Elevated Helipads
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Helipad takeoff!
I have just seen the helipad profile for the EC155. Anyone else seen it yet? It involves a 500fpm vertical (possibly sidewards to retain sight of pad) climb to 100ft, then rotate (TDP).
Any failure before TDP involves a vertical (possibly slightly sideways?) descent back to the pad.
Is it just my tainted view as someone who has used and appreciated a differing slower backward climb that leads me to believe this new method is boll....not so good. You know forward motion, feel the burble of translational lift, reduced power, clear view of pad ahead. It appears now a vertical descent zero airspeed (vortex ring?) poor references plummet is the approved method?
Am I missing something here? Or is the world going mad?
Any failure before TDP involves a vertical (possibly slightly sideways?) descent back to the pad.
Is it just my tainted view as someone who has used and appreciated a differing slower backward climb that leads me to believe this new method is boll....not so good. You know forward motion, feel the burble of translational lift, reduced power, clear view of pad ahead. It appears now a vertical descent zero airspeed (vortex ring?) poor references plummet is the approved method?
Am I missing something here? Or is the world going mad?
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Often wondered myself??
This sounds very similar to the helipad profile flown on the EC135 and I have pondered this very point myself.
I can see clear advantages to the 'old' method but the vertical method does make me feel slightly more anxious during take off for the reasons you have cited.......take care, Zap
I can see clear advantages to the 'old' method but the vertical method does make me feel slightly more anxious during take off for the reasons you have cited.......take care, Zap
My only thought is that if the 155 has a good single engine power margin then although the verticle reject might be bottom clenchingly interesting, the rate of descent should be under control. The huge benefit will be the absence of the rearward take off distance that traditional helipad departures require.
TeeS
TeeS
The EC135 doesn't have a vertical profile culminating in an engine failure pre TDP vertically back down again
I suspect neither does the 155. IF the profile referred to is a CONFINED HELIPORT departure, then the helo climbs to 100' vertically (120' for the 135), it then rotates and transitions from there into forward speed. However, should the donk stop, then there is a MINIMUM requirement of 75metres landing space required within which the rejected takeoff profile can be accomodated.
I suspect neither does the 155. IF the profile referred to is a CONFINED HELIPORT departure, then the helo climbs to 100' vertically (120' for the 135), it then rotates and transitions from there into forward speed. However, should the donk stop, then there is a MINIMUM requirement of 75metres landing space required within which the rejected takeoff profile can be accomodated.
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Take-off from ground Helipad
The profile I refer to is described as "Take-off fom ground helipad", which I assume is not a confined area or one having 75m or so ahead. Indeed neither of these features are mentioned in the description of the profile.
Judging by other performance parameters for the 155, the weights per profile are pushed to the limits, so much so that use of electronics seems to be the only way to guarantee required climb rates. Therefore I assume again, single engine performance will not be great and a reasonably buttock clenching rate of descent will ensue.
I am looking for the benefits of this profile over an up and back, are there any?
Regardless of single engine performance surely forward motion can only help power margins with translational lift! Most of all though references in front of me are far more comforting than those barely if at all visible below.
Judging by other performance parameters for the 155, the weights per profile are pushed to the limits, so much so that use of electronics seems to be the only way to guarantee required climb rates. Therefore I assume again, single engine performance will not be great and a reasonably buttock clenching rate of descent will ensue.
I am looking for the benefits of this profile over an up and back, are there any?
Regardless of single engine performance surely forward motion can only help power margins with translational lift! Most of all though references in front of me are far more comforting than those barely if at all visible below.
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Madness !!
These profiles make a whole load of sense ... yea right !!
Oh yes that's right - IF the mechanical problem you have happens to be an engine then you can theoretically land back on.
Anyone remember any basic principles of flight?
How many occurances of one engine failing during one of these profiles have there ever been? Anyone got actual numbers for this? Has there ever even been one?
Oh yes that's right - IF the mechanical problem you have happens to be an engine then you can theoretically land back on.
Anyone remember any basic principles of flight?
How many occurances of one engine failing during one of these profiles have there ever been? Anyone got actual numbers for this? Has there ever even been one?
