O&G ARA Procedure
Here's the Airborne Radar Approach plate we use when flying offshore to rigs and ships in our S92's, S76C++'s and AW139's. We have to use the radar to reference all distances on the final approach. Our MSA offshore is 1500'. You can join the final approach by flying overhead the station at 1500', flying an arc onto final or doing a straight in approach. On a straight in final approach, be it 6 miles or 20 miles, we must ensure we have no radar targets on our approach path and that it's clear of targets 1 mile either side of track. We can descend down to 1000' Radalt if the aforementioned conditions are met. At 6 miles back we can descend down to 600' Radalt and at 4 miles back we are good to descend to our MDA of 300' Radalt at night and 200' Radalt in the day. It doesn't matter if we are IMC or VMC, we still descend down to our minimums after 4 miles. There's the standard offset of 10 degrees at 1.5 miles and then a further 30 degrees and climb at the MAP of 0.8 miles if we aren't visual. Copilots and Captains use the Radar in GMAP 2 and constantly adjust the tilt and variable gain for the best picture. The radar range is brought down from 10 miles to 1.5 miles incrementally on the final approach as the helicopter gets closer. If any target appears in front of the helicopter or within the 1 mile boundary either side of track the Flight Crew initiates an immediate climb at takeoff power to 1500'. Happened to one of our crews just last week when a supply boat came into the 1 mile zone on a 10 mile straight in approach at night in IMC conditions. There's no chance of flying into a rig, vessel or rock using this approach unless the radar is not being used correctly.