Terms of Service

RotorLab.app: Terms of Service

Effective date: October 9, 2026

These Terms of Service ("Terms") are a binding agreement between you, and, if you register on behalf of an organization, that organization (together, "you", "your"), and RotorLab, Inc., a Delaware corporation with its headquarters in Dubuque, Iowa ("RotorLab", "we", "us", "our"), governing your access to and use of the RotorLab.app websites, applications, tools, and services (the "Service"). By creating an account, checking the box indicating that you accept these Terms, or using the Service, you agree to these Terms, the End User License Agreement, the Acceptable Use and Drone Operations Policy, and the Privacy Policy, each incorporated here by reference. If you do not agree, do not use the Service. If you accept on behalf of an organization, you represent that you are authorized to bind it.

1. The Service. RotorLab provides software for two things. First, modeling, estimating, and analyzing the performance of unmanned aircraft and related components (weight and balance, propulsion and power, endurance, radio link budgets, and trade studies), which produces engineering ESTIMATES generated by mathematical and physical models from the inputs and assumptions you provide. Second, keeping an operator's records: the aircraft register, flight records and stored flight logs, maintenance records and releases to service, pilot credentials and training records, occurrences, authorizations, insurance, safety records, and the documents attached to them (together, "Records"). Section 2 governs the estimates; Section 7A governs the Records.

2. Nature of outputs; no guarantee of real-world results. You understand and agree that every number, chart, verdict, recommendation, margin, warning, and other output of the Service is a theoretical estimate produced by a model. While we design our methods using recognized engineering principles and validate them against reference cases, the Service is a simulation and design aid only. Outputs are not, and must not be treated as, a guarantee, warranty, certification, or representation that any design will perform, fly, remain controllable, remain within thermal, electrical, or structural limits, or be safe, airworthy, or fit for any purpose in the physical world. Actual performance depends on manufacturing, assembly, component tolerances, environmental conditions, maintenance, piloting, and many factors outside the model and outside our control. You are solely responsible for independently verifying any design through appropriate engineering review, bench testing, and incremental real-world flight testing before relying on it, and for all decisions you make using the Service. You agree not to rely on the Service as the sole basis for any safety-critical, operational, financial, or regulatory decision.

3. Regulatory and operational responsibility. You are solely responsible for operating any aircraft you design, build, or fly lawfully and safely, including compliance with all applicable aviation, radio-frequency, privacy, import/export, and other laws and regulations in every jurisdiction where you operate. Nothing produced by the Service constitutes airworthiness certification, a regulatory approval, legal advice, or a determination that any operation is permitted. See the Acceptable Use and Drone Operations Policy for details.

4. Accounts. You must provide accurate registration information and keep it current. You are responsible for safeguarding your credentials and for all activity under your account. Organization administrators are responsible for the users, roles, groups, and data within their organization. Notify us promptly of any unauthorized use.

5. Subscriptions, plans, and billing. (a) Paid plans, add-ons, API credits, and any referral rewards are governed by the plan details and any program terms shown in the Service at the time of purchase. Unless stated otherwise, fees are billed in advance for each billing period and are non-refundable except as required by law. You authorize us and our payment processors to charge your selected payment method. We may change prices and plan features on a prospective basis, with notice for the next billing period. Failure to pay may result in suspension or termination. When you move to a plan that costs less, the Service shows before you confirm when the move takes effect and any credit; between paid plans that renew, the move normally takes effect at the end of the period already paid, with no credit for the rest of that period. Education and nonprofit plans start only once we approve them. A payment that is refunded in full, or lost in a payment dispute, may end what it bought. Where a ticket to an event is paid for after the event's places are gone, no ticket is issued and the payment is refunded. (b) Card subscriptions. A card subscription renews at the end of each billing period until it is cancelled; a cancellation takes effect at the end of the period already paid for. (c) Purchase orders. Where you buy by purchase order, each invoice states its number, your purchase order, its service period and its due date, and what it covers is available for that service period. For a plan or add-on billed monthly or yearly, we issue the renewal invoice for the next period automatically before the current period ends (thirty days before, unless the Service states another number) and email it to your organization's billing contact. An invoice is due thirty days after its invoice date (net 30) unless your organization has agreed other payment terms with us, in which case the invoice states those terms. To stop renewal, an administrator of your organization presses Cancel at period end under My Account, Billing & plan, before the renewal invoice for the next period is issued; access then runs to the end of the period already invoiced. A renewal invoice already issued covers its period and is owed unless we void it. However you pay, one add-on or bundle can be stopped on its own with Stop renewing under Billing & plan: nothing further is charged or invoiced for it, and it runs to the end of what was already paid for or invoiced. (d) When a plan ends. A plan ends when a card subscription is cancelled and its paid period is over; when a card renewal payment fails and is not made within three days; when a purchase-order service period ends and three days pass with no renewal invoice issued; or when a free trial ends without a plan being bought. Section 15 then applies to your Records. (e) Taxes. We charge sales or similar tax only where we are required to collect it, at the rate shown on the invoice; an invoice that shows no tax charges none. You are responsible for any other taxes on your purchase, except taxes on our net income.

