Aberdeen delay question
Helicomparator
After thirty-odd years of watching large helicopters turn final 200 yards behind 757s, Nimrods and other bigjets, I am as frustrated as you at the imposition of the rules which were designed for fixed wing aircraft. However it should be remembered that wake turbulence separation has always been applied between all aircraft on instrument approaches and also between all departing aircraft whether helis or planks.
The major change is that we have to say "Caution wake turbulence. The recommended distance is "x" miles" to every VFR (or visual) helicopter which is following an aircraft of the same or higher wake category. Whether or not you guys follow the recommendation is up to you, but thankfully most of you disregard it.
By the way, none of the rule-writers are able to explain why I can quite legally clear a large helicopter to take-off 100 yards behind another heavily laden helicopter, yet the same two helicopters should be 3nm apart on approach. Do the rotor vortices differ greatly between take off and landing config?
As regards your other point about controllers snapping at you, this was covered in another thread, but it really disappoints me to hear that it is still happening. All I can suggest is that you continue to ask for RW14 etc and if you get a blunt reply, phone the Watch Manager on your return so we can investigate the circumstances.
After thirty-odd years of watching large helicopters turn final 200 yards behind 757s, Nimrods and other bigjets, I am as frustrated as you at the imposition of the rules which were designed for fixed wing aircraft. However it should be remembered that wake turbulence separation has always been applied between all aircraft on instrument approaches and also between all departing aircraft whether helis or planks.
The major change is that we have to say "Caution wake turbulence. The recommended distance is "x" miles" to every VFR (or visual) helicopter which is following an aircraft of the same or higher wake category. Whether or not you guys follow the recommendation is up to you, but thankfully most of you disregard it.
By the way, none of the rule-writers are able to explain why I can quite legally clear a large helicopter to take-off 100 yards behind another heavily laden helicopter, yet the same two helicopters should be 3nm apart on approach. Do the rotor vortices differ greatly between take off and landing config?
As regards your other point about controllers snapping at you, this was covered in another thread, but it really disappoints me to hear that it is still happening. All I can suggest is that you continue to ask for RW14 etc and if you get a blunt reply, phone the Watch Manager on your return so we can investigate the circumstances.
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Helicomparator,
Wake turbulence refers to vortex when in transitional flight,and also ground effect turbulence say when hover taxiing.SRG changed the wording and also we now have to say recommended distance instead of spacing.
As far as 225's off 14.Perhaps you may like to take that up with your company.When the 225 came in we were told that they couldn't take 14.
The times that someone has offered to take 14 in the early morning,it really wouldn't have made much difference.However it would have resulted in a rather large Q jump so I just say your number x to depart.It seems that it's OK to Q jump,but it's wrong if you are on the receiving end. TTFD was complaining about just that.
What would happen if I started saying to half of the 17 helicopter that want start at the same time,standby for start minimum 40 minutes delay? Go and get a cup of tea and a bacon sarny.
Somehow it would be tea and no biscuits for me,because I'm not providing a wonderful ''Service''.Actually I would be,because I would save tons of fuel,far less delays at the hold
.It should be the companies that schedule a maximum of say 5 outbound each between 7 and 8 am at one every 10 minutes for example.(It's not rocket science,and applies to every other airport in the world except ABZ.
)
No I would be seen as a right old grump.who fell out of bed on the wrong side,and not a good guy who says yes to everything.
Well the yes men are the one that tie themselves in knots very quickly.
Also it is the Tower controller who will tell you which runway to depart off,because he/she has the big picture,and is aware of the rules that we have to adhere to.
Wake turbulence refers to vortex when in transitional flight,and also ground effect turbulence say when hover taxiing.SRG changed the wording and also we now have to say recommended distance instead of spacing.
As far as 225's off 14.Perhaps you may like to take that up with your company.When the 225 came in we were told that they couldn't take 14.
The times that someone has offered to take 14 in the early morning,it really wouldn't have made much difference.However it would have resulted in a rather large Q jump so I just say your number x to depart.It seems that it's OK to Q jump,but it's wrong if you are on the receiving end. TTFD was complaining about just that.
What would happen if I started saying to half of the 17 helicopter that want start at the same time,standby for start minimum 40 minutes delay? Go and get a cup of tea and a bacon sarny.
Somehow it would be tea and no biscuits for me,because I'm not providing a wonderful ''Service''.Actually I would be,because I would save tons of fuel,far less delays at the hold
.It should be the companies that schedule a maximum of say 5 outbound each between 7 and 8 am at one every 10 minutes for example.(It's not rocket science,and applies to every other airport in the world except ABZ.)No I would be seen as a right old grump.who fell out of bed on the wrong side,and not a good guy who says yes to everything.
Well the yes men are the one that tie themselves in knots very quickly.
