How do I install the Breguet Range skill?

Run npx skillmds@latest add ashfordeou/breguet-range in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Breguet Range safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Breguet Range?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Breguet Range free to use?

Yes. Installing skills from SkillMD is free. This skill is licensed under Apache-2.

Who published Breguet Range?

ashfordeOU (@ashfordeou) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Breguet Range by ashfordeou — Agent Skill

Name: Breguet Range
Author: ashfordeOU

Breguet Range

Use when you must estimate the cruise range of a transport aircraft with the Breguet range equation: combine speed, thrust specific fuel consumption, and lift to drag ratio with the initial and final masses to produce the cruise range in meters, the cruise time from range and speed, and the final mass from the fuel fraction. Produces the range, cruise time, and final mass that gate the mission performance assessment. Trigger: cruise range, TSFC, lift to drag, fuel fraction, cruise time.

ashfordeOU e63d5db 3 files · 7.9 KB Updated Sep 17, 2026

File contents

Breguet Range (flight-mechanics/performance/breguet-range)

Use when the task is cruise range estimation from the Breguet range equation: speed, TSFC, lift-to-drag, and mass ratio inputs, plus cruise time and final mass from the fuel fraction.

Domain quick reference

The Breguet range equation computes still-air cruise range R from speed V, thrust specific fuel consumption TSFC, lift to drag ratio L/D, and the initial and final masses m0 and m1: R = (V / (TSFC * g0)) * (L/D) * ln(m0 / m1).
Units: speed in m/s, TSFC in kg/(N s), masses in kg, g0 = 9.80665 m/s^2, range in meters, cruise time in seconds.
Cruise time is range divided by speed: t = R / V.
Final mass from the fuel fraction f is m1 = m0 * (1 - f).
Range analysis sits in the FAR-25 / CS-25 transport performance context for cruise fuel planning.

Workflow

Collect speed, TSFC, L/D, and the initial and final masses.
Compute the range with breguet_range.
Compute cruise time with cruise_time.
Compute the final mass with final_mass.
Check the mass ratio and fuel fraction sanity before gating.

Pitfalls

Confusing TSFC units between kg/(N s) and 1/h; the equation needs TSFC per newton second, so g0 converts the thrust terms.
Using the weight ratio upside down as the mass ratio; m1 >= m0 makes ln(m0/m1) undefined or negative.
Using a zero fuel fraction or an empty mass list; final_mass with fuel fraction 1.0 or above leaves no vehicle mass.

Behavior contract (gate 3)

The range, time, and mass logic is exercised by the gate 3 contract test: scripts/test_breguet_range.py against scripts/breguet_range_logic.py (stdlib unittest, offline). Run: python3 scripts/test_breguet_range.py

Compliance

Standards referenced, not reproduced: FAR-25 is US government work (public domain) and CS-25 is a free EASA download; the Breguet range equation is common range methodology, summary-only per standards-map.yaml.
compliance: STANDARDS-REF, gated: false.

---name: breguet-rangedescription: Use when you must estimate the cruise range of a transport aircraft with the Breguet range equation: combine speed, thrust specific fuel consumption, and lift to drag ratio with the initial and final masses to produce the cruise range in meters, the cruise time from range and speed, and the final mass from the fuel fraction. Produces the range, cruise time, and final mass that gate the mission performance assessment. Trigger: cruise range, TSFC, lift to drag, fuel fraction, cruise time.license: Apache-2.0---# Breguet Range (flight-mechanics/performance/breguet-range)Use when the task is cruise range estimation from the Breguetrange equation: speed, TSFC, lift-to-drag, and mass ratio inputs,plus cruise time and final mass from the fuel fraction.## Domain quick reference- The Breguet range equation computes still-air cruise range R from speed V, thrust specific fuel consumption TSFC, lift to drag ratio L/D, and the initial and final masses m0 and m1: R = (V / (TSFC * g0)) * (L/D) * ln(m0 / m1).- Units: speed in m/s, TSFC in kg/(N s), masses in kg, g0 = 9.80665 m/s^2, range in meters, cruise time in seconds.- Cruise time is range divided by speed: t = R / V.- Final mass from the fuel fraction f is m1 = m0 * (1 - f).- Range analysis sits in the FAR-25 / CS-25 transport performance context for cruise fuel planning.## Workflow1. Collect speed, TSFC, L/D, and the initial and final masses.2. Compute the range with breguet_range.3. Compute cruise time with cruise_time.4. Compute the final mass with final_mass.5. Check the mass ratio and fuel fraction sanity before gating.## Pitfalls- Confusing TSFC units between kg/(N s) and 1/h; the equation needs TSFC per newton second, so g0 converts the thrust terms.- Using the weight ratio upside down as the mass ratio; m1 >= m0 makes ln(m0/m1) undefined or negative.- Using a zero fuel fraction or an empty mass list; final_mass with fuel fraction 1.0 or above leaves no vehicle mass.## Behavior contract (gate 3)The range, time, and mass logic is exercised by the gate 3contract test: scripts/test_breguet_range.py againstscripts/breguet_range_logic.py (stdlib unittest, offline). Run:python3 scripts/test_breguet_range.py## Compliance- Standards referenced, not reproduced: FAR-25 is US government work (public domain) and CS-25 is a free EASA download; the Breguet range equation is common range methodology, summary-only per standards-map.yaml.- compliance: STANDARDS-REF, gated: false.

Frequently asked questions