Title

Estimating Aircraft Turbine Engine Costs

Description

This memorandum presents equations for estimating development and production costs of turbojet and turbofan engines. Thrust is found to be the best single variable for estimating both development and production cost, but using thrust alone the differences between actual and estimated costs are unacceptably large. For development, these differences are greatly reduced by incorporating a second explanatory variable--either speed, absolute altitude, or thrust-to-airflow ratio. No combination of engine characteristics produces an acceptable estimating relationship for production cost when all engines are treated as a single class. When the sample is stratified into three classes on the basis of design requirements, it appears that useful estimating relationships are obtained for each class. A limitation on this approach is that the next generation of engines may compose a fourth class for which no estimating relationship can be derived empirically. For such engines, extrapolation from the curves and data shown here will be necessary

Creator

Large, J. P.

Publisher

Santa Monica, CA : The RAND Corporation

Date

1970

Format

ix, 21 pages : ill. ; 28 cm.

Type

report

Date Issued

1970-09

Corporate Author

The RAND Coporation

Report Number

RM-6384/1-PR

AD Number

AD738026

Contract

F44620-67-C-0045

NTRL Accession Number

AD738026

Distribution Conflict

No

Access Rights

THIS DOCUMENT HAS BEEN APPROVED FOR PUBLIC RELEASE AND SALE; ITS DISTRIBUTION IS UNLIMITED.

Photo Quality

Not Needed

Distribution Classification

1

DTIC Record Exists

Yes

Report Availability

Full text available by request

Subject

Turbojet Engines -- Costs

Equations

Thrust

Velocity

Altitude

Identifier

AD0738026

AD0738026

Abstract

This memorandum presents equations for estimating development and production costs of turbojet and turbofan engines. Thrust is found to be the best single variable for estimating both development and production cost, but using thrust alone the differences between actual and estimated costs are unacceptably large. For development, these differences are greatly reduced by incorporating a second explanatory variable--either speed, absolute altitude, or thrust-to-airflow ratio. No combination of engine characteristics produces an acceptable estimating relationship for production cost when all engines are treated as a single class. When the sample is stratified into three classes on the basis of design requirements, it appears that useful estimating relationships are obtained for each class. A limitation on this approach is that the next generation of engines may compose a fourth class for which no estimating relationship can be derived empirically. For such engines, extrapolation from the curves and data shown here will be necessary.

Index Abstract

Contrails and DTIC truncated