Every Screen
CDU, COMM, CHKL, SYS, INFO, and ND — switched from the keypad, like the real thing.
An iPad app for airline pilots
FMS Trainer
Practice the box before the airplane.
The flight management computer, the checklists, the systems, and the map — on an iPad, with nothing to break and no clock running. Load a flight, run the preflight, and press every key you’ve wondered about. Built by a pilot, for pilots.
Coming soon$5.99, one-time purchase
Five Flight Decks
787, 777, 757/767, 737, and the A320 family, each with its own boxes and quirks.
$5.99, Once
One purchase. No subscription, no sign-in, no ads, no tracking.
Key features
Every key, no consequences.
The Whole CDU
Route, legs, performance, takeoff, progress, fix, descent, and approach pages — with the scratchpad, MOD, and EXEC working the way they do on the line.
A Real Preflight
Pick a flight and it’s ready to load. Activate, execute, then performance setup, takeoff data, and winds, in order.
Checklists That Know
Electronic checklists that assume the flow is done — sensed items arrive checked, and you tap only the open items.
Map & Systems
The navigation display in map and plan modes, system synoptics, and status pages, drawn from the same flight you loaded.
Five Flight Decks
The 787, 777, 757/767, 737, and A320 family, each with its own CDU, its own pages, and its own quirks.
Pick Up Where You Left Off
Background the app or close it mid-preflight. When you come back, every page is exactly where you left it.
787
The 787, screen by screen
CDU, COMM, CHKL, SYS, INFO, and ND — switched from the keypad column on the right, like the airplane.
777
The 777, with its own quirks
A separate box with its own pages — from route to takeoff data.
757 / 767
The classic green screen
The 757 and 767 CDU, every key where your thumb expects it.
737
The 737, too
Its own CDU, its own pages, its own flight.
A320 family
And the Airbus MCDU
A whole different philosophy, on the same iPad.
FMS Trainer — Support
Last updated: October 4, 2026
Questions, bug reports, and ideas all go to one place: support@caerus.digital. A real person — the one who wrote the app — reads every message.
What to include
- Your iPad model and iPadOS version (Settings, then General, then About).
- The FMS Trainer version.
- Which aircraft and screen you were on, and what you pressed.
- A screenshot, if you can.
Common questions
Does it need an internet connection? No. The navigation database is built into the app, and nothing is downloaded while you use it.
How do I clear everything? Delete the app and reinstall it. That removes every saved session.
Can I use it in the airplane? No. FMS Trainer is a practice aid only — see the Terms of Use.
FMS Trainer — Terms of Use
Last updated: October 4, 2026
These Terms of Use (“Terms”) govern your access to and use of the FMS Trainer mobile application (“FMS Trainer”, the “App”), operated by Caerus Digital, LLC (“Caerus Digital”, “we”, “us”, “our”). By downloading, installing, or using FMS Trainer, you agree to these Terms. If you do not agree, do not use the App.
1. Eligibility
FMS Trainer is intended for pilots and aviation students. You must be at least 18 years old, or have the consent of a parent or guardian, to use FMS Trainer.
2. Description of Service
FMS Trainer is an unofficial practice tool that simulates flight management computer pages, datalink messages, electronic checklists, system pages, and navigation displays for study on an iPad. FMS Trainer is a training aid only. It is not certified, approved, or intended for use in flight, in any aircraft, or in any approved training device, and it does not replace your company’s manuals, procedures, approved training, or the aircraft’s own systems. Simulated behavior may differ from any real aircraft, software load, or navigation database. You are solely responsible for verifying anything you learn in FMS Trainer against official sources.
3. Navigation Data
The navigation data and sample flights included with FMS Trainer are for training only and must not be used for navigation. Data may be out of date or incomplete.
4. Purchase
FMS Trainer is a one-time purchase through the Apple App Store at the price shown on the App Store (currently 5.99 US Dollars). There is no subscription. Apple processes the payment; Caerus Digital cannot process refunds for App Store purchases. Refund requests must be submitted to Apple directly.
