# TOP OF CLIMB WITH A COURSE CHANGE

#### GRINMEX

##### Filing Flight Plan
Hello everyone! This is my first post on Pilots of America. I have a question that I always have had stuck in my head for a while and hopefully someone here can give me a detailed explanation. I would really appreciate it. Suppose that you are departing from P03. P03 sits at an elevation of 4,146 MSL. In this scenario the flight plan could be either VFR or IFR. Here is the scenario. I want to depart out of P03 and fly to KCGZ. I want to depart P03 and proceed direct to the DUG vortac then continue climbing along V66 as part of my route to 10,500 MSL. Here is the issue that I am running into. I know how to plan a Top of Climb. You plan a Top of Climb by looking into the performance charts to find out the fuel, time, and distance to climb and I am fully aware of that. But those charts only work if you are not going to have a course change during the climb. In this situation I want to depart P03 and climb to an altitude of 10,500 MSL. Once I depart P03 I will proceed direct to the DUG vortac and continue climbing to 10,500 MSL along V66. However, I know that I will not reach 10,500 MSL by the time that I hit DUG because P03 and the DUG vortac are only 8 NM apart from each other. I know that in my little PA-28-161 that I can not climb that fast in only 8NM. I would like to know how would I plan my Top of Climb (fuel, time, and distance) with a a course change and continuous climb.

Thank You,

Alex

Do it in two parts? Math. . . P03>DUG+DUG>TOC = Total

You would know distance to DUG (8 Miles), you know how fast you climb (70 or 75kts for best rate IIRC?) and with that you can find fuel.

Then do the rest starting from there? Wind is the variable on your groundspeed in a course change. How much is it going to change?

Why are you doing this? I'm pretty sure you can get reasonably close by just seeing how much fuel it takes to climb 6500ft starting from 4000. Make sure you climb over lower terrain to avoid making a splat.

The fuel and time will be correct regardless of course change (not factoring the insignicant loss of performance during the turn).

The difference will be WHERE the TOC is because groundspedd will change. It will likely be minimal. I wouldn't worry unless you have a truly honking wind.

Course change doesn't matter. Distance is distance, even if you turned around 180 degrees every mile and flew back and forth back and forth.

Think TOTAL distance flown, not distance from departure location. Or maybe for someone younger with GPS map stuff in their head, think "track line".

Let's just do a silly bad numbers one to show you what I mean.

Let's say you've calculated that you'll need to climb for 10 miles to reach your cruising altitude.

You fly straight north from the airport 5 miles and make a right turn of 90 degrees, and fly another five miles. That's where you'll reach your cruising altitude.

Time from the chart doesn't change. Whatever it said it'd take to go that 10 miles it'll still take to go that 10 miles. Doesn't matter where you point the airplane.

Now if you actually needed to know how far you were from the departure point in straight line from where you ended up after 10 miles, you flew a right triangle so bust out your Pythagoran Theorem. Heh. I'm kinda kidding here. You don't really need to do that. Just lay your plotter on the map and measure it.

Anyway, I think that's what you're getting tripped up on. It's not a prediction of how far away you'll be from the airport when you reach cruising altitude, it's a prediction of how far you've flown through the sky. You could do the entire climb circling above the airport and you'd cover 10 miles of circles.

Now for more fun...

What you really need to know is winds aloft to really get this right. Let's say in the silly scenario I gave above, there's a wind blowing hard from the east.

On your northbound leg, if you're using some Navaid to make that turn exactly 5 miles north of the airport, you're going to fly more than 5 miles through the air by a little bit. Because you're actually tracking a course line and the wind is blowing you to the west. So you'll really be crabbed into that east wind from your right.

When you turn east/right, now you'll really be bucking that headwind and it'll subtract from your groundspeed but not your airspeed. So over the ground, you'll be done flying "5 miles" long before you reach the 5 mile mark over the landmark you picked out there.

Fun, huh? You have to calculate what the wind aloft will do to your groundspeed at whatever TAS you're flying at.

But your distance and time to climb numbers are all about TAS until that correction. Or in a zero wind scenario.

We can do this with more realistic numbers if you're still confused. The idea here is to point out that it's distance through the air for the time to climb and distance to climb numbers, until they're corrected for winds.

Course change doesn't matter. Distance is distance, even if you turned around 180 degrees every mile and flew back and forth back and forth.

Think TOTAL distance flown, not distance from departure location. Or maybe for someone younger with GPS map stuff in their head, think "track line".

Let's just do a silly bad numbers one to show you what I mean.

Let's say you've calculated that you'll need to climb for 10 miles to reach your cruising altitude.

You fly straight north from the airport 5 miles and make a right turn of 90 degrees, and fly another five miles. That's where you'll reach your cruising altitude.

