An md-11; being vectored around weather by approach control; encountered heavy rain and suffered a p...

Attributes
ACN	1138033
Time
Date	201312
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Route In Use	Vectors
Flight Plan	IFR
Component
Aircraft Component	FMS/FMC
Person 1
Function	First Officer Pilot Flying
Experience	Flight Crew Last 90 Days 75 Flight Crew Total 4000 Flight Crew Type 2200
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical Inflight Event / Encounter Weather / Turbulence

Narrative:

On arrival approach descended us from 11;000 ft to 3;000 ft on a vector to the ILS xxr. We were mostly IMC in the descent; with ground contact starting at approximately 10;000 MSL. The aircraft was in a clean configuration with all engine and wing anti-ice on. Our vector took us around a single cell that was to the northeast or our position [during which] we encountered heavy rain and a possible lightning strike at approximately 9;000 MSL. Numerous ead alerts including loss of all FMS data followed. We declared an emergency with ATC and after reporting souls on board and fuel remaining; requested extended vectors at 5;000 MSL to allow time to analyze all alerts/FMS issues. We asked a jumpseating pilot to come to the flight deck to assist as an extra observer and traffic monitor. Our weights were reinitialized; approach reloaded; and speeds cross checked with the QRH for last known landing weight. After running all applicable checklists; and checking the current ATIS; we requested vectors back to the ILS xxr where a normal; uneventful landing was made. Fire and rescue followed us to parking with no further action required.

Original NASA ASRS Text

Title: An MD-11; being vectored around weather by Approach Control; encountered heavy rain and suffered a possible lightning strike which caused the loss of FMS data. They declared an emergency; requested delay vectors while evaluating and re-establishing system functionality; and landed safely.

Narrative: On arrival Approach descended us from 11;000 FT to 3;000 FT on a vector to the ILS XXR. We were mostly IMC in the descent; with ground contact starting at approximately 10;000 MSL. The aircraft was in a clean configuration with all engine and wing anti-ice on. Our vector took us around a single cell that was to the northeast or our position [during which] we encountered heavy rain and a possible lightning strike at approximately 9;000 MSL. Numerous EAD alerts including loss of all FMS data followed. We declared an emergency with ATC and after reporting souls on board and fuel remaining; requested extended vectors at 5;000 MSL to allow time to analyze all alerts/FMS issues. We asked a jumpseating pilot to come to the flight deck to assist as an extra observer and traffic monitor. Our weights were reinitialized; approach reloaded; and speeds cross checked with the QRH for last known landing weight. After running all applicable checklists; and checking the current ATIS; we requested vectors back to the ILS XXR where a normal; uneventful landing was made. Fire and rescue followed us to parking with no further action required.

Data retrieved from NASA's ASRS site as of July 2013 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.

An md-11; being vectored around weather by approach control; encountered heavy rain and suffered a possible lightning strike which caused the loss of FMS data. They declared an emergency; requested delay vectors while evaluating and re-establishing system functionality; and landed safely.