Still can' get autothrottles to work correctly

[Guest]

Still have no way of getting A/Ts to function correctly. I selected crz for EPR, then could not deselect it. If I press EPR, isn't it supposed to cancel the SPD button & vice versa?Also it seems If I have my throttle at idle whel I select the speed button, my lower left corner of the EHSI will read "IDLE". A/Ts only attempt to follow my speed if I have my joystick throttle at something other than idle when I engage the speed button. Pressing the speed button a million times for speed intervention seems to do nothing most times. I'd attach some pictures, but I am getting a "Script error" message every time I try to show them to you all. As you can bet, the A/T is engaged, & the SPD button is pressed, it says SPD on the bottom of my EHSI - yet the jet just blasts through my speed restriction (even if I press the SPD intervention knob inward). Is it because I can't deselect the EPR button?Also, pressing CTRL F12 seems to do nothing on the takeoff roll, even when the A/Ts are armed.Would love for this to work for me. I'm missing out on all the fun. :-(Chris Catalano

[rsrandazzo 6,353]

Chris-We went through this with you on the 777 as well...Before the pilot flies the plane- the pilot must read the books.... ;-)Unfortunately I'm not in a position where I can instruct at the moment- but I assure you the system is working. It needs to be set up to function, however! That is why they put us through so much training to fly airplanes!Robert S. RandazzoPrecision Manuals Development Group http://www.precisionmanuals.com/images/coolcap.gifwww.precisionmanuals.com

[michal 44]

Interesting. So on 757 it is called EPR and on 767 it is called N1 ??I have learned something new.Michael J.

[Guest Henri W]

Michael,Somebody should correct me if I am wrong, but I think it depends on the engine make you are using. If I am correct, GE uses N1 (and N2), PW uses EPR (and N1 and N2) and RR uses EPR (and N1, N2 and N3).Cheers,Henri

[Guest Henri W]

Chris,It does work for me. This is what I do (out of the top of my head).While setting up the FMC be sure to set a value for the outside temperature. This seems to be important. I also enter values for v1, vr en v2. I select a flight plan and if available a SID. Check to see if there are altitude data for the waypoints. Before taking off I arm VNAV, the AT and the FD. Of course I have set the MCP altitude to the altitude I am allowed to reach. After take-off clearance I push the throttles forward until I reach EPR = 1.1, next I press the EPR button. Even though the light does not illuminate, the plane reacts by increasing thrust. After take-off the plane will properly take care of my speed and climb rate. At 1200 feet AGL I press LNAV and turn on the AP (LNAV can be armed on the ground already I think). Make sure you are on an intercept course to the planned flight path.Good luck.Henri

[Guest Henri W]

Also don't forget to enter a cruise altitude in the FMC.Best regards,Henri

[Guest]

We went through this with you on the 777 as well...Actually, again - of course I READ the manual - cover to cover. You seem to forget that the last time I had problems with a PMDG plane & the Autopilot, it turned out my joystick was too sensitive - when I replaced it, I stopped getting the constant random disengage of the A/P. So before you misunderdstand me, I am trying to figure out if it a hardware problem, a software problem, or something else. Last time it wasn't me at all. I have read the new manual. Seems to me that the A/T is not all that different than the 777. In fact, some helpful people have pointed out that there IS a bug w/ the SPD button - when VNAV is engaged, the speed button remains illuminated even when the VNAV buttons are active giving the illusion thatthe A/T speed mode is active. One needs to press the SPD button again to see if SPD shows up on the EHSI. Also, several people have pointed out another annoying bug - that of disengaging the VNAV button & being unable to reselect it. It seems that we get an error message that reads PERF/VNAV unavailable, & then we notice that no temperature exists in our FMC settings any more. We are all trying to learn this new bird. I would sure appreciate your patience. This is suppsed to be fun, right?ChrisPS - sorry if I sound annoyed. I'm just frustrated. You have been great with me. I'm sorry for my tone. I am just growing weary because last time, it turned out it wasn't my fauly at all. Answer me one question please - If I have no flight plan loaded, & I select flight director, dial in a speed on the A/T, select autotthrottle & press speed, shouldn't I be able to control the speed - even if there is no flight plan loaded. I just want to cruise around & play with the speed w/ the auto throttles engaged. Shouldn't this just be as easy as dialing in the speed & pressing the SPD button if the A/T is engaged? Sorry again for my tone. I was upset when I wrote this. I should remember this is supposed to be fun too. :-)Chris

[Guest]

Thanks Henri as always. I am certian I have done these things. I seem to have the most trouble after I try to descend below 10000 ft. Also, I seem to have great trouble with the A/T if I have no flight plan loaded & want to just fly around for fun to learn the airplane's functions & see how it handles. The A/T controls seem to have a mind of their own. They seem to sork only randomly for me, even if I have SPD appear on my EHSI & press the speed intervention knob inward. I am feeling very discouraged at this point. Thanks for your constant help. Flight sim is one of the real pleasures I enjoy, & it makes me sad when I can't escape my problems for an hour or so & have fun. Am I asking for too much? I'm sure you understand!Thanks Henri!Stay well,Chris Catalano

[michal 44]

Chris, if you still have this problem say 10 hours from now, I will be then at home and can grab this other product which I call a "reference" and give you a few quick procedures to work with the A/T. I recall I went through this exercise once (with this other product) and everything worked per my expectation. You do not need FMC, flight plan or even autopilot engaged to test the basic functionality of the A/T. Michael J.

