machine2035

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Everything posted by machine2035

  1. Over the past few weeks (and months), there have been numerous threads and posts regarding calculating performance figures in the PMDG 777-200LR/F, especially takeoff figures including assumed temperatures and V-Speeds. In those threads that I participated in, I mentioned the use of numerous manuals, such as the FCOM and FPPM to gain some figures for take-off performance. This will be a guide on how to do so, particularly for the 777-300ER fitted with GE90-115B’s.I would like to stress that while this is for the 300ER, assuming you have the appropriate manuals for the 200LR, the same method can be used. While I tried to use the FCOM as much as possible, some things are just not available in Volume 1 and therefore I was forced to use the FPPM. First of all, before I start, I would like to make a note that is not how a real crew would calculate/obtain their takeoff performance. They would either use performance manuals created by the airline, which are airport and runway specific, or OPT software on the Boeing fitted EFB or on a small ‘e-laptop’ (10” screen netbook etc.). You will see throughout the guide that a lot of rounding/conserving occurs, therefore there would be some discrepancies compared to if you used OPT software. Some acronyms used throughout this guide are; FPPM – Flight Planning and Performance Manual FCOM – Flight Crew Operating Manual (and for the purposes of this guide, solely Volume 1) OPT – Onboard Performance Tool ATM – Assumed Temperature Method V Speeds – V1, VR, V2 RW – Runway TORA – Take Off Runway Available ETOW – Estimated Take Off Weight I would also like to add, that this is a very primitive way of gaining figures from the FPPM/FCOM. Really, if I was flying a real T7, and only had access to the FCOM or FPPM, and none of the tools I mentioned above, I would go through 5 different charts/tables which contain numerous considerations (Runway Slope, Obstacles, Tire Limits, Brake Energy Limits etc.). For the purpose of this exercise, I will only be using the figures from the Takeoff Field Limit chart and tables. For the purposes on a flight on FSX, this suffices fine IMO. In real life, the performance manuals provided by the airline take into consideration all these things, and therefore the time taken to come up with an assumed temperature and v-speed is considerably quicker than doing so through the FCOM and FPPM. Now, lets get started! First of all, the scenario that I will be using.Today, we are flying a 777-300ER, fitted with GE90-115B’s, out of Sydney (YSSY), with a planned departure of Runway 34L. RW34L, from intersection A6, has a TORA of 3900m (3962m to be exact). For weather purposes, we will assume there is a direct 10kt headwind (so METAR is reporting 335/10), and the runway condition is dry. Our company SOP’s call for a FLAP15 departure with a D-TO1 de-rate setting. The pressure altitude at Sydney is rounded to SLP (0ft). Our ETOW today is 312450 KG’s(312.4T). Now to calculate our figures; Step 1: The first step to complete is to get our compensated TOW which will take into account the 10% decrease in available thrust due to our selection of a D-TO1 de-rate setting. To do that, we go the FPPM. We are working backwards with this table, as with most tables/graphs in the manual. Now in the table, as you can see there is no exact match for our TOW (312.4t). With all these charts, you are taught to be conservative. So for our purposes, we are going to use the figures for a TOW of 314.7t. So looking at the table above, you can see that with a TO1 de-rate setting, with a TOW of 312.4t (conserved up to 314.7t for planning purposes), the TOW that we should plan our figures for is now an amended 340t. This is due to the fact that we will have 10% less thrust available on the take-off roll. N.B: If the airline dictates that D-TO2 is also available, there are similar charts in the FPPM which provide figures for 25% thrust decrease availability. Step 2: It’s now time to find our corrected runway length to take into considering wind component and slope. Now as FSX’s runways aren’t sloped, I won’t be doing any calculations related to the slope. However, I will do so for wind component. The headwind component on RW34L is 10kts. The TORA from A6 sourced from ERSA is 3900m. We now can go to the FCOM and pull out the ‘Field Corrections’ chart. We are once again going to be conservative and choose a shorter runway length then we actually have. In this case I have chosen 3800m. Going horizontally across from my runway length and vertically down from my headwind component, you can see that we arrive at a figure of 3950m. Due to the headwind component, we have virtually obtained another 150m of available takeoff runway. Step 3: It’s now time to find our assumed temperature. For that we have 2 sources. We can either use nice, pretty and easy tables in the FCOM, or a nice graph that we can plot on from the FPPM. For the purposes of this tutorial, I will be using the tables from the FCOM (as most people don’t have access to the FPPM). Once again, we start at our corrected runway length (which has been conserved back down to 3800m from 3950m), work horizontally across till we find our TOW (which has been conserved up to 341.6t from 340t), and go horizontally up to find our max OAT. Therefore today, our assumed temperature, with a D-TO1 rating will be 42°C. Step 4: Time to get those important V-Speeds! Luckily, in the FPPM, we have a table to find our V-Speeds for D-TO1 take-off. Let’s pull out the V-Speed charts, for a dry runway with a D-TO1 rating. Now, since this chart is taking into considering the 10% thrust reduction, we DO NOT use our amended TOW which was calculated in Step 1. With our ETOW being 312.4t, I have rounded it up to 320t. Going horizontally across from 320t, and vertically down from Flaps 15, we arrive at our V-Speeds. V1 = 156, VR = 170 ad V2= 176. However, since we have a 10kt headwind, we must account for that such wind. Therefore we must now pull out the ‘Wind V1 Adjustments’ table. Once again, going horizontally across from 320t, and vertically down from our headwind component of 10kt, a V1 correction of 1kt needs to be accounted for (Yeah, I know, not much!). Therefore our takeoff performance looks something like this; --------------------------------------------- YSSY 34L @ A6, 3960m TORA D-T01, 42C N1: 96.8% V1: 157 VR: 170 V2: 176 ---------------------------------------------- Step 6: Enter all the relevant data into the FMC. De-rate and assumed temperature is done through the THRUST LIM page, and the V-Speeds done through the TAKEOFF REF page. I hope this guide helps some of you when the T7 comes out, and helps you get some rough performance figures until either TOPCAT or another 3rd party developer (Aurasim etc.) is able to produce a 777 takeoff performance tool. Any questions please ask away!
  2. machine2035