Time from the chart doesn't change. Whatever it said it'd take to go that 10 miles it'll still take to go that 10 miles. Doesn't matter where you point the airplane.

Now if you actually needed to know how far you were from the departure point in straight line from where you ended up after 10 miles, you flew a right triangle so bust out your Pythagoran Theorem. Heh. I'm kinda kidding here. You don't really need to do that. Just lay your plotter on the map and measure it.

Anyway, I think that's what you're getting tripped up on. It's not a prediction of how far away you'll be from the airport when you reach cruising altitude, it's a prediction of how far you've flown through the sky. You could do the entire climb circling above the airport and you'd cover 10 miles of circles.

Now for more fun...

What you really need to know is winds aloft to really get this right. Let's say in the silly scenario I gave above, there's a wind blowing hard from the east.

On your northbound leg, if you're using some Navaid to make that turn exactly 5 miles north of the airport, you're going to fly more than 5 miles through the air by a little bit. Because you're actually tracking a course line and the wind is blowing you to the west. So you'll really be crabbed into that east wind from your right.

When you turn east/right, now you'll really be bucking that headwind and it'll subtract from your groundspeed but not your airspeed. So over the ground, you'll be done flying "5 miles" long before you reach the 5 mile mark over the landmark you picked out there.

Fun, huh? You have to calculate what the wind aloft will do to your groundspeed at whatever TAS you're flying at.

But your distance and time to climb numbers are all about TAS until that correction. Or in a zero wind scenario.

We can do this with more realistic numbers if you're still confused. The idea here is to point out that it's distance through the air for the time to climb and distance to climb numbers, until they're corrected for winds.
Distance will indeed change seeing as though ground speed will change. Time and fuel burn will remain constant.

Distance will indeed change seeing as though ground speed will change. Time and fuel burn will remain constant.

Didn't read it all, did you?

Hello everyone! This is my first post on Pilots of America. I have a question that I always have had stuck in my head for a while and hopefully someone here can give me a detailed explanation. I would really appreciate it. Suppose that you are departing from P03. P03 sits at an elevation of 4,146 MSL. In this scenario the flight plan could be either VFR or IFR. Here is the scenario. I want to depart out of P03 and fly to KCGZ. I want to depart P03 and proceed direct to the DUG vortac then continue climbing along V66 as part of my route to 10,500 MSL. Here is the issue that I am running into. I know how to plan a Top of Climb. You plan a Top of Climb by looking into the performance charts to find out the fuel, time, and distance to climb and I am fully aware of that. But those charts only work if you are not going to have a course change during the climb.
To go a bit further, those charts only work if the predicted winds (typically calm) are of crystal ball quality, never change during the climb to altitude, the temperature remains standard throughout, and your pilot technique is legendary enhough that you maintain the exact climb speed to the penny, and never hit a bump. IOW, yet another aviation calc to give "exact" numbers based on estimated ones on tasks accomplished by regular pilots flying with varying technique and ability.

Back when I was taught to fly, My CFI showed it to me and told me to forget it. Instead, he suggested I just add 1 minute for every 1,000 feet to the basic level en route wind calculation to each sediment that had climb to altitude! I used it and eventually incorporated the 1/1,000 formula into a navigation flight tracking sheet I put together in Excel, and used it until websites and apps made it easier by integrating TOC , although I would not be surprised if come of them actually used by instructor's avdice. I startedusing them once I confirmed the 'real' cacluation as as accurate as mine, of coutse.

Didn't read it all, did you?
Well, your post is factually incorrect in most of its statements until you get down to your assertion that the term distance isn't an actual distance but some invented "True air distance" that doesn't match up with a physical distance.

What exactly is "Top of Climb" in this scenario? I've only looked at it as an IFR altitude assignment before.

What exactly is "Top of Climb" in this scenario? I've only looked at it as an IFR altitude assignment before.
It's the same in both IFR and VFR, if you don't confuse it with an IFR "top altitude" restriction.

It a flight planning calculation. How much time will it take and how much distance will it cover to climb from your 250 MSL departure airport to your Selected 3500 cruise altitude given that your climb TAS is 30 KTS less than your cruise speed. It's a pretty common calculation for locating and timing the 1st or 2nd checkpoint on student pilot cross countries.

It's the same in both IFR and VFR, if you don't confuse it with an IFR "top altitude" restriction.

It a flight planning calculation. How much time will it take and how much distance will it cover to climb from your 250 MSL departure airport to your Selected 3500 cruise altitude given that your climb TAS is 30 KTS less than your cruise speed. It's a pretty common calculation for locating and timing the 1st or 2nd checkpoint on student pilot cross countries.