[Jet Tech 31]

Chris,Here is a basic excercise to try out the A/T system. Load a basic short flight plan say SFO to SJC or something short. Don't need any additional waypoints, just ensure that you enter a cruise altitude of say 10,000ft and fill out all of the pages til the preflight complete msg appears. Take the runway and dial in Runway Heading in the HDG SEL window. Turn on the F/D and A/T switches and depress the EPR button. Ensure that EPR annunciates on EADI and Throttles advance to T/O thrust. After lift-off at around 400' radio altitude depress the SPD button (not the speed dial) and veritfy that SPD is annunciated in the A/T mode area of the EADI. A/T system will now keep your throttles at an appropriate level to maintain whatever speed is dialed into the window. The Speed Intervene function is only active when VNAV is active and depressing the Speed Selector may be confusing the A/T system if VNAV is not the active mode. I did use it today during a flight in VNAV and it worked properly so know that it works. Only depress the Speed selector when in VNAV and when you need to slow the A/C down for say for turbulence penetration without dropping out of VNAV.I have played around with this quite a bit and found that in VNAV, the FMC is always trying to maintain whatever speed contraint is in the flightplan for the current leg (usually 315 by default) so you may have to assign a speed contraint if you want it to slow down. FL CH mode does a good job of flying to the Speed selected in the window if you prefer to use that when chagning altitudes.There is a bug with the SPD and EPR light not working exactly right but the mode display on the EADI is exactly as it looks in the Real Thing so fly by the EADI and ignore the SPD and EPR buttons until it is resolved. Good LuckPaul:-cool

[Guest]

Dear Michael & Paul - Thank you both so much - I'll let you know. At this point I want to just check the functionality of the Autothrottles.I'll let you know what I find.Sincerely,Chris CatalanoPS: here is a photo of last night's experiments - notice that SPD is listed on the EHSI, & the air speed indicator is well past the level of the value listed in the speed windoe on the MCP

[Guest]

Michael & Paul:Well I tried your exercise Paul to a T - Guys - here's what I found:Flew a flight plan from Buffalo to BostonI initialized the FMC & got the message that read "prefilght complete message"I armed the A/T & pressed the EPR button.**********PLEASE NOTE: that at no time in the flight did I ever press VNAV on this particular flight. I just want to see if the A/T commands will obey me.*******As usual, everything during the takeoff roll worked perfectly. As you said, I armed the A/P at 400' radio alt.When I did this, the Speed button seemed to already be pressed suddenly, althought I did not press it. At this point I noticed that the EHSI said the following things on it: "F/D & CMD (lower right)(truthfully, I'm not sure what CMD stands for-couldn't find it in the manual- do you guys know?), Anyway, A/T & SPD were in the lower left (as expected). To my surprise, I noticed that V/S was also printed on the EHSI (& I noticed that the V/S window on the right glareshield read +350)! I couldn't disengage this! The A/T nover even came close to approaching my 250 knot restriction in the window! It just kept bleeding speed. Finally, the only way I could clear the V/S window was to press the Hold button for the altitude (it held at 5000ft since that was the altitude currently in the window).When I did this, the A/T disobeyed my wishes by blasting all the way through the 250 speed restriction all the way to the red line limit. At this point, used the speed brakes to slow down - & once again, it would continued to bleed speed until dangerously low. I MADE SURE to notice that SPD was still on my EHSI - it was. I still had a temperature reading on my FMC (13 degrees C)I tried several times to "reset the speed button" by turning it off & then back on to see what would happen (again, every time I did, I made sure to see if the SPD indicator was on the EHSI, & it was) & each time I would reset it would blast through the 250 kt limit in the window. Also, if I "reset" the switch with my joystick throttles at 0, then when I would rearm the SPD button, it would read "IDLE" on my EHSI (not sure if it is really supposed to read this way or not in such instances). When the button was reengaged, it would only continue to bleed speed slowly. The only thing I did that may not have been called for was ont 2 occasions, I hit the alt know inward to see if it would bring me to a new alt, & it did not. However, this should have no bearing on the A/T.Gentlemen, I really appreciate your input & your patience with my situation. Can either of you reccommend a really simple exercise or test I can perform to just test the basic functionality of the A/T? Any other suggestions would also be greatly appreciated (like, stick to the 777 - at least it worked nicely for me!. :-)I am really starting to wonder if maybe it is a hardware or software problem at this point. :-( Or maybe it is something really simple I have not thought of yet. I seem to be getting no where & am losing heart. Maybe if you can reccommedn a simple test, I can find out for sure if the A/T will work for me.Thank you both a GREAT DEAL for all your input. Sincerely,Chris Catalano

