A B747-400's number one engine spinner damaged the engine during climb. Because the only abnormal in...

Attributes
ACN	884008
Time
Date	201004
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZZ.Airport
State Reference	FO
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	B747-400
Operating Under FAR Part	Part 121
Flight Phase	Initial Climb
Flight Plan	IFR
Component
Aircraft Component	Fan
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 50 Flight Crew Total 12000 Flight Crew Type 2100
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

Climbing out passing about fl 150 heard bang and the aircraft shuttered a little. There were no engine indications; warnings; cautions; EICAS messages. Only had the vvvvv showing secondary engine exceedance. All engine readings were normal; only difference was engine one had 5.0 on N1 vib monitor. We pulled number one engine to idle and it went down to at 4.2 N1. Pushed it back up for the rest of the flight and it worked normally. Contacted dispatch and maintenance and discussed the problem. Since everything was reading normal and by this time we were at equal distance to our destination we continued to normal landing. Maintenance called me and said number one engine spinner had caused the problem.

Original NASA ASRS Text

Title: A B747-400's number one engine spinner damaged the engine during climb. Because the only abnormal indication was a slightly high N1 VIB meter; the flight continued to its destination normally.

Narrative: Climbing out passing about FL 150 heard bang and the aircraft shuttered a little. There were no engine indications; warnings; cautions; EICAS messages. Only had the vvvvv showing secondary engine exceedance. All engine readings were normal; only difference was engine one had 5.0 on N1 VIB monitor. We pulled number one engine to idle and it went down to at 4.2 N1. Pushed it back up for the rest of the flight and it worked normally. Contacted Dispatch and Maintenance and discussed the problem. Since everything was reading normal and by this time we were at equal distance to our destination we continued to normal landing. Maintenance called me and said number one engine spinner had caused the problem.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

A B747-400's number one engine spinner damaged the engine during climb. Because the only abnormal indication was a slightly high N1 vib meter; the flight continued to its destination normally.