COMPONENT MAINTENANCE MANUAL
AVIATION RECORDERS
FA2100CVR
Rev. 15 Page 56
Apr. 14/16
Description and Operation
23–70–04
Use or disclosure of information on this sheet is subject
to the restrictions on the cover page of this document.
E.
Push
−
to
−
Test (PTT) Functionality
The Push
−
to
−
Test functionality (already implemented on existing aircraft and stan-
dardized in ARINC 757A specification) is used to provide the flight crew with the abil-
ity to quickly confirm good serviceability of the CVR before flight as required by the
applicable regulation.
Upon test activation, the CVR tests the front end audio inputs (each of the four au-
dios inputs channels) and initiates Built
−
In
−
Test functions of the CVR.
When used with the FA2100CVR, p/n: 2100
−
1X25
−
( ) and the S161
−
1390
−
01 con-
trol unit, the push
−
to
−
test action must be a minimum of one (1) second. During the
test, the monitor output (pin 5/6) will be muted (no sound). If the test passes, a .5
second 600
−
660 Hz tone is activated on the monitor output. For a failure the output
remains muted.
Upon initiation of the Push
−
To
−
Test (PTT) function, the CVR sends status indication
on dedicated outputs, particularly on CVR fault discrete output pin 23 (not used) and
on label 350 (CVR STATUS WORD bit 11 on pins 50/51).
CVR Test activation (PTT switch) is allowed at any time during the flight so that the
crew can re
−
initiate the test after a fault is detected in the hope of recovering the re-
corder (test is specified to act as a reset of the recorder).
F.
Bulk Erase
As per ARINC 757A, the CVR provides a Bulk erase function. In order to ensure reli-
able operation, the function is inhibited to prevent inadvertent or untimely erasure
while the aircraft is capable of moving under its own power. In addition to the means
already provided at A/C level (interlock devices monitored with the aircraft on
−
ground information and effective park brake locked), the CVR provides a timed inter-
lock for erase. The erase starts by connecting CVR pin 55 to pin 57 for a minimum of
2 seconds and then connecting pin 55 to ground (pin17) before erasing the pre-
viously recorded data. This action is initiated by pressing the Bulk Erase push
−
but-
ton on the applicable Control Unit.
The erase is indicated by a 400Hz tone activated during the erase process on Con-
trol Unit Headphone or Boomset to validate bulk erasure. The erasure is activated
once per depression (no cycling).
As per ED112 IV
−
2.2.3 (Data Link part), recorded digital messages shall not be
erased, re
−
written or altered during the process of downloading. In addition, also per
ED112 IV
−
2.1.12 (Data Link part), no means for the erasure of the record shall be
provided in the recorder, except for the overwriting of the oldest data by new infor-
mation.
The document reference is online, please check the correspondence between the online documentation and the printed version.