[Guest]

Thanks Mike. If you read my post below, I think I need a basic exercise to try at this point. I'd sure appreciate your usual expertise at this point. You have been very helpful.Sincerely,Chris

[michal 44]

Chris,I hope you forgive me but I am used to N1 (instead of your EPR). Also when I often say green "A/T" below say "THR HLD" - in your case it may be the opposite - your green "A/T" may actually be above the annunciated autothrottle mode. I am using a Pegasus style PFD that displays the information in a slightly different format. I hope you can make this translation when reading what follows.What follows is based on the 767 aircraft which per my understanding is fully equivalent to 757 in the logic & operation of the AFDS.You do not need FMS for these tests. No need for "preflight". These are very basic modes, they are almost "atomic" in their simplicity. Make sure your joystick is not interfering with your A/T. This is a separate subject. I normally keep my throttle at idle when A/T is working though my product allows me to operate it as well. For simplicity of this test make sure it is only the A/T that is working and not the throttle on your controller.I won't be talking about flaps, gear, trim, etc - I do not want to clutter this discussion with this stuff - I assume you know how to handle those systems.When you first flip the A/T switch (arm the auto-throttle) to the upper position notice there is really NO indication on any of the screens that your A/T is armed. No green A/T on the PFD. It is weird but apparently this is how it works on real aircraft. However as soon as you disarm the A/T the annunicator panel and EICAS both will complain.Now, when ready for takeoff, press N1. Engines are reving up and you start rolling. Now the A/T is annunciated on the PFD with green N1 and A/T just below it. Half way through takeoff roll the green N1 becomes THR HLD (you can read somewhere else what it means). You rotate the aircraft and you are flying. For this test we won't engage the autopilot. You are flying fully manually. At this point you should be able to hit SPD button and the small lite in the button should illuminate. But before you do it make sure you have some reasonable speed dialed in the window, say 200 kts. As Paul said, do NOT use speed intervention button - it is only for VNAV - is useless for those tests. The mode on the PFD panel will now say green SPD with green A/T below it. Now you can experiment and see that A/T will indeed try to maintain this speed - if you lower the nose the throttle will retard, if you raise the nose the throttle will advance reacting to the changes in airspeed.If this works to your satisfaction lets do the whole takeoff again but this time we will engage CMD. When you are at least 1000 ft above ground hit the FLCH button and hit CMD. Again, make sure that you have something around 220 kts in your speed window (I suggest you fly "light" for these tests). Note that the vertical mode now changes to SPD and A/T mode changes to FL CH. Do not hit N1 button. When you finally reach the altitude which is dialed in the window A/T mode should change to SPD and SPD button should illuminate (and FLCH button will extinguish). And what if you DID hit N1 in the above test ??. Then A/T would automatically revert to the SPD mode and your vertical mode should display V/S. The vertical speed window would come to life and you could dial in whatever vertical speed you like. So there is a certain relation here: button pressed: V/S ----- forces A/T: SPD -- vertical mode annunciated: V/Sbutton pressed: FLCH ---- forces A/T: FL CH -- vertical mode annunciated: SPDIn the V/S mode the driving factor is the V/S and A/T will try to maintain the SPD selected. In the FLCH mode the driving factor is the SPD which is maintained by adjusting the pitch. Note that when you engage FLCH after takeoff your TO thrust mode should change to CLB automatically.Another important tip: when confused what state aircraft is in - always look at the PFD and read current A/T, vertical and horizontal modes. Do not rely on illuminated buttons.Michael J.

[Guest Henri W]

Chris,I think I found what the cause of your problem is. I am not sure whether we are doing something wrong (quite likely I guess), but I had the same problems you had when just doing some "free" (i.e. non AP flying). I too had my speed go up to 315 KIAS, even though I only selected 230 knots for the A/T speed. Then I discovered that my speed bug still said 315 knots. The same is true for you (though your screen shot just does not show it). The speed bug would not react to my A/T speed setting. I could get my speed bug to react to my command by ... pressing VNAV. After that the A/T worked just fine. I made a perfect flight after that just using A/T.Let me know what you find. BTW, the A/T and AP modes are annunciated on the EADI, not on the EHSI as you refer to.Have fun.Henri