Flight planning: paper vs foreflight

[cavmedic]

Okay, looking through what you've got to try and see where you may have erred in the paper calculations... I also punched your route into ForeFlight, including the waypoints as close as I could get them, and the 90 knots/4.1 gph figures from your flight plan sheet, so I've got ForeFlight showing pretty much what your screen shot had.

First of all, what winds aloft are you using for the first (climb) leg? The only winds I see on your sheet are the ones at 4500, 260 at 39 knots. On your course of 249, that'll be slightly from your right, but your wind correction angle is listed as 5 degrees left. I would suggest that for the climb you use the winds aloft at 3000 feet interpolated between the AVP and EMI forecasts. Later in the flight, you'll be much closer to EMI, so for the last legs at 4500, the EMI winds interpolated between 3000 and 6000 might make more sense. Either way, IMO you should put the winds aloft that you're using for each leg on that leg's line, that's why all those spaces are there. You may have calculated the first leg correctly if you're using different winds than you are for the rest of the flight, but without knowing what those are, it's difficult to tell.

Second - Your total distance is a bit longer (51.4) than ForeFlight says (50). Check to be sure you're not rounding up on all your legs or something.

Third - On the first leg, there's something wrong. You've got it listed as 54 knots GS, 5.4nm, and 8 minutes. 54 knots for 5.4nm is 6 minutes; Or if you're using 8 minutes as your time to climb, 8 minutes at 54 knots would be 7.2 nm.

Fourth - On the third and fourth legs, you've got 12nm and 10nm as the distances, respectively, but 13 minutes for the time on both of them.

Now, on any of the electronic flight planners that didn't have you enter different speeds/fuel burns for climb, cruise and descent (such as ForeFlight) you may end up with a slightly higher fuel burn and total time on paper because you're taking into account the slower, thirstier climb while they may not be. Also, I believe ForeFlight has a system that results in a "gridded" winds aloft scheme that, while based on the forecasts you're using, is doing a much more complex interpolation so if the winds aloft forecast stations surrounding your flight are showing winds that differ from each other significantly, and you're only using one of them, the calculations will be different.

Hope this helps, let us know what you discover!

Not allot of time to make a full reply right now. In between service calls at the moment but I took my first leg, AKA ground to TOC , based on ground winds and direction as rcvd from the Atis at KRDG.

As for the distances being off, I did notice that last night , but figured it being somewhat due to being brain scrambled , and having to use two sectional for the trip and some rounding. Kinda lazy on my part with that........ I was not really concerned about those at the time as my main issue was the headings. So that may be what you picked up on with those calculations. I do see there are a bunch more replies , so I will try to address them tonight when I get home.

I have a night XC planned tonight directly after work with the instructor and need to get done with my calls , so I can go fly

 

[OzPilot]

When you make a plot line on a sectional, are you converting it based on magnetic variation? Sorry if I missed where you said that

 

[flyingcheesehead]

Not allot of time to make a full reply right now. In between service calls at the moment but I took my first leg, AKA ground to TOC , based on ground winds and direction as rcvd from the Atis at KRDG.

Hmmm... Has your CFI given you any direction as to what winds to use for the climb? I see two reasons to not do what you're describing:

1) ATIS is either "now" or up to an hour old. If you're going to use ground winds to plan a flight, I would suggest using the TAF instead... But I don't suggest that at all, because

2) Winds on the ground often vary significantly from winds as little as 100 feet off the ground. That's why I suggested you use the 3000-foot winds aloft as the number for the climb - You're climbing from a bit under 1500 up to 4500, so I think you'll end up with a more accurate result that way.

 

[TedR3]

What airspeed are you entering in FF?

Here is what foreflight shows WITHOUT any wind data

 

[cavmedic]

When you make a plot line on a sectional, are you converting it based on magnetic variation? Sorry if I missed where you said that

Yes I am , I didn't mention it , but one of the posts has an attachment showing those figures.

 

[cavmedic]

What airspeed are you entering in FF?

90 knots based on POH @ 2400 RPM at cruise for that altitude.

 

[cavmedic]

Hmmm... Has your CFI given you any direction as to what winds to use for the climb? I see two reasons to not do what you're describing:

1) ATIS is either "now" or up to an hour old. If you're going to use ground winds to plan a flight, I would suggest using the TAF instead... But I don't suggest that at all, because

2) Winds on the ground often vary significantly from winds as little as 100 feet off the ground. That's why I suggested you use the 3000-foot winds aloft as the number for the climb - You're climbing from a bit under 1500 up to 4500, so I think you'll end up with a more accurate result that way.

