Terms of Service

1. Acceptance of Terms

1.1 These Terms of Service ("Terms") govern your use of aircraftdesign.io ("the Service"), operated by Nils Kleemann as identified in our Legal Notice.

1.2 By accessing and using the Service, you agree to be bound by these Terms. If you do not agree to these Terms, please do not use the Service.

2. Description of Service

aircraftdesign.io is a web-based platform for aircraft conceptual design, analysis, and optimization. The Service provides — and aircraftdesign.io continues to develop and expand — tools spanning areas such as parametric geometry and aircraft definition, aerodynamic analysis, weight & balance, performance, optimization, and high-fidelity methods (e.g., CFD, FEA). The specific features available to you depend on your plan and are provided as and when made available; aircraftdesign.io may add, change, or remove features from time to time. This description is general and does not guarantee any particular feature, tool, or result. The Service is provided on an “as is” and “as available” basis (see Section 13).

3. Account Registration

3.1 When you create an account on aircraftdesign.io, you agree to: (a) provide accurate and complete registration information; (b) maintain the security of your account credentials; (c) receive email communications about platform updates and service-related notifications; and (d) accept responsibility for all activity under your account.

3.2 You can unsubscribe from promotional emails at any time using the link provided in our emails.

4. Subscription Plans

4.1 Plan structure. aircraftdesign.io offers the following subscription plans:

• Individual plans (Starter, Pro, Max) — billed monthly or annually, providing single-user access to the full analysis capability and a monthly allowance of compute credits;
• Team plan — billed monthly or annually and configured by team size: you choose the number of seats (between the published minimum and maximum), and each additional seat increases both the plan price and the pooled monthly compute allowance by the per-seat amounts published on aircraftdesign.io. The Team plan provides shared workspaces, role-based access management, and a pooled monthly allowance of compute credits shared across the team; and
• Enterprise plan — sold on a custom, separately negotiated basis, providing all Team features plus certification-grade controls and optional services for regulated entities (e.g., EASA DOA, FAA ODA), as described in Section 4.6.

4.2 Plan features and compute credits. Each plan includes a defined allowance of compute credits per billing period. Compute credits pay for the computational work behind aircraft analysis runs, including but not limited to aerodynamic analysis, structural analysis, optimization, and high-fidelity methods such as CFD and FEA. Compute credits are use-it-or-lose-it: your allowance is granted at the start of each billing period and unused credits do not carry beyond that period. For monthly subscriptions, the allowance is granted each month on the monthly anniversary of your subscription start date (for example, a subscription that began on the 29th refills on the 29th of each month, adjusted to the last day of the month where that day does not exist), and any unused balance does not carry into the next month. For annual subscriptions, the full twelve (12) months' allowance is granted upfront at the start of the annual period — you pay for the year and receive the year's credits immediately. Those credits remain available throughout the year (there is no monthly reset) and expire only at the start of your next annual billing period (your annual renewal), after which a new year's allowance is granted.

4.3 Overage. Usage in excess of your monthly compute-credit allowance is metered at the per-credit overage rate published on aircraftdesign.io (currently €0.02 per credit). To prevent unintended overage, the service pauses additional compute when your allowance is exhausted unless you opt into additional credits via your account settings. You may set a spend cap to bound your monthly overage exposure.

4.4 Billing. Monthly subscriptions are billed on a recurring monthly basis. Annual subscriptions are billed once upfront for a twelve (12) month period at a discounted rate published on aircraftdesign.io. All fees are stated in Euro (EUR) and exclude applicable taxes (e.g., VAT), which will be added at checkout where required.

4.5 Plan changes. You may change between plans at any time, subject to reasonable rate limits. Upgrades take effect immediately: the prorated difference between the plans is billed for the remainder of the current billing period, and your compute-credit allowance receives a prorated top-up reflecting the higher tier for the rest of that period. An upgrade does not reset your billing period or your renewal date; the new plan's full allowance applies from your next renewal. Changing only your billing cycle (for example, monthly to annual) on the same plan does not grant additional credits. Downgrades take effect at the end of the current billing period: you keep your current plan and its allowance until the period ends, after which the lower plan and its lower allowance apply. Because credits do not roll over, any unused credits above the lower plan's allowance are lost at that point.

4.6 Enterprise plans, services and custom agreements. The Enterprise plan is sold on a custom basis. Any price shown on aircraftdesign.io for Enterprise (for example, “starting at” a stated amount) is an indicative floor only and is not an all-inclusive price. The actual Enterprise scope, fees, compute allowances and service levels are determined through a sales discussion and set out in a written quote and a separate Enterprise agreement (for example, a Master Services Agreement and/or order form) between you and aircraftdesign.io.

