Users Manual

ALL
EFFECTIVITY
© Honeywell International Inc. Do not copy without express permission of Honeywell.
Page 7-9
22 Apr 2019
23-15-49
SYSTEM DESCRIPTION, INSTALLATION, AND MAINTENANCE MANUAL
ASPIRE-400
(7) The PIESD:
(a) Requests a "PIESD polite disconnect";
(b) Attempt re-attachment and re-registration until successful.
C. Short Service Interruption Handling
(1) The SDU software does not take any actions to user service activation based on primary
power interruptions of less than or equal to a transparency period of 200 ms.
NOTE: Interruptions in voice and data communication may occur due to power
interruption characteristic of RF SATCOM LRUs.
(2) The SDU prevents setting nuisance fault reports in response to any normal electrical
power transient or steady state condition applied to that system including:
(a) Normal power transients identified by RTCA/DO-160G Section 17.4
(b) Normal power fluctuations identified by RTCA/DO-160G Sections 16.5 and 16.6.
(3) For primary power interruptions to the antenna and external power amplifier LRUs, for
which the LRU meets its full requirements within 5 seconds of restoration of its primary
power, the SDU returns within 5 seconds to the previous operating state such that priority
voice and data services resume in the same configuration as before the interruption.
(4) For power interruptions longer than 200 milliseconds duration the SDU recovers to an
operational state without manual reset or power cycle and register on the network for
voice, data and ACARS service (as applicable) automatically.
NOTE: This does not apply if Manual Logon is set.
D. Doppler Compensation
(1) The ACD calculates the expected Doppler correction factor according to satellite position,
including satellite state vectors, the aircraft position (latitude, longitude, and altitude), and
aircraft velocity (ground speed, true track and true heading).
(2) When calculating the expected Doppler correction factor, the ACD:
(a) Uses True Heading if the Ground Speed is less than 50 knots;
(b) Interpolates the True Track using the True Heading data if True Heading is
provided at a rate higher than True Track.
E. Miscellaneous Inmarsat Functions
(1) The SDU does not transmit towards the satellite if any of the following data is not
available or not valid:
(a) Altitude
(b) Latitude
(c) Longitude
(d) True Heading
(e) Pitch Angle
(f) Roll Angle
(g) Ground speed
DRAFT
3rd rvw Draft as of:
29 January, 2020