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Is the data you are quoting from "approved" or "manufacturers data". There is a big difference. Is this approved flight manual info?
This procedure in the A109E involves a back up with the pad in site to 85' to TDP. Failure prior to TDP is to aim the helicopter at the pad and defend your rotor RPM. At high weights you will see a chevron in the AI at about 15 degrees nose down.
After TDP you may of course descend to within 35' of the departure height i.e. lose 50' getting to VTOSS.
Of course the 109 is a Part 27 aircraft and hence is only Cat A "similar" performance. Cat A only applies to Part 29 Transport Category aircraft.
I don't believe you are reading all the correct data that is available.
Fill us in on the rest.
This procedure in the A109E involves a back up with the pad in site to 85' to TDP. Failure prior to TDP is to aim the helicopter at the pad and defend your rotor RPM. At high weights you will see a chevron in the AI at about 15 degrees nose down.
After TDP you may of course descend to within 35' of the departure height i.e. lose 50' getting to VTOSS.
Of course the 109 is a Part 27 aircraft and hence is only Cat A "similar" performance. Cat A only applies to Part 29 Transport Category aircraft.
I don't believe you are reading all the correct data that is available.
Fill us in on the rest.
In answer to QMax's question, I know of at least one incident. Not technically an engine failure, but the HEMS air ambulance in London was in the midst of a Helipad take-off a few years back, when they realised in their haste to win medals, they had forgotten to start one of the engines ! Being in the centre of the East End of London, and on a roof-top helipad, in a fairly underpowered Dauphin, I am sure the ability to go visually forward and down to the helipad assisted with the whole recovery to Mother Earth !
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Special 25 ... Classic !
... of course THAT couldn't happen in a single
But seriously has anyone ever heard of anyone ever benefitting from that ridiculous 'reversing upwards' manoever ?
But seriously has anyone ever heard of anyone ever benefitting from that ridiculous 'reversing upwards' manoever ?
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Special 25
I think you'll find that your story is not quite right. Both of the engines were in fact running, but due to a breakdown in CRM (possibly caused by a bit of personal animosity between the 2 pilots), one of the engines was at ground idle and was rapidly advanced to the flight gate when the crew realised their mistake. HEMS subsequently ceased operations for a few days whilst they carried out a review of their procedures.
I think you'll find that your story is not quite right. Both of the engines were in fact running, but due to a breakdown in CRM (possibly caused by a bit of personal animosity between the 2 pilots), one of the engines was at ground idle and was rapidly advanced to the flight gate when the crew realised their mistake. HEMS subsequently ceased operations for a few days whilst they carried out a review of their procedures.
Qmax: what are you on about
These profiles are designed around engine failure, they are calculated to provide for a recovery from an ENGINE FAILURE!
They are NOT designed for other malfunctions - no one can build in a design for every single malfunction - can they?
Going up and back is the best way of securing a safe landing in the event of an engine failure during takeoff, because (a) you've just flown that route, and (b) you know that the landing site will accept you! Thats why it has been designed as such. If you simply transition fwd, then you don't know what the landing site will be like when you touch down from an engine failure, do you? And you'll have less control over your fwd speed before you hit the deck.
Do you think someone simply 'took a fancy' to designing a peculiar launch profile for the fun of it???
If an engine is going to stop, may I suggest the best time for it to fail, is during the take off, when pressures and temperatures are high and low respectively.
These profiles are designed around engine failure, they are calculated to provide for a recovery from an ENGINE FAILURE!
They are NOT designed for other malfunctions - no one can build in a design for every single malfunction - can they?
Going up and back is the best way of securing a safe landing in the event of an engine failure during takeoff, because (a) you've just flown that route, and (b) you know that the landing site will accept you! Thats why it has been designed as such. If you simply transition fwd, then you don't know what the landing site will be like when you touch down from an engine failure, do you? And you'll have less control over your fwd speed before you hit the deck.
Do you think someone simply 'took a fancy' to designing a peculiar launch profile for the fun of it???
If an engine is going to stop, may I suggest the best time for it to fail, is during the take off, when pressures and temperatures are high and low respectively.
