want to know all about the calculations pilots make during the whole flight

[florismulock]

HI all,

i know this is a very big question.    today i already learned how to calculate v1 vr and v2 (although i am wondering why you would calculate v1  since the fmc is better calculator then a real pilot) ,  but i want to fly this great simulation like a real pilot would. this is why i am aking: if someone could help me out  what calculations i need to learn (and where to find them)  during a whole flight (and during the preparation like fuel calculation).

for example i want to learn how to calculate the length of the runway for takeoff (weights speeds wind etc)   and during a landing (for example you have an engine 1 out and you want to know if this runway is long enough)

its a very big question but would be very happy if someone could help me out!

Thanks

Floris

[skelsey]

Hi Floris,

It is a VERY big question.

The quickest and easiest answer I can give you to start with is to watch all of Peter's training videos here: http://aerowinx.com/board/index.php?topic=2583.0 in sequence and make copious notes as he goes through the process for most of the things you want to know!

[Jeroen Hoppenbrouwers]

Computers are typically better at calculations than humans, but if you feed them garbage, they will dutifully output garbage. Therefore, for critical calculations, typically at least two independent sources/calculations are compared to see whether they agree. Not to three decimals, but the same kind of outcome. One or two knots, who cares.

In many cases today, the FMC is one source, and the EFB the other. Or the FMC and the office-based dispatcher. Or all three.

The FMC is usually the most simplified of all... and the more advanced algorithm, larger lookup table etc. computers can get safely closer to legal limits than the FMC can. You can shave off a ton of fuel this way, or add one more passenger, etc.


Hoppie

[florismulock]

EBF?  you mean EFB electronic flight bag?

[Jeroen Hoppenbrouwers]

Yes. Corrected.

[Will]

Pilots haven't traditionally done much calculating.

That's for the dispatchers and the engineers.

Even before computers, the engineers at the manufacturing plant would come up with look-up tables, where you would go in with known performance factors (runway length, weight, thrust, temperature, and so on) and come out with the desired number. The pilots would go into these look-up tables for their numbers.

The FMC just makes this process automatic, by computer-izing the look-up tables.

[florismulock]

thanks
that may be true, but seems to me that a pilot still have to know all the calculations by heart, so that in the unlikely event (which has happend during an plane accident have to look that one up) the computer calculates the wrong speeds for a landing, the pilot will not just say, what the pc says is always right so lets put these speeds in the fmc. , thats why the pilots during that succesfull landing saw the fault and calculated their own speeds.

thats why i want to learn all about these charts and calculations.  like the calculation how long it will take to get from point a to point B

currently i am watching the britjet videos for my answers which are great but any more information about all the calculations i need to to plan and calculations about the whole flight would be great!!!!!

thanks

[Will]

That's not how it worked in my airline. The pilots only calculated one thing, and that was the center of gravity.

Everything else was in look-up tables. Like V1, VR, V2, and runway distance needed for landing -- all of that was pre-calculated by the engineers and by the dispatchers, and stored in the aircraft in the form of look-up tables. So for example, if we were landing at KSTL on RWY 12, the elevation, slope, and distance were known quantities. So we would go to the KSTL RWY 12 page in the performance book, and would cross-reference variables like weight, pressure, winds, and any inoperative equipment, and answer the question of whether there is enough runway to land.

But if that table flew out of the window, or got eaten by a hungry passenger, there was no way we could construct the actual landing distance from raw performance numbers. Instead, we'd just radio the dispatchers, who presumably had an intact copy of all the performance tables and they would look up the numbers from their look-up tables and then tell us what the answer is.

[florismulock]

Will thanks, i gues it depends on the airline then (i got that scenario from airplane investigations series)

maybe you still have some of these charts?  perhaps you can help me out with calculation the landing length?  britjet has a short video about it but its really hard to find the info (the chart i mean)

[skelsey]

As mentioned above, take-off and landing performance is all from tables which have been constructed in the first instance by Boeing from their flight test data, then airline performance engineers will do the sums for each runway taking in to account obstacles etc and generate their own tables.

These runway-specific tables are not really possible to get hold of, but the generic Boeing data can generally be found in the Performance section of the FCOM/QRH. Likewise landing performance data is also tables within the QRH.

