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Thread: Helicopters

  1. #21
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    Quote Originally Posted by Gregor-y
    'Commercial viability' such as it is is what's been stagnating the industry for forty years.
    And the alternative to that is what, exactly?

  2. #22
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    Quote Originally Posted by BDunnell
    Extra safety margin conferred by having two engines.
    Commerical single engine operation is forbidden in the EU for both fixed wing and helicopters in IFR (Instrument Flight Rules) conditions known as IMC (Instrument Meteorological Conditions), as opposed to VFR (Visual Flight Rules)

    The majority of London is classified as Class A restricted airspace, which can only be entered with a clearance from one of the relevant Air Traffic Service Units (ATSU), and while under the direction of the ATSU, a pilot may be instructed to follow vectors which could take him into IMC conditions. Therefore to enter class A airspace, it is a requisite that the pilot has the relevant IMC qualifications, or enters the Class A airspace under a Special VFR clearance.

    Additionally, Rule 5 of the rules of the air states that pilots need to remain a minimum of 500ft clear of any person, vehicle, vessel or structure. They must also ensure not to fly so low that in the event of an engine faliure, they cannot glide clear.

    Those are the basic outlines, and there's more too it than that.

    So that should explain why the river is a favoured route, and that single engine helicopters would be able to ditch in an emergency in the river, where the twins would still manage to fly on one engine.

    So, you can see from the above that wandering through London's airspace in a single engine light aircraft with no radio would break a lot of the above rules, and those you do see flying in that area are usually highly quailified and experienced.

    I have once flown through the VFR corridor in a Beech Musketeer to the north of the London Class A airspace, and south of Luton's zone, and it gets very busy!
    Adventure without risk is Disneyland.

  3. #23
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    you couldnt do it vertically as you couldnt bleed off your speed at the end. thats why you follow a slop so you can flare the aircraft to stop at the end.

  4. #24
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    Quote Originally Posted by Kneeslider
    Commerical single engine operation is forbidden in the EU for both fixed wing and helicopters in IFR (Instrument Flight Rules) conditions known as IMC (Instrument Meteorological Conditions), as opposed to VFR (Visual Flight Rules)

    The majority of London is classified as Class A restricted airspace, which can only be entered with a clearance from one of the relevant Air Traffic Service Units (ATSU), and while under the direction of the ATSU, a pilot may be instructed to follow vectors which could take him into IMC conditions. Therefore to enter class A airspace, it is a requisite that the pilot has the relevant IMC qualifications, or enters the Class A airspace under a Special VFR clearance.

    Additionally, Rule 5 of the rules of the air states that pilots need to remain a minimum of 500ft clear of any person, vehicle, vessel or structure. They must also ensure not to fly so low that in the event of an engine faliure, they cannot glide clear.

    Those are the basic outlines, and there's more too it than that.

    So that should explain why the river is a favoured route, and that single engine helicopters would be able to ditch in an emergency in the river, where the twins would still manage to fly on one engine.

    So, you can see from the above that wandering through London's airspace in a single engine light aircraft with no radio would break a lot of the above rules, and those you do see flying in that area are usually highly quailified and experienced.

    I have once flown through the VFR corridor in a Beech Musketeer to the north of the London Class A airspace, and south of Luton's zone, and it gets very busy!
    Indeed. It must be noted that the helicopter involved in the accident was operating either VFR or Special VFR — exactly which will no doubt be confirmed in the report. So too, I'm sure, will be the nature of the flight which required it to be made in what would seem to have been decidedly marginal weather en route.

  5. #25
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    Quote Originally Posted by BDunnell
    Indeed. It must be noted that the helicopter involved in the accident was operating either VFR or Special VFR — exactly which will no doubt be confirmed in the report. So too, I'm sure, will be the nature of the flight which required it to be made in what would seem to have been decidedly marginal weather en route.
    Fair point.

    There can be no VFR flight inside class A airspace, that is the principle defining characteristic of this type of airspace compared to the 'normal' class D zones which exist around most of the UK's commercial airports. Regardless of the meteorological conditions (IMC, or VMC) you cannot fly VFR (visual flight rules) within a class A airspace.

