G

gcrane01

Member
Has anyone developed an app for the RV weight and balance program on the Iphone? I have the computer one, just looking for something convenient on a trip. Would be nice to have in case your friendly FAA entertainer wanted to do a ramp check.
 
I run a software business on the side... and the iPad launch caused me, with no speicifc project in mind, to enrol as an iPhone/iPad developer, and even buy a pesky Mac thing :( I have now got to the stage on getting things written and working on the iPhone - but need a proper project to get things established.

So, as an idea, maybe I should write an RV CG Calculator? I doubt it would be free, but at the small ($1-$2?) level - and more than willing to donate whatever was made to a good cause e.g. VAF.

iPhone software specifically needs good "design", and that is best started by the eventual users.

If readers here like the idea of an RV specific/logo'd (even VAF logo'd?) iPhone App, then please let me know below, with some ideas. If the support/ideas are there, suspect it would be better to later move the design/development thread elsewhere on the forum.

As a starter, it would have the RV type limits hard coded in i.e. you would enter for your RV just the Basic Weight/CG and type and identify by Reg. It would include a graphical display of CG Envelope as fuel is used. Whilst initially targeted at the iPhone, the iPad features would be taken into account.

Andy (Hill)
RV-8 G-HILZ
 
RV Weight and Balance

Andy
Sounds like a great idea. Do you have the software program that seems to be the standard for the RV community? I have an RV8 and realize the CG doesn't move that much, but with the FAA wondering around it would be great to have something to show them.
Greg
 
Pilot Wiz

Pilot Wiz (the free one) does a nice job with weight and balance. It draws you a nice graph of the envelope. Particular helpful with the tandem airplanes.
 
Copilot

Call me ancient (e.g. Lycosaurus) because I still use a Palm Vx. Reason for that is that I use a fantastic little program called Copilot. It has most of what you need for flight planning, including W&B, free downloadable airports database, multiple track flight planning, fuel calculations etc.

http://lauriedavis9.tripod.com/copilot/ this is the link for the Palm version (same info though).

It is offered for the iPhone and iTouch as well (check the Apple apps store).

http://www.ljd-tech.com/copilot/ iPhone version
 
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CoPilot for the iPhone (link above) is an excellent app for both flight planning *and* checking W&B. I haven't set up a full envelope for my -6 yet but have used it extensively on Cessnas and other homebuilts. It's very handy as it will show a graph for the W&B envelope, and show dots on the graph for various conditions... Takeoff, landing, tanks empty, etc. so you know how your CG will change if you're making a longer flight. It's so easy that I use it on almost every flight, just as a quick check.

Definitely worth checking out, and I wouldn't bother with a separate app just to do W&B.
 
tried one

After reading these posts this morning, I loaded pilotwizz (the free one) and tried it out. Found weight and balance graph easy to update for my RV7a and tried some typical loadings to check out the result. It worked great and will stay for traveling, and possible ramp checks.
 
where (in the FAA web site) are RV type certificates?

I will be releasing a weight and balance iPhone app to the app store soon and this thread made me consider adding RVs. For other aircraft I can look up a U.S tail number and find an FAA Type Certificate that contains a W&B envelope. However, for RVs each aircraft appears to be build by a different manufacturer (you) and I am having trouble automatically looking up type certificate data.

Does each aircraft have its own type certificate?

::Ken::
Full disclosure: I fly a Cirrus.
 
flyingRhodium said:
I will be releasing a weight and balance iPhone app to the app store soon and this thread made me consider adding RVs. For other aircraft I can look up a U.S tail number and find an FAA Type Certificate that contains a W&B envelope. However, for RVs each aircraft appears to be build by a different manufacturer (you) and I am having trouble automatically looking up type certificate data.

Does each aircraft have its own type certificate?

::Ken::
Full disclosure: I fly a Cirrus.
Click to expand...

Amateur-built aircraft, like RVs, don't have a type certificate, as there is no official approved type design. So don't waste any more time looking for Type Certificate Data Sheets.

But, Van's Aircraft does provide recommended weight and CG envelopes for normal operations, and a reduced weight/CG envelope for aerobatics. It is up to each builder to do the flight testing to determine where he will set his weight and CG limits, and it is quite possible for builders to chose weight and/or CG limits that differ from those recommended by Van's Aircraft.

Or, contact Van's. They may be willing to send you copies of the info they give builders on recommended weight and CG envelopes for each model, and the length of the arms for variable weights.

If you want to make a weight and balance app for RVs, the folks on this site can certainly tell you the recommended weight and CG limits for each model and the arms for the various variable weights. It would make sense to use these as the default, but the app should allow the user to enter his own weight and/or CG limits if he has chosen values that differ from those recommended by Van's.