Im 99% he said to use ground winds, but I will double check again tonight when I talk to him.

I remember him mentioning something about some people use ground and some use Aloft , and some climb to altitude then over fly the airport to pick up their plan . I could have some of this jumbled up though.

Also on some of the fuel and times , I think I switched between wheel and cx2 ,so that may account for the distance , time , fuel discrepancies you noted.

As noted before , i was not concerned about that as much as I was with the headings last night.

 

[denverpilot]

Kent... nice job.

And I learned something there too... the whole "VOR has to be reset" thing...

Makes perfect sense, of course, but I never thought of it, nor have I ever been taught it or anyone mentioned it before. Cool!

"Resetting" would entail a whole pile of chart updates...

 

[jaybee]

90 knots based on POH @ 2400 RPM at cruise for that altitude.

that needs to be corrected for non-standard pressure and non-standard temperature.

 

[flyingcheesehead]

And I learned something there too... the whole "VOR has to be reset" thing...

Makes perfect sense, of course, but I never thought of it, nor have I ever been taught it or anyone mentioned it before. Cool!

"Resetting" would entail a whole pile of chart updates...

Not only chart updates, but I believe re-flying all of the procedures and airways based off of that VOR. DREAR intersection on V2 near here was moved by 0.1nm DME after a VOR update a few years ago.

Heck, take a look at the Badger VOR. If it gets adjusted, you're talking about changes to the following:

* 6 low altitude airways: V2, V30, V63, V170, V191, V217
* 9 high altitude airways: J16, J34, J36, J68, J70, J89, J101, J105, J538
* Sixty (!) airspace fixes - I'm not kidding! ADALE, ATOWN, AUGER, BEERI, BESIE, BGOSH, BITTN, BONOT, BRAVE, BROTS, BURNN, CANUL, CARNA, CORIR, DAANE, DABJU, DARIA, DEBOW, DODGE, DREAR, DUTYS, EWAWI, FLAMS, GARTT, GORRY, GREAS, HAWKN, HISUB, HOGMI, IRITE, JAYBE, JUVMI, KABBE, KINIC, KRSPY, LIIME, LISSI, LYSTR, MAFIW, MAKTR, PETTY, PROOT, RANDO, RASTT, ROBBY, ROSKY, RUDIE, SLING, SLUGR, SUDDS, TALOR, TRUDO, UQACY, VEENA, WAITS, WAUCA, WIDKI, WILDD, WIPED, and WITSU.
* Many arrivals, departures, and approaches - I'm not even going to attempt to count those, but right off the top of my head, the VEENA TWO arrival to KMKE, nearly all the approaches into KMKE, KUES, KMWC, and many other airports in the area - And not even that close, it's an IAF for some of the approaches to Fond du Lac too!

So, I'm sure it is not a trivial exercise to get the VOR adjusted, and get all of the procedures based on it checked and tested. Yikes!

 

[Let'sgoflying!]

what would need to be done in order to make the FF briefings viewed as fulfilling all faa legalities?

 

[denverpilot]

what would need to be done in order to make the FF briefings viewed as fulfilling all faa legalities?

Two thoughts:

Who says they don't? Got a link to an FAA document that says the way they're doing it doesn't count?

On the other hand, FAA doesn't even trust their own ADS-B FIS-B data to be used as official weather data, so ... Well ... Whatever.

End of thoughts. Now for the sarcastic joking...

Look at sky. Blue?

Wet finger, stick in air. Not too cold and finger didn't blow away?

Go flying. Takeoff into the wind, the cold side of said finger.

Don't crash.

Then the lawyers won't have a chance to nit-pick your preflight briefing that they think you should have stored on a 64GB thumb drive that just barely holds all the FDC NOTAMs.

 

[Let'sgoflying!]

Who says they don't? Got a link to an FAA document that says the way they're doing it doesn't count?

Please, please no one go asking them for a legal interpretation, because we know some b'crat will love issuing one of those FAA edicts spelling out just how it is illegal it is.

 

[cavmedic]

OK , sat down tonight for a few minutes with my Chief Instructor before I few out on a night XC.

We looked at my flight form and also the screenshot from FF posted earlier.

