How do I install the Tow Estimation skill?

Run npx skillmds@latest add ashfordeou/tow-estimation 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 Tow Estimation safe to use?

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Which AI agents work with Tow Estimation?

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 Tow Estimation free to use?

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

Who published Tow Estimation?

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

Tow Estimation by ashfordeou — Agent Skill

Name: Tow Estimation
Author: ashfordeOU

Tow Estimation

Use when you must estimate the takeoff gross weight in conceptual aircraft sizing: apply the fuel-fraction method to payload and class-based empty and fuel fractions, iterate the estimate to convergence, and check the weight breakdown balances. Produces the takeoff gross weight estimate, the convergence verdict, and the breakdown check that gate the sizing iteration. Trigger: takeoff gross weight, conceptual sizing, fuel fraction, empty weight fraction, sizing iteration.

ashfordeOU 6dac9df 3 files · 6.3 KB Updated Sep 17, 2026

File contents

Takeoff Gross Weight Estimation (vehicle-design/conceptual/tow-estimation)

Use when the task is conceptual takeoff gross weight estimation: the fuel-fraction method, iteration convergence, and weight breakdown balance.

Domain quick reference

Fuel-fraction sizing: W0 = payload / (1 - empty fraction - fuel fraction).
Empty and fuel fractions are class-based estimates from similar aircraft; the sizing iteration refines them.
The iteration converges when successive estimates change by less than a tolerance.
The breakdown (empty + fuel + payload) must balance the total.

Workflow

Collect payload and class-based empty and fuel fractions.
Estimate W0 with tow_estimate.
Iterate and check convergence with tow_converged.
Balance the breakdown with weight_breakdown_ok.
Gate the sizing on the convergence verdict.

Pitfalls

Empty plus fuel fraction at or above 1.0.
Claiming convergence after one estimate.
Sizing to a payload of zero.

Behavior contract (gate 3)

The estimate, convergence, and balance logic is exercised by the gate 3 contract test: scripts/test_tow_estimation.py against scripts/tow_estimation_logic.py (stdlib unittest, offline). Run: python3 scripts/test_tow_estimation.py

Compliance

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

---name: tow-estimationdescription: Use when you must estimate the takeoff gross weight in conceptual aircraft sizing: apply the fuel-fraction method to payload and class-based empty and fuel fractions, iterate the estimate to convergence, and check the weight breakdown balances. Produces the takeoff gross weight estimate, the convergence verdict, and the breakdown check that gate the sizing iteration. Trigger: takeoff gross weight, conceptual sizing, fuel fraction, empty weight fraction, sizing iteration.license: Apache-2.0---# Takeoff Gross Weight Estimation (vehicle-design/conceptual/tow-estimation)Use when the task is conceptual takeoff gross weight estimation:the fuel-fraction method, iteration convergence, and weightbreakdown balance.## Domain quick reference- Fuel-fraction sizing: W0 = payload / (1 - empty fraction - fuel fraction).- Empty and fuel fractions are class-based estimates from similar aircraft; the sizing iteration refines them.- The iteration converges when successive estimates change by less than a tolerance.- The breakdown (empty + fuel + payload) must balance the total.## Workflow1. Collect payload and class-based empty and fuel fractions.2. Estimate W0 with tow_estimate.3. Iterate and check convergence with tow_converged.4. Balance the breakdown with weight_breakdown_ok.5. Gate the sizing on the convergence verdict.## Pitfalls- Empty plus fuel fraction at or above 1.0.- Claiming convergence after one estimate.- Sizing to a payload of zero.## Behavior contract (gate 3)The estimate, convergence, and balance logic is exercised by thegate 3 contract test: scripts/test_tow_estimation.py againstscripts/tow_estimation_logic.py (stdlib unittest, offline). Run:python3 scripts/test_tow_estimation.py## Compliance- Standards referenced, not reproduced: FAR-25 is US government work (public domain) and CS-25 is a free EASA download; the sizing method is common conceptual design practice, summary-only per standards-map.yaml.- compliance: STANDARDS-REF, gated: false.

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