# SAS - Simple Aircraft Sizing and Optimization

Philosophy
Publications

Diederich Method (on separate page)

Aim of SAS is to provide the aircraft design calculation scheme from Chapter 5 (Preliminary Sizing) of the lecture (with English lecture notes at HOOU) and short course of Prof. Scholz as spreadsheets. The lecture only deals with aircraft design of transport aircraft and business jets certified based on EASA CS-25 or FAR Part 25. So, modules directly helpful for teaching are those for Jets and Part 25.

Jets and CS-25

• SAS-Classic / PreSTo-Classic: Written for the lecture. Used for more than two decades with many more than 1000 students. Download here.
Props and CS-25
It is also of interest (beyond the lecture) to cover the whole field of aircraft with combinations of different propulsion systems (jet, propeller) and certification rules (CS-23, CS-VLA, UL). The additional combinations are listed.

Jets & Props and other Certification Rules

• SAS-Part23-Jet: Not started. Applies only to some very small jets with special certification conditions.
• SAS-Part23-Prop: HAW-internal only. Student needed to prepare nice results that can go online.
• SAS-VLA: Requirements investigated (project by Philipp Gmelin). Will follow after SAS-Part23-Prop.
• SAS-UL: Requirements investigated (project by Philipp Gmelin). Will follow after SAS-Part23-Prop

## Philosophy

Philosophy of SAS is to support the aircraft designer to convert mission requirements into a hand full of the most important aircraft parameters. In order to do this, SAS supplies:
• An efficient well proven calculation sequence and its equations.
• Statistical parameters for landing field length, take-off field length, ... mission fuel fractions, ...
• The matching chart, showing how requirements interact and how the design point is chosen.
• Methods to help calculate the most fundamental parameters from almost no input: Oswald factor, maximum glide ratio, zero lift drag coefficient, minimum drag lift coefficient, specific fuel consumption, ...
• Well proven, openly availalbe optimization methods suitable for aircraft design.
A spread sheet was selected for programming of SAS. The advantages are:
• Efficient integration of input, calculation and output.
• Open and easy to understand programming.
• Easy to adapt to individual needs by the user.
Aircraft preliminary design tools can run in chains to build on each other. SAS can be a link in several possible tool chains:

## Publications

Presentation at Symposium "Kollaboration im Flugzeugentwurf" (Collaboration in Aircraft Design)

SCHOLZ, Dieter: Aircraft Preliminary Sizing Tools @ Aero : SAS => OPerA => PreSTo => further Tool Chain, (Kollaboration im Flugzeugentwurf - 1. CPACS/RCE Symposium, Deutsches Zentrum für Luft- und Raumfahrt, Hamburg, 15. / 16. March 2012 ). - Download: http://PreSTo.ProfScholz.de

PreSTo_PRE_Kollaboration_12-03-15.pdf     Size:  2.2M

Presentation and Paper at Conference "Recent Research and Design Progress in Aeronautical Engineering and its Influence on Education" (RRDPAE 2008)

SCHOLZ, Dieter; NIŢĂ, Mihaela: Preliminary Sizing of Large Propeller Driven Aeroplanes. (RRDPAE 2008, Czech Republic, Brno, 16-17 October 2008). Brno : Brno University of Technology, 2008. - ISSN: 1425-2104, Volume 2008, Paper-Number: 61. CD from: http://lu.fme.vutbr.cz/rrdpae2008. Download: http://paper.ProfScholz.de

## SAS-Part25-Jet

### Abstract

SAS-Part25-Jet supports preliminary sizing of transport jets and business jets. Aircraft are optimized in two hierarchy levels with an Excel spreadsheet. The lower level optimization uses the Excel Solver to optimize the Matching Chart. The upper level optimization finds best aircraft parameters with a Differential Evolution algorithm. The underlying aircraft design model is based on equations and statistics used at HAW Hamburg in teaching and research.

SAS-Part25-Jet runs only with Excel (not e.g. with LibreOffice Calc). Excel is available for members of HAW Hamburg based on a Microsoft Campus License.

If Excel is running, all you need is in the zip-file (below). Download into a folder, unzip, and start SAS-Part25-Jet.xlsm. Read "Getting Started With SAS" (also included in zip-file) and follow its hints. Here is a summary of the Reading List. All is important. I advise to read in the given sequence.

1. SCHOLZ: Chapter 5: Preliminary Sizing (PDF, from Lecture Notes; prerequisite, assumed to be known)
2. HEINEMANN: Chapter 7: Users Guide (helpful; PDF below)
3. SCHOLZ: Tutorial: "How to approach an SAS-Optimization?". Included in the program on the first tab (INPUT), starting in column Z.
4. NIŢĂ: Chapter 5 and 6: Optimization and Algorithm (optimization is not a straight forward task; this background reading helps you to master this challenge; PDF below)
5. SCHOLZ: Drag Estimation - Overview and Wave Drag (explains drag estimation in SAS - wave drag not yet included in this program, tab Emax CR)
6. NIŢĂ, SCHOLZ: Estimating the Oswald Factor - Induced Drag (shows drag estimation in SAS, tab Emax CR)
SAS-Part25-Jet.zip    1.9M    07 May 2022

GettingStartedWithSAS.pdf     Size:  1.0M

HEINEMANN, Joeri: Preliminary Sizing of FAR Part 23 and Part 25 Aircraft. Master Thesis, HAW Hamburg, 2012. - Download: http://SAS.ProfScholz.de, includes:
Chapter 7: Users Guide to SAS Optimization

TextHeinemann.pdf     Size:  4.0M

NIŢĂ, Mihaela Florentina: Contributions to Aircraft Preliminary Design and Optimization. München : Verlag Dr. Hut, 2013. - ISBN 978-3-8439-1163-4, Dissertation, Download: http://OPerA.ProfScholz.de, includes:
Chapter 5: Brief Theoretical Background on Optimization and Algorithms Selection
Chapter 6: Implementation of Selected Algorithms in OPerA

## SAS-Part25-Prop

KRULL, Marlis: Preliminary Sizing of Propeller Aircraft (Part 25). Project, HAW Hamburg, 2022. - Download: https://nbn-resolving.org/urn:nbn:de:gbv:18302-aero2022-04-29.012

LandingKrull.html (report)

DataKrull.zip (Excel files)