Terms of use
What Sydeslip is, what it is not, and where the responsibility sits.
Last updated: 29 September 2026
Sydeslip is a free, independent front end for a MyFlightBook logbook. It presents flights you already keep with MyFlightBook as a paper-style EASA logbook spread and an aircraft technical log.
It is not affiliated with, endorsed by, or operated by MyFlightBook. Your MyFlightBook account, and the records in it, are governed by your agreement with them.
Your logbook is the record — not this app
This is the most important thing here. Your logbook is a legal document and it remains your responsibility. Sydeslip is a way of looking at it and, where you ask it to, of writing to it. It is not the record itself, it is not an authority on what your record should contain, and it is not a substitute for keeping your logbook properly.
- Suggestions are suggestions. Sydeslip can work out night time from the sun’s position and can point out inconsistencies. These are offered for you to accept or ignore — it never edits an entry on its own, because the entry is yours.
- Totals and currency are presented, not certified. Whether you are legal to fly is a question for you and your authority, using your actual records.
- Print layouts are a style, not an approved form. Neither the FAA nor the UK CAA mandates a logbook form — they specify content. Whether a printed page is acceptable is between you and your authority.
Endorsement signatures
Sydeslip lets an instructor sign an entry on your device, in person, and records a fingerprint of the entry as it was at that moment so later changes show up.
This is a local attestation, not a certified or legally recognised electronic signature. The record lives in a file on your own device that you are able to edit. Whether your authority accepts an electronic endorsement at all is a question for them.
Keep your own backups
Your flight log lives in MyFlightBook, not here. Sydeslip reads it and draws a page from it; it does not hold a copy. So backing up your flights is done on MyFlightBook’s own pages, using their export — and it is worth doing. Sydeslip’s Back up now does not do it for you.
What Sydeslip’s backup does cover is the records MyFlightBook has no room for — your certificates and medical, licences, pilot and aircraft profiles, endorsement signatures, airport coordinates you entered, and the tech log. Those live in your browser on your device and can be lost; the privacy notice sets out exactly how.
When you are signed in, importing a CSV or JSON file adds those flights to your MyFlightBook logbook, one at a time — Sydeslip does not keep a second copy of them. If the import cannot finish, it tells you exactly how many reached MyFlightBook and how many were not attempted, and you can undo the whole batch, which deletes those flights from your logbook again.
Before you are signed in, Sydeslip is running on sample data and an import stays on this device, where it is covered by the backup above.
Taking backups is your responsibility. Sydeslip gives you the button and reminds you to use it. Import & export can also write your flights out as CSV or JSON, which is a useful snapshot — but a snapshot taken here is not a substitute for backing up in MyFlightBook.
No warranty
Sydeslip is provided free and as is, with no warranty of any kind. It may contain errors, it may be unavailable, and it may stop being offered. To the fullest extent the law allows, the operator is not liable for any loss arising from your use of it — including lost records, missed currency, or an entry that turns out to be wrong.
Nothing here excludes liability that cannot lawfully be excluded, and if you are a consumer your statutory rights are unaffected.
Fair use, and availability
Please don’t use Sydeslip’s proxy as a general relay to MyFlightBook, script it at a volume that would burden either service, or attempt to reach another person’s data through it. The proxy only accepts requests from Sydeslip’s own pages, which is a technical limit as well as a request.
Sydeslip is a personal project offered without charge. It carries no uptime commitment and may be changed or withdrawn at any time. If it is withdrawn your logbook is unaffected — it is in MyFlightBook — and your device-held records remain exportable for as long as you have the app installed. That is the reason to keep a backup rather than to rely on the service continuing.
Changes, governing law and contact
If these terms change materially, the date above changes and the change is described in plain language.
These terms are governed by the law of Sweden, and the Swedish courts have jurisdiction. If you are a consumer resident elsewhere in the EU or EEA, that does not take away the protection of any mandatory rules of your own country’s law, nor your right to bring proceedings where you live.
Sydeslip is operated by Gavin Jeffries, in Sweden. Contact: privacy@sydeslip.com.