Also it is the Tower controller who will tell you which runway to depart off,because he/she has the big picture,and is aware of the rules that we have to adhere to.
letMfly
To be fair, I haven't asked for 14 for some time due to previously mentioned snaps making me feel its wasn't the done thing. Perhaps that problem has been fixed some time ago, I just haven't tested the water recently. My recent departure from 14 was at the suggestion of the controller
Regarding the turbulence, I can't imagine that there is any difference between a landing and taking-off helicopter - turbulence gets worse at low speed, and you are slow in both the above situations. Do you guys ever feed back to NATS / SRG HQ that you think procedures are inappropriate?
tad - Not trying to jump the queue, just trying to maximise the departure rate. Depending on who is "on" there does seem to be quite a difference in departure rates. Sometimes we sit there saying "could have got 2 helis off in that gap" though I accept that it could be due to co-ordination with Approach going on behind the scenes. Again, back to understanding each other's issues.
Without knowing who told you 225s couldn't use 14, I can't comment. Perhaps it was that we couldn't always use 14 and it was considered simpler for there to be no doubt. But this is not the case, sometimes we can but it does depend on a number of factors. An Easterly component to the wind certianly helps, and we are not allowed to takeoff with even a slight tailwind component.
Regarding scheduling of early morning departure, if we were BA, BMI etc I would quite agree. Trouble is we are not masters of our own destiny - we are chartered by the oil companies and they want departures first thing. Its hard to say to company x "sorry, your deparures will be later because company y is going first". That is not a good way to retain your contracts (which can be cancelled at short notice if the charterer gets too pissed off with you). As I said previously, all my wage and a good chunk of your wage, comes from the oil companies, so we have to try to keep them sweet! Although I suppose you would get your wage regardless of which colour the helicopter is!
It would be interesting to research whether the maximum arrival / departure rate is currently less than it was in the heyday of the 80s. Seems to me there are now far fewer heli flights, but longer delays. To be fair, I guess there are a lot more fixedwing flights that there used to be.
Of course, but one could still accept a suggestion or offer graciously, even if ultimately not going along with it! He is aware of the rules that govern his issues, but perhaps not those of the recipients of the service. Without wishing to get into a "mine is bigger than yours" argument, in fact its the aircrew that have the big picture that relates to the entire flight from start to finish, including issues to do with fuel, weather and payload. The tower controller has the co-ordination of deparures and arrivals at the airport to consider, but this is a thumbnail compared to the big picture (yes, mine is definitely bigger than yours)
HC
To be fair, I haven't asked for 14 for some time due to previously mentioned snaps making me feel its wasn't the done thing. Perhaps that problem has been fixed some time ago, I just haven't tested the water recently. My recent departure from 14 was at the suggestion of the controller
Regarding the turbulence, I can't imagine that there is any difference between a landing and taking-off helicopter - turbulence gets worse at low speed, and you are slow in both the above situations. Do you guys ever feed back to NATS / SRG HQ that you think procedures are inappropriate?
tad - Not trying to jump the queue, just trying to maximise the departure rate. Depending on who is "on" there does seem to be quite a difference in departure rates. Sometimes we sit there saying "could have got 2 helis off in that gap" though I accept that it could be due to co-ordination with Approach going on behind the scenes. Again, back to understanding each other's issues.
Without knowing who told you 225s couldn't use 14, I can't comment. Perhaps it was that we couldn't always use 14 and it was considered simpler for there to be no doubt. But this is not the case, sometimes we can but it does depend on a number of factors. An Easterly component to the wind certianly helps, and we are not allowed to takeoff with even a slight tailwind component.
Regarding scheduling of early morning departure, if we were BA, BMI etc I would quite agree. Trouble is we are not masters of our own destiny - we are chartered by the oil companies and they want departures first thing. Its hard to say to company x "sorry, your deparures will be later because company y is going first". That is not a good way to retain your contracts (which can be cancelled at short notice if the charterer gets too pissed off with you). As I said previously, all my wage and a good chunk of your wage, comes from the oil companies, so we have to try to keep them sweet! Although I suppose you would get your wage regardless of which colour the helicopter is!
It would be interesting to research whether the maximum arrival / departure rate is currently less than it was in the heyday of the 80s. Seems to me there are now far fewer heli flights, but longer delays. To be fair, I guess there are a lot more fixedwing flights that there used to be.
Also it is the Tower controller who will tell you which runway to depart off,because he/she has the big picture,and is aware of the rules that we have to adhere to.
)HC
Last edited by HeliComparator; 24th Feb 2010 at 22:01.
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Helicomparator,
I'm sure the Oil companies are happy because you are burning lots of their product.Why has it taken 30+ years for the same situation to be happening every morning,when there is a finite capacity.I'm not suggesting y company goes first.It's the airport capacity is X, and they can only take so many fixed wing inbounds,outbounds and helis(divided by 3).At the moment Ground is completely overloaded,all rushing out to sit there for 30 minutes.And it's all ATC's fault,for not BREAKING Safety rules.It's madness
.
When you say 2 helicopters could go in a gap.A standard gap is designed for one heli to depart,and have vortex separation on the next arrival.There is a trend amongst several fixed wing operators to sit on the runway,for some time after being cleared take-off.Also with some types they need engine system checks when it is cold.Some heli operators are slower than others.All this slows things down.
