The NASA Design and Analysis of Rotorcraft (NDARC) software is an aircraft system analysis tool intended to support both conceptual design efforts and technology impact assessments. The principal tasks are to design (or size) a rotorcraft or airplane to meet specified requirements, including vertical takeoff and landing (VTOL) operation, and then analyze the performance of the aircraft for a set of conditions. For broad and lasting utility, it is important that the code have the capability to model general rotorcraft configurations, and estimate the performance and weights of advanced rotor concepts. The architecture of the NDARC code accommodates configuration flexibility, a hierarchy of models, and ultimately multidisciplinary design, analysis, and optimization. Initially the software is implemented with low-fidelity models, typically appropriate for the conceptual design environment.

An NDARC job consists of one or more cases, each case optionally performing design and analysis tasks. The design task involves sizing the aircraft to satisfy specified design conditions and missions. The analysis tasks can include off-design mission performance calculation, flight performance calculation for point operating conditions, and generation of subsystem or component performance maps. For analysis tasks, the aircraft description can come from the sizing task, from a previous case or a previous NDARC job, or be independently generated (typically the description of an existing aircraft).

The aircraft consists of a set of components, including fuselage, rotors, wings, tails, and propulsion. For each component, attributes such as performance, drag, and weight can be calculated; and the aircraft attributes are obtained from the sum of the component attributes. Description and analysis of conventional rotorcraft configurations is facilitated, while retaining the capability to model novel and advanced concepts. Specific aircraft configurations considered are single main-rotor and tailrotor helicopters; tandem helicopters; coaxial helicopters; tiltrotors; compound helicopters; autogiros; multi-copters; and airplanes. The architecture of the code accommodates addition of new or higher-fidelity attribute models for a component, as well as addition of new components.

NDARC distribution is controlled by the NASA Ames Software Release Authority, and requires a Software Usage Agreement. Information about the software and the form needed to complete the SUA is at Foreign access to NDARC is restricted to academic institutions; foreign academic institutions should contact the Ames Software Release Authority at to obtain the NDARC Software Usage Agreement.

NDARC users covered by a Software Usage Agreement can obtain access to the complete NDARC web site, including documentation, examples, training information, compiler instructions, and executables. For information about and assistance with the NDARC web site, contact Wayne Johnson ( or Christopher Silva (

RCOTOOLS, a software package to integrate NDARC with Python software (specifically targeted to OpenMDAO), is also available separately from the NASA Software web site, at For information about RCOTOOLS, contact Larry Meyn (

Current release: NDARC 1.17c (November 2023)