6600-NG User’s Manual
125-9110A
Page 49
Instant Pt leak rate:
While the leak-check is going on, the Actual values are still updated every 250 msec
in the Upper section of the screen. The Actual Pt Rate is the “instant” leak rate and will instantly indicate
any change in the leak. This is especially helpful when adjustments are made to the Pt system (including
tightening fittings, adjusting adapters etc) to reduce the leak.
Excessive Pt Leak:
If the ‘instant’ leak-rate is excessive, to protect the aircraft instruments, the 6600-NG
will automatically put Pt back into Control mode and abort the leak check. An error message:
ERR 7: Pt leak excessive. Exiting Leak mode.
Press
CANC
will be displayed on the last line of the screen. Pressing
CANC
will clear the Lower section.
Independent Ps1 Leak-check
The ideal way to perform a Ps1 leak-check is to keep Pt in Control at 120 knots, Ps2 in Control at 0.0 Dfin
and control Ps1 to a minimum of 3000 feet
above
“Ground”, before starting the leak check. Below is a
step-by-step process of performing the Ps1 leak-check. It is assumed that the Self-Test has already been
performed as described in Section 3.1
1.
Close all three output ports (tightly, please).
2.
Set the Units as follows: Pt=knots, Ps2=Dfin, Ps1=feet. (Key sequence:
1, 1, ENTER, 9, 2, ENTER,
5, 1, ENTER, GO
)
8.
Press
GND
to perform the Go-To-Ground function. The pumps will turn On and the tester will
go through the EQZN process. The targets will automatically be set to Pt=0 knots, Ps2=0.0 Dfin,
Ps1= the feet equivalent to “Ground” (ambient pressure).
3.
Once the EQZN process is completed, the tester will control the Actual values at the Targets.
4.
Change the Pt Target to 120 knots. (Key sequence:
2, 1
,
2
,
0
,
ENTER
). The new Target value will
be blinking. Do
NOT
press
GO
.
5.
Assuming that “Ground” is 0 feet, change the Ps1 Target to 3000 feet. . (Key sequence:
6, 3, 000,
ENTER
) The new Target value will be blinking.
6.
Press
GO
to activate both targets simultaneously. The Pt Actual value will ramp to 120 knots.
The Ps1 Actual value will ramp to 3000 feet. Ps2 will still control at 0.0 Dfin.
7.
Once the Actual values reach their targets, allow them to stabilize for a few seconds.
8.
Change the Ps1 mode to Leak. (Key sequence:
8, 2
). ‘Leak’ will be blinking in the Ps1 mode field.
Press
GO
to activate. Note that Pt and Ps2 will still be in Control at 120 knots and 0.0 Dfin.
The Lower section of the screen will appear similar to Figure 3.36 below, with the 1-min, 2-min and 3-min
values appearing as the leak time crosses 1, 2 and 3 minutes.
Figure 3.36 : Ps1 Leak (after 3 min)
Leak Time: 3.45
Leak
Control
Control
4
±
8
000
Hide/Show Ps2
AC
92%
Start:
Ps1: 3000 feet
( 1 min)
2980 20
( 2 min)
2975 25
( 3 min)
2965 35
Press
CANC
to exit
