AW139 G-LBAL helicopter crash in Gillingham, Norfolk
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The term RVR implies that a runway is available and an RVR measurement system is in place. Unfortunately, neither are available at most private HLSs.
The commander is therefore left to decide whether the departure can be safely made, all factors considered. The commander of a private flight, as this was, has the option of not using the performance class departure profiles.
The commander is therefore left to decide whether the departure can be safely made, all factors considered. The commander of a private flight, as this was, has the option of not using the performance class departure profiles.
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SND
Ah I see, I thought you meant they had a legal get out, as in that they were ok to go - but understand you mean legal get out as in not to go with respect the owner !
Sorry to say, but I think that ANO article only applies if the RVR is reported. It is not assessable by crews. In UK, Runway visual range is usually assessed electronically, or otherwise by the human observer method in accordance with CAP493 or CAP168. No runway, no RVR report - then 109(2)(b) does not apply in my view.
For instance, at an airport, if RVR is not reported, only met viz, there is no restriction as far as this article is concerned. The same applies to approach minima, there is no approach ban for met visibility, only for RVR.
The list of factors is certainly worth a mention, it helps to enlighten and hopefully prevent reoccurrence.
One thing we can be sure of, a similar accident will occur again. If we can reduce the frequency, then there's progress. I'm sure that's one of the aims here.
Ah I see, I thought you meant they had a legal get out, as in that they were ok to go - but understand you mean legal get out as in not to go with respect the owner !
Sorry to say, but I think that ANO article only applies if the RVR is reported. It is not assessable by crews. In UK, Runway visual range is usually assessed electronically, or otherwise by the human observer method in accordance with CAP493 or CAP168. No runway, no RVR report - then 109(2)(b) does not apply in my view.
For instance, at an airport, if RVR is not reported, only met viz, there is no restriction as far as this article is concerned. The same applies to approach minima, there is no approach ban for met visibility, only for RVR.
The list of factors is certainly worth a mention, it helps to enlighten and hopefully prevent reoccurrence.
One thing we can be sure of, a similar accident will occur again. If we can reduce the frequency, then there's progress. I'm sure that's one of the aims here.
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Actually the response is fairly simple;
"I couldn't legally take off from an equipped airfield, therefore I can't legally or safely take off from this garden"
No matter what the owner says/does the pilot is covered, I know the risks of being jobless, but at least if you can provide yourself with irrefutable evidence then he will think twice as you the pilot are less likely to take his threats.
SND
"I couldn't legally take off from an equipped airfield, therefore I can't legally or safely take off from this garden"
No matter what the owner says/does the pilot is covered, I know the risks of being jobless, but at least if you can provide yourself with irrefutable evidence then he will think twice as you the pilot are less likely to take his threats.
SND
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The ANO provides the answer to a pushy passenger.
Section 10, Article 87.
Words along the lines of "My apologies but as commander of the aircraft, in my opinion the flight cannot be safely made" is all that is needed.
I'd willingly go to court or to any employment tribunal having said that.
I have had cause to say it in the past, thankfully very infrequently and I've not had to take it any further. I have walked away from the aircraft though.....
Section 10, Article 87.
Words along the lines of "My apologies but as commander of the aircraft, in my opinion the flight cannot be safely made" is all that is needed.
I'd willingly go to court or to any employment tribunal having said that.
I have had cause to say it in the past, thankfully very infrequently and I've not had to take it any further. I have walked away from the aircraft though.....
The following is not a comment on the accident - which is the subject of this thread - but a response to the many posts stating how a 'safe' departure 'could have been achieved'.
It is some time since I delved into the ANO but, with respect to commercial operations (not applicable here of course), visibility can be used in most aspects of approach/departure as follows:
The approval to apply the reduced minima for a low visibility take-off - i.e. an RVR of less than 400m - requires an approval in accordance with a set of stringent requirements specified in the regulations. These were originally in JAR-OPS but have been transposed to EASA OPS (and they remain virtually the same). Because application of low visibility take-off procedures require that the LVPs be in force, they appear to be available only to aerodromes which can apply such procedures (leaving out such as Den Helder which, I am told, 'cannot' qualify).
Providing AWO approvals for private operations in the UK was always problematical because there was no (specified) criteria by which the approval could be assessed - unless it was in accordance with commercial practices. There was also no structure for reimbursement of costs although Shell Aircraft did manage to have their AWO operations approved.
Applying the intent of such procedures to a private location is impractical, in my view, and any take-off should have been to the VFR limits applicable at the time - maintaining visual contact. A similar situation obtains with performance - whilst a Cat A procedure could be used at such locations, the notion that it provides any guarantee is not sustainable (unless tailored to the data collected in a site survey).
