Part 107 groundspeed check
Checks your groundspeed, including the wind, against the Part 107 limit of 87 kt (100 mph). A tailwind can push a legal airspeed over the limit.
Planning and education aid. Not for primary navigation. Full disclaimer
Experimental: not yet fully verified. How results are checked
Your groundspeed is 105 mph, over the limit of 100 mph. Not legal advice.
- Limit
- Margin
- Status
- Notice
Provenance
- Computed by
- drone.ops.speed-check 1.0.0, core 0.1.0
- Model
- Groundspeed = airspeed + along-track wind, compared with 87 kt
- Accuracy
- Exact for a steady wind along the track.
- Notes
- 1 shown with the answer
- Cites
- Federal Aviation Administration, 14 CFR Part 107, Small Unmanned Aircraft Systems
Something look off?
How we got thisFormula, worked example, sources, and proof
Model: Groundspeed = airspeed + along-track wind, compared with 87 kt
Accuracy: Exact for a steady wind along the track.
Worked example: 90 mph airspeed with a 15 mph tailwind. Source: 14 CFR 107.51(a): 87 kt (100.1 mph) groundspeed. It is golden test vector v001, and every build checks the tool still gives its answer within its tolerance.
You enter
- Airspeed
- 90 mph
- Tailwind
- 15 mph
You get
- Groundspeed
- 105 mph
- Limit
- 100 mph
- Margin
- -4.9 mph
- Status
- over the limit
- Notice
- Summary of rules as of 2026-09-18. Not legal advice. Check the current regulation and any waivers, authorizations, or local restrictions: https://www.ecfr.gov/current/title-14/chapter-I/subchapter-F/part-107/subpart-B/section-107.51
Review: Not yet independently reviewed by a Part 107 remote pilot.
Last verified: 2026-09-18, when a maintainer last confirmed this tool's sources at the issuer. See the sources ledger.
Status: version 1.0.0, core 0.1.0. See this tool in the verification report.
Checked against: 5 golden test vectors (download the test vectors, each with its source and tolerance). See how results are checked and every source.
Sources
- 14 CFR Part 107, Small Unmanned Aircraft Systems, Federal Aviation Administration, eCFR, current text (dated on the page as "Rules as of"). §107.51 (operating limitations) and §107.120 (operations over people, category 2). Rules as of 2026-09-18.
Experimental means this tool has not yet met the stable bar: at least 20 golden vectors, differential tests, and an independent worked example.