The Aircraft Performance Program APP™ is a specialized software for aircraft performance analysis. APP computes the complete range of aircraft performance parameters over a user-specified range of altitudes, speeds and other variables.
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The software is designed for speed, simplicity and flexibility in its use. It provides users with useful quick-look (evaluate) functions for the examination of a wide variety of data e.g. thrust, fuel flow, lift, drag, SEP, turn rate, etc.
Other features of APP include the capability to compute and optimize all kind of mission profiles based on defined mission specifications. The types of mission flight phases (e.g. takeoff, climb, cruise, loiter, descent, etc.) are suitable for civil as well as military aircraft.

A very useful feature of the software is the capability to work in either metric or British units and to be able to switch to either unit system during program execution. This feature allows a rapid conversion of results into either system of units.


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The Aircraft Performance Program APP is used for the following main tasks:

  • Practical and theoretical performance analysis
  • Concept development and detail design
  • Competitor performance analysis
  • Flight test and Certification support
  • Flight handbooks, Performance and Marketing brochures
  • University and academic teaching

APP is a valuable tool for all kinds of users, from small design teams to large aerospace companies. The latter will find it effective for producing quick assessments without having to resort to their own large, but very expensive, computer programs. Aircraft operators, research establishments, universities, government agencies and air forces will use it as a very cost-effective tool by avoiding expensive and lengthy subcontracting in many phases of their work.

APP can be operated with on any PC running Windows with a minimum of 20 Mbytes hard-disc storage. Input to the program comprises basic aircraft mass and aerodynamic characteristics as well as powerplant performance tabular data files which are created using an intuitive graphical user interface (GUI). Output from the program can be presented in graphical or tabular form.

For more information on features download the APP product presentation here: PDF

For special requirements regarding APP’s functionality custom solutions are available, contact us.

APP’s Workflow – from Input to Output

APP enables obstacle-free integration into existing working procedures. Existing in-house tools, procedures and methods may be kept to create APP models and the desired analyses. Information on required input data may be found here and here, see also our downloads section.

Flexibility by Design

  • Flexibility through tabulated data input
  • No Restriction on aircraft type or configuration
  • Jet and propeller propulsion
  • Electric and hybrid-electric propulsion
  • Use external tools to generate data: Input accounts for additional effects (e.g. engine installation effects, trim-drag, payload power off-take,..)
  • User-defined level of detail
  • Create various aircraft configurations (e.g. takeoff-flaps, cruise,..) for desired analyses


Advanced and expert users of APP do often like to enhance APP’s features or include APP into an existing in-house toolchain. This kind of scenario is covered by pyAPP, a Python package to interact with APP.

Purchase APP Licences

APP is sold by selected resellers world-wide.


ALR is providing APP licences to support eligible student projects and competitions in fields related to aircraft design. If you are a student or hosting a competition and would like to use APP, please contact us here.


Since its creation in 1981, ALR has developed a unique capability in aircraft performance and preliminary design analysis. This was achieved through its own design activity of light fighter, trainer and light aircraft.

The first version of APP originated in the early 1980’s. The project group involved with the design of the Piranha Lightweight Fighter Concept developed APP initially as a tool that would allow to predict point- and mission performance in a fast, flexible and precise way. At that time, APP was the first software for aircraft performance analysis that did run on a personal computer and not a mainframe computer.

Since its initiation, APP has continuously been developed and improved by ALR and other well-known companies in the aircraft industry. Until today, these and other companies as well as leading experts in the industry have provided input and feedback to complement an extremely reliable, proven and efficient code-base. APP has been validated independently by many companies, universities as well as established research institutes all over the world.


If you are an APP user and experience trouble or unexpected behavior while using APP we are always happy to help you solve your problem. Please make sure to first contact your reseller in such cases.

In case of specific problems, such as if you need assistance in creating an aircraft model or a very specific analysis, feel free to contact us. Remember, APP is in use at ALR since the early 1980’s so we might have just the right advice for you. We are also happy about feedback or feature suggestions.

APP in Publications and Research

APP is cited in the following publications:

  • Walther, J., Gastaldi, A., Maierl, R. et al. Integration aspects of the collaborative aero-structural design of an unmanned aerial vehicle. CEAS Aeronaut J 11, 217–227 (2020). link
  • P.G. Juretzko, M. Immer and J. Wildi, Performance analysis of a hybrid-electric retrofit of a RUAG Dornier Do 228NG, J. CEAS Aeronaut J (2019). link
  • C. Bapst et al.,  Science to Practice – From the ETH to the ITJ, International Transport Journal, 27-30 2019 link
  • P. Juretzko, M. Immer and J. Wildi, Performance Analysis of a Hybrid-Electric Retrofit of a RUAG Dornier Do-228NG,  Deutscher Luft- und Raumfahrtkongress (DLRK), Munich, 5-7 September 2017, Download
  • M. Immer and P. Juretzko, Advanced Aircraft Performance Analyses, CEAS Symposium on Collaboration in Aircraft Design (SCAD), Warsaw University of Technology, 12-14 September 2016, Download
  • M. Breyer, Development of a Preliminary Design Method for Performance Analysis of Propeller Engines, Institute of Fluid Dynamics, ETH Zurich, 2015
  • M. Gartmann, Flexible Integration of Conceptual Aircraft Design Methods for Multiple Design Disciplines into a Multidisciplinary Sizing and Optimization Framework, Institute of Fluid Dynamics, ETH Zurich, 2013
  • Bougas, L. and Hornung, M., Propulsion system integration and thrust vectoring aspects for scaled jet UAVs, CEAS Aeronautical Journal (2013) 4: 327, Download
  • M. Gartmann, “Optimal Simulation of Take-off and Landing as Part of Flight Performance Calculation”, Institute of Fluid Dynamics, ETH Zurich, 2011
  • D. Brulhart, Simulation of take-off and landing as part of flight performance calculation, Institute of Fluid Dynamics, ETH Zurich, 2010
  • W. Anemaat, K. Po and B. Kaushik, Aircraft Performance Prediction: Comparison of Classical Handbook Methods to Detailed Time Integration Computer-Aided Methods, SAE International Journal of Aerospace 1:630-635, 2009 Download
  • M. Böhm, Gesamtentwurf eines ökonomischen und ökologischen Lufttransportsystems unter Ausnutzung von Synergieeffekten, Universität der Bundeswehr München, 2007, Download
  • M. Guillaume, Preliminary Flight Performance Analyses of a reconnaissance UAS, RUAG Aerospace, published in Aerodynamic Newsletter, 2007, Download
  • L. Fornasier, Multidisciplinary integration of numerical simulation methods in conceptual design of advanced aircraft and space vehicles, Daimler-Benz Aerospace AG, Munich, Germany, AIAA, NASA, and ISSMO, Symposium on Multidisciplinary Analysis and Optimization, 6th, Bellevue, WA, Sept. 4-6, 1996, Download

How to cite APP

In case you are referencing APP or the technical reference in a book or publication you should use the following reference information:

APP 7.0 User Manual (2019), ALR Aerospace, Zurich

APP 7.0 Technical Reference Manual (2019), ALR Aerospace, Zurich

APP 6.0 User Manual (2016), ALR Aerospace, Zurich

APP 6.0 Technical Reference Manual (2016), ALR Aerospace, Zurich

You can also download a BiBTeX File: BiBTeX