The operation of complex helicopters in passenger operations (even though they may be private) should demand the highest standard. These should not be the subject of invention of procedures, or adoption of military practices. They deserve better - in fact they deserve the application of the highest standards; if those standards are those for commercial air transport, that then should be the aspiration of the operator - whoever that might be.
Jim
It is some time since I delved into the ANO but, with respect to commercial operations (not applicable here of course), visibility can be used in most aspects of approach/departure as follows:
Where RVR is not available, RVR values may be derived by converting the reported visibility in accordance with Appendix 1 to JAR-OPS 3.430, sub-paragraph (h).
Providing AWO approvals for private operations in the UK was always problematical because there was no (specified) criteria by which the approval could be assessed - unless it was in accordance with commercial practices. There was also no structure for reimbursement of costs although Shell Aircraft did manage to have their AWO operations approved.
Applying the intent of such procedures to a private location is impractical, in my view, and any take-off should have been to the VFR limits applicable at the time - maintaining visual contact. A similar situation obtains with performance - whilst a Cat A procedure could be used at such locations, the notion that it provides any guarantee is not sustainable (unless tailored to the data collected in a site survey).
The operation of complex helicopters in passenger operations (even though they may be private) should demand the highest standard. These should not be the subject of invention of procedures, or adoption of military practices. They deserve better - in fact they deserve the application of the highest standards; if those standards are those for commercial air transport, that then should be the aspiration of the operator - whoever that might be.
Jim
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Problem is, Jim, some owners do not want to comply with PT criteria. Instead, they just want the flight to take place. Been there, seen it. I was once "investigated" by an external auditor for daring to delay a flight for ten minutes whilst checking if an IFR alternative was available before departing a private site in marginal met conditions, to another private site.
I don't work there now.....
I don't work there now.....
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SND
I entirely agree, but have found the more specific one can be, the better the pax understands and co-operates.
Jim L
Agreed, the pax need to be educated re safety standards - easier said than done.
The problem here is if you say it should be VFR minima for departure and pax says "why? we've been doing this for years" - it's best if you can be more specific, otherwise it can be seen as just a difference of opinions ..
For info - the table you refer to in (h) which is (table 6) is not for departure.
1.430 a.3.(iv) "Table 6 below, for converting reported meteorological visibility to RVR, must not be used for calculating take-off minima."
Shytorque
I can second that .. too many owners just want the trip completed ....
I entirely agree, but have found the more specific one can be, the better the pax understands and co-operates.
Jim L
Agreed, the pax need to be educated re safety standards - easier said than done.
The problem here is if you say it should be VFR minima for departure and pax says "why? we've been doing this for years" - it's best if you can be more specific, otherwise it can be seen as just a difference of opinions ..
For info - the table you refer to in (h) which is (table 6) is not for departure.
1.430 a.3.(iv) "Table 6 below, for converting reported meteorological visibility to RVR, must not be used for calculating take-off minima."
Shytorque
I can second that .. too many owners just want the trip completed ....
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Just a general question about the AW139 and its autopilot. If you were going to do an IF departure which required a vertical climb (just say you were going to go from zero vis as in this case), does the aircraft have an attitude hold so all the pilot had to do was pull up smoothly on the collective to high power and the attitude and heading would remain the same, so conducting a safe vertical climb?
If it did, then apart from the (IMHO) inherent risk of departing in fog at night, trying to over-ride the autopilot by hand flying it does seem to indicate a lack of awareness of aircraft system and a waste of a four axis system.
If it did, then apart from the (IMHO) inherent risk of departing in fog at night, trying to over-ride the autopilot by hand flying it does seem to indicate a lack of awareness of aircraft system and a waste of a four axis system.
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Sunnywa:
Depending on configuration, the AW139 could perform such a maneuver.
I have difficulty, however, in reconciling using such a procedure into what has been described as IMC conditions.
Vmini is 50kts. That limitation is found in the mandatory Section 1 of the RFM.
Depending on configuration, the AW139 could perform such a maneuver.
I have difficulty, however, in reconciling using such a procedure into what has been described as IMC conditions.
Vmini is 50kts. That limitation is found in the mandatory Section 1 of the RFM.
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Sunnywa, how high would you suggest a pilot might climb vertically with no visual references and no airspeed?
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how high would you suggest a pilot might climb vertically with no visual references and no airspeed?
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High enough to clear any ground obstructions before attempting vmini.
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You don't understand VMinI, do you?
However that would be a suitable profile when you can see where you are going. Not much point in trying for 50 kts before climbing if you have obstacles you can not see though is it?
