Simviation Forums

1) Flight Planning.

Every flight starts with some sort of plan. Even if it's just to make sure the weather will be VFR; the winds are within your ability, and there's enough fuel on board to fly a few touch-and-gos... All the way up to checking density altitude, the plane's loading, and how long each leg of the flight can be, given the amount of fuel you can carry with passengers and baggage... Can each runway on the route (including alternate airports) handle your plane at take-off weight ?... Will the weather and winds be favorable along the route ?... How will the winds affect your heading and ground-speed, and consequently, your fuel burn ? We'll get into non-VFR flight planning much later. All we're trying to accomplish, is to get the piloting frame of mind going.. and to make sitting down in front of the monitor something worth thinking through, as though you were about to really climb into an airplane.

By no means will we cover comprehensive, real-world flight planning.. but we will concentrate aspects relative to simming, without getting laborious or requiring the purchase of charts and flight computers (there are plenty of on-line E6B emulators).

1.a) A Sim Private Pilot will be expected to calculate a magnetic heading needed to maintain a magnetic course for a known wind aloft.

1.b) A Sim Private Pilot will be expected to calculate true airspeed (TAS) and the resulting ground speed for a known wind aloft.

1.c) A Sim Private Pilot will be expected to calculate a climb/cruise/descent fuel burn for a known ground speed, for each leg of a flight.

1.d) A Sim Private Pilot will be expected to submit a complete flight plan utilizing data from parts 1.a.b.c... including airport information for each planned stop (including alternates) consisting of; available runways, pattern data, and airport elevation... and any nav-aids to be used en-route.

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OK.. let the questions and discussion begin. The idea here will be to get an informal, fun and friendly way to acknowledge our progress through ratings and endorsements issued by members already holding a rating or endorsement. Until we can come up with a better method; the only tool we have at hand for check-rides, is the FSX shared cockpit. Obviously, there will be some bugs to work out, and it will take some time before there is some consistency. I figure we gotta start somewhere. So here it is

Sounds good.  Do you know of any online reference materials that can be used for this?  If you don't, I can scan some performance pages from my PIM for the 172 that could be used.  It should be pretty close to the values we get in the sim.

Please do...

I was going to use the one of the airplane in the tree behind the learn to fly sign, but decided against it.


Here are a few links that might be helpful for flight planning:

Online Aviation Charts - http://skyvector.com/

Airport information - http://www.airnav.com/airports/

Online E6B - http://www.csgnetwork.com/e6bcalc.html

Weather - http://adds.aviationweather.noaa.gov/

FAA Flight Plan Form - http://forms.faa.gov/forms/faa7233-1.pdf

I changed my sig so maybe a few more people will get interested in this too.

Excellent !  I use all those sites, quite regularly, for real planning. Edit this weather link into that post too, if you will  http://adds.aviationweather.noaa.gov/  ... to keep things organized (I'll edit it out of this post).

Now... I'll put together a basic, sim flight plan, as an example, using those sites...

We'll get into more accurate and advanced performance data for the C172 later. For the purposes of Sim training, all we need to know is fuel consumption under normal cruise settings (2400rpm, properly leaned, 9gph at a typical cruising altitude of 4500msl)... and we'll know that 3 gallons will be used for start-up/taxi/takeoff/climb. The MSFS C172's

In all my years of flying, I've yet to come across a paved runway not long enough to get a safely loaded C172 up and over the trees; even on the hottest of summer days. Granted, I've not done much mountain flying, where field elevation is a concern, but for the sake of sim flight-planning, at this time, we'll assume that all paved runways will be long enough... and we'll touch on density altitude, in its simplest form.

Density altitude is the first thing to address during your weather planning. More times than not, it will just be a formality, but if you ever get to flying heavier/faster airplanes, it's good that your first instinct is to consider density altitude. For sim-planning, all we need to worry about is the temperature. Hotter air is less dense, and that's a triple-edged sword to a normally-aspirated, piston airplane.

1) There is less air available for the wings to generate lift.
2) There is less air for the propeller to generate thrust.
3) There is less oxygen for the engine to generate horse-power.

The affect can be dramatic. On a hot, summer day, where the C172 is well past the departure end of a 5,000ft runway, almost ready to turn to the crosswind leg before reaching pattern altitude (normally 1000agl).. that same C172 can be at pattern altitude by the end of that 5,000ft runway, on a cold winter morning.

