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iPhone App - Weight & Balance

H

humptybump

Well Known Member
If you have an iPhone and want a simple weight and balance app, I just finished writing one.

http://thesalmonfarm.org/blog/p/2620

It's optimized for the RV-8 but should work for the 3, 4, 6, 7, 8, 9, and 12. (sorry RV-10 pilots, I didn't set it up for four passengers).

It's a web app but will run off-line and without a data service after the first run. Just save it to your home screen for best results. It remembers your data so subsequent flight planning is quick !
 
Thanks for the link. Works great as a webpage, but I can't get it to install on my ipad - that's probably the issue since you said it was for an iphone. I do have iOS 4.3 on my pad.
 
I'll try to teat the iPad

I dont have an iPad but I have a techie pilot friend and will ask what might be the issue.
 
how do i fine this app?

I have a new I-Phone, i can not find this app to intall, any help would be appreciated. Thank You
 
Also see FlightScale, a general-purpose app which works fine on the iPad and is graphical.

Sorry for interjecting this....

Dave
 
anyone have numbers for thier -9a?

I think i totally understand W & B....but then once in a while I see some figures for the -9 that are different....so wonder if anyone out there has used this app?
I changed the arm for the passenger to the same as pilot, and actually have the typical bags that are Right behind the seat, then the stuff that's back in the baggage area, at that arm.
just a note; due to me needing more weight forward, I'm planning a bracket to hold a 2 quart water bottle between my legs, just ahead of the spar. ( for those long x-countries!)
I know it won't Add fwd CG, but at least it won't push it further Back!...like when it's behind the seats.
 
bjconst said:
I have a new I-Phone, i can not find this app to intall, any help would be appreciated. Thank You
Click to expand...

The link for the web app is burred in the original blog post (here for convenience - http://6472.us/wb )

It was originally only designed for a smartphone sized screen so it will stretch un-naturally on a tablet. I may find a reason to update it for tablets and take advantage of the bigger screen.

The intended usage is for you to open the URL in your smartphone browser and then "add to home screen". One that is done, it is a full screen app and works off-line (no longer needs wifi or 3G connectivity).
 
Excellent job! This will sure save some time before having to print out the official W&B to carry on the airplane!

Thanks for sharing such great tool with all of us!:D
 
flyboy1963 said:
I think i totally understand W & B....but then once in a while I see some figures for the -9 that are different....so wonder if anyone out there has used this app?
I changed the arm for the passenger to the same as pilot, and actually have the typical bags that are Right behind the seat, then the stuff that's back in the baggage area, at that arm.
just a note; due to me needing more weight forward, I'm planning a bracket to hold a 2 quart water bottle between my legs, just ahead of the spar. ( for those long x-countries!)
I know it won't Add fwd CG, but at least it won't push it further Back!...like when it's behind the seats.
Click to expand...
I have W&B for my 9A in a spreadsheet I built specific for my airplane. What information are you looking for? Datum points, weights, arms?
 
I have successfully loaded the app on both the iPhone 4S and the new iPad. It works well to quickly calculate the data on both. However, I have to say it is not going to be all that useful to me unless I can memorize all of the Arm numbers for everything since I do not fly an 8. The Arm numbers default to the original settings which Glen has stated are for the 8 whenever the app is closed and re-opened. Sometimes I have a hard time remembering my own name. I don't think I can commit all the necessary Arms to memory easily.

Glen, if you have the capacity to set up this app for multiple RV types I think it would work very well. Or perhaps you can offer a way to store user entered data so that it will always use whatever data I input into it rather than having it revert back to the original RV8 numbers every time a user opens the app.

Anyway, those are my observations for using this. It will work great for all you 8 flyers. All others will have to remember what all the Arms are for your individual RV model.
 
