Is there any sort of app (for android) that will calculate take-off, landing, and distance to clear a 50' obstacle.... or something like that? Anything that can produce a fairly accurate elevation vs. distance profile would do the job I suppose. Seems like it would be a fairly simple thing and could be very useful, especially in determining the numbers for one's plane.

Try "Takeoff" I assume you can get it for andoid as well. As per usual you're probably better testing real world numbers in your aircraft rather than relying on an app.

It's not exactly a takeoff/landing distance app, but Terry here turned me on to the "measure your land" app in another thread. It can be used for measuring distances using landmarks, and is useful for lots of other things as well.

NZMaule wrote:Try "Takeoff" I assume you can get it for andoid as well. As per usual you're probably better testing real world numbers in your aircraft rather than relying on an app.

I just checked that out - seems like it could be a useful app, thanks. But, I guess I didn't word my question very well. I am not referring to a calculator that you plug temperature and altitude, among other things, into that will spit out an answer. I was thinking of something that uses the GPS in a tablet to determine what the ground roll of the aircraft actually was after performing a take-off or landing.

The vertical measurement and refresh speed probably wouldn't be accurate enough for such an app to accurately guess when you land or take-off, but it would be pretty easy to write an app where you tap the screen to start and stop the measurement.

My search of iTunes doesn't show such an app.

You would want a passenger to operate the app for you so you can fly the plane instead of messing with the app.

Still appealing? Maybe I'll put one together.

Cloud Ahoy is as close as I've ever found.

[quote="rw2"]The vertical measurement and refresh speed probably wouldn't be accurate enough for such an app to accurately guess when you land or take-off, but it would be pretty easy to write an app where you tap the screen to start and stop the measurement.

My search of iTunes doesn't show such an app.

You would want a passenger to operate the app for you so you can fly the plane instead of messing with the app.

Still appealing? Maybe I'll put one together.[/quote]

Look for "Takeoff Calc HD"

I actually wrote some prototype code for something like this a while back for the iPhone/iPad. My goal was a little more ambitious, and it was designed to be "start it up, lay on the seat next to you and forget."

I was able to get fairly decent accuracy by doing a bit of filtering and applying some heuristics, using the accelerometer in conjunction with the GPS, but you're never going to get perfect accuracy. Accurately detecting the touchdown point on landing is especially difficult if you land too smoothly.

I might start dorking around with that project again. It was pretty fun.

Oregon180 wrote:I actually wrote some prototype code for something like this a while back for the iPhone/iPad. My goal was a little more ambitious, and it was designed to be "start it up, lay on the seat next to you and forget."

I was able to get fairly decent accuracy by doing a bit of filtering and applying some heuristics, using the accelerometer in conjunction with the GPS, but you're never going to get perfect accuracy. Accurately detecting the touchdown point on landing is especially difficult if you land too smoothly.

Yeah, when I was noodling it early those were the kinds of problems I had in mind. Take off can be hard to detect if it's smooth (and/or have a tire that wobbles so the accelerometer detects ground rumble until you hit the brakes and stop the wheel from spinning in the air), landing can be hard to detect if it's a greaser (as all of mine are *cough*) and GPS isn't accurate enough by itself (as you already know). But if you're willing to have a person in the co-pilot seat hit the big Easy button twice (once on start of roll, once on take-off) you should be able to get somewhere between 3% and 10% accuracy (with the less accurate measurements being on the shorter rolls). That seems like enough for this use case. If you want to get accuracy to the foot then GPS isn't the technology to use. Have your buddies stand next to the runway and take actual measurements if that's your requirement.

I actually would like a calculator. Maybe one of you smart guys could make the slide rule calculator that you can buy from Sporty's into an app. I have it but would love to be able to just use sliders on my iPad!

Anyone ever thought of the old fashion way? POH. DA,s change so does distance

cropduster13 wrote:Anyone ever thought of the old fashion way? POH. DA,s change so does distance

I think it's fun to get real world data and see how it matches up.

Grassstrippilot wrote:I actually would like a calculator. Maybe one of you smart guys could make the slide rule calculator that you can buy from Sporty's into an app. I have it but would love to be able to just use sliders on my iPad!

The app GliderGeek mentioned above seems to be quite a bit like that. I haven't tried it yet.

Neither computer nor POH is as accurate and safe as self generated experimental data. Start light and increase loads until you know what is comfortably doable in various conditions. When spraying we adjust loads as conditions change. With people, it is safest to do a circuit solo before loading passengers.

They may make an ap for that, but you would be trusting the computer rather than the pilot. Of course, some think the computer is safer than the pilot. Ever ride in a big airliner?

cropduster13 wrote:Anyone ever thought of the old fashion way? POH. DA,s change so does distance

Or.... "Hold my beer and watch this"

I figure the easiest way is early in the morning with dew on the grass. It is plain (plane?) where the wheels leave the ground and where they touch down. It could be measured to the inch quite easily.
That would be your baseline at that temperature, altitude, and on grass (hopefully short turf). There is math to solve all the variable conditions and altitudes from there, right?

Ok, the conditions are not that easy to 'set up'....
But it is a method you could do by yourself, and would be very accurate-for that moment....

lc

And the grass would never tell how you did.....

cropduster13 wrote:Anyone ever thought of the old fashion way? POH. DA,s change so does distance

Not bragging here BUT what the POH says and what really happens are not even close

58Skylane wrote:

cropduster13 wrote:Anyone ever thought of the old fashion way? POH. DA,s change so does distance

Or.... "Hold my beer and watch this"

Since you mentioned it Pat...

aktahoe1 wrote:

58Skylane wrote:

cropduster13 wrote:Anyone ever thought of the old fashion way? POH. DA,s change so does distance

Or.... "Hold my beer and watch this"

Since you mentioned it Pat...

Blahaha!! Is that Pastrana?? If so, that guy is a nut!! LOL