day
Status
Completed · report January 23, 2017
Report
Approved by Office Director
NTSB office
Major Investigations Division
Parties
FAA, Atlas Air/Polar Air Cargo, Boeing
FAA report
20100517035569A
Case key
76055

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

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Probable cause

impact of the fore flap with the aft fuselage after fatigue failure of the right wing fore flap carriage assembly attachment fitting at position 6.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Wing structure: trailing edge flapsAircraft › Aircraft structures · Fatigue/wear/corrosionBoeing 747-47UF: 1 caseAll aircraft: 33 casesProbable cause
Wing structure: trailing edge flapsAircraft › Aircraft structures · FailureBoeing 747-47UF: 1 caseAll aircraft: 33 casesProbable cause
Fuselage: fuselage main structureAircraft › Aircraft structures · Damaged/degradedBoeing 747-47UF: 1 caseAll aircraft: 24 cases

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

On May 17, 2010, an Atlas Air Cargo Boeing 747-400F, N498MC, lost a section of the left fore-flap while on approach to Miami International Airport (KMIA), Miami, Florida. The airplane was substantially damaged when the flap portion impacted the fuselage. There were no injuries to the flight crew and the airplane landed without further incident. The cargo flight originated from Rio de Janeiro-Galeão-Antonio Carlos Jobim International Airport (BGL), Rio de Janeiro, Brazil. According to the operator, the flight crew heard and felt a large impact after 30 degree flaps was selected during the approach. Postflight inspection revealed that approximately twelve feet of the right wing inboard fore flap was missing and had caused substantial damage to the aft fuselage. The separated section of the fore flap was recovered and examined. The examination revealed that a large portion of the enamel was missing from the fore flap attachment fitting of the carriage assembly and that there was a large amount of contamination and grease buildup around the lubrication fitting. Extensive corrosion byproducts covered up the lubrication passage in the attachment, which prevented passage of grease to the bearing, causing extensive corrosion in the bore and propagated by fatigue before final ductile separation.

Factual narrative

On May 17, 2010, an Atlas Air Cargo Boeing 747-400F, N498MC, lost a section of the left fore-flap while on approach to Miami International Airport (KMIA), Miami, Florida. The airplane was substantially damaged when the flap portion impacted the fuselage. There were no injuries to the flight crew and the airplane landed without further incident. The cargo flight originated from Rio de Janeiro-Galeão-Antonio Carlos Jobim International Airport (BGL), Rio de Janeiro, Brazil. According to the operator, the flight crew heard and felt a large impact after 30 degree flaps was selected during the approach. Postflight inspection revealed that approximately twelve feet of the right wing inboard fore flap was missing and had caused substantial damage to the aft fuselage. The separated section of the fore flap was recovered and examined. The examination revealed that a large portion of the enamel was missing from the fore flap attachment fitting of the carriage assembly and that there was a large amount of contamination and grease buildup around the lubrication fitting. Extensive corrosion byproducts covered up the lubrication passage in the attachment, which prevented passage of grease to the bearing, causing extensive corrosion in the bore and propagated by fatigue before final ductile separation.

Aircraft

Registration
N498MC
Reported as
Boeing 747 (400F)
Category
Airplane
Serial number
29259
Airframe hours
47,281
Engines
CF6 80C2BF5, turbo fanCF6 80C2BF5, turbo fanCF6 80C2BF5, turbo fanCF6 80C2BF5, turbo fan
Damage
Substantial damage
Flight
Part 121
Operator
Atlas Air Inc
Registered owner
NCC Kay Co
Airworthiness certificate
Standard, Transport
Last inspection
Continuous airworthiness · March 31, 2010
Departed
SBGL · Rio de Janeiro
Destination
MIA · Miami, FL
Flight plan
IFR
Airport
MIA · Miami International Airport

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
50
Injuries
None
Certificate
Airline transport
Airplane ratings
Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, With waivers/limitations
Seat
Left
Restraint
5-point
Flight hours
23,000 total · 944 in this make and model
Role
Co-pilot
Age
54
Injuries
None
Certificates
Commercial, Airline transport
Airplane ratings
Single-engine land, Multi-engine sea, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, Without waivers/limitations
Seat
Right
Restraint
5-point
Flight hours
19,300 total · 249 in this make and model

Weather

Conditions
Visual (VMC) · Day

Docket · 4

The files NTSB released with the investigation on January 26, 2017, on NTSB’s docket system: statements, records, photos and specialists’ reports. 5.4 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.