Time to remove T/O-trolleys?
Thread Starter
Joined: Nov 2003
Posts: 90
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From: Scandinavia
Time to remove T/O-trolleys?
After reading about yet another trolley accident, it got me thinking about those contraptions again. 
What is it that keeps them around in this industry? My guess is misconceived economics.
Normal day to day use of a trolley is usually no problem, but there is a hazard introduced into the operation of the helicopter, that shouldn't need to be there. To me it's a simple case of risk-management.
Looking att the economic side of things; After one helicopter beeing written off, it isn't the cheapest way to move the helicopter around anymore, is it?
I can think of lots of ways that are safer when moving a helicopter with skids on the ground than a trolley, none of them as fast, but all of them with no added risk to the flying side.
As a pilot, telling the boss that it's unsafe to work off trolleys, is that similar to saying "I'm a bad pilot"?
These things will probably be around until there is some good statistics that shows how many accidents are related to taking off and landing on them. With the pilot experience in the mix as well.
Any thoughts on how to improve them while waiting for them to disappear? What is the worst and best trolley you have been operating on from pilot, safety or moving around point of view?
If there are some pictures also, that would be nice.
Cheers!
/2beers
What is it that keeps them around in this industry? My guess is misconceived economics.
Normal day to day use of a trolley is usually no problem, but there is a hazard introduced into the operation of the helicopter, that shouldn't need to be there. To me it's a simple case of risk-management.
Looking att the economic side of things; After one helicopter beeing written off, it isn't the cheapest way to move the helicopter around anymore, is it?
I can think of lots of ways that are safer when moving a helicopter with skids on the ground than a trolley, none of them as fast, but all of them with no added risk to the flying side.
As a pilot, telling the boss that it's unsafe to work off trolleys, is that similar to saying "I'm a bad pilot"?
These things will probably be around until there is some good statistics that shows how many accidents are related to taking off and landing on them. With the pilot experience in the mix as well.
Any thoughts on how to improve them while waiting for them to disappear? What is the worst and best trolley you have been operating on from pilot, safety or moving around point of view?
If there are some pictures also, that would be nice.
Cheers!
/2beers
Joined: Jan 2001
Posts: 3,008
Likes: 62
From: North Queensland, Australia
You say 'yet another trolley accident', implying there are heaps of them, but as you say, meaningful stats would be useful, rather than a discussion based on feelings.
Certainly, there have been a few well publicised and sad mishaps in recent years, but every other phase of flight or ground ops can lead to accidents too.
Why not look up the safety records yourself (many available online these days) and see how many accidents could be attributed to trolley ops; and, why should we be 'waiting for them to disappear'?
Certainly, there have been a few well publicised and sad mishaps in recent years, but every other phase of flight or ground ops can lead to accidents too.
Why not look up the safety records yourself (many available online these days) and see how many accidents could be attributed to trolley ops; and, why should we be 'waiting for them to disappear'?
Joined: Feb 2004
Posts: 187
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From: St Pierre et Miquelon
aotw
I think 2 beers has a valid point. I personally know of at least 2 trolley accidents, one of which resulted in the write-off of a Bell 212, and have seen several trolley incidents.
Just because every other phase of flight can lead to accidents is no reason to keep trolleys just because they save money over other methods of moving skidded helicopters. If something is deemed to be unsafe it should be discarded when there are alternative methods or pieces of equipment which do the job more safely (albeit more slowly or more expensively). I got rid of the landing trolleys in a company I worked for after we had a number of incidents. It made life a bit more difficult for the engineers, but after the source of incidents was removed, the possibity of an accident caused by it was also removed.
I think 2 beers has a valid point. I personally know of at least 2 trolley accidents, one of which resulted in the write-off of a Bell 212, and have seen several trolley incidents.
Just because every other phase of flight can lead to accidents is no reason to keep trolleys just because they save money over other methods of moving skidded helicopters. If something is deemed to be unsafe it should be discarded when there are alternative methods or pieces of equipment which do the job more safely (albeit more slowly or more expensively). I got rid of the landing trolleys in a company I worked for after we had a number of incidents. It made life a bit more difficult for the engineers, but after the source of incidents was removed, the possibity of an accident caused by it was also removed.
