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darian

N1 wont exceed 87%, A343

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im doing my second flight with PSS A340 and the n1 wont go higher than 87% with the autothrottle engaged. whats the reason for this, and how can it be fixed. In fact if i disengaged autothrottle i take the n1 up to 100% then engage AT and it drops back to 87%. This is at any ALT.


Darian Phillips

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Guest vrandar

Just as a starter as you are new to PSS Airbuses, make sure you start your FS session with default MS aircraft with avionics ON and engines OFF and saved as the default flight (I use the default Boeing 737 but have never ever flown it). Then switch to the PSS Airbus. Also if you have registered FSUIPC make sure you set battery life to indefinite. This will cure some of the electrical problems that might strike due to the MS dead battery glitch. Now to your particular issue with N1%. The thrust doesn't just go immediately to the maximum which is, if my memory is correct about 105% but is based a calculation taking into account temperature, elevation and takeoff weight. I've just fired up the sim with an A343 with ZFW of 146 tonnes, block fuel of 74.4 tonnes. At Anchorage (PANC) where the Outside temp was -20 deg C TOGA N1% showed 90.3%. At Sydney(YSSY) where outside temp was +20 dec TOGA N1 was 95.9%. At Jo'burg (FAJS) where the outside temp was +23 deg C but runway elevation was 5500 ft (compared to about zero for PANC and YSSY) the TOGA N1% was 100.6%. This all seems about right to me and shows quite correctly that a hot and high departure will require greater thrust. What airport, weights and temps did you use when you were doing your flights.If the N1 thrust still worries you can change the Flex Temp and enter a fairly high figure (greater than zero rather than a minus figure which you would normally enter on the PSS Airbuses) which will then probably give you a higher N1% than with TOGA!Rob Elliott, EGPE InvernessPSS Airbus Support andAirbus Fleet Training Captain, British Airways Virtual airbus@speedbirdonline.co.ukhttp://www.speedbirdonline.co.uk/airbus.htmlhttp://www.bavirtual.co.uk

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ok i didnt start the flight from default cessna at KSEA ill do that next flight. second where do i enter the flex temp, because i was entering the same values you put for temp and still no change in the n1 limit. and where do i go to view TOGA n1. I'm still in flight right now and the TAT says -27C and TAT says -56C, currently at FL360 AT off otherwise i will go down to 87% n1 and drop my speed too low. current GW 411,000 lbs and CG 25.


Darian Phillips

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Guest vrandar

It doesn't have to be KSEA, it can be any airport in the world.IF you are not sure where to enter the flex temp it makes me wonder whether you are entering the other data correctly in the MCDU, primarily the ZFW and Block Fuel on the INIT page 2 and the v-speeds on the PERF page. Ask me if you are not sure about these.Flex temp "fools" the aircraft into thinking the outside air temp is hotter than it really is, so a lower thrust can be used for takeoff and this reduces engine maintenance and prolongs engine life. Flex temp is entered as part of your MCDU preparations before you pushback. It is on the PERF page at LSK4R (line select key 4 down on the right hand side). The same page as you enter the v-speeds. For a flex temp you enter a minus figure due to a programming error years ago by PSS. I often use -25. Flex temp is not used for a hot and high departure, when the runway is wet, slippery or short anbd must never be less than 25% below TOGA thrust.The image below shows where to enter the Flex temp if you are planning a FGlex takeoff. It shows the default temp of 42 degrees. If you are doing a TOGA thrust takeoff you can leave it at this setting. If doing a Flerx takeoff see what I said in the prevous paragraph about the setting.http://forums.avsim.net/user_files/164004.jpgAh, I think I understand now you were trying to change the thrust in flight, sorry I mis-understood your earlier poist. In flight the N1% is controlled by the FADEC (full authority digital engine computer). You shouldn't be trying to change the thrust in flight and indeed if the autothrust is on you can't. You might be able to on Boeing aircraft but the Airbus is a very different airplane. It is quite correct Airbus behaviour - as a pilot you let the computers do the work of calculating the correct thrust. The computers set the appropriate thrust to maintain the cruise mach, usually .78 or whatever cruise you have set in the PERF page for the stage of flight you are at. In flight it is not Airbus Standard Operatring Procedure to switch off autothrust in flight.To answer your question about where you see TOGA N1%, this is when you have moved the thrust levers to the FLEX/MCT or TOGA "gates" on the pedestal on your takeoff roll. This is shown in the image below. But as I mentioned above, I had not understood that your question was actually related to trying to change thrust in the air which is something you don't do in an Airbus.http://forums.avsim.net/user_files/164003.jpgGet back to me with any questions.Rob Elliott, EGPE InvernessPSS Airbus Support andAirbus Fleet Training Captain, British Airways Virtual airbus@speedbirdonline.co.ukhttp://www.speedbirdonline.co.uk/airbus.htmlhttp://www.bavirtual.co.uk

