Required descent rate API

Computes the descent rate (fpm), glidepath angle and gradient needed to lose a given altitude over a given distance at ground speed. Answers 'What fpm do I need to lose 3000 ft in 10 nm?', 'What glidepath angle does that imply?'.

Price$0.04per request

MethodPOST

Route/v1/nav/descent-rate

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

aviationdescent-ratefpmglidepathgradientapproacharrivalvertical-speed

API URLhttps://x402.hexl.dev/v1/nav/descent-rate

Integration docs

Example request

{
  "altitudeToLoseFt": 3000,
  "distanceNm": 10,
  "groundSpeedKt": 120
}

Example response

{
  "requiredDescentRateFpm": 600,
  "timeToPointMin": 5,
  "glidepathAngleDeg": 2.83,
  "gradientPercent": 4.94,
  "gradientFtPerNm": 300,
  "interpretation": "Descend 600 fpm to lose 3000 ft in 10 nm (2.83 deg path, 300 ft/nm)."
}

Input schema

{
  "type": "object",
  "required": [
    "altitudeToLoseFt",
    "distanceNm",
    "groundSpeedKt"
  ],
  "properties": {
    "altitudeToLoseFt": {
      "type": "number",
      "examples": [
        3000
      ]
    },
    "distanceNm": {
      "type": "number",
      "examples": [
        10
      ]
    },
    "groundSpeedKt": {
      "type": "number",
      "examples": [
        120
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}