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Old 17th Apr 2017, 10:40
  #41 (permalink)  
DOUBLE BOGEY
 
Join Date: Dec 2006
Location: UK and MALTA
Age: 61
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Normally the wind dictates the direction the nose is pointing for the landing. If there is little or no wind the options are increased for a deck like this one to provide tail boom/rotor clearance from obstacles in the undershoot.

However, when forced by the wind to land in the direction they did, the brief should always be for an OFFSET landing:

"Obstacles in the undershoot, I will fly forward until my bum is 90 degrees from the forward edge of the aiming circle, confirm with you that it is (to the PNF), and then cross laterally to the bumline".

Valid only of course if no hazards crosshatching is in play. This should be briefed as an "Offset Landing".

Therein leaving only 2 horizontal profiles to the deck:-

NORMAL - crossing from the DP at 45 degrees from for forward edge of the aiming circle.

OFFSET - crossing at 90 degrees from the forward edge of the aiming circle.

This type of landing is the reason why I personally do not believe that the added complexity of trying to fly a critical "Performance" approach will ever by a sensible option for offshore operations. PC2 With Exposure provides the most flexibility to deal first and foremost with the obstacle environment.

The last serious event like this was the Brent Spar which led to a free descent some 170 feet to the ocean with loss of all on board.

Carrying vertical momentum from the DP is a mistake. You are already accelerating vertically so if a critical power failure occurs the devil has already got a head start on you.

For most PLATFORMS above 200 feet deck height, the DP should be at 40' above the deck height. You can hover there safely with your rotor tips just co-incident with the deck edge and make a final assessment for either PRH or obstacles, and still have a safe flyaway should engine fail, provided you are conforming to the WAT for PC2 with Exposure (OGE Hover AEO).

It s a big mistake to try and carry inertia towards the deck both from a performance perspective and the ultimate requirement to fly a safe trajectory.

Are these two horizontal profiles till being taught to offshore pilots? or, like many other hard earned lessons, have they been forgotten amidst the plethora of confusing requirements about performance?
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