Re-engaging autothrottle 744-FS9

[basa 0]

Good morning 747 captains.The question is about the FS9-PMDG 747.When inflight, everytime I've disconnected the A/T (for some hand flying) I've never been able to re-engage it again.I've tried all the possible combinations of switching on-off the FD, AP and AT, but without any success.Anyone knows the correct procedure to disengage and reengage the A/T ?.Thanks.

[craig_read 43]

It would help to know exactly what it is you're doing to disconnect the A/T. Are you throwing the A/T Arm switch on the MCP? If so, simply switching it back to ARM won't make the A/T turn back on. It simply returns it back into the armed state until you activate it. You can do this be pressing the VNAV button again, if the A/C is in VNAV. This should then re-activate the autothrottle system. There are many ways to do it, FLCH etc. But if you are simply replacing the A/T switch to the ARM position, that will not activate it, it will simply allow it to be activated when an appropriate mode is selected.Think of it this way.. turning the socket on for you PC doesn't make your PC turn on, you have to press the power button. If you turn the switch off at the socket, the PC powers off as it loses power, turning the switch back on again doesn't mean the PC starts up automatically, you must push "POWER". Same with the A/T, the switch on the MCP is like your mains socket, turning that off kills it stone dead, but switching it on again just means you can turn the 'power' (appropriate mode) on.Have a look in the manual with regard to A/T modes, how they are activated and controlled. Try disengaging (NOT the same as disarming) FMC control of the A/T using the rotary knob, to allow you to dial in a manual speed. Try switching it off by the switch, then turning it back on, hit VNAV or SPD, or FLCH (or any appropriate mode) and watch the system light up again as you switch it 'on'... I hope I've explained that well and not confused you further! lolCheersCraig*CORRECTED*

[basa 0]

> Try disengaging (NOT the same>as disarming) the A/T using the rotary knob, try switching it>off by the switch, then turning it back on, hit VNAV or SPDThanks a lot Craig I'll give it a go, but, which rotary knob are you referring to ?

[engwerda 0]

A very good explanation Craig. Thank you.Gerry

[craig_read 43]

"Try disengaging (NOT the same as disarming) the A/T using the rotary knob, try switching it off by the switch, then turning it back on, hit VNAV or SPD.">Thanks a lot Craig I'll give it a go, but, which rotary knob>are you referring to ?Sorry that was a mistake, I didn't mean disengage the A/T, I meant disengaging the FMC control of the A/T which is different, I will correct and explain myself here. The rotary knob you use to dial in a speed into the speed window can be pushed, this will enable you to take manual control of the speed selection even when the aircraft is in a VNAV mode which usually has FMC control of the speed. When the FMC is commanding speed changes the window will be blank, when manual control of speed is available the window shows the current commanded speed. Pressing this knob again will relinquish control back to the FMC and once again the window will blank. If you were to press the knob again after this, the speed that will be displayed within the window, will not be the last manually dialed speed, but the speed set by the FMC. You can give control back to the aircraft FMC by pressing the dial knob for speed, or you can re-initiate the throttle mode by pressing that mode again. EG.MCP shows VNAV, LNAV, LEFT AP, A/T ARM, Speed window blankPilot in command pressed speed knob, window opens displaying the previously commanded FMC speed, pilot dials in -10knots speed. Aircraft slows 10knots to new commanded speed. Pilot presses VNAV again (which is still lit as it is still the active pitch mode, I've not disengaged it), speed window blanks, aircraft begins to accellerate 10 knots.. Why? By pressing VNAV I'm saying "here, have the speed control back..." and because the FMC speed will was 10knots above what I commanded, it will reclaim those lost 10 knots, the aicraft speed is now under FMC control. You can edit this speed in the FMC. E.G.MCP shows VNAV, LNAV, LEFT AP, A/T ARM, Speed window blank and aircraft in cruise.Pilot opens FMC VNAV pages, goes to CRZ page, and sets cruise speed -10 knots.. EXEC lights, pilot accepts change. NO CHANGE TO MCP.. Aircraft slows 10 knots as the FMC commanded speed is now -10knots of previous..Does that help you understand a bit more? Probably a bit TMI there really.. lolGive it a try, we get a lot of questions regarding various modes of the automatics etc. Best way to learn.. Take her up to 30k, and fiddle.. lol..ONE FINAL EXAMPLE.. relevant to your question.MCP shows VNAV, LNAV, A/T ARM, LEFT AP, Speed window blank.Pilot in command throws A/T ARM to DISARM, EICAS chimes with A/T DISCONNECT, speed window re-opens to FMC previous set speed. Pilot in command silences caution message. Pilot reduces speed manually 10knots. PFD showing NO A/T mode, set speed on MCP disagrees with a/c speed by +10 knots. Pilot throws A/T switch to ARM. PFD still shows no A/T mode, no throttle mode means pilot in command of throttle, REMEMBER to check your PFD, you will know instantly what you are in control of. Pilot wishes to re-engage autothrottle, Pilot presses VNAV, speed window blanks, FMC given control of A/T and A/T active, PFD shows A/T mode in green box indicating it's a recent change. Aircraft speeds up 10 knots to cruise speed and continues as previous.CheersCraig

