Narrative:

After takeoff got a gear door message. Completed communication and solved problem but got another gear door message on other side. Leveled off FL200 maximum altitude for flaps. Crew decided to slow to 265 KTS (270 KTS maximum gear extend) to try procedure again. When flap handle was moved got brief stick shaker. Captain (PF) was on first leg of oe (operating experience) and I was the ip in right seat. I immediately brought flaps up PF adding power; disconnected autoplt; aircraft did not stall but disconnecting autoplt and taking control loss of 150 ft. Requested lower altitude descended to 12000-15000 ft; moderate turbulence; descended to 8000 ft. Dumped fuel and eventually returned to ZZZ. Looking back probably should have stayed lower and remained near ZZZ. Supplemental information from acn 716907: after dumping fuel we declared an emergency and landed ZZZ airport. We then had emergency truck check our gear before taxiing to the gate.

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Original NASA ASRS Text

Title: A B747-400 GEAR DOOR WARNING MESSAGE DISPLAYED ON TKOF. THE CREW RETURNED TO LAND WHEN UNABLE TO SOLVE THE PROB AND AFTER DUMPING FUEL.

Narrative: AFTER TKOF GOT A GEAR DOOR MESSAGE. COMPLETED COM AND SOLVED PROB BUT GOT ANOTHER GEAR DOOR MESSAGE ON OTHER SIDE. LEVELED OFF FL200 MAX ALT FOR FLAPS. CREW DECIDED TO SLOW TO 265 KTS (270 KTS MAX GEAR EXTEND) TO TRY PROC AGAIN. WHEN FLAP HANDLE WAS MOVED GOT BRIEF STICK SHAKER. CAPT (PF) WAS ON FIRST LEG OF OE (OPERATING EXPERIENCE) AND I WAS THE IP IN R SEAT. I IMMEDIATELY BROUGHT FLAPS UP PF ADDING PWR; DISCONNECTED AUTOPLT; ACFT DID NOT STALL BUT DISCONNECTING AUTOPLT AND TAKING CTL LOSS OF 150 FT. REQUESTED LOWER ALT DSNDED TO 12000-15000 FT; MODERATE TURB; DSNDED TO 8000 FT. DUMPED FUEL AND EVENTUALLY RETURNED TO ZZZ. LOOKING BACK PROBABLY SHOULD HAVE STAYED LOWER AND REMAINED NEAR ZZZ. SUPPLEMENTAL INFO FROM ACN 716907: AFTER DUMPING FUEL WE DECLARED AN EMER AND LANDED ZZZ ARPT. WE THEN HAD EMER TRUCK CHK OUR GEAR BEFORE TAXIING TO THE GATE.

Data retrieved from NASA's ASRS site as of January 2009 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.