Then there are the controllers,who try and pack inbounds at the same time as a long line of outbounds are waiting.These are the yes men,try and please everyone.It doesn't work and they are pushing their luck often.The controllers you don't seem to like (like me)are the one who have gaps always set up,but overall have a lot less holding.I can achieve a steady departure rate,and if you are very very lucky 2 in a gap,but only with the right combination of traffic.However the overall departure rate is high because I'm not having to chance 2 in a non existant gap.The down side is that I hold inbound helis more,to be fair on the departures.Hence the moans about ''What's the delay'' etc.
Also in the good old days the inbound rush was later.Now it starts about 7.20am.I managed 52 outbounds in one hour,many years ago.I don't do anything different from then to now.There was no inbounds.
Oh it was your company that said a 225 couldn't take 14.
I'm sure the Oil companies are happy because you are burning lots of their product.Why has it taken 30+ years for the same situation to be happening every morning,when there is a finite capacity.I'm not suggesting y company goes first.It's the airport capacity is X, and they can only take so many fixed wing inbounds,outbounds and helis(divided by 3).At the moment Ground is completely overloaded,all rushing out to sit there for 30 minutes.And it's all ATC's fault,for not BREAKING Safety rules.It's madness
.When you say 2 helicopters could go in a gap.A standard gap is designed for one heli to depart,and have vortex separation on the next arrival.There is a trend amongst several fixed wing operators to sit on the runway,for some time after being cleared take-off.Also with some types they need engine system checks when it is cold.Some heli operators are slower than others.All this slows things down.
Then there are the controllers,who try and pack inbounds at the same time as a long line of outbounds are waiting.These are the yes men,try and please everyone.It doesn't work and they are pushing their luck often.The controllers you don't seem to like (like me)are the one who have gaps always set up,but overall have a lot less holding.I can achieve a steady departure rate,and if you are very very lucky 2 in a gap,but only with the right combination of traffic.However the overall departure rate is high because I'm not having to chance 2 in a non existant gap.The down side is that I hold inbound helis more,to be fair on the departures.Hence the moans about ''What's the delay'' etc.
Also in the good old days the inbound rush was later.Now it starts about 7.20am.I managed 52 outbounds in one hour,many years ago.I don't do anything different from then to now.There was no inbounds.
Oh it was your company that said a 225 couldn't take 14.
Last edited by throw a dyce; 24th Feb 2010 at 22:54.
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HC,
just a quick reply for now....
I think you are probably right - the achieved rate is less now. A number of reasons contribute to that. Earlier, I reminisced about what we used to get away with. One example - two helicopters side by side at what is now D2 (can't remember now what its previous identity was Holding point Charlie maybe?) with 2 side by side we could alter the order of departure to give the most efficient rate - dependant on speed and HMR - put the 76 ahead of the 61 for instance. Now the types are much more similar in speed and they have to line up in line-astern which makes cherry picking difficult. Thats just one area where changes have had a negative impact. (also remember that back in the early-mid 80's up to 50% or more of the heli departures were VFR or SVFR not an all IFR set as now)
The 14 issue IIRC - we were told by CHC-Scotia that Mark 2's and 225's couldn't take 14 at all - I guess some people took that to mean that it was also true for Bristow. The other problem is that we have largely been on 34 for what seems like months! - it is natural to 'get out of the habit' (of using 14) so do give us a nudge from time-to-time. Any disrespectful replies should be dealt with as indicated above.
Final point for now:
One thing that is maybe not immediately apparent with the 'wake turbulence issue'. When any helicopter departs 16 from W4 or W5, we have to ensure that we apply the correct separation against the next landing as it has been decreed that the landing will fly through the 'wake' So a heli departing from W4 or W5 has to be airborne and away before a landing Jetstream gets to 4nm - this also applies to a heli departing from E3 on 34. In a strong headwind you will end up sitting twiddling your thumbs waiting for the landing traffic.......
Another current reason for extended waits for 16 - we are limited to using 5nm radar separation to the south of the airport instead of the previous 3nm. This means that departures have to be spaced further apart.
Finally, yes we have and do make representations but the CAA are fairly intransigent as I am sure you are aware.
I am full support of any move to arrange another get-together....
DD
just a quick reply for now....
It would be interesting to research whether the maximum arrival / departure rate is currently less than it was in the heyday of the 80s. Seems to me there are now far fewer heli flights, but longer delays. To be fair, I guess there are a lot more fixedwing flights that there used to be.
The 14 issue IIRC - we were told by CHC-Scotia that Mark 2's and 225's couldn't take 14 at all - I guess some people took that to mean that it was also true for Bristow. The other problem is that we have largely been on 34 for what seems like months! - it is natural to 'get out of the habit' (of using 14) so do give us a nudge from time-to-time. Any disrespectful replies should be dealt with as indicated above.
Final point for now:
Sometimes we sit there saying "could have got 2 helis off in that gap"
Another current reason for extended waits for 16 - we are limited to using 5nm radar separation to the south of the airport instead of the previous 3nm. This means that departures have to be spaced further apart.
Finally, yes we have and do make representations but the CAA are fairly intransigent as I am sure you are aware.
I am full support of any move to arrange another get-together....
DD
tad - Look, there is only room for one bitter and twisted individual on this site and I got here first! Less of the self-loathing, nobody hates you.
