I have a few questions for you today that I have yet to figure out.

1. What's the proper way to predetermine what my flight distance is going to be? Of course, a flight planner gives me the distance, but that's without SID/STARs. I never include SID/STARs in my flightplans, because I don't know which one I will be given by the controllers on IVAO or VATSIM. So is there any certain rule, for adding up a certain distance to account for SID/STARs? Such as, let's say, an extra 25 nm?
If I have my total distance, only then I can calculate my trip fuel properly

 

2. How do I predetermine what my cruising altitude is going to be? In a few 3rd party add-ons, I have to enter this value before the flight. Of course, I can also enter it as soon as the FMC has given me this value, but personally I don't like to ALT+ENTER all the time to access programs, if there's a way to get it out of the way before the flight. Of course, for calculating the cruising altitude, I will need my gross weight, but then what? Is there a certain table showing me what cruising altitude I should be using with certain weights?

3. How do I predetermine my cruising speed? As far as I know, this is the same as TAS, correct? If I look at people flying on IVAO, they always have very specific values entered like, 461, or 448, but how I do I properly predetermine this? Otherwise, I don't know what to enter in my flightplan on IVAO.

I have a few questions for you today that I have yet to figure out.

 

1. What's the proper way to predetermine what my flight distance is going to be? Of course, a flight planner gives me the distance, but that's without SID/STARs. I never include SID/STARs in my flightplans, because I don't know which one I will be given by the controllers on IVAO or VATSIM. So is there any certain rule, for adding up a certain distance to account for SID/STARs? Such as, let's say, an extra 25 nm?

If I have my total distance, only then I can calculate my trip fuel properly

 

2. How do I predetermine what my cruising altitude is going to be? In a few 3rd party add-ons, I have to enter this value before the flight. Of course, I can also enter it as soon as the FMC has given me this value, but personally I don't like to ALT+ENTER all the time to access programs, if there's a way to get it out of the way before the flight. Of course, for calculating the cruising altitude, I will need my gross weight, but then what? Is there a certain table showing me what cruising altitude I should be using with certain weights?

 

3. How do I predetermine my cruising speed? As far as I know, this is the same as TAS, correct? If I look at people flying on IVAO, they always have very specific values entered like, 461, or 448, but how I do I properly predetermine this? Otherwise, I don't know what to enter in my flightplan on IVAO.

Hi Arjen,

 

I will try to answer your questions without going into too much detail and confusing you.

 

1. Rather than using an average distance and then converting that into a fuel burn figure, most airlines which don't factor in the exact SID into their flight planning software add addition 'PAD' fuel in their fuel analysis. For example, for a normal SID/STAR in Australia, an airline for example would add 220KG for departure and 220KG for arrival. Depending on if the approach requires a longer procedure, additional fuel can be added. As a rule of thumb I just add 250KG for DEP/ARR, so a total of 500KG additional 'pad' fuel. IMO, converting 25nm into a fuel burn would require too many calculations as a different fuel burn is being consumed during every minute of the departure.

 

2. If you check out the 'Operating Manual Vol 1' that comes with the NGX when installed (can be found under Start Menu -> PMDG -> PMDG NGX -> Operating Manual Vol 1.pdf), you will find tables with OPT Altitude vs Weight. Just use the find option with a tag of 'Optimum Altitude' and it will find all the numerous tables with information regarding OPT ALT vs Weight. Be advised this is with a setting of LRC so using a higher/lower CI may affect the accuracy of these tables.

 

3. Crusing speed filed in a flightplan is filed in TAS as you indicated in your OP. There are a number of variables which contribute to the calculation of your TAS. If you don't feel like doing this for every single flight, 440-450 TAS is a general ball park figure that you will generally be between when flying the NGX at a normal cruise speed (.77,.78 etc). Anyway if you wish to calculate it manually for each flight, use an online calculator here (Or if you have a whizz wheel such as the E6B, you can do it physically with your hands :p0317: ).

As you can see with the online calculator, it has a default OAT Estimate correction of 0.02 (or 2% for every 1000ft increase). The usual temperature correction is usually in the range of 2%, so thats a good figure to use if your a simmer.

 

Anymore questions don't hesitate to ask.

This numbers are not too exacting in practice. Don't get wound up about pulling out a chart and scale. You might file for .78/456 and end up slowing for turbulence. Make any required reports, and keep on trucking.

 

I did a flight from SEA-BOS a while back. We ended up staying almost 10,000' lower that our planned cruise. We still made it there with almost the same fuel, time, etc. Old turbojets would not have made that flight. CFM-56 can handle that.

 

Of course, I'm accustomed to having a dispatcher do this work for me, so I'm one to talk. . . 