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ok looks like my next flight ill have to try out these procedures i didn't know. i thought only the items in the FMS with the square brackets were the only required fields to enter data to fly a successful flight.


Darian Phillips

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Guest vrandar

Just to add to my earlier comments, the N1% in the cruise as shown on my current flight:http://forums.avsim.net/user_files/164006.jpgI will post here shortly the sequence of events for entering data into the MCDU. Additionally there is a (now very old) MCDU tutorial in the airbus hangar at speedbirdonline in my address below.Rob Elliott, EGPE InvernessPSS Airbus Support andAirbus Fleet Training Captain, British Airways Virtual airbus@speedbirdonline.co.ukhttp://www.speedbirdonline.co.uk/airbus.htmlhttp://www.bavirtual.co.uk

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Darian:Take a look at this www site - http://www.airbusdriver.net/Airbusdirver is a great site to understand how the A34X flies, and the design philosopy towards 'human control' of the aircraft.In order to successfully fly the airbus one must unlearn boeing (and default FS 737, 747 and 777 ) aircraft flying patterns.--


D. Scobie, feelThere support forum moderator: https://forum.simflight.com/forum/169-feelthere-support-forums/

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Guest vrandar

MCDU:LSK=line select key followed by the number down and which side it's on, so LSK1L is the top line select key on the left hand side.Always work top right round to top left on each screen if a lot of data has to be entered.1) if you already have a flightplan from an external flightplanning utility then load it from the DATA page. Otherwise stay on the INIT page and we will enter it manually.2) Enter the departure/arrival airport combination into the scratchpad, eg, FAJS/FACT, and press LSK1R3) enter your alternate airport at LSK2R4) click LSK3R Align IRS.5) Enter your planned flight level into the scratchpad and press LSK6L, eg 3506) Enter the cost index: BA has just changed its cost indexes across the fleet to 0 so that is what we will enter here. I will describe cost index another time.7) Enter your flight number into the scrathpad and press LSK3L, eg BAW 6401- INIT page 1 is now complete as shown belowhttp://forums.avsim.net/user_files/164007.jpg8)Go to the FS Fuel and payload section and cehck/change your ZFW and fuel. In this case ZFW is 146.1 tones (129.3+16.8) and fuel is 40 tonnes. If yu are not sure about fuel planning I'll go into this on another occasion.http://forums.avsim.net/user_files/164008.jpg9) Click the Next Page button on the MCDU to go to the INIT Page 2. Enter the 146.1 ZFW at LSK1R and the 40.0 fuel at LSK2R. Takeoff and Landing Weights are then entered for you further down the right hand side:http://forums.avsim.net/user_files/164009.jpg10) Go to the PERF page and if you plan a Flex takeoff enter the Flex temp at LSK4R, eg -25. 11) Still on the PERF page, if you have v-speed charts you can enter the v-speeds manually, but in the case right click LSK1L, LSK2L and LSK3L to get the computer to enter them for you.http://forums.avsim.net/user_files/164010.jpg12) Go to the F-PLN page, press the CLR key on the MCDU then click the left LSK next to any white F-PLAN Discontinuity. There will normally be one after the departure airport if you have entered the dep/arr pair manually.13) Click the left LSK next to the departure airport, then click LSK1L DEPARTURE and choose your runway and click the left LSK next to it:http://forums.avsim.net/user_files/164011.jpg14)You will then be taken to a list of SIDs (Standard Instrument Departures). Choose the one you want and click the left LSK next to it then press LSK6R INSERT.http://forums.avsim.net/user_files/164012.jpg 15) Do the same as 13 and 14 above for the STAR (Standard Terminal Arrival Route) at the arrival airport.That's basically it, get back to me if you have any questions.Rob Elliott, EGPE InvernessPSS Airbus Support andAirbus Fleet Training Captain, British Airways Virtual airbus@speedbirdonline.co.ukhttp://www.speedbirdonline.co.uk/airbus.htmlhttp://www.bavirtual.co.uk