I realised that it was BHL that indicated that 225s couldn't use 14, my question was which individual? You have to bear in mind that if you ask a group of 4 people a technical question, you will get 4 different answers. No, on second thoughts if its pilots you will get 5 different answers!
The point was just that, from our eyes, there seems to be a significant variation in the efficient use of FW arrival gaps to allow helis to depart, according to which shift is on or whatever. I understand and have seen some unreasonable delays in FW pushing their throttles forward on the runway, some helis clearing the runway etc, and can see how that can easily unravel a plan, and therefore why a slightly increased error margin can in fact make things run more smoothly. However perhaps more use could be made of "can you accept immediate takeoff" with the helis- after all a heli running at the holding point is just desperate to get airborne, I just have to pull up this lever and its off...
HC
I realised that it was BHL that indicated that 225s couldn't use 14, my question was which individual? You have to bear in mind that if you ask a group of 4 people a technical question, you will get 4 different answers. No, on second thoughts if its pilots you will get 5 different answers!
The point was just that, from our eyes, there seems to be a significant variation in the efficient use of FW arrival gaps to allow helis to depart, according to which shift is on or whatever. I understand and have seen some unreasonable delays in FW pushing their throttles forward on the runway, some helis clearing the runway etc, and can see how that can easily unravel a plan, and therefore why a slightly increased error margin can in fact make things run more smoothly. However perhaps more use could be made of "can you accept immediate takeoff" with the helis- after all a heli running at the holding point is just desperate to get airborne, I just have to pull up this lever and its off...
HC
DataDad
Thanks for that - I understand the importance of heli vortex vs landing FW, but couldn't more common sense be applied? There is a massive difference between nil wind when a vortex can linger over the runway for a long time (and be very dangerous to FW), vs the normal Dyce strong crosswind where the vortex is blown off the runway in seconds. Surely the goal is safe but expeditious operations, not rules for the sake of the rules?
Regarding CAA intransigence I have to say that Flight Ops are pretty reasonable, whereas other departments are less so. Perhaps this is because in general Flight Ops personnel still fly, whereas others have forgotten what the sharp end of aviation is like (assuming they ever knew!).
HC
Thanks for that - I understand the importance of heli vortex vs landing FW, but couldn't more common sense be applied? There is a massive difference between nil wind when a vortex can linger over the runway for a long time (and be very dangerous to FW), vs the normal Dyce strong crosswind where the vortex is blown off the runway in seconds. Surely the goal is safe but expeditious operations, not rules for the sake of the rules?
Regarding CAA intransigence I have to say that Flight Ops are pretty reasonable, whereas other departments are less so. Perhaps this is because in general Flight Ops personnel still fly, whereas others have forgotten what the sharp end of aviation is like (assuming they ever knew!).
HC
Last edited by HeliComparator; 24th Feb 2010 at 23:32.
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Helicopter vortex wake is likely to be of lower intensity when landing than when taking off.
Firstly, a landing helicopter in a steady descent will have a lower angle of attack on the rotor blades than the same aircraft lifting to the hover and climbing.
Secondly, being at the end of its sector, it is likely to be at a lighter weight.
I don't work from ABZ but sometimes find myself more than a little bemused when I am given permission to hover taxy to line up on the runway then held in the hover for vortex wake reasons behind a departed fixed wing.
I'm already airborne.
Firstly, a landing helicopter in a steady descent will have a lower angle of attack on the rotor blades than the same aircraft lifting to the hover and climbing.
Secondly, being at the end of its sector, it is likely to be at a lighter weight.
I don't work from ABZ but sometimes find myself more than a little bemused when I am given permission to hover taxy to line up on the runway then held in the hover for vortex wake reasons behind a departed fixed wing.
I'm already airborne.
"I don't work from ABZ but sometimes find myself more than a little bemused when I am given permission to hover taxy to line up on the runway then held in the hover for vortex wake reasons behind a departed fixed wing."
There are similar bemused comments here when a helicopter asks for a backtrack and can do so in the hover. Anyone care to explain?
With regard to using different runways.
A question which arose today with the wind at 050/12kt. We have noticed that no one seems to want a 05 departure anymore since the runway was shortened. Obviously it wasn't used today because of the low cloud. Is it too short to be of any use now?
There are similar bemused comments here when a helicopter asks for a backtrack and can do so in the hover. Anyone care to explain?
With regard to using different runways.
A question which arose today with the wind at 050/12kt. We have noticed that no one seems to want a 05 departure anymore since the runway was shortened. Obviously it wasn't used today because of the low cloud. Is it too short to be of any use now?
There are similar bemused comments here when a helicopter asks for a backtrack and can do so in the hover. Anyone care to explain?
So it has to be possible to accelerate to the critical speed, and with a worst case failure at that point has to be able to either stop in the distance still remaining, or climb away. The length of runway required to do this depends on the critical speed and the headwind component on the runway in question.
Hope that explains it!
The problem with 05 is that its not only shorter now, but has relatively high buildings just off the end of the runway. If the aircraft is light and with a headwind it could still be done, but unless we go into the graphs its less intuitive that we would clear the obstructions by the minimum required height in the event of an engine failure just after we are committed to continue the takeoff.