The tables themselves tell you how to use them. In airlines where manual performance calculations are carried out there may be a 'vital data card' that is filled out for each takeoff.

The basic procedure involves finding the maximum RTOW (Regulated Takeoff Weight) for the runway and conditions. This normally involves entering the table at the current OAT, which will provide the maximum TOW for that runway length at that OAT but in otherwise standard conditions. The actual RTOW may then be founs by taking the current QNH and applying a weight correction per hPa above or below standard, applying a similar correction for head or tailwind component (add weight for a headwind, reduce for a tailwind) and applying further corrections for MEL items, anti-ice, air conditioning usage etc (the actual values will depend on the specific engine type and airframe configuration).

Once the RTOW has been found, it is then necessary to compare this to the planned TOW. All being well, the RTOW will be greater than or equal to the planned TOW.

Assuming that the RTOW is greater than the actual TOW, it may then be possible to calculate an assumed temperature reduction. To do this one applies all the corrections above in the reverse sense and adds them to the actual TOW. You then enter the table at this 'assumed TOW' and read across to the temperature.

i want to learn all about these charts and calculations.  like the calculation how long it will take to get from point a to point B

Time = Distance/Speed

[Jeroen D]

I'm just a meagre private pilot and all private pilots tend to do all the calculations themselves as part of your fight planning/preparation. Some of it is a bit simpler for the single engine planes I'm rated for.

Take off and landing performance is all done via look up tables in the respective AOM.
Weight and balance could be piece of paper or these days an app. For instance:
https://itunes.apple.com/us/app/cirrus-proflite/id574293396?mt=8

Fuel planning is a piece of paper and their are a few (planning) apps around that come in handy too.

I did my check ride not to long ago, but as part of that you had to be able to demonstrate to master all these calculations and tables. No apps allowed!

Jeroen

[Jeroen Hoppenbrouwers]

One app allowed   :-)

[Frank Jacobs]

Love it Hoppie thxs.......:-)

[Jeroen D]

One app allowed   :-)

I have one of those! More importantly, I know how to use it too!

My CFI was most impressed, but could not understand why I would want to understand one of those things. The FAA does allow electronic flight computers these days. Even during your check ride.

I'm a bit of a sucker for slider rules, got various ones and a Breitling watch with its slide rule bezel. Not very practical in a cockpit I must admit.

Jeroen

[florismulock]

i will try to get a hold on these FCOM documents.  maybe buy the new pmdg 747 (which comes with the official documents).  and ofcause watch all the tutorial videos.

i hope you guys dont mind if i have more questions about this!

thanks!

[skelsey]

One app allowed   :-)

You'll be pleased to know (I was!) that there's a (free!) app for that (and I don't mean a digital, plug in the numbers and get an answer back, app -- an actual virtual whizz wheel):

https://play.google.com/store/apps/details?id=dao.DaoSoftware.FlightComputerSim&rdid=dao.DaoSoftware.FlightComputerSim (Android)
https://itunes.apple.com/gb/app/flight-computer-sim/id951334562?mt=8 (iDevice)

Hours of fun...

[cagarini]

Hi Floris.

I think you are young enough to consider a job as a Flight Operations Officer / Dispatcher.

The few positive cases of friends who were willing to get a job as airbus drivers around here all had in common having worked as flight dispatchers - at least TAP gives a good deal of importance to that, probably even more than logged flight time with an ATPL, but still being mostly a private pilot.

Your question is, unfortunately, answered by tables and computer calculations, but just as you, and since I still use a map and that same calculator Jeroen posted above on my gliders flights ( I'm probably the only guy in the airfield carrying a Map for an x-country :-) ) I really like to know how to do the calculations, just in case there are no putters available :-)

[Hessel Oosten]

Floris,

Rod Machado's: Private Pilot handbook is a wonderful source of information/calculations/basics etc.

Here a few pages as example:

https://www.simshack.net/media/files/Private_Pilot_Handbook_Sample_Pages.pdf

Hessel

[florismulock]

thakns jcom that is an interesting job but if aviation i would prefer to be a pilot. still cant complain got a great job in the hospital pharmasist technician. yeah iam a person who wants to know the who what and why. makes the sim so much more fun!

thanks for the information, like i said before right now iam reading a lot of info so maybe later this week or next week i will ask more questions about calculation etc   thank you all for the help so far!!!!