All aircraft with a maximum take-off mass of over 27,000 kg operating over oceanic areas are to be fitted with the low frequency underwater locator beacon (ULB) by January 2018. According to TSO-C200a the ULB will be mounted directly to the airframe and will be operating for 90 days after activation. All these requirements and those of the ARINC Project Paper 677 is the new SID88 justice.
Aircraft in service today are equipped with flight recording devices with underwater locator beacons (ULBs) attached. The detectable acoustic range of the currently used ULBs is limited due to the transmission frequency of 37.5 kHz.
An initiative was launched to fully investigate wreckage localization technology where an LF-ULB transmitting on a frequency of 8.8 kHz was recommended. The device is intended to be installed on the aircraft structure.
SAE International has published Aerospace Standard SAE AS6254A to cover the minimum performance standard for low frequency underwater locator beacons transmitting at 8.8 kHz.
ICAO Annex 6 Amendment 36, published November 2012, states that an LF-ULB shall be installed on all aircraft with
a maximum take-off mass of over 27,000 kg, operating over water at particular distances to land suitable for making an emergency landing.
ICAO Annex 6 Amendment 36: At the earliest practicable date but not later than January 1, 2018 a securely attached underwater locator beacon operating at a frequency of 8.8 kHz is required
An LF-ULB transmitting at 8.8kHz is essential to improve the range of underwater detection. With SID88 a sum of circumstances and ideas turns into reality. While the flight recorder ULB describes as a means to find a needle in the haystack, the SID88 describes as a means to find the haystack and is therefore the logical supplement.