Perhaps ATC could consider if there is significant benefit to using 05 and 14 for departure more often? If so, we could formulate some guidance for crews about using these runways, map out the obstacles in the climb-out etc. Of course we don't want to go to that trouble if ATC doesn't really want us to use them.
Is there more of a noise issue departing on 05?
HC
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What would happen if I started saying to half of the 17 helicopter that want start at the same time,standby for start minimum 40 minutes delay?
Actually what you said above has happened some mornings. I have asked for start and been told not to and call back in 10-15 minutes, the reason being staff shortages in ATC. Fair enough, at least we know the reason why and we can tell our Ops that there is an ATC delay. Maybe it should happen more often and then perhaps the oil companies might actually start listening when we tell them it is all due to the fact that they want all their flights to go at the same time. Of course, that also requires the three respective helicopter company commercial managers to tell their clients this as well!
It not only causes ATC problems, as there are also problems in the heliport terminals as well with the mass influx of passengers all wanting to check in, go through security, get their passenger briefings, etc.exlatccatsa
Runway 05 is now shorter than it used to be and even with the wind you stated, a 225 would need almost all of that length for its transition assuming that it was at or below a weight that allows for that length. With a headwind component less than 10kts the runway is not long enough, unless the aircraft is light enough to use a Vtoss 45 profile - not that often I suspect. Also most operators tend to use Vtoss 50 as the minimum speed profile for a 225 I believe. AS332Ls may be able to use the runway more than the heavier types.
Similarly, these issues apply to the use of 14 as well. However, it being longer does mean that EC225s can more readily accept a 14 departure if the aircraft is within the specified performance criteria at the time.
Yes we can lift to the hover and we are able to hover-taxi for a back track if needed, but the flight manuals for all types have supplements for Category A Operations (i.e. Public Transport) and these dictate the procedures and distances we require for a transition to forward flight from the hover with a reject distance to land and stop should an engine fail (or some other emergency occur). As HC mentions, we are not allowed to accept a downwind take-off or landing for Cat A operations. However, I will admit there is some question as to what is actually meant by "take-off" - is it the act of actually getting airborne, or the transition from the hover to forward flight? I believe the latter is what is inferred but certainly the 225 Cat A Operation Supplement says "takeoff and landing with tail wind are not permitted". HC, your thoughts?
As with the AS332L2 (and I suspect the S92 as well), the distances required for a transition to forward flight vary for all sorts of reasons including AUM (or AUW if you prefer) and the headwind component. The EC225 does not require to backtrack as often as the AS332L2 or the S92 might, but it does happen occasionally.
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HC
I agree 100% with you – however decisions to get that through have to be taken at levels way above where I stand and are fraught with difficulties: At what x-wind component can we stop apply the separation just being one.
In case it's not widely known and with credit to Lori Bergman - the following is most apt:
Common Sense was preceded in death by his parents, Truth and Trust; his wife, Discretion; his daughter, Responsibility; and his son, Reason. He is survived by three stepbrothers; I Know My Rights, Someone Else is to Blame, and I'm A Victim.
I will throw a ‘common-sense’ idea back at you….
With regards the back-tracking for departure on 34. The area beyond the end of the runway is a fairly smooth piece of grass which had a considerable amount of hardcore placed down on it in the mid-90’s when a 146 went gardening. The efficacy of it was proven when a Dornier went the same way a couple of years ago – could not this perfectly good piece ground be considered as a suitable reject onto area/de-facto runway extension, thereby negating the need for the backtrack?
The request for a backtrack is another reason why crews may feel gaps are being missed – if a helicopter (or fixed-wing for that matter) is back-tracking we CANNOT allow a sectorised landing so it can lead to one needing a back-track having to wait for a longer time and with the lack of ‘cherry-picking’ opportunities I have already mentioned it may look like we are not being the most efficient we can be. (First thing in the morning we regularly send a back-track one to A4 for that reason but that option is largely closed off once inbounds start arriving)
ShyTorque
Holding in a hover you are not actually flying through a ‘Wake’ – fixed wing Wake turbulence only starts being generated when the aircraft rotates which I assume would be someway beyond where you are holding.
TTFD
Haven’t got any answers yet regarding Balmedie etc. However the question has been ‘escalated’.
DD
I understand the importance of heli vortex vs landing FW, but couldn't more common sense be applied? There is a massive difference between nil wind when a vortex can linger over the runway for a long time (and be very dangerous to FW), vs the normal Dyce strong crosswind where the vortex is blown off the runway in seconds. Surely the goal is safe but expeditious operations, not rules for the sake of the rules?
In case it's not widely known and with credit to Lori Bergman - the following is most apt:
Common Sense was preceded in death by his parents, Truth and Trust; his wife, Discretion; his daughter, Responsibility; and his son, Reason. He is survived by three stepbrothers; I Know My Rights, Someone Else is to Blame, and I'm A Victim.
I will throw a ‘common-sense’ idea back at you….
With regards the back-tracking for departure on 34. The area beyond the end of the runway is a fairly smooth piece of grass which had a considerable amount of hardcore placed down on it in the mid-90’s when a 146 went gardening. The efficacy of it was proven when a Dornier went the same way a couple of years ago – could not this perfectly good piece ground be considered as a suitable reject onto area/de-facto runway extension, thereby negating the need for the backtrack?
