BHS - CHC in Brazil S92 recent event
Join Date: Dec 2006
Location: UK and MALTA
Age: 61
Posts: 1,297
Likes: 0
Received 18 Likes
on
4 Posts
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?
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?
No I do not hover next to the deck, no that is untrue, I have but those were in exceptional high winds trying to get onto a moving vessel with the helideck on the bow. In normal practice I avoid using the sideways appoach if at all possible. Please forgive me for the inappropriate use of the word hover.
Join Date: Dec 2006
Location: UK and MALTA
Age: 61
Posts: 1,297
Likes: 0
Received 18 Likes
on
4 Posts
Albatross. Hovering next to the deck is acceptable if you have the height above the water and its necessary. Whatever happens the horizontal profile MUST come first when obstacles are in play.
Unwarranted fear of being too slow is just that, unwarranted. Its better to be slow with virtually no ROD from all perspectives.
The issue gets more complex when the deck is very low and there is little wind. In a sensible operation further restrictions on the WAT to supplement the PC2 Exposure requirements should be in place to offer the safety margin required.
However, commercial considerations at the tender do the most damage to the options available to the pilot in these conditions.
Unwarranted fear of being too slow is just that, unwarranted. Its better to be slow with virtually no ROD from all perspectives.
The issue gets more complex when the deck is very low and there is little wind. In a sensible operation further restrictions on the WAT to supplement the PC2 Exposure requirements should be in place to offer the safety margin required.
However, commercial considerations at the tender do the most damage to the options available to the pilot in these conditions.
Albatross. Hovering next to the deck is acceptable if you have the height above the water and its necessary. Whatever happens the horizontal profile MUST come first when obstacles are in play.
Unwarranted fear of being too slow is just that, unwarranted. Its better to be slow with virtually no ROD from all perspectives.
The issue gets more complex when the deck is very low and there is little wind. In a sensible operation further restrictions on the WAT to supplement the PC2 Exposure requirements should be in place to offer the safety margin required.
However, commercial considerations at the tender do the most damage to the options available to the pilot in these conditions.
Unwarranted fear of being too slow is just that, unwarranted. Its better to be slow with virtually no ROD from all perspectives.
The issue gets more complex when the deck is very low and there is little wind. In a sensible operation further restrictions on the WAT to supplement the PC2 Exposure requirements should be in place to offer the safety margin required.
However, commercial considerations at the tender do the most damage to the options available to the pilot in these conditions.
I should know better than to post before I have had my morning coffee. Brain still not up to speed.
Ref Brent spar - there were 7 survivors (all pax) and 6 fatalities. A very good example of how lucky this aircraft's occupants were though, and the pictures seem to indicate it would have been a much bigger fall.
Join Date: Jun 2002
Location: home and abroad
Posts: 582
Likes: 0
Received 0 Likes
on
0 Posts
Double Bogey, Albatross: I believe we are more or less in agreement.
However I try to avoid a real hover OGE as much as possible; it takes a lot of power, more opportunity to get disoriented and it does nothing for stability. When heavy I prefer to be high in power and slowly move continuously towards the deck; 45 degree angle being my preferred method in case I cannot get on clear of obstacles into wind. I will not crash into something solid in a misguided attempt to avoid a theoretical risk of an engine failure after commital point.
Ships being a different matter with added movement to compensate for, sometimes a hover OGE is unavoidable. And those decks are rarely 200 ft high.
In this case I fail to see the reasoning for the chosen approach path and the risks accepted.
However I try to avoid a real hover OGE as much as possible; it takes a lot of power, more opportunity to get disoriented and it does nothing for stability. When heavy I prefer to be high in power and slowly move continuously towards the deck; 45 degree angle being my preferred method in case I cannot get on clear of obstacles into wind. I will not crash into something solid in a misguided attempt to avoid a theoretical risk of an engine failure after commital point.
Ships being a different matter with added movement to compensate for, sometimes a hover OGE is unavoidable. And those decks are rarely 200 ft high.
In this case I fail to see the reasoning for the chosen approach path and the risks accepted.
In this case I fail to see the reasoning for the chosen approach path and the risks accepted.
You can see when the MR blade finally stops, and comes to rest over the Tailboom, the blade tip cap is damaged, and missing a bit. Have a look at the video again in full screen.
skadi
Last edited by skadi; 17th Apr 2017 at 16:46.
I'm curious, as KiwiNedNZ has said, what happens now?
How long is that going to sit on the heli deck? What does the rig do in the meantime to get people on and off? Could be a long boat ride?
As someone who has NO experience of these sorts of things, how does the process work?
How long is that going to sit on the heli deck? What does the rig do in the meantime to get people on and off? Could be a long boat ride?
As someone who has NO experience of these sorts of things, how does the process work?
A few measurements will establish if a smaller helicopter can land alongside the stricken S92 with a couple of engineers, toolkit to remove the blades and a lifting kit. Blades will be removed and the rig crane will lift the aircraft onto a supply boat. Been done many times before.
If a second heli can't land, it's either a winching job or the engineers and kit will come out on a supply boat.
If a second heli can't land, it's either a winching job or the engineers and kit will come out on a supply boat.