6. License to use the Service. Subject to these Terms and the End User License Agreement, we grant you a limited, non-exclusive, non-transferable, revocable right to access and use the Service for your internal purposes during your subscription. All rights not expressly granted are reserved.

7. Your content. You retain ownership of the designs, parameters, notes, and other content you submit ("Your Content"). You grant us a worldwide, non-exclusive license to host, process, display, and transmit Your Content solely to operate the Service and as you direct (for example, when you share a build with your organization or publish it to the community). We improve the Service from Your Content only through aggregate, de-identified statistics as Section 7A(f) describes, and Your Content trains a model shared with other organizations only where your organization opts in to training inclusion, which is off by default and can be withdrawn. You are responsible for Your Content and represent that you have the rights to submit it. Content you choose to make public or share may be seen and copied by others as described in the Service.

7A. Records of record. Where you use the Service to keep Records, the following applies. (a) Your Records are Your Content, and you are the controller of them; we process them only to provide the Service to you and as this agreement and the Privacy Policy describe. (b) The Service is built so that a filed Record is not destroyed: a flight is voided rather than deleted and kept in a ledger with the reason, corrections are kept field by field with the person who made them, released maintenance records are amended rather than edited, occurrences are versioned, and a person on a Record is deactivated rather than deleted so their name stays on what they flew and signed. You agree that these behaviors are features of the Service and not a failure to honor a deletion request, and that a request to destroy a Record before its retention period is one you make as controller, in writing, through the support contact; for a flight, you void it first, and we carry out the request under the support access your administrator gives us, as Section 11 of the Data Processing Addendum describes. (c) Retention is yours to set within the Service (the stored-log window, the position window, and "keep for life" on either; the window after which a person who has left is minimized; and the window for photos and documents removed from a Record); the default windows are stated in the Service. We do not shorten a window you have set. (d) Legal hold: a Record you place on hold, or that an occurrence names, is kept past every window until you lift the hold. (e) Your Records remain available to you for export, in the formats the Service provides (the organization export, the audit binder and audit packages, and the public API), at any time while your account is active and, after a plan ends, for the ninety days of read-only access with export in Section 15. (f) We do not read, use, or disclose your Records for any purpose other than providing the Service to you, responding to your requests, complying with law, or as Section 4 of the Privacy Policy describes; aggregate, de-identified statistics that cannot identify you, your people, or your aircraft may be used to improve the Service. (g) The Service records who did what and when in an activity log that is hash-chained; that log is part of your Records and is exported with them. (h) Where the Service lays out entries from your Records for you to copy into another system of record (for example, Army flight records), the layout is drawn from your Records; it is not that system's own form or an approved import, and you remain responsible for the records you keep in that system.

8. Feedback. If you give us suggestions or feedback, you grant us a perpetual, irrevocable, royalty-free license to use it without restriction or obligation to you.

9. Acceptable use. You agree to comply with the Acceptable Use and Drone Operations Policy. We may investigate and take action, including suspension or termination, for violations.

10. Intellectual property. The Service, including its software, models, content, and trademarks, is owned by us or our licensors and is protected by law. Except for the limited rights granted here, we grant you no rights in the Service.

11. Third-party services. The Service may interoperate with or link to third-party products (for example, payment processors or component data). We are not responsible for third-party products, and your use of them is governed by their terms.

12. DISCLAIMER OF WARRANTIES. THE SERVICE AND ALL OUTPUTS ARE PROVIDED "AS IS" AND "AS AVAILABLE", WITHOUT WARRANTIES OF ANY KIND, WHETHER EXPRESS, IMPLIED, OR STATUTORY, INCLUDING WITHOUT LIMITATION IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE, NON-INFRINGEMENT, ACCURACY, AND ANY WARRANTY THAT OUTPUTS WILL BE CORRECT, COMPLETE, RELIABLE, OR THAT AN AIRCRAFT WILL PERFORM OR BE SAFE. WE DO NOT WARRANT THAT THE SERVICE WILL BE UNINTERRUPTED OR ERROR-FREE. SOME JURISDICTIONS DO NOT ALLOW CERTAIN DISCLAIMERS, SO SOME OF THE ABOVE MAY NOT APPLY TO YOU.