The request for a backtrack is another reason why crews may feel gaps are being missed – if a helicopter (or fixed-wing for that matter) is back-tracking we CANNOT allow a sectorised landing so it can lead to one needing a back-track having to wait for a longer time and with the lack of ‘cherry-picking’ opportunities I have already mentioned it may look like we are not being the most efficient we can be. (First thing in the morning we regularly send a back-track one to A4 for that reason but that option is largely closed off once inbounds start arriving)
ShyTorque
I don't work from ABZ but sometimes find myself more than a little bemused when I am given permission to hover taxy to line up on the runway then held in the hover for vortex wake reasons behind a departed fixed wing.
TTFD
Haven’t got any answers yet regarding Balmedie etc. However the question has been ‘escalated’.
DD
the 225 Cat A Operation Supplement says "takeoff and landing with tail wind are not permitted".
I think the reason for the statement in the Cat A supplement is that the graphs don't cater for tailwind, so its not possible to calculate climb gradient, obstacle clearance etc with a tailwind, something which is a fundamental element of a Cat A takeoff. Also it probably would not be too hard to get into a situation where the landing speed from a reject was over the RFM limit of 40kts. As usual, beurocratic correctness supercedes common sense, so they can't say "slight tailwind OK provided no obstacles" etc.
Data Dad - appreciate the point but Aberdeen is the primary location in the UK where large helis and FW mix - if the unthinking rules are going to get changed by pressure from any airport, it will be from Abz. Abz is not just a small provincial airport, its the UK capital of heli operations and should be a key player in setting the rules!
If the x-wind component is known, its relatively easy to determine how long it will take for a vortex to drift away more than the half-span of a FW from the edge of the runway since the vortex will be drifting with the wind. A few rules of thumb could be created with some safety margin if there was a will to do it. A good project for Helios when they have finished the Multilat analysis!
Regarding the over-run area, it might be feasible to use it but we would have to be certain that it could cope with 11 tonnes running on at 20kts or so without digging the wheels in / folding the noseleg. When a FW slithers past the end the worst case is gear folding / belly scraped. For a heli, its main rotors hitting the ground, breaking up and trashing anything or anyone in the vicinity.
HC
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ShyTorque
Quote:
Holding in a hover you are not actually flying through a ‘Wake’ – fixed wing Wake turbulence only starts being generated when the aircraft rotates which I assume would be someway beyond where you are holding.
Quote:
Holding in a hover you are not actually flying through a ‘Wake’ – fixed wing Wake turbulence only starts being generated when the aircraft rotates which I assume would be someway beyond where you are holding.
We hardly ever use the full runway length unless mandated by ATC for an IFR departure, which is rare. We usually use an intermediate access point for VFR/SVFR. We are therefore sometimes immediately adjacent to the airliner 'rotate' point for entry to the runway. Obviously, in such cases, I will ground taxy to line up, bearing in mind the wind velocity and likely path of the preceding wake.
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This has become a bit of a “bash the east side operators” forum. Where does your term “legal” come from? Is there an airport by-law that states thow shalt not take-off from abeam E4?
Correct me if I’m wrong but there is more than enough space departing 16 from E4
This has become a bit of a “bash the east side operators” forum. Where does your term “legal” come from? Is there an airport by-law that states thow shalt not take-off from abeam E4?
Correct me if I’m wrong but there is more than enough space departing 16 from E4
Training Centre:
Not sure how you can depart 16 from E4 - E4 being the holding point on the E taxiway leading up to H23 and the BMI hangar? In any case as has been mentioned the required take-off distances depend on aircraft type as well as procedures (some operators allow Class 2 procedures within their ops manual).
Also having operated on both the east and west side for a good number of years I am slightly surprised at what appears to be a bit of a grievance towards the east side operator by ABZ ATC for not being expeditions enough in clearing the runway?
As posted above, clearing down 18 or 32 is expeditious as it leaves plenty of distance to wash off speed and the aircraft can land behind the holding point to save time (you can even run it on across the holding point).
In contrast, to vacate at E2 or E3 a full 90+ degree turn is required. Regardless of whether the aircraft vacates in the hover or not it almost needs to come to a full stop to complete the landing profile before starting a turn. Dependant on aircraft type and wind conditions a crosswind hover can be too uncomfortable for passenger flights (or out of limits) and the aircraft needs to land on the runway. I’ve experienced a good number of approaches where pilots (both current and previous east side operators) tried to expeditiously fly round the corner towards E2 or E3 at speed which more often than not ended up in an uncomfortable situation.
I agree for an inexperienced pilot the above might take slightly longer but then the time is required and I will not compromise the safety of the aircraft. I will however always be as expeditious as possible under the circumstances and if I perceive an expeditious vacation? of the runway is required (we can usually tell by the voice) I have the option to take control of the aircraft if I think this will help matters.
Bottom line is that for an east side aircraft vacating at E2/E3 (regardless of operator) the time from crossing the threshold to vacating the runway will be longer in comparison to an aircraft vacating down 18 or 32. It would be an interesting experiment to give west side helicopters clearance to land 16 but vacate through the 23 instead of the 32 intersection, you would probably see a marked.
