IsogonicTerms of Use
Last updated 8 August 2026. These terms are the End User License Agreement for Isogonic.
Last updated: 8 August 2026 By using Isogonic you accept these terms. If you do not, please delete the app; Apple's standard refund process applies.
1. What Isogonic is
Isogonic is a calculation and training aid for pilots. It performs arithmetic and geometry on values you type in.
2. What Isogonic is not
Isogonic is not certified. It is not an approved Electronic Flight Bag, it is not avionics, and it has not been evaluated by any civil aviation authority. It does not replace, and must not be used instead of:
- your aircraft's Pilot's Operating Handbook or Aircraft Flight Manual;
- your aircraft's current weight and balance record;
- any document approved by your civil aviation authority;
- published charts, procedures or performance data.
Isogonic is not for navigation.
3. You are the pilot in command
Under 14 CFR 91.3(a) and its equivalents elsewhere, the pilot in command is directly responsible for, and is the final authority as to, the operation of the aircraft. Nothing in this app changes that, and nothing in this app can. You are solely responsible for confirming, before every flight, that:
- the aircraft is loaded and operated within its weight and centre of gravity
limits;
- every performance figure you rely on matches the approved flight manual;
- the data in any aircraft profile you have created is correct.
4. Aircraft profiles
The aircraft templates included in Isogonic are published type figures, provided as a starting point only. They may contain errors, they may become outdated, and they do not describe your particular airframe. **Basic empty weight and empty centre of gravity must come from your aircraft's most recent weighing record, not from the handbook.** An aircraft in service commonly differs from the book figure by a significant margin of accumulated equipment, and that single unverified number silently invalidates every result downstream. Isogonic will not display a weight and balance result until you have explicitly confirmed a profile against your own documents. That confirmation is yours, not ours.
5. Examinations
Personal electronic devices are not permitted in FAA knowledge testing rooms. Isogonic may not be used during the written examination. Whether it may be used during a practical test is at the discretion of your examiner.
6. No warranty
Isogonic is provided "as is", without warranty of any kind, express or implied, including without limitation any warranty of merchantability, fitness for a particular purpose, accuracy or non-infringement. We do not warrant that the app is free of errors, that its results are accurate, or that it will be available or function without interruption.
7. Limitation of liability
To the maximum extent permitted by law, we are not liable for any indirect, incidental, special, consequential or punitive damages, or for any loss of data, aircraft, property, income or life, arising out of or in connection with your use of Isogonic, whether or not we were advised of the possibility. Where liability cannot lawfully be excluded, it is limited to the amount you paid for the app. Nothing in these terms excludes or limits liability for death or personal injury caused by negligence, for fraud, or for anything else that cannot lawfully be excluded. Consumers in the European Union and the United Kingdom retain their statutory rights, which these terms do not affect.
8. Licence
You are granted a personal, non-exclusive, non-transferable licence to use Isogonic on devices you own or control, in accordance with the App Store Terms of Service. You may not reverse-engineer, resell or redistribute the app, except to the extent that restriction is prohibited by applicable law.
9. Purchase
Isogonic is a one-time purchase. There is no subscription and no in-app purchase. Purchases, refunds and family sharing are handled entirely by Apple under its own terms.
10. Changes
We may update these terms. The date at the top will change, and material changes will be noted in the App Store release notes.
11. Governing law
These terms are governed by French law. This does not deprive you of the protection of mandatory consumer law in your country of residence.