Two more complications:
  1. the recommended gross weight for RV-9s and -9As varies depending on which engine model is installed.
  2. the aerobatic gross weight for RV-8 and -8As depends on when the wing kit was delivered, as there was a design change in the wing spar part way through production (this may also apply to early -7s and -7As, as they share the wing design with the -8s).
 
my garmin 396 does it for me. If the fed asks, I just turn it on and show him. It's always the same anyway. Me and the plane...
 
flyingRhodium said:
I will be releasing a weight and balance iPhone app to the app store soon and this thread made me consider adding RVs. For other aircraft I can look up a U.S tail number and find an FAA Type Certificate that contains a W&B envelope. However, for RVs each aircraft appears to be build by a different manufacturer (you) and I am having trouble automatically looking up type certificate data.

Does each aircraft have its own type certificate?

::Ken::
Full disclosure: I fly a Cirrus.
Click to expand...

Weight and balance data for all Van's models except the 3 and the 12 are available here:

Vans W&B Data

You will find it just over half way down the page.

What Kevin Horton says about builders being able to decide on their own weight and CG parameters may well be true in the US and Canada but it is certainly not true here in Europe. The RV-3B is limited to a max weight of 1175lbs in the UK for example.
 
Kevin Horton said:
Amateur-built aircraft, like RVs, don't have a type certificate, as there is no official approved type design. So don't waste any more time looking for Type Certificate Data Sheets.

But, Van's Aircraft does provide recommended weight and CG envelopes for normal operations, and a reduced weight/CG envelope for aerobatics. It is up to each builder to do the flight testing to determine where he will set his weight and CG limits, and it is quite possible for builders to chose weight and/or CG limits that differ from those recommended by Van's Aircraft.

Or, contact Van's. They may be willing to send you copies of the info they give builders on recommended weight and CG envelopes for each model, and the length of the arms for variable weights.

If you want to make a weight and balance app for RVs, the folks on this site can certainly tell you the recommended weight and CG limits for each model and the arms for the various variable weights. It would make sense to use these as the default, but the app should allow the user to enter his own weight and/or CG limits if he has chosen values that differ from those recommended by Van's.

Two more complications:
  1. the recommended gross weight for RV-9s and -9As varies depending on which engine model is installed.
  2. the aerobatic gross weight for RV-8 and -8As depends on when the wing kit was delivered, as there was a design change in the wing spar part way through production (this may also apply to early -7s and -7As, as they share the wing design with the -8s).
Click to expand...

Kevin,

I didn't realize there are no TCDSs. Thanks for the info. And thanks to Anthony for pointing me to recommended weight limits and envelopes for all but the 3 and 12.

I'm trying to figure out how to best serve the RV community. I hesitate to supply 'recommended' data for an aircraft instead of data specific to an aircraft via serial number and type certificate. I don't have a problem, however, loading that data from a source supplied by someone else, say the RV community. But I'm just not sure where that data could be hosted. I suspect the data can't be hosted here because this site probably has a non-commercial policy, as it should. Thanks for putting up with my pondering.

Cheers...

::Ken::
Full disclosure: I fly a Cirrus.
 
islandmonkey said:
Weight and balance data for all Van's models except the 3 and the 12 are available here:

Vans W&B Data

You will find it just over half way down the page.

What Kevin Horton says about builders being able to decide on their own weight and CG parameters may well be true in the US and Canada but it is certainly not true here in Europe. The RV-3B is limited to a max weight of 1175lbs in the UK for example.
Click to expand...

Anthony,

Thanks for the info. Looks like only a couple of dozen total (recommended) configurations if you include aerobatic configurations as well as two engines on the -9s and wing options on the -7s and -8s (as Kevin mentioned). Bottom line: for any specific aircraft there is not a lot of data to enter in any case. I'm used to dealing with not-a-rectangle envelopes, gear retraction moment changes, and non-linear fuel-moment relationships that require a long table of data.

I'm definitely not, however, used to being test pilot and determining my own limits. Scary... Hats off to you guys!

::Ken::
Full disclosure: I fly a Cirrus.
 
flyingRhodium said:
Anthony,

Thanks for the info. Looks like only a couple of dozen total (recommended) configurations if you include aerobatic configurations as well as two engines on the -9s and wing options on the -7s and -8s (as Kevin mentioned). Bottom line: for any specific aircraft there is not a lot of data to enter in any case. I'm used to dealing with not-a-rectangle envelopes, gear retraction moment changes, and non-linear fuel-moment relationships that require a long table of data.

I'm definitely not, however, used to being test pilot and determining my own limits. Scary... Hats off to you guys!

::Ken::
Full disclosure: I fly a Cirrus.
Click to expand...

No Problem Ken.

I have knocked together a spreadsheet for the RV-3B. It can be downloaded from here:

RV-3B Weight and Balance Spreadsheet.
 
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