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OK, this is now my third flight with PSS A343 KLAX LFPG and i entered flex temp with -25 and now the n1 is limited to 89% clearly not enough power for a safe ride. So again i have to fly the whole flight w/out AT. What value must I enter so my n1 limit is at least 100% or maybe 98% at the very least. I fixed my default flight with engines off and avionics on, but I didnt start with cessna though. I also set up the pss A330/340 panel config with cold dark cockpit, same with pss A319/320/321 but the n1 limit with those is much higher than 87 and 89%. lax-lfpg.jpgAs you can see i have no n1 limit on my ECAM screen.I use a 2 multi monitor configuration, top for windows bottom for cockpit instruments.


Darian Phillips

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Guest vrandar

The immediate thing I notice here is that you still have the Takeoff Memo on. This is incorrect. You must press the TO Config button on your taxi checks once you have set autobrake, signs and flaps.Secondly you are at FL350: why are you worried about the N1%? This is being controlled by the FADEC(full authority digital engine control computers) which will keep the thrust at a setting to maintain the Mach .82 which is what you have dialled in to the glareshield. Unfortunately I can't tell from the speed tape exactly what mach you have at the moment. Normally in the cruise you would be flying the aircraft under managed speed for fuel efficiency. Your statement that there is "not enough power for a safe ride" is frankly just wrong. What did you say you are expecting, 98-100%? If so that is not what you would get in a real world Airbus at this stage of the flight and would break the engines where thrust at that sort of level is not permitted for more than 10 minutes at a time. Look at the image I posted of my N1% in the cruise and you will see that it is quite normal at about 83%. Jet aircraft do not fly with the engines at full or near full thrust except perhaps at takeoff if they are using TOGA thrust rather than flex.The other aspect is that you have a tail wind so naturally the fadec computers will "throttle back" in order to keep the speed constant at your selected .82 mach.You mentioned the flex of -25: this is only relevant for takeoff and has no bearing on the cruise.Disconnecting the A/T in the cruise is not correct procedure and I hope from what I have said here that you are starting to understand why. Just let the computers do their job, they a re doing it correctly.The final thing is that you have not pressed (left clicked) the alt knob for managed alt. You should do this if you are remaining at FL350 otherwise the aircraft will tend to "hunt" FL350 leading to some bobbing over it and under it which also causes more N1% movement and is bad for fuel efficiency. You will see from an earlier image I posted that I hadn't either, but I had been adjusting the vertical speed in the climb (good practice to prevent a speed dropoff) and hadn't yet changed to managed speed. You should keep it pressed in the cruise which will show a dot next to the altitude on the glareshield.As far as I can tell from the image the aircraft is behaving the way it should based on the how you have got it setup. But there are a few things for you to correct here and perhaps a bit more assistance is needed on how to setup and fly the Airbus which is very different from a Boeing. I'm happy to help with this.***Edit: re-reading my post here it might come across as though I was being unnecessarily tough on a new Airbus pilot. I did not intend to criticize and hope it is not taken that way.Rob Elliott, EGPE InvernessPSS Airbus Support andAirbus Fleet Training Captain, British Airways Virtual airbus@speedbirdonline.co.ukhttp://www.speedbirdonline.co.uk/airbus.htmlhttp://www.bavirtual.co.uk

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the mach I was at was .818 and the n1 limit which was 89% was not enough power for it to maintain that mach. And clearly not enough power to climb and reach stable mach .82 The planes speed would drop dramatically. Also i know 98-100% n1 is too much power for cruise im not not that new to airbus I was only referring to climb phases. But I just read the tutorial again and I see i missed some steps so my next flight I will try these new steps. As long as my default flight is set with engines off and avionics on do i have to start with the cessna or can i start with the pss airbus.