13. LIMITATION OF LIABILITY. TO THE MAXIMUM EXTENT PERMITTED BY LAW, IN NO EVENT WILL ROTORLAB OR ITS SUPPLIERS BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, EXEMPLARY, OR PUNITIVE DAMAGES, OR FOR ANY LOSS OF PROFITS, DATA, GOODWILL, OR FOR PROPERTY DAMAGE, PERSONAL INJURY, OR DEATH, ARISING OUT OF OR RELATING TO THE SERVICE OR ANY AIRCRAFT DESIGNED, BUILT, OR OPERATED WITH ITS HELP, WHETHER BASED ON WARRANTY, CONTRACT, TORT, OR ANY OTHER THEORY, EVEN IF ADVISED OF THE POSSIBILITY. OUR TOTAL AGGREGATE LIABILITY FOR ALL CLAIMS RELATING TO THE SERVICE WILL NOT EXCEED THE GREATER OF THE AMOUNTS YOU PAID US FOR THE SERVICE IN THE TWELVE MONTHS BEFORE THE EVENT GIVING RISE TO THE CLAIM, OR ONE HUNDRED U.S. DOLLARS (USD 100). THESE LIMITATIONS ARE A FUNDAMENTAL BASIS OF THE BARGAIN BETWEEN US.

14. Indemnification. You will defend, indemnify, and hold harmless RotorLab and its officers, employees, and agents from and against any claims, damages, liabilities, and expenses (including reasonable legal fees) arising out of or related to your use of the Service, Your Content, any aircraft you design, build, or operate, or your breach of these Terms or violation of law.

15. Suspension, termination, and when a plan ends. (a) You may stop using the Service at any time, and may cancel a plan as Section 5 describes. We may suspend or terminate your access if you breach these Terms, create risk or legal exposure, or fail to pay, and we may discontinue the Service on at least ninety days' written notice. (b) When a plan ends, as Section 5(d) describes, your right to use the Service ends and the following applies to your organization's Records, from the day the plan ended: (i) for ninety days the Records are read-only with export: your organization's administrators may sign in, read the Records and export them through the organization export, the audit binder and the public API, nothing can be changed, and other members cannot sign in; (ii) for the twelve months after that the Records are retained with no access: your administrators may sign in only to buy or restore a plan, and no Record can be read or exported; (iii) thirty days before those twelve months end we email your administrators an alert, and seven days before, a final notice; and (iv) after the twelve months, and no sooner than seven days after the final notice, we may delete your Records and every file attached to them, in one step, and record the deletion with counts in our own activity log; the deletion certificate is available on request for twelve months. We also email your administrators when the plan ends, thirty days and seven days before the read-only period ends, and when retention begins. Buying or restoring a plan at any time before the deletion restores full access. A deletion is carried out by a person and is never automatic, and we do not delete a Record on legal hold while the hold stands. (c) We delete your Records sooner only at your written request or where the law requires it. (d) While we suspend your access, your organization's administrators keep read-only access with export, and we do not delete your Records except as (b) and (c) allow. (e) Sections that by their nature should survive termination will survive, including Sections 2, 7, 7A, 8, 10, 15, and 12 through 18.

16. Changes to these Terms. We may update these Terms. If a change is material, we will provide notice (for example, in the Service or by email) at least thirty days before it takes effect for paid plans, and will ask you to accept the updated Terms in the Service before you continue. A change that reduces your rights in your Records under Section 7A or shortens a period in Section 15 does not apply to a paid term already in progress. Your acceptance in the Service, or your continued use after an update takes effect where acceptance was not asked, constitutes acceptance.

17. Governing law and disputes. These Terms are governed by the laws of the State of Delaware, United States of America, without regard to conflict-of-laws rules. You and we submit to the exclusive jurisdiction of the state and federal courts located in that jurisdiction, except that either party may seek injunctive relief in any court of competent jurisdiction to protect its intellectual property. You agree to first attempt to resolve any dispute informally by contacting us. To the extent permitted by law, any claim must be brought within one year after it arises. If you are a public body, the Government Customer Addendum modifies this Section and Sections 13, 14 and 18 as it states, and controls where the two conflict.

18. General. These Terms, together with the documents incorporated by reference (including, where you have entered into it, the Data Processing Addendum and the Government Customer Addendum), are the entire agreement between you and us regarding the Service and supersede prior agreements. If any provision is unenforceable, the rest remains in effect. Our failure to enforce a provision is not a waiver. You may not assign these Terms without our consent; we may assign them in connection with a merger, acquisition, or sale of assets. Nothing here creates a partnership, agency, or employment relationship. Legal notices to us go in writing to RotorLab, Inc., Dubuque, Iowa, and by email to legal@rotorlab.app; other questions go through the support contact shown in the Service. We give notices to you by email to your organization's administrators or in the Service.

By using RotorLab.app you acknowledge that you have read and understood these Terms and agree to be bound by them.

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