Isogonic

Support

https://github.com/Nadir-Bensalah/Isogonic/issues Write to us and a human answers. There is no ticket system and no chatbot. If you are reporting a wrong number, please include the exact inputs you typed, the answer Isogonic gave, and the answer you expected. That is usually enough to reproduce it in a minute.

Common questions

Can I use Isogonic on the FAA written exam?

No. Personal electronic devices are not permitted in the testing room. FAA knowledge tests allow a mechanical E6B or an approved dedicated electronic flight computer with erasable memory. Isogonic is built for preparing for the exam, for the checkride, and for real flying.

Can I use it on my checkride?

That is your examiner's call, and most allow it. The ACS explicitly permits an Electronic Flight Bag and accepts a computer-generated flight plan. Two things worth knowing. Expect to be asked how a number was derived, which is exactly why every result in Isogonic opens into its full derivation. And expect the examiner to "fail" your device to see what you do next; have a backup, and know the mental shortcuts. Isogonic shows those beside each exact answer, with the error each one carries.

Why does it ask me to confirm the aircraft profile?

Because the included templates are published *type* figures, and your aircraft is not the type. The basic empty weight and empty CG belong to one individual airframe and come from its most recent weighing record. An aircraft in service commonly differs from the handbook by a meaningful margin of accumulated equipment. That single number silently invalidates every downstream result while looking entirely normal, which is why Isogonic will not show you a result until you have checked it.

The CG moves between take-off and landing. Is that right?

Yes, and it is the reason the whole path is drawn rather than just two points. Burning fuel removes weight at the fuel station's arm, so the centre of gravity shifts away from it. In moment-versus-weight space that shift is a straight line, but in CG-versus-weight space it is a curve, which means the CG can leave the envelope somewhere in the middle of the flight while both the take-off and landing points are perfectly legal. Isogonic samples the entire burn and reports the worst point.

Can I use kilograms and millimetres?

Yes. Units are set per quantity, not globally, because that is how real flying works: a French pilot flies in knots and feet, fuels in litres and weighs in kilograms. There are four presets, US, International, UK and glider, and every field can be overridden individually.

Why does the app need no permissions and no network?

Because it genuinely does not use them. Isogonic makes no network requests of any kind. Every calculation happens on the device, and nothing you type leaves it. That is also why it works at zero bars.

Does it sync between my devices?

Not in version 1.0. Data lives on the device it was entered on. If you have iCloud Backup enabled, your device backup includes it as it would for any app.

Why is the density altitude different from the one I get elsewhere?

Almost certainly because Isogonic is right and the other one is rounding. The decimal constants for the standard atmosphere that circulate on the web disagree with each other in the fifth decimal place. One widely copied value produces roughly eighteen feet of density altitude at exact standard conditions, where the answer must be exactly zero. Isogonic derives every constant from first principles instead of transcribing them, and returns exactly zero at ISA. If you provide a dew point, Isogonic also accounts for humidity, which raises density altitude, often by another 100 to 250 feet on a hot, damp day. Most tools ignore it.

I found a calculation I think is wrong.

Please tell us, with the inputs. Every formula in the app is covered by an automated test suite, and if you have found a case the tests miss, that case becomes a test.

Requesting a feature

Tell us what you were trying to do when you wanted it. The workflow is more useful to us than the feature name, and it is usually what makes the design obvious.