    The Helicopter in question a Bell Agusta 109 is a twin engine design, and would be equipped for full IFR flight.

    The NOTAM (NOtice To AirMen) for the crane which it hit is here:-

    Q) EGTT/QOBCE/IV/M/AE/000/008/5129N00008W001
    B) FROM: 13/01/16 15:30C) TO: 13/01/24 09:00 EST
    E) HIGH RISE JIB CRANE (NOT LIT) OPER WI 1NM 512903N 0000745W HGT 770FT
    AMSL (VAUXHALL, CENTRAL LONDON). OPS CTC 02078203151. 12-10-0429/AS 2

    Notice that it is notified that it is not lit (though this was after the accident).

    It wil be interesting to look in the Air Accident Investigation Report which will be issued in a few months.
    Adventure without risk is Disneyland.

  6. #26
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    Quote Originally Posted by Kneeslider
    There can be no VFR flight inside class A airspace, that is the principle defining characteristic of this type of airspace compared to the 'normal' class D zones which exist around most of the UK's commercial airports. Regardless of the meteorological conditions (IMC, or VMC) you cannot fly VFR (visual flight rules) within a class A airspace.

    The Helicopter in question a Bell Agusta 109 is a twin engine design, and would be equipped for full IFR flight.
    Helicopters may operate within the London control zone under SVFR conditions. I am very much under the impression that this was the case regarding the accident flight. I would imagine that this provision will be one focus of the investigation, given the conditions then prevailing.

    Quote Originally Posted by Kneeslider
    The NOTAM (NOtice To AirMen) for the crane which it hit is here:-

    Q) EGTT/QOBCE/IV/M/AE/000/008/5129N00008W001
    B) FROM: 13/01/16 15:30C) TO: 13/01/24 09:00 EST
    E) HIGH RISE JIB CRANE (NOT LIT) OPER WI 1NM 512903N 0000745W HGT 770FT
    AMSL (VAUXHALL, CENTRAL LONDON). OPS CTC 02078203151. 12-10-0429/AS 2

    Notice that it is notified that it is not lit (though this was after the accident).
    Would a light of any colour have been much use given that the top of the crane appeared, at least in images taken shortly after the accident, to have been in cloud?

  7. #27
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    Sorry, bit of a misunderstanding...

    SVFR isn't VFR from a legal standpoint... The two are seperate things. SVFR is what allows people with no IMC qualification into class A airspace.

    Complicated, isn't it?

    You are right, I would expect the helicopter to be operating SVFR and to have lost sight of the crane in cloud, and having to fly low to maintain visual contact with the ground, which is a requisite for SVFR operation.

    I doubt that any sort of lighting on the crane would have done any good.

    The only answer would have been to fly the whole flight IFR which would require a flight plan, and then the ATSU would have been able to give a clearance to ascend vertically to a point where the helicopter would have been visible on radar, then in IMC, and under direction from the ATSU to maintain seperation from other aircraft and obstacles.

    I'm not IFR or IMC qualified, the person to ask here about such things is Daniel aka Gannex, he used to be an instructor supervising transition between military and civil roles in the US.
    Adventure without risk is Disneyland.

  8. #28
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    Quote Originally Posted by Kneeslider
    Sorry, bit of a misunderstanding...

    SVFR isn't VFR from a legal standpoint... The two are seperate things. SVFR is what allows people with no IMC qualification into class A airspace.
    My apologies — I thought you were including SVFR in your previous comments.

    Without wishing to speculate unduly, would you question the manner in which — hypothetically, and as a general point — a pilot operating under SVFR could find themselves in a situation where they're fairly low over a built-up area in such weather conditions as would appear to have been prevailing at the time of the accident?

  9. #29
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    While in the military I was involved in a helicopter incident, and it was the first time I had every been in a helicopter. We witnessed another incident where a gunship and a UH-1 struck rotors slightly when helocasting. Scary stuff.

    Unfortunately several years later an acquaintance of mine lost his life during an accident at sea when striking a ship and they went into the water.

  10. #30
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    Interim — must stress that word — report now published.

    Air Accidents Investigation: S1/2013 - Agusta A109E, G-CRST

    Very interesting reading, even without any conclusions being reached at this early stage.

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