What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
After landing and runway turn off at nrt a loud pop and hissing sound was heard. The second officer observed fire under his table. He quickly extinguished the fire using a halon bottle. During flight the 32 generator field relay and generator breaker opened, pressurization system auto-fail light illuminated and the 32 engine N1 gauge failed. Disconnected 32 csd, reset pressurization system and N1 indicator came back. Preliminary shop teardown revealed the #2 t/r burnt. The adjacent #3 t/r had an internal dust build-up of approx. 1/2". Preliminary engineering analysis suspects the voltage transient from the generator trip caused the filter capacitors to explode generating sufficient heat to ignite dust build-up.
As the FAA filed it
AFTER LANDING AND RUNWAY TURN OFF AT NRT A LOUD POP AND HISSING SOUND WAS HEARD. THE SECOND OFFICER OBSERVED FIRE UNDER HIS TABLE. HE QUICKLY EXTINGUISHED THE FIRE USING A HALON BOTTLE. DURING FLIGHT THE 32 GENERATOR FIELD RELAY AND GENERATOR BREAKER OPENED, PRESSURIZATION SYSTEM AUTO-FAIL LIGHT ILLUMINATED AND THE 32 ENGINE N1 GAUGE FAILED. DISCONNECTED 32 CSD, RESET PRESSURIZATION SYSTEM AND N1 INDICATOR CAME BACK. PRELIMINARY SHOP TEARDOWN REVEALED THE #2 T/R BURNT. THE ADJACENT #3 T/R HAD AN INTERNAL DUST BUILD-UP OF APPROX. 1/2". PRELIMINARY ENGINEERING ANALYSIS SUSPECTS THE VOLTAGE TRANSIENT FROM THE GENERATOR TRIP CAUSED THE FILTER CAPACITORS TO EXPLODE GENERATING SUFFICIENT HEAT TO IGNITE DUST BUILD-UP.
Other reports on N622US · 1
Matched to the same aircraft by N-number and date.