Darian Phillips

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[blockquote]on Wed Jan-03-07 01:11 AM darian said:As long as my default flight is set with engines off and avionics on do i have to start with the cessna or can i start with the pss airbus.[/blockquote]the default flight must start w/a default FS aircraft (737, 777, cessna, etc.). NOT the PSS airbus. you can be at any airport for a default flight.could you post specifics for your flight so other may attempt to duplicate your challenge? ie:*fuel loaded*passenger & cargo loaded*flight plan--


D. Scobie, feelThere support forum moderator: https://forum.simflight.com/forum/169-feelthere-support-forums/

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Guest vrandar

>the mach I was at was .818 and the n1 limit which was 89% was>not enough power for it to maintain that mach. And clearly>not enough power to climb and reach stable mach .82 Unless you were very very heavy I don't actually understand what you are saying here: if you are mach .818 that is very close to mach .82 and with selected speed rather managed I am not really surprised if there is a slight deviation from .82. And your image shows nothing about a drop off in mach. It WILL show a dropoff in IAS but that is normal due to air pressure and is why mach is used not IAS at those flight levels. Are you perhaps confusing IAS and mach here and getting worried that IAS is much lower than you expected?You didn't post a picture of the airplanes speed that you say had dropped dramatically. That would be useful. I still think you are very wrong stating that there is "clearly not enough power for cruise". You are in the cruise at FL350 and with no evidence from your photo of a dropoff in mach (not IAS).>Also i know 98-100% n1 is too much power for cruise im not not that new to airbus I was only referring to climb phases. Forgive me but you are clearly in the cruise in the image you showed.>But I just read the tutorial again and I see i missed some steps so my next flight I will try these new steps. What did you miss out? If it was enter ZFW and block fuel or not making sure that that the FS weight and fuel matched the Airbuses I could understand it. Let us know which bits you omitted from the instructions.As long as my default flight is set with engines off and avionics on do i have to start with the cessna or can i start with the pss airbus.It must not be the Airbus but a default MS Aircraft. I use the Boeing 737 but have never flown it. So as Scoob says, if you can let us know the flightplan, weights and fuel and an image of the mach dropping off dramatically after you have followed all the instructions in the tutorial that would help us resolve the problems.Rob Elliott, EGPE InvernessPSS Airbus Support andAirbus Fleet Training Captain, British Airways Virtual airbus@speedbirdonline.co.ukhttp://www.speedbirdonline.co.uk/airbus.htmlhttp://www.bavirtual.co.uk

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>>The other aspect is that you have a tail wind so naturally the>fadec computers will "throttle back" in order to keep the>speed constant at your selected .82 mach.>>Rob Elliott, EGPE Inverness>PSS Airbus Support and>Airbus Fleet Training Captain, British Airways Virtual >airbus@speedbirdonline.co.uk>http://www.speedbirdonline.co.uk/airbus.html>http://www.bavirtual.co.ukRob,A minor point, but a tailwind will not affect the power needed to maintain Mach 0.82. Mach number is an air speed, not a ground speed (specifically the ratio of true airspeed to the local true speed of sound). A tailwind means you will get to your destination faster at the selected Mach number. However, to maintain a schedule with a tailwind you might select a lower cruise Mach, and so require less power.It doesn't matter whether you are in manual or auto thrust, the engine thrust limits will be the same (FADEC sees to that). So if Darian can achieve more 100% N1 in manual thrust, then the problem is with his FCU settings. For what it's worth, my guess is that the guy is flying the A340 like a default MSFS aircraft and climbing in V/S mode. The default MSFS autopilot causes more confusion to newbies than anything else I know in the sim when it comes to using complex add-ons.Happy New YearKevin


ki9cAAb.jpg

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Guest vrandar

Whilst I would agree with you in the real world, in the sim I have found a slight tendency for a throttle back with a tailwind. Although it could well have been other factors at play.Yes I agree with para 2.Rob Elliott, EGPE InvernessPSS Airbus Support andAirbus Fleet Training Captain, British Airways Virtual airbus@speedbirdonline.co.ukhttp://www.speedbirdonline.co.uk/airbus.htmlhttp://www.bavirtual.co.uk

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