Oops. The ARM and load values should all persist. I've got the default RV-9a numbers and will be updating the app with a drop-down for the defaults. With that said, it will also remember actual ARM and loads (once I fix it). :confused:
 
If pilots with the standard / default values (arm and weight) for the -3, -4, -6, -7, -8, and -12 (plus the relevant "A" models could post "plans numbers" here, I'll add them to the drop-down for the app. I have the -8 and was just sent the -9A so I am looking for the other eight aircraft. Appologies to the -10 pilots. The four seater will need to wait.
 
I tried this. Am I understanding it properly? It's not an app that appears with my other apps, but one I need to access with Safari, then bookmark it? That's what I did - if that's wrong, can you provide some guidance as to how to make it appear as an app icon with my other iPhone apps?

A suggestion - for fuel, don't ask for pounds , but ask for gallons, then do the *6 multiplication for me and plug in the weight.
 
also, here are the numbers I plugged in for my -6A. I don't know if they are "standard", but they're what the builder used for my plane:

empty 1069 70.97
gross 1650

cg 68.7 76.8

flight data arms:
fuel 70
pilot 87.4
pass 87.4
fwd baggage 0 (n/a)
aft bagg shelf 0 (n/a)
aft baggage floor 117
 
RV7

Nice app. It downloaded well and works well.
I have an RV7 so I will wait to use it until the mentioned drop down various RV RV7 model is available.

Nice job and thanks for supporting all us RVers.
 
NickAir, ill be adding the rv-7 to the new drop-down as soon as someone can PM or post them for me. If you have the build plans, could you post the default ARM values for the RV-7 ?
 
Arm Values

humptybump said:
NickAir, ill be adding the rv-7 to the new drop-down as soon as someone can PM or post them for me. If you have the build plans, could you post the default ARM values for the RV-7 ?
Click to expand...

Thanks humpty- here are your numbers for the dropdown. Your awesome!

RV7A
CG range: 78.7" to 86.82" Aft of Datum

ARM:
Aircraft: 78.87
Fuel: 80
Pilot: 97.48
Co-Pilot: 97.48
Baggage:126.78
 
app?

People talk about this like it's an app, but I seem to be missing something. All I see is connecting to the web page via the browser. Am I missing something? Can you explain how this app gets installed? Or is it just used via Safari?
 
brian said:
People talk about this like it's an app, but I seem to be missing something. All I see is connecting to the web page via the browser. Am I missing something? Can you explain how this app gets installed? Or is it just used via Safari?
Click to expand...

It is a web-based app. An "App" doesn't mean it has to be a self powered, self contained program to use on a mobile device. Building such App
Style not only requires great programming and developing skills, but also requires money and sometimes even sponsorship to even get it approved and running. In this case it is far easier and simplified to have the application's source code written on a mobile-size website.
Yes, it will need safari to run, but it definitely is way better than nothing, and we owe it to Humptybump for giving up his time (even building time) to write the app. Let alone even sharing it with us for free. :cool:
 
I wasn't questioning the way he implemented it - I just wanted to make sure i was using it correctly - and apparently i am. Thanks for the feedback.
 
w & B for dummies?

again, not a criticism, just need clarification.....

Glen, I've been wanting a W&B i can do standing beside the plane as I load.
will this do it? I don't get how web access or safari is involved.
is it really just a spreadsheet that gets 'loaded' on my iphone 'like' an app, but it's just a little calculator?

really like to use it for my -9a

really don't get it.

thanks from all us tech-challenged troglodytes.
 
Brian, a "web app" is a special kind of web page. You access it initially using the iPhone browser (Mobile Safari). When you use the "Save to Homescreen" button in Mobile Safari, it does some extra stuff. Assuming the web app was written correctly, you get a nice app icon (similar to those for apps downloaded fr the iTunes app store). Additionally, all of the web "stuff" (the HTML, images, and JavaScript) are all cached on the phone. From then on, when you launch the app using the homescreen icon (rather than revisiting the web URL) it runs locally and doesn't need an Internet connection.

I'm still working on a complete re-write of my web app. A lot has changed in the 18 months since I originally authored it. It will be a few more evenings before I finish. I'll post back here when it's ready.