Join Date: Apr 2008
Location: London
Posts: 24
Likes: 0
Received 0 Likes
on
0 Posts
Join Date: Feb 2005
Location: On the green bit near the blue wobbly stuff
Posts: 674
Likes: 0
Received 1 Like
on
1 Post
Yes, I witnessed a Sea King put its rotor disc into a ship antenna. When it made it to the beach for an emergency landing, IIRC one blade had about a foot missing, one had minor damage, and the others were OK. (Imagine the vibration on board!)
http://www.pprune.org/rotorheads/584...m-circles.html
No, but it appears a solid structure will...
With some experience and knowledge.....
Sadly, we continue to see this.....
I'd rather spilt hairs than my skull....
Captain to copilot, who has just flown his/her first approach in a 92 to an offshore platform, "Son/Lass, you need to land further forward in the circle, else 212man is going to chew your ass".
Sorry but these are remarks from a retired or office-bound pilot ......
That said I introduced an Helideck test into a training exercise and it was met with blank stares so the lack of knowledge regarding helidecks is I believe widespread. The fault lies both with the pilot, for the information is available, and the training departments for not ensuring all crews are familiar with the deck markings.
Didn't it occurre to any of the hair-splitting deck-positioning regulation-quoting gurus here...
When a Retired Pilot with a broad experience level and many thousands of accident/incident free hours offers some advice.....it pays to listen and perhaps learn from the old Pelican!
There is a reason he lived to retire and do so without an incident or accident on his record!
Generally that is he listened to other Old Farts as he was coming up in the trade.
There is a reason he lived to retire and do so without an incident or accident on his record!
Generally that is he listened to other Old Farts as he was coming up in the trade.
When a Retired Pilot with a broad experience level and many thousands of accident/incident free hours offers some advice.....it pays to listen and perhaps learn from the old Pelican!
There is a reason he lived to retire and do so without an incident or accident on his record!
Generally that is he listened to other Old Farts as he was coming up in the trade.
There is a reason he lived to retire and do so without an incident or accident on his record!
Generally that is he listened to other Old Farts as he was coming up in the trade.
Join Date: Dec 2006
Location: UK and MALTA
Age: 61
Posts: 1,297
Likes: 0
Received 18 Likes
on
4 Posts
Lycra, it's really hard not to vent at head following your post. It was a gin clear day. The landing brief from the PF should have identified the obstacles in the undershoot and the PNF should confirm his assessment.
From that brief, given in a stabilised approach at a point in space where both pilots can see the helideck environment, the only acceptable approach is OFFSET, i.e. 90 degrees across to the forward edge of the aiming circle.
If that assessment and brief did not conclude the OFFSET approach then they were doomed from that point.
However, if the brief was correct, the LTCs sole mission is to keep the PF moving forward until his arse is in line with the bumline. This is perfectly assessable by careful spatial awareness in the latter stages. Any sense that the PF is trying to cross early must be immediatlety corrected.
To accept a 45 degree crossing with obstacles in the undershoot is Russian roulette and the key to understanding that is knowledge of CAP437 and the minimum safety distances required which in truth, will chill your piss when you are at any time less than level with the bumline.
Hitting an object with your rotor in 8/8s blue! I am sorry there are no excuses and no hiding places.
Knowledge drives technique and the fear knowledge instills, when technique is flawed, should motivate pilots to invest in the SAFEST solution.
That is, if no cross hatching is in play, on deck equal to, or greater than your D value, if you cross the deck with your arse level with the bum line (90 degrees) your tail will be safe. This type of landing should be taught and perfected LONG before the pilot is ever permitted to cross at 45 degrees. The crossing at 45 degrees SHOULD be the exception, when both pilots 100% agree that the undershoot is clear.
This is a Mantra I hammered into my students from day 1.
From what you post, I say poor CRM, poor decision making and failure to understand just how small the safety margins are when you choose to cross at 45 degrees.
Caused, in majority of cases, by over obsessing about engine failures.
From that brief, given in a stabilised approach at a point in space where both pilots can see the helideck environment, the only acceptable approach is OFFSET, i.e. 90 degrees across to the forward edge of the aiming circle.
If that assessment and brief did not conclude the OFFSET approach then they were doomed from that point.
However, if the brief was correct, the LTCs sole mission is to keep the PF moving forward until his arse is in line with the bumline. This is perfectly assessable by careful spatial awareness in the latter stages. Any sense that the PF is trying to cross early must be immediatlety corrected.
To accept a 45 degree crossing with obstacles in the undershoot is Russian roulette and the key to understanding that is knowledge of CAP437 and the minimum safety distances required which in truth, will chill your piss when you are at any time less than level with the bumline.
Hitting an object with your rotor in 8/8s blue! I am sorry there are no excuses and no hiding places.
Knowledge drives technique and the fear knowledge instills, when technique is flawed, should motivate pilots to invest in the SAFEST solution.
That is, if no cross hatching is in play, on deck equal to, or greater than your D value, if you cross the deck with your arse level with the bum line (90 degrees) your tail will be safe. This type of landing should be taught and perfected LONG before the pilot is ever permitted to cross at 45 degrees. The crossing at 45 degrees SHOULD be the exception, when both pilots 100% agree that the undershoot is clear.
This is a Mantra I hammered into my students from day 1.
From what you post, I say poor CRM, poor decision making and failure to understand just how small the safety margins are when you choose to cross at 45 degrees.
Caused, in majority of cases, by over obsessing about engine failures.
Last edited by DOUBLE BOGEY; 19th Apr 2017 at 02:39.