5. Acceptable Use
You agree not to (a) use FMS Trainer for actual flight planning, navigation, or any operational decision, (b) reverse engineer, decompile, or attempt to extract source code or bundled data from FMS Trainer, (c) redistribute or resell FMS Trainer or its content, or (d) use FMS Trainer in any way that violates law, regulation, or your employer’s policy.
6. No Affiliation
FMS Trainer is an independent product. It is not affiliated with, endorsed by, or sponsored by The Boeing Company, Airbus, any avionics manufacturer, any airline, or any pilot union. Aircraft names, model numbers, and industry terms are used only to describe what the App simulates and remain the property of their owners.
7. Intellectual Property
FMS Trainer, its source code, design, branding, and content are owned by Caerus Digital and protected by United States and international copyright, trademark, and other intellectual-property laws. We grant you a personal, limited, non-exclusive, non-transferable, revocable license to use FMS Trainer for your own personal training.
8. Disclaimers
FMS TRAINER IS PROVIDED “AS IS” AND “AS AVAILABLE” WITHOUT WARRANTIES OF ANY KIND, WHETHER EXPRESS, IMPLIED, OR STATUTORY, INCLUDING WITHOUT LIMITATION ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, ACCURACY, OR NON-INFRINGEMENT. CAERUS DIGITAL DOES NOT WARRANT THAT FMS TRAINER WILL BE UNINTERRUPTED OR ERROR-FREE, OR THAT IT ACCURATELY REPRESENTS ANY AIRCRAFT, AVIONICS SYSTEM, PROCEDURE, OR NAVIGATION DATABASE. FMS TRAINER IS NOT FLIGHT-CRITICAL SOFTWARE AND MUST NOT BE USED FOR NAVIGATION OR AS A SUBSTITUTE FOR APPROVED TRAINING, AIRCRAFT MANUALS, FEDERAL AVIATION REGULATIONS, COMPANY PROCEDURES, OR PROFESSIONAL JUDGMENT.
9. Limitation of Liability
TO THE MAXIMUM EXTENT PERMITTED BY LAW, CAERUS DIGITAL SHALL NOT BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, EXEMPLARY, OR PUNITIVE DAMAGES, INCLUDING LOST PROFITS, LOST PAY, FAILED CHECKRIDES, DISCIPLINARY ACTION, OR LOSS OF GOODWILL, ARISING OUT OF OR IN CONNECTION WITH YOUR USE OF FMS TRAINER, EVEN IF CAERUS DIGITAL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. IN NO EVENT WILL CAERUS DIGITAL’S TOTAL LIABILITY EXCEED THE GREATER OF (A) THE AMOUNT YOU PAID FOR FMS TRAINER IN THE TWELVE MONTHS PRECEDING THE CLAIM OR (B) FIFTY US DOLLARS.
10. Indemnification
You agree to defend, indemnify, and hold harmless Caerus Digital and its officers, members, and employees from any claim, demand, loss, or expense (including reasonable attorneys’ fees) arising out of your use of FMS Trainer, your breach of these Terms, or your violation of any third party’s rights, including your employer’s policies.
11. Termination
You may stop using FMS Trainer at any time by uninstalling the App. We may suspend or terminate your access if you violate these Terms or if we discontinue FMS Trainer. Sections that by their nature should survive termination (including Disclaimers, Limitation of Liability, Indemnification, and Governing Law) will survive.
12. Changes to These Terms
We may update these Terms from time to time. Material changes will be communicated through the App or by updating the “Last updated” date above. Continued use of FMS Trainer after changes take effect constitutes acceptance of the revised Terms.
13. Governing Law
These Terms are governed by the laws of the Commonwealth of Virginia, without regard to its conflict of laws principles. Any dispute arising out of or relating to these Terms or your use of FMS Trainer will be resolved exclusively in the state or federal courts located in Virginia, and you consent to the jurisdiction of those courts.
14. Contact
Questions about these Terms can be sent to support@caerus.digital.
