Jump to content
Sign in to follow this  
Guest adesmith

General trip and performance planning

Recommended Posts

Guest adesmith

Fairly new to PMDG QoS, but I did spend a great deal of time flying Aerowinx PS1 (am I allowed to say that here without getting spat at?)During that time I created (following hours of extensive testing) an EXCEL spreadsheet which would calculate whether I could get off the available runway length with current gross weight (something I can't find in the QoS manual) and also calculate total fuel required for the trip allowing for take off weight, fuel required on landing, forecast upper winds and optimum flight level (it even allows for eastbound/westbound levels)In two flights I have so far made using that sheet for the calculations I have found it to be remarkably accurate (without ever recalibrating any of the data), being within one tonne of predicted fuel all the way on a 4 1/2 hour flight.If others have beaten me to it and made such spreadsheets available to the PMDG community then I apologise for not reading through all of the forum posts before uploading this.Alternatively if anyone would like a copy of this spreadsheet then please post a message here with email address and I will happily send on a copy.Equally if anyone thinks they have the appropriate skills to translate the formulae (some of them are rather large!) into Lotus 123 or other spreadsheet styles then I would be happy to provide an "unlocked" copy with access to the formulae and data tables.Adrian Smith

Share this post


Link to post

Hi Adrian,this sounds like something ive been searching for! any chance you could send me a copy via email?paulmcmahonie@yahoo.iemany thanks

Share this post


Link to post
Guest phileypoo

Would be nice if I could get a piece of that. phileypoo1@aol.comThanks in advancePhil

Share this post


Link to post
Guest Matthias1975

If you wouldn

Share this post


Link to post
Guest adesmith

I think I have sent a copy to everyone who asked.Any questions on filling it in or using it please let me know.

Share this post


Link to post

A quick question on ZFW. Mine was 516.9 and i get 'TOO ZFW' in red beside it. Forgive the simplistic question, the figures are filled in the top right hand side after the temp, runway length and zfw are input how do i know which type of take off is required? Is there a way of finding out the assumed temperature based on the calculated figures?

Share this post


Link to post

Hi Adrian, excuse the late response but I would love an unlocked copy if you please, I may be able to convert this into a webpage using some of my whizz-bang-ery at work. Only if you're happy with this!mark.adeaneparadise.net.nzCheers!


Mark Adeane - NZWN
Boeing777_Banner_BetaTeam.jpg

Share this post


Link to post
Guest adesmith

It should say "TOO HEAVY ZFW", it appears that at some time I have reformatted the column to the wrong width and the word "heavy" has dissapeared.Why is the weight you specify too heavy? simple, the spreadsheet worksd in KGs not Lbs so all weights are in Metric Tonnes (000s of Kgs)I have changed the sheet to correct this error (if you find any more apparent errors please let me know)I am trying to get the file uploaded so everyone can D/L it.If so I will post the link here.

Share this post


Link to post
Guest adesmith

Sorry Paul I only answered half of your question.I haven't a clue about assumed temperatures.Once you have entered the runway length, temperature and ZFW the table top right will populate.The figures it gives are as follows.1st cloumn - between ( and shows the max RTOW (Regulated Take Off Weight) for that runway, at that temperature, on a dry surface, at Derate 2 (top line) Derate 1 (2nd line) and full Take Off Power (3rd line)column AFTER shows the same data but for a wet runway.Example.Dry Runway length 14,000' temperature 25 (degrees Celsius please)Derate 2 you could get 409 Tonnes off that runway - well OK that is well above structural MTOW so there is no problem.Wet Runway length 6,000' temperature 30 degrees.You can't do it! (says NO in red in wet column)In between - 8,500' runway, temperature 20From a dry runway you could get 287 Tonnes off with derate 2 or 320 Tonnes at full thrust.If the runway was wet you could get only 257 Tonnes off at derate 2, 279T at derate 1 or 297T at full thrust.Once the full fuel plan is complete look at your GROSS WT (in R4) and compare it to these figures to see how much thrust you need bearing in mind the runway surface condition.The figure given will allow acceleration to V1 and abort from that speed WITHOUT use of reverse thrust.I am fairly certain that I built in a safety factor of up to ten knots tail wind component in the calculations, but don't quote me on that if you run off the end on a RTO.

Share this post


Link to post
Guest adesmith

The planner has been uploaded to AVSIM.Once I determine a URL I will post it here.Adrian Smith

Share this post


Link to post

If you wouldn


Regards,


Victor Quebec

Share this post


Link to post
Guest D17S

There's a discussion going on a couple of posts forward about how the V1 number is calculated. The following question was presented. To paraphrase. . . 'It seems odd that as GTOW increases, so does V1, given all other factors remaining equal.' I looked at an MD11 runway Vspeed chart for SFO's 28R and found this occurring too. V1 increased with GTOW and all other parameters remaining equal. The math you are using to calculate V1 might just provide answer. After all, math is just another language and can be a very precise method of communication. Could you upload an unlocked version to Avsim too? I'd like to get a look the math that is used to calculate the Vspeeds. That would probably answer the question.Thanks,

Share this post


Link to post
Guest adesmith

The planner does not calculate V speeds, I left that up to the FMC.However, there are two things to consider for V1.Fly capability (which must increase the speed as GTOW increases) and Stop capability.For any runway the max weight which you can accelerate to V1 and then bring to a stop is limited by power and braking capability.AFAIK the runway length is NOT used in determining V1, hence V1 is weight dependant so will increase with increasing GTOW.The runway length required for that accelerate/stop must also increase with increasing GTOW and V1 until the point is reached where runway available = runway required, you are now at limiting field length.The fuel and performance calculator will show you the RTOW (regulated Take Off Weight) for a given runway length and temperature, which may frequently display as greater then MTOW meaning that the runway is not of limiting length.If RTOW is less than MTOW then the runway IS of limiting length and you must select a thrust rating appropriate to the runway from the figures given.

Share this post


Link to post

I wonder what would be involved in calculating the rate of acceleration under TO, TO1 and TO2 at varying weights and temperatures to throw into the equation? Or has anyone got this data already?Given that we know the rate of deceleration afforded by RTO autobraking we could use these figures to come up with a calculator.


Mark Adeane - NZWN
Boeing777_Banner_BetaTeam.jpg

Share this post


Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  
  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
×
×
  • Create New...