[basa 0]

>>MCP shows VNAV, LNAV, A/T ARM, LEFT AP, Speed window blank.>Pilot in command throws A/T ARM to DISARM, EICAS chimes with>A/T DISCONNECT, speed window re-opens to FMC previous set>speed. Pilot in command silences caution message. Pilot>reduces speed manually 10knots. PFD showing NO A/T mode, set>speed on MCP disagrees with a/c speed by +10 knots. Pilot>throws A/T switch to ARM. PFD still shows no A/T mode, no>throttle mode means pilot in command of throttle, REMEMBER to>check your PFD, you will know instantly what you are in>control of. Pilot wishes to re-engage autothrottle, Pilot>presses VNAV, speed window blanks, FMC given control of A/T>and A/T active, PFD shows A/T mode in green box indicating>it's a recent change. Aircraft speeds up 10 knots to cruise>speed and continues as previous.>Craig, Went for a test flight with my 744 from Rome Fiumicino to Milan Linate (LIRF-LIML, ISD sceneries, the best freeware out there by the way), and followed your instructions. For the first time I was able to bring the A/T to life again, but I had to press the VNAV or FLCH buttons twice. A single push did not produce any effect.I also tested the inflight engine re-start procedure a couple of times. I turned off the #1 & #2 fuel control switches (throttle console), got all the warnings on the EICAS and an A/T disconnect, turned back on the fuel switches and both engines restarted without any problem.Tried the same a second time but nothing happened. I had to open the overhead, selected continuous ignition, pulled the starters for 1 & 2, turned on again both fuel control switches, and now yes the engines started again.How many things have I done the wrong way...?Thanks again.

[craig_read 43]

Hello there again, it's great to see people who are keen to learn by the way.. About your comment above.. I am certain you should be able to do the following.SPD LNAV VNAV PTH are the active modes, a/c in cruise..PIC (Pilot in Command) flips A/T switch to OFF, PFD shows no A/T mode just LNAV and VNAV PTH.... Upper EICAS chimes and shows warning A/T DISCONNECT... PIC silences the warning.. has manual control of throttle... PIC flips A/T switch to A/T ARM... still no A/T mode on PFD.. just LNAV.. VNAV PTH.... PIC presses VNAV... A/T mode restored on PFD.. A/T now in command of throttle mode... previous mode is restored.. PFD now showing... SPD ... LNAV.... VNAV PTHThat should work.. I have not tried restarting in flight.. do you have autostart set to on? Also.. engines won't start well at high levels... often the aircraft must descend to attempt relight.. I am sure Robert will shed more light here..ThanksCraig

[basa 0]

>>PIC presses VNAV... A/T mode restored on PFD.. A/T now in command>of throttle mode... previous mode is restored.. PFD now>showing... SPD ... LNAV.... VNAV PTH>Hi again,The fact is, as I told you, that if VNAV is pressed only once nothing happens...well, at least in my 744.>>..do you have autostart set to on?>Yes, from cold and dark to the end of the flight. I also switched on continuous ignition to ensure some kind of redundancy, but I really don't know if it should be necessarily done.

[craig_read 43]

"PIC presses VNAV... A/T mode restored on PFD.. A/T now in commandof throttle mode... previous mode is restored.. PFD nowshowing... SPD ... LNAV.... VNAV PTH"I have verified this behaviour in my FSX 747, I have not looked at FS9 yet, but I can check this evening. As far as I am aware that is how the autothrottle should be operating.CheersCraig