Description / Abstract:
The purpose and intent of Subcommittee E-33E's effort, the reporting
objectives, and the
limitations inherent in the reported findings and recommendations are
reviewed since these factors
are the basis of the information contained in this document.
SAE E-33E Subcommittee was formed to assess the level of industry
experience that exists in the
area of thrust determination during aircraft time-variant operating
conditions. A prime objective
was to provide a center for gathering expertise and to be a forum for
the exchange of ideas and
viewpoints. The committee recognized that a practice for the rigorous
treatment of time-dependent
thrust did not exist and that several critical aspects of its
accounting would need to be
investigated.
The specific objectives of this document are:
a. To examine aircraft and engine operating conditions under which the
quasi-steady thrust
assumption is valid.
b. To determine the extent to which time-dependent (nonstationary)
force accounting for engine net
thrust and propulsion system throttle-dependent terms is required,
consistent with existing and
developing thrust-minus-drag techniques.
c. To report time-dependent thrust methodologies and measurement
techniques used for flight and
ground testing.
d. To present the results of a data review of state-of-the-art
methodology appropriate to the
determination of aircraft-installed thrust during quasi-steady and
dynamic maneuvers.
e. To provide guidelines for validating and improving time-dependent
thrust determination as
appropriate to a specific program.
Limitations:
This document addresses definitions of thrust, force, and drag from
test principles (when possible)
based on steady practices as defined in AIR1703. It is limited to
fixed-wing and variable swept
wing aircraft employing turbojet or turbofan engines with nonvectoring
or fixed vectored nozzle
position but not with time-variant vectoring terms. It is not the
purpose of this document to
detail onboard high-response data systems or develop new in-flight
thrust methodologies.
Conclusions and recommendations are valid only where criteria and data
for a specific program or
application have been identified and measurement uncertainty aspects
of the data understood. It is
anticipated that this document will be updated periodically as new
developments in ground and
flight testing occur.