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TC - 'religious fundamentalist'
.... sure I understand the principal.
But has it ever been of use?
How many examples of an engine failing in this narrow time window have there ever been?
Can you name an example?
Any?
How many up****s have there been as a result of this dogmatic approach? (probably several!)
In fact there's one in a 355 on the AIDS data base where the tail rotor failure would (IMHO) not have been a problem if they had speed. - There are many ways to skin a CAT. To deliberately prolong such an energy inefficient state of flight - in the process exposing the A/C to other vunerabilities - on the off-chance that a favorable theoretical chain of events might occur is obviously mad.
TC: there are millions people who believe that banging their head against a wall till it bleeds has religious merit. - very difficult to change their minds, they do it because they were raised that way (i guess) - you're not one of those are you?
But has it ever been of use?
How many examples of an engine failing in this narrow time window have there ever been?
Can you name an example?
Any?
How many up****s have there been as a result of this dogmatic approach? (probably several!)
In fact there's one in a 355 on the AIDS data base where the tail rotor failure would (IMHO) not have been a problem if they had speed. - There are many ways to skin a CAT. To deliberately prolong such an energy inefficient state of flight - in the process exposing the A/C to other vunerabilities - on the off-chance that a favorable theoretical chain of events might occur is obviously mad.
TC: there are millions people who believe that banging their head against a wall till it bleeds has religious merit. - very difficult to change their minds, they do it because they were raised that way (i guess) - you're not one of those are you?
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To Delta free
The Dauphin profile goes to 130 feet for whatever reason, 'H' in the chin bubble, and in training works fine. Having said that I wouldn't like to lose a donk at max Cat A loads ISA ++, in between the pad and CDP - I think it would be interesting.
The Dauphin profile goes to 130 feet for whatever reason, 'H' in the chin bubble, and in training works fine. Having said that I wouldn't like to lose a donk at max Cat A loads ISA ++, in between the pad and CDP - I think it would be interesting.
Q Max - yes I had to make use of the full procedure and reject back to the spot several years ago. It actually wasn't an engine failure but a transient surge caused by a biscuit wrapper sucked into the number one engine. I have to confess that at the time it happened I did not have a clue what it was, there was just a bang, a fierce judder and when I looked down all the engine indications were normal. At that moment I was just very glad that I still had the aiming point in the chin window just where it was in all the base checks. I know that both engines were still running but the power required was very low and I am confident that we would have been OK single engine.
It was a very very tight site in the middle of Birmingham with nowhere else to go - In the circumstances we could have flown away quite happily but that was knowledge only gained during the post incident engine inspection. If the engine had failed for real we would have ended up on the railway line if we had not flown the procedure.
Cheers
TeeS
It was a very very tight site in the middle of Birmingham with nowhere else to go - In the circumstances we could have flown away quite happily but that was knowledge only gained during the post incident engine inspection. If the engine had failed for real we would have ended up on the railway line if we had not flown the procedure.
Cheers
TeeS
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Category A procedures are based on trying to achieve a level of safety that is predicated on engine failure probability. Currently the expected failure rate of an engine is once every 10,000 hours. So for Part 29 helicopters (and those Part 27 machines that decide to use Category A), something has to be done to ensure the level of safety is met. Body counts of more than 9 get civil aviation authority leaders (ministers, administrators, etc) in hot water, so the end result is the Category A procedure.
It does not address everything, and someone said, no procedure can.
The Category A procedures in the FM are tested and proven by the company and the certification authority in the country of certification. In some places, the certification authority in the country of use will verify them. They are generally conservative and give margin for error and abuse. The procedures must be read in conjunction with the appropriate limitations of the supplement / section of the FM. If it says there is a size limit on the helipad, then that's a limit.
Have an accident doing a Category A procedure to a helipad that is smaller than the minimum, and you have just invalidated your Cof A and your insurance.
As for the backward takeoff - has anyone looked at the Bell Helicopter sideways slide technique? Easy to use, little loss of performance and very repeatable. Also much easier on the passengers...
It does not address everything, and someone said, no procedure can.
