These terms govern your use of the Landblink software application and associated network services.
Landblink is developed and operated by one person, referred to here as the developer.
1. Description of the Application
Landblink is an offline flight observation application designed for airline passengers. It receives broadcast satellite signals on your personal Android device to display estimated flight telemetry, moving map position, cabin pressure readings, and satellite constellation telemetry from a passenger window seat.
The application is distributed directly as an Android package (APK) file for personal sideloading. It is not distributed through the Google Play Store.
2. Aviation Safety and Operational Disclaimer
Landblink is an informational utility for passengers. It is not an aviation instrument.
Not for Flight Navigation or Operational Use
- No operational approval. Landblink has not been certified, evaluated, or approved by the Federal Aviation Administration (FAA), the European Union Aviation Safety Agency (EASA), the International Civil Aviation Organization (ICAO), or any other civil aviation authority.
- Prohibited in the cockpit. The application must not be used for pilot navigation, terrain avoidance, flight planning, approach monitoring, fuel calculation, or any operational decision-making in the cockpit or cabin.
- Not a primary or secondary source. The software is not a substitute for onboard avionics, certified navigation equipment, primary flight displays, cabin altitude warning systems, or flight attendant announcements.
Passenger Compliance and Cabin Safety
- Crew instructions take priority. You must obey all instructions given by the flight crew, cabin attendants, and airline representatives at all times. Crew instructions legally supersede any information shown in the application.
- Electronic device regulations. You are responsible for complying with airline policies and aviation authority regulations regarding portable electronic devices.
- Radio silence. Devices must be operated in airplane mode during flight. Do not activate cellular or Wi-Fi data unless permitted by the operating carrier.
- Stowage during critical flight phases. You must securely stow your phone during pushback, taxi, takeoff, approach, and landing, or whenever instructed by the flight crew. Do not hold the device up, wedge it into window shades, or affix suction mounts to cabin windows during critical flight phases. Cables and charging accessories must never obstruct aisles, exits, or emergency egress paths.
Technical Limitations of Passenger Telemetry
- Degraded satellite reception. Aircraft fuselages attenuate satellite signals. Reception through a passenger window provides a restricted view of the sky, resulting in geometric dilution of precision, multipath reflections from wing surfaces, or complete signal loss.
- Extrapolated data. When satellite reception drops, the application bridges short gaps using dead reckoning. These positions are mathematical projections based on previous heading and speed. They do not reflect real-time wind drift, pilot turns, or altitude adjustments made during the gap.
- Unvalidated turbulence forecasts. Turbulence predictions shown in the application are derived from numerical wind models and forecast shear indices. They are predictive estimates, not real-time measurements of atmospheric turbulence, and have not been validated against aircraft flight telemetry.
- Cabin pressure limitations. Barometer readings reflect cabin pressurization controlled by aircraft environmental systems. They do not measure external atmospheric pressure or true flight altitude.
3. Licence to Use
Subject to these terms, the developer grants you a personal, revocable, non-exclusive, non-transferable, royalty-free licence to install and run the Landblink APK on your personal Android devices for non-commercial, observational purposes.
You may not:
- Decompile, reverse engineer, or disassemble the binary distribution, except to the extent permitted by mandatory statutory law.
- Use the software or backend APIs to build automated scrapers, denial-of-service tools, or competing data harvesting services.
- Misrepresent Landblink telemetry as certified aeronautical data.
4. User-Contributed Data Licence
Landblink provides an optional, opt-in feature allowing users to contribute completed flight tracks to improve crowdsourced route corridors.
If you choose to enable flight contribution, you grant the developer a worldwide, perpetual, irrevocable, royalty-free, non-exclusive licence to store, process, analyze, downsample, aggregate, and publish derived route summaries and statistical corridors based on your contributed tracks.
As described in the Privacy Policy, contributed tracks undergo automated trimming of coordinates within 15 kilometers of departure and arrival locations prior to transmission. You may delete your stored contributions at any time using the in-app deletion control while your device retains its installation credential.
5. Modifications and Withdrawal of the Service
Landblink is an independent personal project.
The developer reserves the right at any time to:
- Modify, update, or discontinue the application or any of its features without notice.
- Restrict, rate-limit, or terminate access to backend services, including orbit ephemeris sync, route weather downloads, and crowdsourced route queries.
- Withdraw the project, backend infrastructure, or distribution downloads permanently.
You acknowledge that backend availability is provided on a best-effort basis. The application is designed to function offline without backend access.
6. Disclaimer of Warranties
Landblink is provided "as is" and "as available", without warranty of any kind.
To the maximum extent permitted by applicable law, The developer expressly disclaims all warranties, whether express, implied, statutory, or otherwise, including but not limited to implied warranties of merchantability, fitness for a particular purpose, title, quiet enjoyment, and non-infringement.
No advice or information, whether oral or written, obtained from the application or its documentation creates any warranty. The developer does not warrant that:
- The software will meet your specific requirements.
- The software will operate uninterrupted, secure, or free from bugs or errors.
- Any position, altitude, speed, estimated arrival time, cabin pressure reading, or weather forecast provided by the software is accurate, complete, reliable, or timely.
7. Limitation of Liability
To the maximum extent permitted by applicable law, The developer shall not be liable for any indirect, incidental, special, consequential, punitive, or exemplary damages whatsoever.
This limitation includes, without limitation, damages for:
- Personal injury, illness, or loss of life.
- Property damage.
- Flight delays, missed connections, diversion expenses, or travel disruptions.
- Loss of profits, data, goodwill, or business interruption.
This limitation applies under any theory of liability, whether in contract, tort (including negligence), strict liability, product liability, or otherwise, even if the developer has been advised of the possibility of such damages.
In jurisdictions where the exclusion or limitation of liability for certain categories of damages is restricted by law, liability is limited to the fullest extent allowed by applicable law.
8. Governing Law
Landblink's backend runs on a single rented virtual server in Oracle Cloud's us-phoenix-1 region, in Arizona, United States. The developer has not yet designated a governing jurisdiction for these terms; until one is stated here, nothing in this section waives any right you have under the law of the country you live in.
9. Contact
For inquiries regarding these terms, please contact:
Contact: github.com/leonaffi-byte/flygps/issues
The following literal placeholders appear in this document and must be replaced with verified details:
Technical Notes and Reconciliation with Code
This document reflects the application codebase. Where earlier project briefs or informal summaries differed from the codebase, the code was treated as the authoritative source of truth:
- Passenger scope and avionics isolation: The app runs purely on Android consumer hardware with foreground-only sensor access (
app/src/main/AndroidManifest.xml). It does not interface with ARINC, avionics buses, or cockpit data links. - Turbulence and estimation labeling: As reflected in
README.md and DESIGN.md, turbulence data is an unvalidated estimate derived from forecast winds aloft, and all dead-reckoned samples are flagged in code (isDeadReckoned in LocationSample.kt and TrackPoint.kt). The terms reinforce these programmatic boundaries. - Voluntary project status: The backend infrastructure is hosted on a single virtual private server behind Caddy with automated database backups, operated as a personal project rather than an enterprise service.