ACARS - I-am-alive
NigelOnDraft
"That's a long step from "mandating" a standard across all airlines / types a data stream and protocol that is used for "flight monitoring". For starters, not all types/airlines will use Satcom for ACARS, and it is not cheap. I work for a large UK company, and one of our LH types only has ACARS via VHF (or did when I flew it). If the ACARS is in VHF comms, then so generally will the crew...
For those using the various ACARS systems, they frequently go to standby, or someone retunes / uses VHF3 etc. To call out the full SAR system for a mid ocean rescue everytime the ACARS / Satcom goes on the blink will keep them well occupied
Accidents / incidents such as this are relatively rare, and the cost of uploading effectively FDR type information via satellite will not be trivial across the whole world's fleets. Far rarer will be the occasion it makes 1 jot of difference to survivability."
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Nigel, all good points, but you have missed my point.
Where available (e.g. narrow band satcom) a once a minute message could be used.
All long haul overwater aircraft are still required, are they not, to be HF equipped, hence, if ACARS equipped, an Alive message could be sent, say, every 10 mins.
The ground based computer auto triggering could be set quite wide in the case of HF to say something like, trigger an alarm after 4 messages missed (ie. alert after 40 minutes which is usually longer than mandatory ops normal radio calls).
What the ground does with the triggered alert is not unlike what happens with SAR phases, ie. uncertainty phase, distress phase, search phase etc. Obviously, there would be protocols around this.
Purpose is to cut wait times for positive determination of a lost aircraft from hours (elapsed time from last contact to ETA), down to an hour or half an hour or less, depending on comms methods implemented.
Again, these are all rules-based decisions that can be programmed into the ground based computers to make allowances for variations in comms used.
As to "standard message protocol", ACARS implementations incorporate many industry standards anyway. There probably exist message structures/protocols defined by ARINC standards. The value of defining a standard protocol to an I-am-alive message is, particularly where noisy open channels are used like HF, that a possibility exists someone else may hear a message that is missed by the "owner" airline's ACARS ops system. Hence, an opportunity is created for any airline's ACARS ground system to automatically reroute a heard message destined for another airline. The owner airline's system can automatically determine if received re-routed messages are copies of an already received message, or replacements of unheard messages.
I am not suggesting this is necessarily simplistic, or without cost, but it appears to be technically well within the capabilities of currently installed hardware requiring only additional software functionality.
It doesn't even have to be implemented by all airlines ... it can start with one and grow from there.
Given that the likely total incurred costs of AF-447's loss will run into hundreds of millions of dollars, the industry incurring a few tens of millions to implement R&D for a software change would appear to be well worthwhile if it could trigger a faster initiation of a search phase, increasing potential for rescue of lives or earlier retrieval of recorders.