An A300 master caution alerted aft cargo loop fault a; followed by a master warning cargo smoke. Bot...

Narrative:

Climbing through approximately FL200; I was pilot flying;we received a master caution ecas warning aft cargo loop fault a. Master caution (mc) went out by itself; and then reappeared seconds later. Captain as pilot not flying began to initiate the QRH procedures for the mc when a master warning (mw) cargo smoke illuminated. We agreed to immediately divert back to the departure airport. I began a 180 turn; captain described event to center. Cleared direct the airport; descend 10;000 ft. As captain was declaring emergency with ATC I was changing destination in FMS when mw smoke extinguished. I pointed this out to the captain and we both agreed to continue with the divert. No actual smoke was ever detected nor did the mw or mc ever re-illuminate. At this time; captain was talking with ATC and company. I was flying and navigating. There was a minor discussion with ATC if an emergency had been declared; and I heard the captain respond in the affirmative; but later events may show ATC did not understand or receive the intent of our precautionary divert and declaration of emergency. Since we were close at around 10;000 ft we were handed off the approach. I asked for early descent and stated I requested high speed below 10;000 ft. ATC responded affirmative to high speed below 10;000 ft. Flew 325 KTS onto high key; then vectored for tight approach ILS just outside outer marker. [We] made a normal landing.

Original NASA ASRS Text

Title: An A300 Master Caution alerted AFT CARGO LOOP FAULT A; followed by a Master Warning CARGO SMOKE. Both alerts extinguished but an emergency was declared and the flight returned to the departure airport.

Narrative: Climbing through approximately FL200; I was pilot flying;we received a Master Caution ECAS warning AFT CARGO LOOP FAULT A. Master Caution (MC) went out by itself; and then reappeared seconds later. Captain as pilot not flying began to initiate the QRH procedures for the MC when a Master Warning (MW) CARGO SMOKE illuminated. We agreed to immediately divert back to the departure airport. I began a 180 turn; Captain described event to Center. Cleared direct the airport; descend 10;000 FT. As Captain was declaring emergency with ATC I was changing destination in FMS when MW SMOKE extinguished. I pointed this out to the Captain and we both agreed to continue with the divert. No actual smoke was ever detected nor did the MW or MC ever re-illuminate. At this time; Captain was talking with ATC and company. I was flying and navigating. There was a minor discussion with ATC if an emergency had been declared; and I heard the Captain respond in the affirmative; but later events may show ATC did not understand or receive the intent of our precautionary divert and declaration of emergency. Since we were close at around 10;000 FT we were handed off the Approach. I asked for early descent and stated I requested high speed below 10;000 FT. ATC responded affirmative to high speed below 10;000 FT. Flew 325 KTS onto high key; then vectored for tight approach ILS just outside outer marker. [We] made a normal landing.

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.

Attributes
ACN	1055351
Time
Date	201212
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Make Model Name	A300
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Component
Aircraft Component	Cargo Compartment Fire/Overheat Warning
Person 1
Function	First Officer Pilot Flying
Experience	Flight Crew Last 90 Days 150 Flight Crew Total 11000 Flight Crew Type 4000
Person 2
Function	Captain Pilot Not Flying
Experience	Flight Crew Last 90 Days 95 Flight Crew Total 12500 Flight Crew Type 3100
Events
Anomaly	Aircraft Equipment Problem Critical Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor

An A300 master caution alerted aft cargo loop fault a; followed by a master warning cargo smoke. Both alerts extinguished but an emergency was declared and the flight returned to the departure airport.