Joined: Feb 2001
Posts: 542
Likes: 5
From: Europe
Rather than generalising about whether trolleys should be used or not I think it would be more valuable to look at which particular aspect of trolley use has caused accidents, and then address specific high risk areas.
I do recall that the Australian B47 accident was considered to be caused by the skid hitting a lip to the trolley after drifting, and it has been rumoured the Germany MD900 was caused by a similar problem, both triggering dynamic roll over. Answer - never have raised lips/obstructions on trolleys.
Other obvious risk areas for example are trolley size, height differential to the ground (which should be as minimal as possible), lack of anti skid surface, and poor braking security.
I do recall that the Australian B47 accident was considered to be caused by the skid hitting a lip to the trolley after drifting, and it has been rumoured the Germany MD900 was caused by a similar problem, both triggering dynamic roll over. Answer - never have raised lips/obstructions on trolleys.
Other obvious risk areas for example are trolley size, height differential to the ground (which should be as minimal as possible), lack of anti skid surface, and poor braking security.
Joined: Sep 2000
Posts: 338
Likes: 0
From: UK
Indeed, a large number of accidents on trolleys have been attributed to dynamic rollover following snagging of skids and trolley lips/sides etc. About a million years ago, or so it would seem, a 212 performed an amazing backward dynamic rollover on a trolley on a North Sea installation when the rear of the skids snagged under a bar at the back of the trolley.
However, taking away the lip then permits other alternatives - the skid sliding straight off the trolley edge for example! Also, during startup/shutdown on the trolley, there is a degree of safety in having raised edges on the trolley in case of uncommanded rotation of the aircraft on its skids at low rotor rpm.
Having said that, it is fair to say that you shouldn't just trash anything without conducting a proper analysis of the possible causes.
However, taking away the lip then permits other alternatives - the skid sliding straight off the trolley edge for example! Also, during startup/shutdown on the trolley, there is a degree of safety in having raised edges on the trolley in case of uncommanded rotation of the aircraft on its skids at low rotor rpm.
Having said that, it is fair to say that you shouldn't just trash anything without conducting a proper analysis of the possible causes.
- Are landings made with/without marshalling assistance
- What forward, lateral and vertical references are there to assist the pilot to land in the correct position on the trolley?
- What training is given, and how often is competency assessed?
Joined: Jul 2002
Posts: 515
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From: Denver, CO and the GOM
An Idea?
So we call 'em dollys in Minnesota...
Anyway, as a very inexperienced dolly-lander, every time I have to land our fixed-float R44 on our dolly, I wonder if there is a safe way to provide that last bit of landing guidance, which seems to be the undoing in so many cases. I keep returning to the idea of a set of full-length, 45-degree wedge "rails" on the landing deck, which would be inside of the skids when the helicopter was positioned. Something like:
_____/==.......==\_____
(^ you are looking from the rear of the dolly)
.[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[
.[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[
///////////////////////////////////////////
]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
==========================
==========================
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.[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[
.[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[
(^ looking at the dolly from above)
They would only have to be about 4"/10cm high, made out of steel (or something else hard and smooth. Inside of the wedges, the deck would be raised to match the top edge, so if the pilot got on the inside of the rail, there would be no chance of getting caught. Since the wedge would be on the inside of the skids only, it could not contribute to the possibility of rollover.
Thoughts?
Anyway, as a very inexperienced dolly-lander, every time I have to land our fixed-float R44 on our dolly, I wonder if there is a safe way to provide that last bit of landing guidance, which seems to be the undoing in so many cases. I keep returning to the idea of a set of full-length, 45-degree wedge "rails" on the landing deck, which would be inside of the skids when the helicopter was positioned. Something like:
_____/==.......==\_____
(^ you are looking from the rear of the dolly)
.[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[
.[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[
///////////////////////////////////////////
]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
==========================
==========================
]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
.[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[
.[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[
(^ looking at the dolly from above)
They would only have to be about 4"/10cm high, made out of steel (or something else hard and smooth. Inside of the wedges, the deck would be raised to match the top edge, so if the pilot got on the inside of the rail, there would be no chance of getting caught. Since the wedge would be on the inside of the skids only, it could not contribute to the possibility of rollover.
