712 PERFORMANCE DATA
SECTION I. INTRODUCTION
The purpose of this chapter is to provide the best available
performance data for the CH-47D helicopter. Regular use
of this information will enable you to receive maximum safe
utilization from the aircraft. Although maximum perfor-
mance is not always required, regular use of this chapter
is recommended for the following reasons.
a. Knowledge of your performance margin will allow
you to make better decisions when unexpected
conditions or alternate missions are encountered.
b. Situations requiring maximum performance will be
more readily recognized.
c. Familiarity with the data will allow performance to
be computed more easily and quickly.
d. Experience will be gained in accurately estimating
the effects of variables for which data are not presented.
The data presented covers the maximum range of condi-
tions and performance that can reasonably be expected.
In each area of performance, the effects of altitude, tem-
perature, gross weight (GW), and other parameters re-
lating to that phase of flight are presented. In addition to
the presented data, your judgement and experience will
be necessary to accurately obtain performance under a
given set of circumstances. The conditions for the data
are listed under the title of each chart. The effects of
different conditions are discussed in the text accompany-
ing each phase of performance. Where practical, data is
presented at conservative conditions. However, NO
GENERAL CONSERVATISM HAS BEEN APPLIED. All
performance data presented is within the applicable lim-
its of the aircraft.
Exceeding operating limits can cause per-
manent damage to critical components.
Over limit operation can decrease perfor-
mance, cause immediate failure, or failure
on a subsequent flight.
Applicable limit lines are shown on the charts. The
dashed lines on the cruise charts are estimated airspeed
limits with an operating cruise guide indicator (CGI).
Airspeed limits with the CGI inoperative are in Chapter 5.
If limits are exceeded, minimize the degree and time.
7-1-4. Use of Charts.
a. Chart Explanation. The first page of each section
describes the chart(s) and explains its use.
b. The primary use of each chart is given in an exam-
ple and a guideline is provided to help you follow the
route through the chart. The use of a straight edge (ruler
or page edge) and a hard fine point pencil is recom-
mended to avoid cumulative errors. The majority of the
charts provide a standard pattern for use as follows:
enter first variable on the top left scale, move right to the
second variable, deflect down at right angles to the third
variable, deflect left at right angles to the fourth variable,
deflect down, etc. until the final variable is read out at the
final scale. In addition to the primary use, other uses of
each chart are explained in the text accompanying each
set of performance charts.
An example of an auxiliary use of the charts
referenced above is as follows: Although the
hover chart is primarily arranged to find
torque required to hover, by entering torque
available as torque required, maximum wheel
height for hover can also be found. In general,
any single variable can be found if all others
are known. Also, the tradeoffs between vari-
ables can be found. For example, at a give
pressure altitude (PA), you can find the maxi-
mum GW capability as free air temperature
c. Dashed Line Data. Data beyond conditions for
which tests were conducted, or for which estimates are
used, are shown as dashed lines.
7-1-5. Data Basis.
The type of data used is indicated at the bottom of each
performance chart under DATA BASIS. The applicable
report and date of the data are also given. The data
provided generally is based on one of the following cate-
a. Flight Test Data. Data obtained by flight test of the
aircraft by experienced flight test personnel at precise
conditions using sensitive calibrated instruments.