Got it. Thanks

Hello everyone! This is my first post on Pilots of America. I have a question that I always have had stuck in my head for a while and hopefully someone here can give me a detailed explanation. I would really appreciate it. Suppose that you are departing from P03. P03 sits at an elevation of 4,146 MSL. In this scenario the flight plan could be either VFR or IFR. Here is the scenario. I want to depart out of P03 and fly to KCGZ. I want to depart P03 and proceed direct to the DUG vortac then continue climbing along V66 as part of my route to 10,500 MSL. Here is the issue that I am running into. I know how to plan a Top of Climb. You plan a Top of Climb by looking into the performance charts to find out the fuel, time, and distance to climb and I am fully aware of that. But those charts only work if you are not going to have a course change during the climb. In this situation I want to depart P03 and climb to an altitude of 10,500 MSL. Once I depart P03 I will proceed direct to the DUG vortac and continue climbing to 10,500 MSL along V66. However, I know that I will not reach 10,500 MSL by the time that I hit DUG because P03 and the DUG vortac are only 8 NM apart from each other. I know that in my little PA-28-161 that I can not climb that fast in only 8NM. I would like to know how would I plan my Top of Climb (fuel, time, and distance) with a a course change and continuous climb.

I'm assuming you're asking because the groundspeed and distance will change unless there is no wind, which raises the question—what are you doing now to correct the chart for wind for a straight course?

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Well, your post is factually incorrect in most of its statements until you get down to your assertion that the term distance isn't an actual distance but some invented "True air distance" that doesn't match up with a physical distance.

That's what you're really calculating, a time and distance through the air. Then you have to adjust it for winds to reference it to the ground. Airplanes do not care at all about ground distances, ever.

The scenario starts out no-wind because he was confused about turns.

Like I said, he could circle the airport for the entire climb and essentially go nowhere over the ground, but he would have covered exactly the distance he calculated it would take him to climb that much in those circles.

Or for a simpler example...

Vy in his airplane is 65 knots. He takes off (perhaps a little too bravely) into a 65 knot constant headwind at all altitudes...

His time to climb won't change.
His distance to climb... reference to the ground, will be 0.
His distance to climb... inside the airmass... will still be whatever he calculated it to be.
It's just that the airmass is also moving, toward his tail. So he's not going anywhere.

Given that virtually everything in flight planning is guesswork, what difference does it make? The chances of the actual winds at your location and altitude being exactly what the winds aloft forecast predicts are virtually nil; the variation is probably several years out of date; the performance numbers in the book are based on a brand new airplane/engine/prop with a test pilot at the controls; you cannot steer your airplane within one or two degrees of a desired course. You are burning brain cells for nothing.

Bob Gardner

Given that virtually everything in flight planning is guesswork, what difference does it make? The chances of the actual winds at your location and altitude being exactly what the winds aloft forecast predicts are virtually nil; the variation is probably several years out of date; the performance numbers in the book are based on a brand new airplane/engine/prop with a test pilot at the controls; you cannot steer your airplane within one or two degrees of a desired course. You are burning brain cells for nothing.

Bob Gardner
As you know, I agree with you completely. Besides, our apps do it for us if we let them.

But he's likely burning the brain cells because DPEs sometimes ask for those calculations.

As you know, I agree with you completely. Besides, our apps do it for us if we let them.

But he's likely burning the brain cells because DPEs sometimes ask for those calculations.

Once again, I am no longer a DE...but back in the day there was precious little time for such niceties, given the number of tasks to be evaluated. Today's DEs will accept an electronic flight log: In the ACS, (Applicants Checklist:  Flight Plan Form and Flight Logs (printed or electronic)). The OP should go to fltplan.com for his flight log and divert his energies to more important things.

Bob

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Once again, I am no longer a DE...but back in the day there was precious little time for such niceties, given the number of tasks to be evaluated. Today's DEs will accept an electronic flight log: In the ACS, (Applicants Checklist:  Flight Plan Form and Flight Logs (printed or electronic)). The OP should go to fltplan.com for his flight log and divert his energies to more important things.

Bob
I agree about the use of tools. I used a DUAT flight plan for my IR back in 1992. And not from my earlier post that, even in the days of pad and pencil, I was taught a shortcut.

But a DPE would be well within his rights to inquire about a pilot's understanding of the information generated by a website or app (or shortcut) and expect a little better than,"well it was from the Internet so it must be right" or " I never saw that chart in the Performance section of the POH before?" So I certainly don't have the same issue you seem to with the OP seeking to understand.

I agree about the use of tools. I used a DUAT flight plan for my IR back in 1992. And not from my earlier post that, even in the days of pad and pencil, I was taught a shortcut.