Thoughts?
Joined: Sep 2000
Posts: 338
Likes: 0
From: UK
Why not just make the trolleys a lot bigger?
On the other hand they could always make helicopters a lot smaller so that they would fit onto the trolley more easily! Or am I missing the point now?
212man - Check your PM.....
Last edited by flyer43; 17th March 2005 at 20:02.
Joined: Sep 2003
Posts: 730
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From: Australia
Weve Been using trolleys for a little while now for our 206 and a private 407 thats based here...our trolleys are very solid, low to the gound and FLAT yes no !!!!! like lips etc sticking up!
We have markers on the trolley to line up with when hoovering. we also have 4 jacks on each corner of the trolley that are mounted below deck height to add extra stability to the trolly when landing. it as solid as a rock.
Makes it a one man job especially when deaprting early as well.
if wind conditions arent favourable to land on the trolley we land on the concrete or grass!....simple.
having said all this ill probably go out this afternoon and roll it off the trolley now!!!
We have markers on the trolley to line up with when hoovering. we also have 4 jacks on each corner of the trolley that are mounted below deck height to add extra stability to the trolly when landing. it as solid as a rock.
Makes it a one man job especially when deaprting early as well.
if wind conditions arent favourable to land on the trolley we land on the concrete or grass!....simple.
having said all this ill probably go out this afternoon and roll it off the trolley now!!!
Joined: Aug 1999
Aviation Qualifications: ATP+Mil
Posts: 4,411
Likes: 83
From: Gold Coast, Australia
A lot of this was covered in previous posts, but the design of the trolley/platform is important: surely a standard for trolley design is more important than "time to remove T/O trolleys"?
Points to consider:
Flat, no obstructions
Large enough to get good visual reference in the hover
Rubber mat/non slip surface for the helicopter skids
Earthing chain from the trolley & earthing strap over the rubber mat, to bond the helicopter
Secure chocks to prevent the trolley moving
Strong enough for the helicopter: stress loading dynamic and static
Aiming marks to assist line up
North Sea 212 roll over, another memory to look back on. Remember the mad panic to find a ladder to get up to the doors of the beast lying on its side? There must have been a lot of us around at the time
When the Noggies put that hydraulic control on the platform, it was pointed out as a snagging hazard, so they then put a bar over the top to protect it. Neatly designed to snag the heel of a 212 as it slid on take off, IIRC 
Points to consider:
Flat, no obstructions
Large enough to get good visual reference in the hover
Rubber mat/non slip surface for the helicopter skids
Earthing chain from the trolley & earthing strap over the rubber mat, to bond the helicopter
Secure chocks to prevent the trolley moving
Strong enough for the helicopter: stress loading dynamic and static
Aiming marks to assist line up
North Sea 212 roll over, another memory to look back on. Remember the mad panic to find a ladder to get up to the doors of the beast lying on its side? There must have been a lot of us around at the time
When the Noggies put that hydraulic control on the platform, it was pointed out as a snagging hazard, so they then put a bar over the top to protect it. Neatly designed to snag the heel of a 212 as it slid on take off, IIRC
Joined: May 2003
Posts: 921
Likes: 30
From: Europe
It should really meet the ICAO Standard for TLOF enumerated in Annex 14, Volume II, chapter 3
3.1.1 I The touchdown and lift-off area (TLOF) shall be of sufficient size to contain a circle of diameter 1.5 times the length or width of the undercarriage, whichever is the greater, of the largest helicopter the area is intended to serve.
Note.- A touchdown and lift-off area may be any shape.
3.1.12 Slopes on a touchdown and lift-off area shall be sufficient to prevent accumulation of water on the surface of the area, but shall not exceed 2 per cent in any direction.
3.1.13 A touchdown and lift-off area shall be capable of withstanding the traffic of helicopters that the area is intended to serve.
Note.- A touchdown and lift-off area may be any shape.
3.1.12 Slopes on a touchdown and lift-off area shall be sufficient to prevent accumulation of water on the surface of the area, but shall not exceed 2 per cent in any direction.
3.1.13 A touchdown and lift-off area shall be capable of withstanding the traffic of helicopters that the area is intended to serve.