Observation number 1. Looking carefully on the FF screenshot , and as I noted in that post , winds aloft were not calculated on FF. ( for what ever reason , they weren't available all last night , but neither here or there)

Looking at the CMC ( paper form) , it is within a few degrees of what FF says
. ( why did I not see that) I know last week it was way off. grrr , who looks like the ass now

As to one of the questions earlier about winds on climb out. He said for me to use the winds aloft for 3000 feet. Due to the variations of obstructions at ground level , being in a valley etc etc. ( makes sense )

As for what he and I seen last week ( that prompted this whole thing ) He said to basically not worry about it , because things change , **** happens and don't obsess over it

But I must say it has helped me understand the whole planning stage a bit more and I did get more practice doing it.

Some of the other things mentioned about the VOR resets and changing approaches and whatnot . Just a bit over my head , but it does look like my little misfortune or error has brought a few things out that some guys have not given much thought. Just glad it didn't turn into an IPAD measuring contest like some threads do . I thank all participants for that.

Now that I'm home , I'm exhausted and it is time to hug the dog and kick the wife a bit ...

See everyone later and thanks for all the info , tips and responses.

 

[OzPilot]

Foreflight will calculate winds aloft and adjust your plan if you enter the altitude you want to fly at in your route. Are you putting it in?

That being said, VFR is just that, Visual. I generally pick a landmark along the route to fly over which then begins my log and plan of my wind adjustments for heading and groundspeed and ETI etc.

Sometimes I would evendepart above the departure airport to log/time and set on course as per closest calculated winds at 2000 ft.

Cheers

 

[flyingcheesehead]

what would need to be done in order to make the FF briefings viewed as fulfilling all faa legalities?

Nothing - When you go to File & Brief and tap the "Brief" button, it downloads a full DUATS briefing, which is a "legal" source. Make sure you've got the right tail number in there though...

 

[jesse]

Often times for winds aloft I'll base it on skew-t instead of the winds aloft product.

You should have seen how excited the sky divers got over the skew-t when I showed it to them and explained it. Based on my experiences flying them, where the wind at 10,000 ft really does matter, it's been a LOT more accurate then the official winds aloft.

 

[Richard]

Often times for winds aloft I'll base it on skew-t instead of the winds aloft product.

You should have seen how excited the sky divers got over the skew-t when I showed it to them and explained it. Based on my experiences flying them, where the wind at 10,000 ft really does matter, it's been a LOT more accurate then the official winds aloft.

As the two are derived from the same soundings, I am curious how you 'explained it" to the divers.

 

[jesse]

As the two are derived from the same soundings, I am curious how you 'explained it" to the divers.

Entirely different models - very different products and beasts.

Winds aloft:

• Only updates 4 times a day, and has no human intervention
• You must choose an airport that may be nowhere near you and just hope conditions are the same
• If the weather is changing the 4 times a day update cycle will cause major inaccuracies
• You only see every 3,000 ft

Skew-T:

• Based on RUC2 model, which updates hourly. Hourly is good.
• You can type in an airport identifier where you ACTUALLY are and get relevant data - not data for 50 miles east of you.
• You can see changes in detail, not just one value every 3,000 ft. This is a big deal.

You're better off with the Skew-T using the RUC2 model. I teach private students both and their limitations. I really push the skew-t onto instrument students and stress the advantages.

It amazes me that there are so many pilots running around there making decisions on the winds aloft product when there is a better option. I just don't get why it's not on aviationweather.gov.

 

[TMetzinger]

Are there legal issues using Skew-T since it's not given as a product in an FAA briefing?

I expect there are "process" issues involved that prevent it from being part of the data that makes up our standard briefing.

 

[dbman5]

Naviator uses something called the World Magnetic Model to determine the magnetic declination for lat/lon coordinates. I assume foreflight and online flight planners are using the same model.

You can look up the the magnetic declination for a coordinate using this tool:
http://ngdc.noaa.gov/geomagmodels/IGRFWMM.jsp?defaultModel=WMM

I'm not sure if this is related to your particular problem or not, but I thought I'd mention it.

Cheers,
Mike

Great to hear that Naviator is using that! I hope more of the on-line apps are starting to do the same but I can assure you that many of them weren't a few years ago. Worse yet, most of them gave me some really arrogant responses when I contacted them about the discrepancies I was seeing and why it seemed to be the a result of using VOR headings - which they confirmed and then did their best to justify. (And some of the justifications were really contrived.) And I did try to be very nice in my approach so I don't think that was the issue. Maybe my contacts with some of those on-line sources did some good in the long run.

And, FWIW, I use the WMM program you linked to in the navlog program that I created for myself in a database about 4 years ago. The database program is a great learning tool, much more powerful than a spreadsheet, and I still use it quite a bit since it already has all my local info in it. However, the new on-line stuff is much easier to use.