Finally I firmly believe we all (pilots and ATC) try to be as professional and expeditious as possible within the rules and regulations we are given and judging by radio calls this attracts mutual appreciation. However I would challenge the view that crews deliberately take their time when manoeuvring at the airport or that they lack the required skills. Communication is certainly key and as suggested we probably need more.
Not sure how you can depart 16 from E4 - E4 being the holding point on the E taxiway leading up to H23 and the BMI hangar? In any case as has been mentioned the required take-off distances depend on aircraft type as well as procedures (some operators allow Class 2 procedures within their ops manual).
Also having operated on both the east and west side for a good number of years I am slightly surprised at what appears to be a bit of a grievance towards the east side operator by ABZ ATC for not being expeditions enough in clearing the runway?
As posted above, clearing down 18 or 32 is expeditious as it leaves plenty of distance to wash off speed and the aircraft can land behind the holding point to save time (you can even run it on across the holding point).
In contrast, to vacate at E2 or E3 a full 90+ degree turn is required. Regardless of whether the aircraft vacates in the hover or not it almost needs to come to a full stop to complete the landing profile before starting a turn. Dependant on aircraft type and wind conditions a crosswind hover can be too uncomfortable for passenger flights (or out of limits) and the aircraft needs to land on the runway. I’ve experienced a good number of approaches where pilots (both current and previous east side operators) tried to expeditiously fly round the corner towards E2 or E3 at speed which more often than not ended up in an uncomfortable situation.
I agree for an inexperienced pilot the above might take slightly longer but then the time is required and I will not compromise the safety of the aircraft. I will however always be as expeditious as possible under the circumstances and if I perceive an expeditious vacation? of the runway is required (we can usually tell by the voice) I have the option to take control of the aircraft if I think this will help matters.
Bottom line is that for an east side aircraft vacating at E2/E3 (regardless of operator) the time from crossing the threshold to vacating the runway will be longer in comparison to an aircraft vacating down 18 or 32. It would be an interesting experiment to give west side helicopters clearance to land 16 but vacate through the 23 instead of the 32 intersection, you would probably see a marked.
Finally I firmly believe we all (pilots and ATC) try to be as professional and expeditious as possible within the rules and regulations we are given and judging by radio calls this attracts mutual appreciation. However I would challenge the view that crews deliberately take their time when manoeuvring at the airport or that they lack the required skills. Communication is certainly key and as suggested we probably need more.
Last edited by Woolf; 26th Feb 2010 at 07:29. Reason: Typo
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I am a Scotia Pilot. This thread is getting a bit silly to be honest.
We operate L2s to a cut-down performance solution giving us 2 take-off options that require either 505m or 800m of runway for ASDR (Accleration and Stop Distance Required). Ie the amount of prepared surface required following a failure of a critical power unit - right at the most critical point - just before TDP (Take-off decision point).
Thanks to Mr Eurocopter - neither profile takes account of the effect of headwind component so when the headwind component is strong we actually need less runway - but we just do not have data to support this.
Hence an experienced pilot may decide to go from C3/34 without a backtrack if he is light or has a strong headwind - but in doing so he is taking the risk upon himself.
As regards clearing the runways expeditiously - if we are trying to operate to tolerances that mean a poor Bond pilot struggling to turn downwind (as most of their runway clearances involve turning downwind in the prevailing Westerlies) - is been pressurised to get off the runway - then we are all expecting too much.
I like ATC and I have an enormous respect for them - BUT when a controller starts to question why a 10 ton helicopter can't get off the runway so he can rack something in behind then that respect gets eroded.
PUMAs hate been turned around in the wind, partly due to the autopilot fighting our inputs and mostly due to the fact that it is big slab sided beast that is designed to sit nose into the wind. I think I have around 8,500 hours on the beast in its various guieses now, am and I still treat this kind of descending, turning manouvre with the utmost of respect.
God knows how it must feel when you are an ex robo jockey who has a few hours on type trying to execute these kinds of manouvre.
Added to this - the manouvre one day works very nicely, and on another day, same conditions, the PUMA seems to grunt and groan and threaten to depart its nice controlled flight path all the way the ground.
In aviation we hammer in to ourselves that IF THERE IS DOUBT - THERE IS NO DOUBT.... this is why some pilots make a beautifull sweeping exit landing like a butterfly on the safe side of the stop line and others take a more cautious route. As experience grows we tend to "Listen" to what the machine is telling us and execute a more sympathetic manouvre with safety being the overiding consideration.
The bottom line is that the runway belongs to the landing aircraft UNTIL HE HAS SAFELY EXITED.
We operate L2s to a cut-down performance solution giving us 2 take-off options that require either 505m or 800m of runway for ASDR (Accleration and Stop Distance Required). Ie the amount of prepared surface required following a failure of a critical power unit - right at the most critical point - just before TDP (Take-off decision point).
Thanks to Mr Eurocopter - neither profile takes account of the effect of headwind component so when the headwind component is strong we actually need less runway - but we just do not have data to support this.
Hence an experienced pilot may decide to go from C3/34 without a backtrack if he is light or has a strong headwind - but in doing so he is taking the risk upon himself.