4.6.1 Illustrative Enterprise services. The following are examples of optional services and capabilities that an Enterprise agreement may include; they are illustrative only, are provided solely where and as expressly agreed in that separate agreement, and may carry additional one-time or recurring fees. By way of example and without limitation: implementation and onboarding (data migration, workflow configuration, controlled-document template setup); tool-qualification / validation (V&V) packages and their ongoing maintenance; custom integrations with third-party PLM, ERP, ALM or requirements-management tools; dedicated, sovereign, single-tenant, or on-premise / air-gapped hosting and EU data-residency; tiered SLA support (including named contacts and guaranteed response times); audit and security-review support (including responses to your auditors and sharing of available compliance attestations); and custom legal and contracting terms (e.g., MSA, DPA, liability and indemnification terms). These examples are not a commitment or representation that any specific service is or will be available, are not guaranteed by these Terms or by any feature comparison published on aircraftdesign.io, and none of them is included in the Individual or Team plans.

4.6.2 Precedence. To the extent of any conflict between these Terms and a separately executed Enterprise agreement, that Enterprise agreement governs for the customer who executed it.

4.6.3 Not included in Individual or Team plans. For the avoidance of doubt, the certification-grade controls and Enterprise services described in this Section 4.6 are not included in the Individual plans (Starter, Pro, Max) or in the Team plan, and are not available on those plans. The Team plan provides the platform's full analysis capability together with collaboration features such as shared workspaces, role-based access, pooled compute, peer review and commenting; it does not include the Enterprise certification controls or services described in this Section 4.6.

5. Money-Back Guarantee

5.1 aircraftdesign.io offers a 30-day money-back guarantee on the first paid Individual plan (Starter, Pro, or Max) you subscribe to. If you decide the product isn't the right fit within 30 days from your initial subscription start date, you may request a full refund — no questions asked.

5.2 The money-back guarantee applies once per account and to your first paid Individual plan only. It does not apply to renewals, subsequent plan changes, Team or Enterprise plans, or additional compute-credit purchases.

5.3 To request a refund, submit a request through your account settings within the 30-day window. The refund is granted no questions asked; if you're open to sharing what didn't work for you, we'd genuinely appreciate the feedback, but it is entirely optional.

5.4 Eligible refunds are processed automatically to your original payment method as soon as you submit a valid request. Funds typically post within 5-10 business days, though it may take longer if a payment, verification, or other processing issue arises. Any compute credits purchased separately (additional credit top-ups) are non-refundable.

6. Cancellation and Termination

6.1 You may cancel your subscription at any time through your account settings. Cancellation takes effect at the end of the current billing period; you retain access to the service and your compute-credit allowance until that date. No refund is provided for the unused portion of the current billing period unless covered by the Money-Back Guarantee (Section 5).

6.2 We reserve the right to suspend or terminate any user account at our discretion for breach of these Terms, including but not limited to misuse of the service, unlawful activity, or non-payment. Where termination is for cause and you have an active prepaid subscription period, we will provide a pro-rata refund of the unused portion, excluding any consumed compute credits and any compute credits purchased separately.

7. Data Retention

7.1 Following termination or expiry of your subscription, you will have 90 days to export or download your project data.

7.2 After the 90-day period, we may delete your data from our servers without further notice.

7.3 You are responsible for maintaining your own backups of important project files. aircraftdesign.io is not liable for any data loss.

8. User Content and Data Ownership

8.1 You retain all ownership rights to the aircraft designs, project data, and other content you create or upload through the Service ("User Content").

8.2 You grant aircraftdesign.io a non-exclusive, worldwide, royalty-free license to use, store, and process your User Content solely for the purpose of providing and improving the Service.

8.3 You represent and warrant that you have all necessary rights to upload and use your User Content, and that your User Content does not infringe any third-party intellectual property rights.

9. Service Availability

We strive to offer constant availability of the Service but cannot warrant uninterrupted access. The Service may be temporarily unavailable due to maintenance, updates, or circumstances beyond our control. We are not liable for any downtime or service interruptions.

10. Price Increases

10.1 aircraftdesign.io reserves the right to increase plan prices, adjust compute-credit allowances, and update overage rates. Any such change always takes effect at the start of your next billing period and never affects billing periods that have already been invoiced.