The Category A procedures in the FM are tested and proven by the company and the certification authority in the country of certification. In some places, the certification authority in the country of use will verify them. They are generally conservative and give margin for error and abuse. The procedures must be read in conjunction with the appropriate limitations of the supplement / section of the FM. If it says there is a size limit on the helipad, then that's a limit.
Have an accident doing a Category A procedure to a helipad that is smaller than the minimum, and you have just invalidated your Cof A and your insurance.
As for the backward takeoff - has anyone looked at the Bell Helicopter sideways slide technique? Easy to use, little loss of performance and very repeatable. Also much easier on the passengers...
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DGAC Approved
The vertical profile for the 155 is taken from the FM and marked DGAC approved so should be CAA approved with little or no changes.
I feel happy with the up and back procedure I have practised before, but am still inviting anyone to sell me the advantages of this vertical profile. Yes yes I know it is tried and tested, but what are the benefits? I may be missing something obvious not having tried it. I await my education.
I feel happy with the up and back procedure I have practised before, but am still inviting anyone to sell me the advantages of this vertical profile. Yes yes I know it is tried and tested, but what are the benefits? I may be missing something obvious not having tried it. I await my education.
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DeltaFree,
Maybe this procedure is all the aircraft is capable of demonstrating. If you do the "backup" manouevre it won't get back to the pad. It would sound that it is possibly of little benefit but it is there. Is there not another page in the manual which refers to this procedure like the "corrected weight" pages often found in Eurocopter flight manuals.
It is difficult to understand your concerns without information as to how the procedure is determined.
On the original Puma all this procedure was based on pitch angle and timing there being few other usable cues to the pilot.
The procedures for the Cat A vertical can differ from type to type and are not "generic". They are published in the flight manual. It would be interesting for you to post the useful load that is claimed for this procedure at say S/L ISA+10.
Maybe EC have not developed a procedure as yet. I know for a fact that the certified envelope has not yet been extended to the true capabilities of the aircraft. There is a 155B1 in the wings.
Maybe this procedure is all the aircraft is capable of demonstrating. If you do the "backup" manouevre it won't get back to the pad. It would sound that it is possibly of little benefit but it is there. Is there not another page in the manual which refers to this procedure like the "corrected weight" pages often found in Eurocopter flight manuals.
It is difficult to understand your concerns without information as to how the procedure is determined.
On the original Puma all this procedure was based on pitch angle and timing there being few other usable cues to the pilot.
The procedures for the Cat A vertical can differ from type to type and are not "generic". They are published in the flight manual. It would be interesting for you to post the useful load that is claimed for this procedure at say S/L ISA+10.
Maybe EC have not developed a procedure as yet. I know for a fact that the certified envelope has not yet been extended to the true capabilities of the aircraft. There is a 155B1 in the wings.
Delta Free
The current short field/helipad profiles require either a good clear run on area in front or a clear gradient behind, all fine and good for a pre-planned hospital site (if you can get them to give up the parking spaces!) or nice hotel helipad. However what about landing at HEMS sites etc. where a traditional helipad profile can't be flown because of surrounding lamps and buildings.
Surely, if the test pilots have come up with a vertical profile that we mere mortals can cope with and the aviation authorities are happy then it must be better to have that profile available. Lets face it once you have loaded your patient onboard, if the only way out is straight up then that is the way you are going to go. At least if there is an appropriate profile you will have practiced it and have a pre-planned decision point, that has got to improve your chances if you are the unlucky 1 in 10000.
TeeS
The current short field/helipad profiles require either a good clear run on area in front or a clear gradient behind, all fine and good for a pre-planned hospital site (if you can get them to give up the parking spaces!) or nice hotel helipad. However what about landing at HEMS sites etc. where a traditional helipad profile can't be flown because of surrounding lamps and buildings.
Surely, if the test pilots have come up with a vertical profile that we mere mortals can cope with and the aviation authorities are happy then it must be better to have that profile available. Lets face it once you have loaded your patient onboard, if the only way out is straight up then that is the way you are going to go. At least if there is an appropriate profile you will have practiced it and have a pre-planned decision point, that has got to improve your chances if you are the unlucky 1 in 10000.
TeeS