DATCOM: Ready Aircraft Models & Aerodynamic Output Files

Tue, 09 Dec 2025 00:00:00 +0000

USAF Digital DATCOM – Ready-to-Use Aerodynamic Dataset

What is Digital DATCOM?

Digital DATCOM (Data Compendium) is a computer program developed by the United States Air Force to estimate aircraft stability and control characteristics. It implements the methods documented in the classic USAF Stability and Control DATCOM handbook and was originally created at Wright–Patterson Air Force Base.

From these models, the code can compute:

Lift coefficient (CL) and lift‑curve slope (CLα)
Drag polar and zero‑lift drag (CD0)
Pitching‑moment coefficient (Cm) and static margin
Lateral–directional derivatives (Cyβ, Cnβ, Clβ)
Dynamic derivatives (CLq, Cmq, Clp, Cnr)

This makes DATCOM a practical tool for early‑stage design, stability analysis, and flight‑simulation models.

The Input Format Problem

Digital DATCOM uses a strict FORTRAN NAMELIST input format. On a modern machine, most “mysterious” errors are actually formatting issues, not aerodynamic problems.

Some frequent pitfalls are:

Comments: The * character is not a valid comment symbol.
NACA card: Use dashes, for example NACA-W-5-23014 instead of NACA W 5 23014.
Blank lines: Empty lines inside a namelist will stop the parser.
Namelist prefix: Each $NAMELIST must start in column 1 (no leading spaces).
Inline comments: The ! character generally breaks the parser.
Case termination: Each case must be closed with a NEXT CASE card.

Typical error messages look like:

** ERROR ** UNKNOWN NAMELIST NAME
** ILLEGAL CONTROL CARD
ERROR(S), THIS CASE NOT RUN

If you see these, the first thing to check is the file format and card layout.

Ready-to-Use Package

To avoid spending hours chasing format errors, this package provides corrected input files and pre‑computed output files that you can use directly for analysis, plotting, or MATLAB post‑processing.

Included Aircraft Models

ASW 20, B 737, Canard, Citation, Navion, Seneca2, MiG 17, Cessna 172

Aircraft	Type	Alpha Range	Mach	Description
ASW‑20	Sailplane	-2°–4°	0.10	High‑performance glider
B‑737	Transport	-16°–24°	0.20	Commercial jet airliner
Canard	Research	-6°–24°	0.60	Canard‑configuration study
Citation	Business jet	-16°–24°	0.40	Cessna Citation II (Model 550)
Citation_simple	Business jet	-16°–24°	0.40	Simplified Citation model
Citation_airfoil	Business jet	-16°–24°	0.40	Citation with custom airfoil
Navion	General aviation	-2°–20°	0.158	Ryan Navion light aircraft
Seneca2	Twin‑engine	-8°–20°	0.24	Piper PA‑34‑200T
MiG‑17	Fighter	-4°–14°	0.60	Classic Soviet jet fighter
Cessna172	General aviation	-4°–16°	0.12	Cessna 172 Skyhawk, popular trainer

Package Contents

The archive datcom_pack.zip contains:

datcom.exe – Digital DATCOM executable
*.dcm – DATCOM input files (same format, different extensions)
*.out – Pre‑computed output files (ready for MATLAB or other tools)

MATLAB Integration

The .out files provide tabulated aerodynamic data that can be read directly into MATLAB and other numerical tools for:

Flight‑simulation models
Static and dynamic stability analysis
Control‑system design and gain tuning
Performance and envelope calculations

Each case has already been run and checked, so you can go straight to plotting, curve fitting, or building state‑space models.

For MATLAB usage:

aero = datcomimport("filename.out"); % Load Digital DATCOM output

Download

You can download the full package here:

All input cases have been tested and verified to run correctly with the provided executable and MATLAB post‑processing.

Reference: AFWAL‑TR‑79‑3032; DATCOM‑Tools (GPL‑3.0) by YANG‑DEMIN; USAF Stability and Control DATCOM.

Aerospace | Khaled HAMIDI