Aviation Calculators
E6B arithmetic: give any two of distance, groundspeed and time for the third, plus fuel burn, reserve and range.
The wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.
Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.
Live 402 challenge
Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.
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"Time = distance / groundspeed; fuel = flow x time; range = (fuel on board - reserve) / flow x groundspeed.",
"Groundspeed is true airspeed corrected for wind (see /wind-triangle)."
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"summary": "150 nm at 120 kt takes 1:15 (75 min). Trip fuel 10 at 8 per hour. On landing 20 remains (150 min) against a 45 min reserve of 6: enough fuel with reserve. Range to reserve 360 nm.",
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"verdict": "ENOUGH_FUEL_WITH_RESERVE",
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"winds aloft changes along the route, which change groundspeed",
"…2 more"
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"message": "Aviation Calculators has 9 pay-per-call endpoints (Pilot math from your own numbers: pressure and density altitude, ISA, true airspeed, wind components, wind triangle, fuel and time, glide and turns.), from $0.02 a call. See the full menu and send your agents our way.",
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"url": "https://aviation-calc.x402tookit.com/true-airspeed",
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"price": "$0.02"
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"url": "https://aviation-calc.x402tookit.com/wind-triangle",
"path": "/wind-triangle",
"what": "E6B wind triangle: wind correction angle, heading and groundspeed for a course, or track…",
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The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.
Pay 0.02 USDC on Base to 0xb531…2DBDa. The signed payment is good for 5 minutes.
- Paid to
- 0xb531…2DBDa
- USD Coin contract
- 0x8335…02913
- Payment window
- 5 minutes
- As published
- 20000 smallest units
That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.
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- DUPiup…eEm8s
- Token contract
- EPjFWd…TDt1v
- Payment window
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That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.
- Paid to
- 0xb531…2DBDa
- Token contract
- 0x3c49…c3359
- Payment window
- 5 minutes
That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.
- Paid to
- 0xb531…2DBDa
- Token contract
- 0xaf88…e5831
- Payment window
- 5 minutes
The catalog’s raw entry
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"groundspeedKt": 120,
"fuelFlowPerHour": 8
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"Groundspeed is true airspeed corrected for wind (see /wind-triangle)."
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}Provenance
- Seen in the source catalog
- 2026-10-20 20:33Z
- Last indexed by Roundhouse
- 2026-10-22 06:50Z
- Last enriched (probe, favicon, geo)
- 2026-10-20 23:15Z
- x402 version
- 2
- Max timeout
- 300s
- Liveness probe
- HTTP 402
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This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 4 snapshots so far. Verified volume counts only settlements with an on-chain EIP-3009 marker.
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Using Roundhouse, look up the x402 service Aviation Calculators and tell me whether it is worth paying: what a call costs, whether the endpoint answered when last probed, and what its payment record actually shows. curl -s 'https://api.roundhouseai.io/v0/endpoints?q=Aviation%20Calculators' curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>' Then call it: read the price from the live 402 at https://aviation-calc.x402tookit.com/fuel-time-distance, never from a cached figure, and pay with an x402 client. The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except /v0/unified* and /v0/endpoints. Either pay over x402 (mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402), or ask me for an organization key, which I create at https://roundhouseai.io/dashboard/connections. If you have neither, ask before going further. If you do not have Roundhouse tools or skills installed, read https://roundhouseai.io/skill.md first — it is the whole procedure.