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349 

Federal Aviation Administration, DOT 

Pt. 60, App. C 

2.c.3.a. ........

Long-Term Response. 

±10% of calculated period, 

±10% of time to 

1

2

or dou-

ble amplitude, or ±0.02 of 
damping ratio.For non-peri-
odic responses, the time 
history must be matched 
within ±3° pitch; and ±5 kts 
airspeed over a 20 sec pe-
riod following release of the 
controls. 

Cruise Augmentation On and 

Off. 

For periodic responses, 

record results for three full 
cycles (6 overshoots after 
input completed) or that 
sufficient to determine time 
to 

1

2

or double amplitude, 

whichever is less. 

The test may be terminated 

prior to 20 sec. if the test 
pilot determines that the re-
sults are becoming uncon-
trollably divergent. 

X  The response may be 

unrepeatable throughout 
the stated time for certain 
helicopters. In these cases, 
the test should show at 
least that a divergence is 
identifiable. For example: 
Displacing the cyclic for a 
given time normally excites 
this test or until a given 
pitch attitude is achieved 
and then return the cyclic 
to the original position. For 
non-periodic responses, re-
sults should show the 
same convergent or diver-
gent character as the flight 
test data. 

2.c.3.b. ........

Short-Term Response. 

±1.5° Pitch or ±2°/sec. Pitch 

Rate. ±0.1 g Normal Accel-
eration. 

Cruise or Climb. Augmenta-

tion On and Off. 

Record results for at least 

two airspeeds. 

X  A control doublet inserted at 

the natural frequency of the 
aircraft normally excites 
this test. However, while 
input doublets are pre-
ferred over pulse inputs for 
Augmentation-Off tests, for 
Augmentation-On tests, 
when the short-term re-
sponse exhibits 1st-order 
or deadbeat characteristics, 
longitudinal pulse inputs 
may produce a more co-
herent response. 

2.c.4. ...........

Maneuvering Stability. 

Longitudinal Control Posi-

tion—±10% of change from 
trim or ±0.25 in. (6.3 mm) 
or Longitudinal Control 
Forces—±0.5 lb. (0.223 
daN) or ±10%. 

Cruise or Climb. Augmenta-

tion On and Off. 

Record results for at least 

two airspeeds at 30°–45° 
roll angle. The force may 
be shown as a cross plot 
for irreversible systems. 
May be a series of snap-
shot tests. 

X X X 

2.d. .............

Lateral and Directional Handling Qualities 

2.d.1. ..........

Control Response 

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