    RXP 430 fix

    Hey, Does anyone yet have a fix which allows the RealityXP GNS430 to actually show the screen of the unit in the VC. Currently the screen just stays back, and the GPS is only useable in the 2D popup. Cheers!
  3. Does anyone who has more knowledge than me in panel.cfg etc know if the following would be possible (having two Reality XP 430W's in the places I marked). If it is, would someone (Bert??) be kind enough to provide the entry for the panel.cfg to do so Danke!
  4. machine2035

    Able to change engine models?

    Hey Guys, Quick question.. Is there a way to change engine models e.g. 26K, 24K, 27K. Couldn't seem to find the answer in the manual.
  5. Yeah, unless pushback routes are able to be customised, I won't be getting this.. We can already see with how GSX uses the AFCAD taxiways for pushback and what a shambles that is at some airports which have ground polys differing from AFCADS and pushback routes which are completely seperate of the taxiways created in the AFCAD.
  6. Yes, Air Canada along with some other 777 operators have the Honeywell weather radar (RDR-4000 with Intervue3D), the one that PMDG have decided to model is the Collins WXR2100 (which is more popular compared to the more expensive Honeywell system). WXR-2100 Control Panel: RDR-4000 Control Panel:
  7. Besides the WXR, I got slightly excited because I thought I saw Radius-To-Fix legs on the ND matching the Abbortsford RNP 07 departure....but then I realised it's the right airport but not the right departure... :lol: B) ... Me thinks about having latest ARINC format in PMDG buses :Drooling: :Drooling:
  8. machine2035

    Delta Air Lines - B737-700/800/900 - Enthusiast

    Should be the same as they run both aircraft on the same flight briefing software. Some FIR's/ANSP's require different things under NAV (such as RNP4 or GPSRNAV etc), so this is something to keep in mind. Just check in the countries AIP for flight planning requirements, however the basic Field 18 layout should be the same. Field 10 equipment changes on aircraft (i.e. newer delivered aircraft might not have ADF installed for example).
  9. machine2035

    Delta Air Lines - B737-700/800/900 - Enthusiast

    Hi, Here is a DL plan from the FAA AISR/NADIN system, from early 2013. FF KZLAZRZX 060626 KATLDALQ (FPL-DAL1428-IS -B738/M-SDE2E3GHIRWXZ/S -KLAS0715 -N0449F390 DCT BCE J100 EKR DCT BFF J94 OBK DCT LFD DCT CRL J584 ZORBO DCT SLT J584 FQM DCT LVZ LENDY6 -KJFK0404 KBDL -PBN/A1B1C1D1O1S1T1 NAV/RNVD1E2A1 REG/N3771K EET/KZLC0022 KZDV0040 KZMP0142 KZAU0214 KZOB0254 CZYZ0303 KZNY0331 SEL/ABEF RMK/ NRP
  10. machine2035

    Carenado B1900D Released

    I knew this would be the case....While it is a shame, it certainly doesn't come as a suprise.
  11. machine2035

    Guide/Tutorial: Takeoff Performance in the 777

    Yes, that would work to. I have been usually calculating my TO PERF during flight-planning just for the sakes of saving time. Unless the winds are forecasted to change rapidly in the TAF, the conditions will usually be stable within the 45minutes that I flight planned within.
  12. machine2035

    Guide/Tutorial: Takeoff Performance in the 777

    No. Pressure Altitude is what the altimeter would display when you set it to the standard barometric setting (1013hPa/29.92inHg). To correct your field elevation to pressure altitude; [a] Obtain current QNH at airport (For this example, we will say 1021hPa and FE = 1000ft). Find the difference (so 1021-1013 = 8hPa). [c] 1hPa = 30ft. Since QNH is higher than standard, pressure elevation will be less than field elevation. [d] Pressure Altitude = Field Elevation - (30ft x hPa differences). [e] In this example, Pressure Altitude = 1000 - (30x8) = 976ft. Most the time the pressure altitude won't be a huge difference to the field elevation and the same table/chart in the manual will be used.
  13. machine2035

    Takeoff V-Speed problem

    Just remember that one of the conditions for auto v-speeds is that the ADIRU is alligned (as someone mentioned above).
  14. machine2035

    FPS. What FPS do you get?

