B747 flight crew reported diverting due to a fire main deck message during cruise. No evidence of fi...

Narrative:

While at cruise on a maintenance ferry flight; (4 pilots; no fas or passengers) FL390; 350 NM east of ZZZZ; we received 'fire main deck' message on primary EICAS; coupled with two caution messages; and five status messages. Captain immediately reviewed QRH for relevant checklist; discovering there was none for fire main deck. Captain [advised ATC] as well as sent a report via cpdlc. Due to delay receiving clearance to divert to ZZZZ (nearest suitable airport) we began a 180 degree turn off track to the left; descending. 500 feet after cleared track 10 NM. I began broadcasting in the blind on 121.5; our call sign; position; our 180 degree turn north off track; nature of our problem; all whilst turning on all external lighting. A flight came on frequency and offered assistance; I asked he relay to ATC we needed an immediate clearance to ZZZZ as we were a aircraft in distress due to cabin fire warnings. We awoke relief pilots (who were on break) and informed of situation. They immediately proceeded to the cabin armed with pbe (personal breathing equipment) and flashlights to investigate. They thoroughly searched entire cabin; felt for heat on floors; walls; looking for smoke and searched the east&east compartment; finding no evidence of fire. Shortly thereafter; we received clearance from ATC for direct zzzzz intersection; FL390. Captain contacted dispatch and maintenance control to inform and obtain assistance on our warnings; cautions and messages. I handled ATC comms and flew max speed to ZZZZ. Relief pilots took turns in each individually searching cabin for evidence of fire; smoke or heat; until we began descent for landing. Enroute to ZZZZ we reviewed ditching checklist and discussed fire/smoke removal checklists should we discover a fire onboard. Upon beginning our descent for landing; we flew max speed for the arrival and ILS to runway xxr at ZZZZ. We landed without incident and were able to immediately clear runway whereupon ZZZZ fire department assessed our aircraft for evidence of fire. Finding none we were cleared to taxi to the gate.

Original NASA ASRS Text

Title: B747 flight crew reported diverting due to a FIRE MAIN DECK message during cruise. No evidence of fire was found from an inspection of the entire cabin and E&E compartment.

Narrative: While at cruise on a Maintenance Ferry Flight; (4 pilots; no FAs or passengers) FL390; 350 NM east of ZZZZ; we received 'FIRE MAIN DECK' message on primary EICAS; coupled with two CAUTION messages; and five STATUS messages. Captain immediately reviewed QRH for relevant checklist; discovering there was none for FIRE MAIN DECK. Captain [advised ATC] as well as sent a report via CPDLC. Due to delay receiving clearance to divert to ZZZZ (nearest suitable airport) we began a 180 degree turn off track to the left; descending. 500 feet after cleared track 10 NM. I began broadcasting in the blind on 121.5; our call sign; position; our 180 degree turn north off track; nature of our problem; all whilst turning on all external lighting. A flight came on frequency and offered assistance; I asked he relay to ATC we needed an immediate clearance to ZZZZ as we were a aircraft in distress due to cabin fire warnings. We awoke Relief Pilots (who were on break) and informed of situation. They immediately proceeded to the cabin armed with PBE (Personal Breathing Equipment) and flashlights to investigate. They thoroughly searched entire cabin; felt for heat on floors; walls; looking for smoke and searched the E&E compartment; finding no evidence of fire. Shortly thereafter; we received clearance from ATC for direct ZZZZZ intersection; FL390. Captain contacted Dispatch and Maintenance Control to inform and obtain assistance on our warnings; cautions and messages. I handled ATC comms and flew max speed to ZZZZ. Relief Pilots took turns in each individually searching cabin for evidence of fire; smoke or heat; until we began descent for landing. Enroute to ZZZZ we reviewed Ditching Checklist and discussed Fire/Smoke removal Checklists should we discover a fire onboard. Upon beginning our descent for landing; we flew max speed for the arrival and ILS to runway XXR at ZZZZ. We landed without incident and were able to immediately clear runway whereupon ZZZZ Fire Department assessed our aircraft for evidence of fire. Finding none we were cleared to taxi to the gate.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1457268
Time
Date	201706
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZZ.Airport
State Reference	FO
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	B747 Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Oceanic
Flight Plan	IFR
Component
Aircraft Component	Fire/Overheat Warning
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Total 6184 Flight Crew Type 4835
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Total 5224 Flight Crew Type 324
Events
Anomaly	Aircraft Equipment Problem Less Severe Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor

B747 flight crew reported diverting due to a fire main deck message during cruise. No evidence of fire was found from an inspection of the entire cabin and east&east compartment.