Mystery alarm on takeoff

[Guest Ricardo Sevarant]

Hi Guys,I'm having a recurring problem with the 747 SP1.1 on takeoff. I've never had the same problem before the official patch, only post-patch.On seemingly random takeoff events I'll get an alarm sounding right after unstick and positive rate of climb. I don't get any warnings or advisories on any displays, just a resounding "WHOOP WHOOP WHOOP". After this there is nothing I can do to silence this mystery alarm except restart the flight.I have the FMC properly programmed with all correct Vspeeds selected and displaying, flaps and stab trim set correctly, V2+10 set on the MCP speed window, FD's on, autothrottle armed, brakes RTO, pax signs on, PACK 1 on, PACK 2 +3 off, engine bleed and hydraulics set normal, con ignition on, autostart on, windshield heat on, yaw dawpers on.I get the alarm after either engaging authrottle via TOGA or manual throttle up on takeoff.I had at first thought I was encountering a tailstrike, but I've tried the same scenario many times being very careful to rotate at 3 deg/sec and never exceeding 8 deg nose up until positive rate. Still get the alarm on random takeoffs.I've uninstalled completely, then reinstalled and run the official update. Still have the random alarms on takeoff.Just to clarify one more time, I'm only getting the alarm immediately after I'm airborne, never on takeoff roll. Anyone have any ideas as to what the heck is going on? :)Thanks very much. This problem is plaguing me like no other.

[Guest Hawkeyeted]

I'm not sure if you issue is setup/configuration problem or not. But, here are some "real world" reasons for the Takeoff Warning horn to sound that may be worth checking out:-Parking brake set-Stab trim not in green band (T/O range)-Speedbrake not in the DOWN detent-Flaps not in the T/O range (10 or 20)Again, you may already have checked this stuff, but just a thought....

[Guest]

maybe you forgot to turn the APU off?

[Guest Ricardo Sevarant]

Hi Ted and Alex,APU is off on the above scenarios. I will double check the spoiler lever to make sure it's at full retracted detent also. Weird problem, just can't seem to figure this one out.Thanks for your input you guys.

[Guest RHAWKG]

Hello Rico ...are you sure the autopilot is ingauged i did not see any mention of this ?..i had a problem with my joystick and throttle programable buttons where if i hit the button it would do like a rapid fire sometimes enguaging and some times not ...i found in the settings turn off (or slide the slider) so the button push is not repeated .russell g