As regards clearing the runways expeditiously - if we are trying to operate to tolerances that mean a poor Bond pilot struggling to turn downwind (as most of their runway clearances involve turning downwind in the prevailing Westerlies) - is been pressurised to get off the runway - then we are all expecting too much.
I like ATC and I have an enormous respect for them - BUT when a controller starts to question why a 10 ton helicopter can't get off the runway so he can rack something in behind then that respect gets eroded.
PUMAs hate been turned around in the wind, partly due to the autopilot fighting our inputs and mostly due to the fact that it is big slab sided beast that is designed to sit nose into the wind. I think I have around 8,500 hours on the beast in its various guieses now, am and I still treat this kind of descending, turning manouvre with the utmost of respect.
God knows how it must feel when you are an ex robo jockey who has a few hours on type trying to execute these kinds of manouvre.
Added to this - the manouvre one day works very nicely, and on another day, same conditions, the PUMA seems to grunt and groan and threaten to depart its nice controlled flight path all the way the ground.
In aviation we hammer in to ourselves that IF THERE IS DOUBT - THERE IS NO DOUBT.... this is why some pilots make a beautifull sweeping exit landing like a butterfly on the safe side of the stop line and others take a more cautious route. As experience grows we tend to "Listen" to what the machine is telling us and execute a more sympathetic manouvre with safety being the overiding consideration.
The bottom line is that the runway belongs to the landing aircraft UNTIL HE HAS SAFELY EXITED.
DB
Have to disagree with you, I think this thread is quite good. Far better to have the gripes from ATC on E side operator's expeditiousness aired and explained with reasoned argument, ditto the gripes on wake separation discussed. Otherwise we all sit in our boxes moaning and feeling agrieved about the behaviour of others and getting wound up. Its all about communication!
Regarding your point on no data for wind effect on ASDR, this is surely incorrect? The 225 has figure 20 in the CAT A supplement to give wind effect, and although its a long time since I flew the L2 I am 99% certain there is the same info in its Supplements. Do you fly the L2 CAT A or Group A these days?
If there is a limitation not to allow for wind, this is a CHC limitation not a Eurocopter one.
I am aware that CHC decided to use only two of the many possibilities of Vtoss for takeoff profiles. I suspect this was legacy from the 332L which had 2 profiles, and Trainers introducing the L2 thought that pilots would struggle to cope with the 8 (?) possibilities in the Supplement. Its perhaps worth considering whether, whilst this was a non-issue when CHC was an E side operator, since the move its now too restrictive? Did you carry the same company restriction onto the 225?
When we introduced the 225 to Bristow it was decided to allow all the possible Vtoss choices (all 10 of them) since the profiles are the same, its just the numbers that change. After all, fixed wing pilots seem to manage with different V speeds for each takeoff, depending on weight etc.
For training we just distinguish between a Vtoss = Vy and a Vtoss < Vy since as you know the actions OEI at the end of the first segment climb are different in these two cases. We have never found this to cause a problem / issue in BHL.
This allows BHL pilots to choose an optimal Vtoss and possibly explains why CHC tend to backtrack for 34 more / further than BHL do (assuming that to be the case?)
Whilst it is of course up to CHC to decide how they want to operate their aircraft, perhaps its time for them to re-evaluate whether their current policy is optimal?
HC
Have to disagree with you, I think this thread is quite good. Far better to have the gripes from ATC on E side operator's expeditiousness aired and explained with reasoned argument, ditto the gripes on wake separation discussed. Otherwise we all sit in our boxes moaning and feeling agrieved about the behaviour of others and getting wound up. Its all about communication!
Regarding your point on no data for wind effect on ASDR, this is surely incorrect? The 225 has figure 20 in the CAT A supplement to give wind effect, and although its a long time since I flew the L2 I am 99% certain there is the same info in its Supplements. Do you fly the L2 CAT A or Group A these days?
If there is a limitation not to allow for wind, this is a CHC limitation not a Eurocopter one.
I am aware that CHC decided to use only two of the many possibilities of Vtoss for takeoff profiles. I suspect this was legacy from the 332L which had 2 profiles, and Trainers introducing the L2 thought that pilots would struggle to cope with the 8 (?) possibilities in the Supplement. Its perhaps worth considering whether, whilst this was a non-issue when CHC was an E side operator, since the move its now too restrictive? Did you carry the same company restriction onto the 225?
When we introduced the 225 to Bristow it was decided to allow all the possible Vtoss choices (all 10 of them) since the profiles are the same, its just the numbers that change. After all, fixed wing pilots seem to manage with different V speeds for each takeoff, depending on weight etc.
For training we just distinguish between a Vtoss = Vy and a Vtoss < Vy since as you know the actions OEI at the end of the first segment climb are different in these two cases. We have never found this to cause a problem / issue in BHL.
This allows BHL pilots to choose an optimal Vtoss and possibly explains why CHC tend to backtrack for 34 more / further than BHL do (assuming that to be the case?)
Whilst it is of course up to CHC to decide how they want to operate their aircraft, perhaps its time for them to re-evaluate whether their current policy is optimal?
HC