Performance Offshore - the Evolution of Helideck Performance Procedures

[JimL]

I was surprised and pleased with the reaction to the paper 'Performance - from Runways to Heliports in City Centres' in the Category A - PC1 or PC2 thread - and the positive responses received privately since.

Because of that, I decided to add to the discussion by penning a further paper 'Performance Offshore - the Evolution of Helideck Procedures'. It can be found here: (does anyone know how to show this in the post?)

https://www.dropbox.com/scl/fi/uru5cby0ho94cne9hp0ww/The-introduction-and-development-of-helideck-procedures.pdf?rlkey=9mi2mv44d0xy0iojoc6uj8bnd&dl=0

Your comments are welcome and will receive a response if required.

Jim

[ApolloHeli]

A very interesting and informative read.

Two questions regarding incidents mentioned but not sourced in the paper:

What was the "very serious incident in the Norwegian sector of the North Sea" you refer to in footnote #2?
What was the incident referred to on page 17 "an incident in the Southern North Sea where, even with an early failure well before RP, the pilot opted to continue the take-off. This did not result in an accident but was a close call"?

[JimL]

The first incident was when a pilot-pedal turned the helicopter on deck and put the tail rotor several metres into the obstacle sector. I did read the report but can't remember if it was provided to me on a need-to-know basis or as a public issuance.

The second was a pilot flying a Dauphin who had an engine failure shortly after applying pitch; he rotated, just missed the deck edge and then struggled to achieve fly-away.

The description of the first incident may be available through the Norwegian accident investigation process. The second was reported through the UK MORs system - which may or may not have survived (it was some time ago).

I should add that the paper is best picked up from the URL and not downloaded. It is very likely that it will be amended in light of comments received here and on LinkedIn.

It is also likely that, because of the apparent confusion that surrounds PC2e, practical examples with be added to the text.

[212man]

I started reading it but had to leave at an early stage to do some chores, and am still away from my laptop. The unrestrained pedant in me could not help but notice the reference to offshore decks being 50% smaller than onshore pads. 1D is actually 33.33% smaller than 1.5D, although 1.5D is 50% bigger than 1D.

I’ll get my coat…..

[JimL]

Thanks 212man - I should have said that onshore are 50% larger.

I deserve more from you but, rest assured. when you once again doff your coat and pick up the paper, it will only be 33% smaller.

I would be astonished if that is the worst error you can find.

Jim

[JimL]

The latest version of the paper now includes corrections, improvements, and worked examples of PC2e.

https://www.dropbox.com/scl/fi/uru5cby0ho94cne9hp0ww/The-introduction-and-development-of-helideck-procedures.pdf?rlkey=9mi2mv44d0xy0iojoc6uj8bnd&dl=0

Jim

[JimL]

An interesting point has been raised concerning the PC2e example on Pages 23 and 24 (take off with the wind through the Limited Obstacle Sector (LOS)) - when flown at night:

The pilot sits in the hover pointing towards the LOS (holding just enough yaw to keep within tail rotor limitations), applies the power then, when reaching the TDP/RP, rotates - involving forward and (mostly) sideways application of the cyclic.

As the pilot crosses the deck edge, there will likely be a loss of visual cues (inky blackness). The AH will be providing quite a complex and changing picture - certainly one that would be difficult to maintain if on instruments.

Compare this to the sideways procedure where: visual cues are maintained, the attitude is held constant and, at the TDP/RP control is transferred to the pilot-monitoring (already on instruments) to rotate into a continued take-off which - compared to the dynamic procedure - will be a much more sedate event.

Is this the exemplar for the sideways procedure, for the reasons stated on Pages 17 and 18 of the paper?

https://www.dropbox.com/scl/fi/uru5cby0ho94cne9hp0ww/The-introduction-and-development-of-helideck-procedures.pdf?rlkey=9mi2mv44d0xy0iojoc6uj8bnd&dl=0