 

[harrytflight]

Just starting to use FF for flight planning. My instructor requires me, of course, on my sectional to draw a straight line from airport to airport and mark my checkpoints every 10 miles or so to begin my cross country journey. In FF, I draw a true course lets say 80 miles to my destination and I don't know how to just mark the checkpoints that I have selected without the true course line zig sagging to my destination. That wouldn't fly on the sectional for proper cross ctry planning. I hope you follow me.
I'm sure there's a simple answer, sorry

 

[jesse]

Just starting to use FF for flight planning. My instructor requires me, of course, on my sectional to draw a straight line from airport to airport and mark my checkpoints every 10 miles or so to begin my cross country journey. In FF, I draw a true course lets say 80 miles to my destination and I don't know how to just mark the checkpoints that I have selected without the true course line zig sagging to my destination. That wouldn't fly on the sectional for proper cross ctry planning. I hope you follow me.
I'm sure there's a simple answer, sorry

I would have no problem with a primary student using Foreflight - that said - I would turn off location services for some of their cross countries and randomly throughout others.

 

[midlifeflyer]

Are there legal issues using Skew-T since it's not given as a product in an FAA briefing?

I expect there are "process" issues involved that prevent it from being part of the data that makes up our standard briefing.

Huh? I must be misunderstanding your question since it sounds like:

Are there legal issues watching the Weather Channell using Skew-T since it's not given as a product in an FAA briefing?

Do either meet the sort of "safe harbor" of a "legal" weather briefing? Is there any problem with using them to supplement a "legal" briefing? Of course not. (indeed, Scott's, and others' primary mantra about the Skew T is that it supplements other information and is not a substitute for them).

 

[midlifeflyer]

Just starting to use FF for flight planning. My instructor requires me, of course, on my sectional to draw a straight line from airport to airport and mark my checkpoints every 10 miles or so to begin my cross country journey. In FF, I draw a true course lets say 80 miles to my destination and I don't know how to just mark the checkpoints that I have selected without the true course line zig sagging to my destination. That wouldn't fly on the sectional for proper cross ctry planning. I hope you follow me.
I'm sure there's a simple answer, sorry

If I understand correctly, your instructor is having you draw a course line directly between your departure and destination airports and then choose checkpoints that are within sight of but not directly on the course line.

Yes, if you want to actually mark those off-course checkpoints in some way that's currently one of the remaining limitations in ForeFlight - an inability to write on charts and maps.

But there's an easy alternative in your situation that I'd be fine with as an instructor (yours might not). Mark your checkpoints as user waypoints on the course line even thought what you are looking for is off the course line. If you've chosen good checkpoints they will be so obvious that you don't need to circle them. That's not a bad way to do it, paper or plastic.

 

[AggieMike88]

that's currently one of the remaining limitations in ForeFlight - an inability to write on charts and maps.

That actually sounds like a nice feature. Have the ability to insert something like a custom waypoint, but it's more of an informational "dot". And when we get close to the dot, or we touch it, something expands with the information we added.

I see it not only for useful waypoint details, but for additional information like expected frequency changes, desired altitudes, and more.

 

[JasonM]

That actually sounds like a nice feature. Have the ability to insert something like a custom waypoint, but it's more of an informational "dot". And when we get close to the dot, or we touch it, something expands with the information we added.

I see it not only for useful waypoint details, but for additional information like expected frequency changes, desired altitudes, and more.

You can already do this with ForeFlight. Click somewhere on your route, then click on the + symbol next to the Long/Lat info, then enter the name, then click done, then click about where you did before on your route, select waypoints, then select your custom waypoint.

 

[flyingcheesehead]

You can already do this with ForeFlight. Click somewhere on your route, then click on the + symbol next to the Long/Lat info, then enter the name, then click done, then click about where you did before on your route, select waypoints, then select your custom waypoint.

Or, I think this is more what the OP wants:

1) Tap and hold, then hit the + next to the lat-long in the resulting menu to create a user waypoint that's off of your route (do not add it to the route)
2) Repeat for each of your checkpoints.
3) Go to the map overlay menu and choose "User Waypoints" (3rd from the bottom, right-hand column) to display them on the map.

Done!

 

[JasonM]

Or, I think this is more what the OP wants:

1) Tap and hold, then hit the + next to the lat-long in the resulting menu to create a user waypoint that's off of your route (do not add it to the route)
2) Repeat for each of your checkpoints.
3) Go to the map overlay menu and choose "User Waypoints" (3rd from the bottom, right-hand column) to display them on the map.

Done!

oh.. I see. Not actually on your route, rather off to the side of your route.