PMDG 747-400X

[Rickie Welsh 27]

Hi, Looking for some help, scrolled back to previous posts but could not see similar problem. During my last attempts to fly the 747X, this problem occurs without it happening before, flight is all programmed with no warning messages, the SID has a 24nm 6000ft alt restraint which the FMC adheres to and the speed shows 250kts., but the speed continues to increase well into the overspeed warning. Does anyone know what is causing this and what the answer is. Many thanks. richard welsh.

[Samwise 1]

A couple of things to note: I presume you have armed the autothrottle prior to takeoff? How are you flying the aircraft, manually, or fully managed using VNAV and LNAV? Check that you havn't activated the speed intervention whilst in VNAV. This will overrule the preset speed restrictions etc. Something else to consider is that if your using a throttle thats built into your joystick or a seperate throttle this can sometimes play havoc with autothrottle settings however it's never happened to me in the 747.Hope this might be of some use.

[downscc 1,327]

Do you mean you have to remain at or below 6000 ft for 24nm or at or above?? Even a MTOW 747 will easily climb above 6000 in that distance, if you have to stay low then I am wondering where in the world are you running into this restriction?

[Samwise 1]

Do you mean you have to remain at or below 6000 ft for 24nm or at or above?? Even a MTOW 747 will easily climb above 6000 in that distance, if you have to stay low then I am wondering where in the world are you running into this restriction?

Many UK SID's have these limits, for example most of London Heathrows SID's have a 6000ft restriction for a good 30-40nm after takeoff. Obviously ATC usually clears to a higher altitude before then.

[Rickie Welsh 27]

Many UK SID's have these limits, for example most of London Heathrows SID's have a 6000ft restriction for a good 30-40nm after takeoff. Obviously ATC usually clears to a higher altitude before then.

Thanks Samuel and Dan for your replies. Dan, I concur with Samual re UK alt restrictions. richard welsh.