    I am seeing slightly better performance than the NGX.
  15. machine2035

    Guide/Tutorial: Takeoff Performance in the 777

    Sorry, misread your original post. Thought you meant you can't cancel a de-rate, period (as in it was a permanent fixture like a factory de-rate). It is also possible to cancel any derate thrust limits by pushing the TO/GA switch a second time.
  16. machine2035

    Guide/Tutorial: Takeoff Performance in the 777

    Are we talking about factory de-rates here or a de-rate entered through the FMC? Obviously there is the GE90-110 and GE90-115 which are both the exact same engine but one is factory de-rated to 110,000lbs. However, you can still de-rate each of them through the FMC, and these can obviously be cancelled and are used when deemed neccesary by the performance manuals/software.
  17. machine2035

    Guide/Tutorial: Takeoff Performance in the 777

    Ok, yes, I was just able to obtain an assumed temp. I might play around more with the program and profiles and see what I can come up with.
  18. machine2035

    Guide/Tutorial: Takeoff Performance in the 777

    You are able to get V-Speeds on the released OFP, hence why in the flight planning template there is a whole section on take-off performance. Numerous commands include; <&TO_V1> <&TO_Thrust> etc etc. Just had a look at this. Using the included PSS 777 profile, it calculates a de-rate but no assumed temperature. Most airlines use the ATM (Assumed Temperature Method), so right now this program is unfortunately no use to me.
  19. machine2035

    Guide/Tutorial: Takeoff Performance in the 777

    Does it begin with S... I have a sneaking suspicion (damn thats alot of alliteration) :lol:
  20. machine2035

    Guide/Tutorial: Takeoff Performance in the 777

    There are also charts/tables which will calculate the neccesary reductions required to your v-speeds to provide a selected margin. Therefore the speeds can be un-balanced (For those unfamiliar, a balanced v speed means stop distance = take off distance required). Remember, that airlines and software developers all get their data from somewhere in the first place - Every thing is able to be calculated manually... It is just very time consuming, and for most of the general public, such manuals/info from the manufacturer is not available (I am just fortunate I have it). I agree TOPCAT would make it a tonne easier, hoping Christian can create a profile sometime in the future once PFPX settles down.
  21. machine2035

    Guide/Tutorial: Takeoff Performance in the 777

    Hi Richard, The FMC is only able to calculate V-Speeds. As mentioned by some others, it is unable to calculate using the ATM (Assumed temperature method) for an assumed temperature and associated de-rate rating. Usually if the figures in the FMC are conservative compared to what we calculated, we will use them anyway (but keep the assumed temp/de-rate that was calculated). In regards to your TOPCAT/PFPX question, I am not too sure what you are asking. TOPCAT is not needed at all to use PFPX for it's main purpose - to generate/build a flightplan and hence release an Operational Flight Plan. On aircraft which are supported by TOPCAT (not the 777 at this stage), the only advantage of having TOPCAT with PFPX is that you can incorporate the TO DATA directly into the OFP release rather than calculating it at a later stage individually with TOPCAT application. I assume we will see another 3rd party dev such as Aurasim or that bloke that made the freeware NGX take-off data calculator some time in the near future... I just hope those which would like to have some primitive performance method prior to these such tools being released.
  22. machine2035

    Guide/Tutorial: Takeoff Performance in the 777

    Okay. So basically, the purpose of the 'TO1 Takeoff Weights' table is to be able to convert the figures calculated by the 'Takeoff Charts' into ones that take-into account the 10% less thurst available For example, you find, after plotting your lines on your 'Obstacle Limit' chart, that your obstacle limit weight is 280t. If you look at the TO Takeoff Weight table, you can see that corresponds to 251.9t. So therefore, using a TO-1 derate, due 10% less thrust, your now limited to a MTOW of 251.9t. On a OPT or similar tool in real life, usually the MTOW is follow by a letter. A number followed by S, usually means structural MTOW (so what the plane is designed to go to), or a L which means limit (due to obstacles, brake energy etc.) I have only ever seen a few cases were MTOW are limited by brake energy or tire speed, but there are a few airports where obstacles play into the game. It all just depends where you are flying out of. Hope this helps a bit.
  23. machine2035

    Guide/Tutorial: Takeoff Performance in the 777

    Currently at work on my iPad, but when I finish in a few hours ill explain it all - unless someone beats me to it :-).
  24. machine2035

    Guide/Tutorial: Takeoff Performance in the 777

    You're welcome. If anyone has any other questions regarding understanding some of the data presented in the Performance Dispatch/Inflight sections of the FCOM, please ask away!
  25. machine2035

    Guide/Tutorial: Takeoff Performance in the 777

    ..... Obstacles only limit the take-off weight. Unless there is a signifcant obstacle, which @ Sydney I assure you not there is not, MTOW is not penalised very much (and no, before anyone asks, centrepoint tower is not in the way :lol: ). In any case, it is hard to find obstacle data with distance from brake release etc.