A “Precautionary Down-Manning” may be required in a situation where there is no immediate threat to human life at the very moment, but there is a real possibility of the situation deteriorating and requiring an “Emergency Evacuation” in due time. In order to reduce the number of people having to be transferred during an “Emergency Evacuation”, a “Precautionary Down-Manning”, involving all non-essential personnel, is the first step. Such precautionary down-manning can be performed by both the commercial passenger helicopters and, if necessary, with the addition of the SAR helicopter. The SAR helicopter in this case will operate as a normal helicopter taking a maximum of 9 passengers, which relates to the number of seats available.
Source: NOGEPA Industrial Guideline No. 20, Alerting Procedure SAR Helicopter for Drifting Vessel (NUC) Offshore, Netherlands, Version 0, January 2009. Global Standards