This numbers are not too exacting in practice. Don't get wound up about pulling out a chart and scale. You might file for .78/456 and end up slowing for turbulence. Make any required reports, and keep on trucking.

 

I did a flight from SEA-BOS a while back. We ended up staying almost 10,000' lower that our planned cruise. We still made it there with almost the same fuel, time, etc. Old turbojets would not have made that flight. CFM-56 can handle that.

 

Of course, I'm accustomed to having a dispatcher do this work for me, so I'm one to talk. . . 

Yep, definately.

 

Many people online the VATSIM network pull plans from FlightAware and copy cruising altitudes etc. They then wonder why the aircraft stops climbing 2000ft or 4000ft below what it planned. Some don't seem to realise that it is only that, a plan, and plans can always change for weather, operational requirements (weight) etc. Same for planned stepclimbs in filed ATS plans, just because its planned means they are going to do it at that waypoint. Could be before, could be after B)

Hi Arjen,

 

I will try to answer your questions without going into too much detail and confusing you.

 

1. Rather than using an average distance and then converting that into a fuel burn figure, most airlines which don't factor in the exact SID into their flight planning software add addition 'PAD' fuel in their fuel analysis. For example, for a normal SID/STAR in Australia, an airline for example would add 220KG for departure and 220KG for arrival. Depending on if the approach requires a longer procedure, additional fuel can be added. As a rule of thumb I just add 250KG for DEP/ARR, so a total of 500KG additional 'pad' fuel. IMO, converting 25nm into a fuel burn would require too many calculations as a different fuel burn is being consumed during every minute of the departure.

 

2. If you check out the 'Operating Manual Vol 1' that comes with the NGX when installed (can be found under Start Menu -> PMDG -> PMDG NGX -> Operating Manual Vol 1.pdf), you will find tables with OPT Altitude vs Weight. Just use the find option with a tag of 'Optimum Altitude' and it will find all the numerous tables with information regarding OPT ALT vs Weight. Be advised this is with a setting of LRC so using a higher/lower CI may affect the accuracy of these tables.

 

3. Crusing speed filed in a flightplan is filed in TAS as you indicated in your OP. There are a number of variables which contribute to the calculation of your TAS. If you don't feel like doing this for every single flight, 440-450 TAS is a general ball park figure that you will generally be between when flying the NGX at a normal cruise speed (.77,.78 etc). Anyway if you wish to calculate it manually for each flight, use an online calculator here (Or if you have a whizz wheel such as the E6B, you can do it physically with your hands :p0317: ).

As you can see with the online calculator, it has a default OAT Estimate correction of 0.02 (or 2% for every 1000ft increase). The usual temperature correction is usually in the range of 2%, so thats a good figure to use if your a simmer.

 

Anymore questions don't hesitate to ask.

Thank you James. Don't mind making things complicated, I am a pretty advanced FSX user, which just a few question that I've had for a long while. 

 

One more question though, where do I find the EO ACCEL HEIGHT for my specific departure airport. I wanna know this because the BARO knob should be set to runway elevation + EO ACCEL HEIGHT. I looked on all kinds of charts for a specific airport, but couldn't find them. Is there any default rule of thumb? I know for EHAM it's 1000 ft, not sure about other airports though.

 

 

One more question though, where do I find the EO ACCEL HEIGHT for my specific departure airport. I wanna know this because the BARO knob should be set to runway elevation + EO ACCEL HEIGHT. I looked on all kinds of charts for a specific airport, but couldn't find them. Is there any default rule of thumb? I know for EHAM it's 1000 ft, not sure about other airports though.

That is more operator specific and is based on what their engineering department finds.

 

If you have an airline profile that you try to use, they'll have a basic EAH. It might be 500' or 1000'.

Thank you James. Don't mind making things complicated, I am a pretty advanced FSX user, which just a few question that I've had for a long while. 

 

One more question though, where do I find the EO ACCEL HEIGHT for my specific departure airport. I wanna know this because the BARO knob should be set to runway elevation + EO ACCEL HEIGHT. I looked on all kinds of charts for a specific airport, but couldn't find them. Is there any default rule of thumb? I know for EHAM it's 1000 ft, not sure about other airports though.

Hi Arjen,

 

As Matt said above, airlines usually have their own EO procedures and for where I am we have Jeppesen publish EO charts for us which we have in our airway manuals. We also have the instructions on our AAM's (Airport Analaysis Manuals) and we write the procedure down on our TOLD cards (Take off and Landing Data Cards). However, we set our BARO bug to ACCEL height (not EO ACCEL), so depending if were using NADP1/NADP2 (Noise abatement departure procedures), we will usually either set 1000" AFE or 3000" AFE respectively.