Apple-Required EULA Provisions
You acknowledge that these Terms are between you and Caerus Digital only, and not with Apple Inc. (“Apple”). Apple is not responsible for FMS Trainer or its content. Apple has no obligation to provide any maintenance or support for FMS Trainer. In the event of any failure of FMS Trainer to conform to any applicable warranty, you may notify Apple, and Apple will refund the purchase price of FMS Trainer to you, if applicable; to the maximum extent permitted by law, Apple will have no other warranty obligation with respect to FMS Trainer. Apple is not responsible for addressing any claims by you or any third party relating to FMS Trainer or your possession or use of FMS Trainer, including product-liability claims, claims that FMS Trainer fails to conform to any applicable legal or regulatory requirement, and claims arising under consumer-protection or similar legislation. In the event of any third-party claim that FMS Trainer or your use of FMS Trainer infringes that third party’s intellectual property rights, Caerus Digital, not Apple, will be solely responsible for the investigation, defense, settlement, and discharge of that claim. You represent and warrant that you are not located in a country that is subject to a US Government embargo, or that has been designated by the US Government as a “terrorist supporting” country, and that you are not listed on any US Government list of prohibited or restricted parties. Apple and Apple’s subsidiaries are third-party beneficiaries of these Terms, and upon your acceptance, Apple will have the right (and will be deemed to have accepted the right) to enforce these Terms against you as a third-party beneficiary.
FMS Trainer — Privacy Policy
Last updated: October 4, 2026
Caerus Digital, LLC (“Caerus Digital”, “we”, “us”, “our”) built FMS Trainer (“FMS Trainer”, the “App”) to help pilots practice flight management systems. This Privacy Policy explains what data FMS Trainer handles, how it handles it, and the choices you have.
The short version: FMS Trainer works entirely on your iPad. It makes no network connections, has no accounts, and contains no analytics, advertising, or tracking. Nothing you do in the App is sent to us or anyone else.
1. Information FMS Trainer Handles
a. Your practice session. So you can pick up where you left off, the App saves the state of each aircraft’s session — the pages, entries, and flights you load — in the App’s own storage on your iPad. It never leaves your device. It also remembers two settings: the aircraft you chose and which side the screens sit on.
b. Navigation data. The navigation database is built into the App, and the App keeps a working copy in its own storage. It contains no personal information.
2. Information FMS Trainer Does Not Collect
FMS Trainer does not ask for or collect your name, email address, phone number, employee number, location, contacts, photos, camera, microphone, or device identifiers. It uses no analytics SDKs, advertising SDKs, crash-reporting services, or tracking of any kind, and it does not track you across other apps or websites. The App does not request any device permissions.
3. Servers and Services FMS Trainer Connects To
None. FMS Trainer makes no network connections while you use it. Caerus Digital runs no server for the App and receives no data from it. Apple handles the purchase, download, and updates through the App Store under Apple’s own Privacy Policy; we do not receive your Apple ID, name, or payment details.
4. Email You Send Us
If you write to support@caerus.digital, we receive whatever you choose to include, along with your email address, and use it only to answer you.
5. Data Retention and Deletion
Everything the App stores lives on your iPad. To delete it all, delete FMS Trainer from your iPad. To have an email you sent us deleted, write to support@caerus.digital.
6. Security
The App’s data is stored in its private storage on your iPad, protected by iPadOS and your device passcode. Because nothing is transmitted, nothing can be intercepted in transit. No security system is perfect; we follow industry best practices but cannot guarantee absolute security.
7. Children
FMS Trainer is intended for pilots and aviation students. It is not directed to children under 13, and we do not knowingly collect information from children.
8. Your Rights
Because the App keeps your information on your device, you control it directly: delete the App to remove it entirely. If you are located in a jurisdiction with specific privacy rights (such as the GDPR in the European Economic Area or the CCPA in California), those rights apply to any email you have sent us; contact support@caerus.digital and we will delete it within 30 days.
9. Changes to This Policy
We may update this Privacy Policy from time to time. Material changes will be communicated through the App or by updating the “Last updated” date above. Your continued use of FMS Trainer after changes take effect constitutes acceptance of the revised Policy.
10. Contact
Questions about this Privacy Policy can be sent to support@caerus.digital.
The moment is now
Practice the box before the airplane.
FMS Trainer is coming to the App Store for iPad — $5.99, one-time purchase. Questions? Ask the pilot who built it.
Coming soon$5.99, one-time purchase