PS - Perry, a native app must be submitted to Apple to get into the App Store. Given my day job, I am not permitted to sign the Apple Legal agreements needed to write and submit native apps through Apple. I have learned to write some useful mobile web apps - W&B is a simple but handle example.
 
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now i get it

I didn't know about the "save to home screen" part. Now I get it. Thanks for the tip and thanks for the app.
brian
 
Update: I burned about 30hrs of midnight oil and have finished a re-write of the W&B app. It now is configurable to support all the RV models (including the new RV-14 with 1+2 seating).

That's the good news. The bad news is I won't release it as I don't trust the app framework I chose to work with. Gorey details here. I'll be burning another 30hrs to re-write it again. I'm getting pretty good at it !
 
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No worries.

Given the heat his summer, I want to also work on an app that estimates ground roll and clearance over a 50' object based on calculating density altitude. I'm not sure where I'll rand the base data but given some short runways I use, I can see using it for a ballpark go/no-go decision tool.
 
W&B 2.0

Sorry for the delay in the update. I had some personal things I needed (and still need) to focus on.

I finished the update. It supports all currently available RV models (and pretty much most GA aircraft with at most two rows of seats and up to three baggage areas. It will support Tsam with its single seat and cheek storage and Brandi & Brian's RV-10 with lots of seats and cargo.

There is one-time setup/configuration for how many seats and baggage areas and the various aircraft specific weights and CG points. All of that is remembered. You can go back and make changes but that is less common so it's not on the main page.

Here is now a graphical representation of your flying CG. It made a noticeable impression on me. With just the numerical weight and CG, I knew I was 'OK' but now I see I fly most of the time with a noticeable forward CG.

Anyway, you can read more about it, get the app, and watch the demo video over on my blog.
 
directions

Glen,
I have downloaded your updated app. It looks like it will be a handy tool. I will use it in few days when I load up the plane and head to OSH.

One comment on the configuration page. Without watching the video it is not intuitive that you enter the datum information for the CG in inches on the configuration page. On that page the user begins by inputting weight info for empty and max weights. Then the user has to enter CG LIMIT information but there is nothing that defines the type of information needed. So, I, being the stone brain person I am, just kept entering weight information in the CG section. Perhaps there could be something in each section's title that would tell the user what type of data needs to be input into that section (i.e. CG LIMITS (in. from datum)) or something similar.

Other than this issue, I think you have a winner here.
 
Great App!!
Thanks for the update, for your hard work and precious time developing it for people you don't even know.
If I ever meet you in person, the beer rounds are on me!
 
Glen, great little ap! I have it on both the iPhone and the iPad and it works great for my -6. Thanks!

Here's a suggestion for a future add on or little improvement: have another line in the "Calculate" row that offers a solution for "zero fuel weight CG." This would just be the fuel zeroed out, but it would allow you to see that your CG remains within limits throughout the flight. :)
 
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Pat Hatch said:
Glen, great little ap! I have it on both the iPhone and the iPad and it works great for my -6. Thanks!

Here's a suggestion for an add on or little improvement: have another line in the "Calculate" row that offers a solution for "zero fuel weight CG." This would just be the fuel zeroed out, but it would allow you to see that your CG remains within limits throughout the flight. :)
Click to expand...
Pat,
I had thought about this issue also but all we really need to do is just change the amount of fuel to zero (0 gallons) or any other amount desired and re-calculate to accomplish this.
 
In general, I deliberately left out explicit "units of measure" and used the section headers to indicate which fields were weight/load data vs CG. The theory was that a user could use metric just as easily as English units.

That turns out to be a good theory but I goofed. I incorporated a user requested enhancement such that fuel is entered in US gallons. I convert it to lbs during the calculation. Clearly that is a mistake for European pilots and those using liters or kilograms.

I guess that goes on the wish list for next time.:rolleyes:
 
Glen, I love your disclaimer about your choice of launch icon. Well played, sir. :D :D :D
 
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