But a DPE would be well within his rights to inquire about a pilot's understanding of the information generated by a website or app (or shortcut) and expect a little better than,"well it was from the Internet so it must be right" or " I never saw that chart in the Performance section of the POH before?" So I certainly don't have the same issue you seem to with the OP seeking to understand.

Absolutely! PA.1.D.K4 and PA.1.D.S1 both require that the applicant know the elements of a flight plan and explain how they are used. "What is the difference between magnetic course and true course? Where did you find that? How would you apply it?"

Extreme nit-picking: The words "top of climb" do not appear in the ACS (or the PTS, for that matter).

Bob

To add another perspective to this discussion, I'm not sure I would want to climb a Piper Cherokee over 6,000 feet at Vy, the required climb speed in the Section 5 Time, Fuel, and Distance to Climb tables/charts in Arizona. Even in mild fall temperatures of the midwest, I would routinely experience near-red-line oil temperatures in the Cherokees I used to fly there. Now working in Texas, there's no way I'd do that in any of the airplanes I fly, which happen to have the same engine as most Cherokees.

For this reason I take Bob's approach by asking "What difference does it make?" It would be better for you to make a roundabout guess as to when you'll be at your desired altitude. To predict times en-route while climbing, use a true airspeed consistent with a "cruise climb" pitch attitude in that aircraft -- which, by the way, will also have to be a guess. In a Cherokee I would guess that to be in the 80-90 KTAS range, considering Vy is in the 70-80 KIAS range in those aircraft. Of course, you'll then have to adjust that KTAS value for the wind aloft.

I'm with Bob on this one. It's just an estimate that provides you with a little more situational awareness (at least for VFR, I know nothing of IFR).

Maybe this is horribly wrong for some reason, but in order to have some sort of rough estimate for how many miles I will fly before I reach my TOC, I just divide the approximate climb delta (rounded to the nearest 500 ft) by an assumed climb rate of 500 fpm to get the number of minutes of climbing. Then, assuming there's no wind such that GS equals AS, I multiply Vy (speed) by the time to get the approximate distance (D=ST).

Using the OP’s scenario, you can estimate TOC like this:
1. Climb Delta is about 6500 feet (10,500 MSL minus 4,146 MSL)
2. Minutes of climbing is about 13 (6500 ft. divided by 500 fpm, or just 6.5 doubled)
3. Distance to TOC (assuming Vy is 65 kts) is 65 x 13/60 = 14 nm

If Vy was 60 kts, the distance would be the same as the minutes, making it mental math.

So, whenever Vy is more than 60 kts, the climb delta, doubled, is a little less than TOC in miles.

I try to designate a checkpoint that's about that many miles out.

I assume 500 fpm for descents too in order to rough out a TOD at the end of the flight.

That seems close enough for the little planes I fly.

Is it really necessary to account for the wind, TAS, etc., etc.?

Seems like false precision.

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Didn't read it all, did you?
Nope. I do respect your posts, your experience, and your opinion, but sometime I see your long posts and give up after I get the gist from the first paragraph.
That's on me for sure. I just can't read a novel on a message board.

Nope. I do respect your posts, your experience, and your opinion, but sometime I see your long posts and give up after I get the gist from the first paragraph.
That's on me for sure. I just can't read a novel on a message board.

That's really all about it being a message board. That whole explanation is a lot simpler with a model airplane and two minutes.

That's really all about it being a message board. That whole explanation is a lot simpler with a model airplane and two minutes.

I just read the post you guys are referring to, and was reading for comprehension not speed....it took me all of 1:06 minutes. I'm a student, and just now have come to navigation in ground school and your post made sense to me.

I'm a reader, so "long posts" (it really wasn't very long in my opinion) are no problem when they are written well enough and yours definitely was. But others seem to think anything longer than a few sentences are too long to read. Not knocking it, we all go on forums with different expectations, goals, etc. and also an experienced pilot may not need to read much further where a student like me is trying to soak up all useful helpful knowledge.

I think it's important to go through the exercise nitpicking calculations once or twice so you understand the variables at play, but I also agree with Bob as well. If I know I'm going on a two hour flight and I have five hours of fuel, I call it good and go.

I think it's important to go through the exercise nitpicking calculations once or twice so you understand the variables at play, but I also agree with Bob as well. If I know I'm going on a two hour flight and I have five hours of fuel, I call it good and go.

That's probably the stage where the OP is at... CFI said "plan a flight from X to Y..." and they're going to nitpick the numbers and then fly it and see the difference. That's my guess anyway.

The best exercise is probably to write your own Excel spreadsheet to do the calculations for you. Not hard if you understand how to do them manually, but not possible if you don't. And it will come in handy for years down the road.