10.2 We will notify you at least thirty (30) days before a price increase takes effect, by email to the address associated with your account.

10.3 If you do not accept a price increase, you may cancel your subscription before it takes effect, in accordance with Section 6. Cancelling before the increase applies means you are never charged the higher price.

11. User Responsibilities and Export Controls

11.1 You agree to: (a) provide accurate information when registering; (b) not use the Service for any unlawful purpose; (c) not attempt to gain unauthorized access to the Service; and (d) not interfere with or disrupt the Service.

11.2 You shall not reverse engineer, decompile, or disassemble any portion of the Service, except to the extent permitted by mandatory applicable law.

11.3 You shall comply with all applicable export control laws and regulations, including those of the European Union, Germany, and the United States. You shall not use the Service from any country subject to comprehensive sanctions or if you are a person or entity on any applicable sanctions list.

11.4 You acknowledge that the Service may be subject to export restrictions and agree not to export or re-export any technical data or analysis results in violation of applicable laws.

12. Intellectual Property

The Service and its original content, features, and functionality are owned by aircraftdesign.io and are protected by international copyright, trademark, and other intellectual property laws.

13. Disclaimer

13.1 The Service is provided "as is" without warranties of any kind, express or implied, including but not limited to warranties of merchantability, fitness for a particular purpose, or non-infringement.

13.2 aircraftdesign.io provides aircraft simulation software. You acknowledge that aircraftdesign.io is not responsible for: (a) the correctness, completeness, or accuracy of any data you upload or input; (b) any conclusions drawn from any analysis, simulation, calculation, or optimization performed by or through the Service; (c) the technical, scientific, regulatory, or commercial feasibility of any aircraft design or project; and (d) any decisions made based on the results of our tools.

13.3 The Service is not a substitute for flight testing, wind tunnel testing, structural testing, or any regulatory certification process. Analysis results are intended for preliminary design exploration and must be validated independently for any safety-critical, certification, or production applications.

13.4 The Service is intended for use by qualified engineers and professionals who can independently evaluate the validity and applicability of simulation results to their specific use case.

13.5 You assume full responsibility for all engineering decisions made based on the results of the Service. aircraftdesign.io shall not be liable for any consequences arising from the use of simulation results in design, manufacturing, certification, or operation of aircraft.

14. Indemnification

14.1 You agree to indemnify and hold harmless aircraftdesign.io and its officers, employees, and agents from any claims, damages, losses, or expenses (including reasonable legal fees) arising from: (a) your use of the Service; (b) your violation of these Terms; (c) your violation of any third-party rights, including intellectual property rights; or (d) your User Content.

14.2 aircraftdesign.io will promptly notify you of any such claim and reasonably cooperate with your defense. You may not settle any claim without our prior written consent.

15. Limitation of Liability

15.1 aircraftdesign.io shall be liable without limitation for damages arising from injury to life, body or health, for intent and gross negligence, and for claims under the German Product Liability Act.

15.2 For breaches of essential contractual obligations (obligations whose fulfillment is necessary for the proper execution of the contract), liability for slight negligence is limited to foreseeable, typically occurring damages.

15.3 In all other cases, liability for slight negligence is excluded.

15.4 Subject to the above, our total liability shall not exceed one hundred percent (100%) of the fees paid by you in the twelve (12) months preceding the event giving rise to the liability.

15.5 The disclaimers and limitations set forth in Section 13 apply without limitation.

16. Changes to Terms

We reserve the right to modify these terms at any time. We will notify users of any material changes via email or through the Service. Continued use of the Service after such modifications constitutes acceptance of the updated terms.

17. Governing Law and Jurisdiction

17.1 These Terms shall be governed by and construed in accordance with the laws of the Federal Republic of Germany. The United Nations Convention on Contracts for the International Sale of Goods (CISG) shall not apply.

17.2 The exclusive place of jurisdiction for all disputes arising out of or in connection with these Terms shall be Darmstadt, Germany.

18. Severability

Should any provision of these Terms be or become ineffective or invalid in whole or in part, the effectiveness and validity of the other provisions shall not be affected. Such ineffective or invalid provision shall be replaced by a provision which comes as close as legally possible to what the parties would have agreed pursuant to the meaning and purpose of the original provision.

19. Entire Agreement

These Terms, together with any applicable Agreement, represent the entire agreement between you and aircraftdesign.io regarding the Service and supersede all prior negotiations, agreements, and understandings between the parties, whether written or oral.

20. Contact

If you have any questions about these Terms, please contact us at: info@aircraftdesign.io