In short... air gets less dense as altitude increases. Hot air is already less dense and can make the plane "think" it's already at a higher altitude, before even taking off. Hence, density altitude is the actual altitude, adjusted for temperature (and atmospheric pressure and relative humidity, but we don't need to be that advanced in simming, yet). It's so important, that most AWOS/ASOS/ATIS broadcasts will include density altitude.

Since all our flights at this time will be VFR, all we'll account for in our planning is winds aloft... and that there isn't a fore-casted crosswind beyond our ability, at any of our stops, or alternate airports. Terminal Aerodrome Forecasts (TAF) are your best source for weather at specific airports. These (along with winds aloft) can be found at the weather planning site listed earlier in this thread.

I'm going to include the pertinent data for our flight... we can discuss how to navigate the weather site as we go.

A TAF map gives us a glimpse at the prevailing surface winds...



The little flag from each reporting station points to direction from which the wind is coming... and each line on the flag represents 10knots, Since there are no flags showing more than 15knots along our route, it's safe to assume that there will be no crosswinds with greater than 15knot components (the C172's published limit). This map also shows that there will be marginal, if not IFR weather, at times... but for now, we're just concerned about winds.

TAF data for a couple of stations along the route (green arrows) confirms things for us.

KTOL 151501Z 26011G15KT 10SM

KTOL 151501Z 26011G15KT 10SM  (Toledo)

KMBS 151453Z 32011G14KT 10SM   (Bay City)

KPLN 151512Z 33015KT 9SM      (Pelston)

Just a quick one Brett, as I've never flown in the states (hopefully not for too much longer); looking at those TAFs, 10SM, 9SM etc - I take it that is met vis in Statute Miles (SM)?...

...I only ask as in TAFs over here it is quoted in Km (5Km and above) or metres (4999m and below) - but is always written in X000 (m)...

Yes.. that is the visibility in statute miles..  There is much more data in a TAF, but we won't get to that, until later...

Yes.. that is the visibility in statute miles..  There is much more data in a TAF, but we won't get to that, until later...

Quite! Seeing "SM" though immediately struck me as being odd to my (European) eye...

Seeing that many of the simmers here are European...  keep pointing things like this out.. we'll all learn more  :)

The next step is to choose our planned fuel stop. Somewhere well past the 1/2-way point will work nicely. Since I've taken this flight for real, many times, we'll use my favorite stop;

All looks good to me. My only tip (or cunning cheat when not paying for the fuel) is fly at a mutiple of 60kts TAS. Makes MDR so much easier.

Talking of MDR, using just basic rules of thumb can be used to check it quite nicely. Calling 107KTAS roughly 1.8miles/min (ie, roughly 2), we can calculate our max drift with the 35kt wind: Windspeed (kts)/TAS (miles/min), in this case very roughly 35/1.8ish, so about 20

You're getting a little ahead of me and applying a more "real world" approach to this, but that's a good thing. Eventually I was going to point out that this regiment of flight planning is mostly a student pilot thing. There is no pilot alive who can hold a heading +/- a few degrees for more than a few nautical miles... and no winds aloft forecast is accurate enough in either it's direction, or velocity to justify exact calculations.

I'm reminded of my first oral exam. The examiner posed a runway and wind (runway 27.. wind 235@25knots) and asked me to tell him the crosswind component. I couldn't for the life of me find the conversion chart.. so I said.. "If the wind were exactly 1/2-way between pure crosswind and runway heading (225), the crosswind component would be slightly more than 1/2...  since 235 is less than 1/2-way toward a pure crosswind, the crosswind component would be about 1/2 the wind.. or, 13knots, give or take"...

The reason students are drilled like this, is to nail home the whole concept of how wind affects both heading and ground speed. To some new pilots, it's a completely foreign concept. Methods like yours, or even an experienced pilot's mental estimates are accurate enough, so long as you're not pushing the limits (like I have for the first leg). I could glance at a flight plan like this and know right away that that first leg would be in the neighborhood of 3 hours, and at the limit for the C172 as we have it loaded...

I'd still like to see a few alternate fuel stops posted with reasonable estimates for the fuel required...  :)

This is interesting so far (a little review never hurt any pilot), and a lot of nice work, but if you are looking to get non-RL pilots interested in proper flight planning etc., this thread might be better situated in the sim forums ... I see that so far, only RL pilots seem to have taken any interest.
I realize that this section is for real and sim training discussion, but the majority seem to look at threads specific to their sim for information.
Just a thought... maybe an announcement in the FSX/FS2004 forums to get the attention of those who might want to learn about this and apply it to the sim?

Or am I completely missing the purpose of this discussion?