So although we may all agree this flight should should not have happened, had the pilot simply climbed on AP and left the stick alone until two hundred feet or so then looked for 50 kts (or vmini) the outcome may have been very different.
Just my opinion.
Last edited by chopjock; 13th Apr 2014 at 12:40.
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Now we get back to reality.
We have take off Vis requirements to remain VMC.
We have VminI.
We have Take Off Profiles.
We have a four Axis Auto Pilot.
We have another bunch of Rules that are pretty lax when it comes to private operations.
We have stringent Rules that apply to on Airport Operations.
We have stringent Rules that apply to Public Transport.
We have Insurance requirements.
We have all sorts of Rules including the dreaded Rule 5.
Question: Does VminI apply to coupled Autopilot flight only or to any use of the Autopilot system? If you elect to use only the "Attitude" hold function, must you only do that at or above VminI?
For those of you that clearly know about VminI, perhaps you might educate the "unknowing" of exactly what that magic speed is ALL about.
I am willing to bet there are some huge misconceptions about the 139 and its VminI of 50 Knots.
Which one of you cares to prove you know what you are talking about?
We have take off Vis requirements to remain VMC.
We have VminI.
We have Take Off Profiles.
We have a four Axis Auto Pilot.
We have another bunch of Rules that are pretty lax when it comes to private operations.
We have stringent Rules that apply to on Airport Operations.
We have stringent Rules that apply to Public Transport.
We have Insurance requirements.
We have all sorts of Rules including the dreaded Rule 5.
Question: Does VminI apply to coupled Autopilot flight only or to any use of the Autopilot system? If you elect to use only the "Attitude" hold function, must you only do that at or above VminI?
For those of you that clearly know about VminI, perhaps you might educate the "unknowing" of exactly what that magic speed is ALL about.
I am willing to bet there are some huge misconceptions about the 139 and its VminI of 50 Knots.
Which one of you cares to prove you know what you are talking about?
Vmini is the speed, in accordance with RFM limitation, that must be achieved before the pilot can enter IMC (which, as has been explained before, might, or might not, be a requirement - as, for example, it is in the US under Part 91.9(a)); there is also an implication that, before Vmini is achieved, visual references must be available to maintain control of flight.
Jim
Jim
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We have VminI.
I am willing to bet there are some huge misconceptions about the 139 and its VminI of 50 Knots.
Which one of you cares to prove you know what you are talking about?
Which one of you cares to prove you know what you are talking about?
In general terms, this may be for reasons of AP capabilities and/or because of lack of reliable airspeed sensing/indications; which are directly related. If you have no forward airspeed indication, and no visual references, whilst in a hover attitude the aircraft may be traveling forwards, backwards, or sideways, you can't reliably tell, and neither can the aircraft.
To fly on instruments at very low speeds (i.e. where IAS indications become unreliable) requires doppler equipment. This can be tied in to some autopilots to provide auto hover/auto transition & climb capability. But even so, that does not provide an obstruction avoidance capability, hence the regulatory inclusion of helicopter RVR limits at airfields.
The transition to forward speed and climb is a critical stage of flight, both from an aircraft point of view and for the pilot himself, if he is changing from outside visual cues to instruments only. The trick is not to have both occurring at the same time.
If you have no outside visual references you are by definition relying entirely on aircraft instruments, so you cannot be operating under VFR. If an aircraft is going to depart in conditions of low vis/low cloud and climb under IFR, Vmini by definition must be achieved with reference to visual cues. Which is why attempting a Class A takeoff profile may not be a good idea at all; sufficient forward visibility and room to safely accelerate to Vmini along a clear path is required.
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Shy,
We have seen it typed both ways here, with an "i" and with "I". We know what is intended no matter which way it is typed.
The question remains.
What is the 139 Vmini of 50 Knots predicated upon? How was it determined?
JimL gave a perfect CAA type response (yet again) that is factually correct but does not answer the question.
You begin to provide a better answer but still no Cigar.
We have seen it typed both ways here, with an "i" and with "I". We know what is intended no matter which way it is typed.
The question remains.
What is the 139 Vmini of 50 Knots predicated upon? How was it determined?
JimL gave a perfect CAA type response (yet again) that is factually correct but does not answer the question.
You begin to provide a better answer but still no Cigar.
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Boudreaux Bob
From CS-29
VMINI means instrument flight minimum speed, utilised in complying with minimum limit speed requirements for instrument flight.
It relates to;
Static longitudinal stability
(a) General. The helicopter must possess positive static longitudinal control force stability at critical combinations of weight and centre of gravity at the conditions specified in sub* paragraphs IV (b) to (f) of this appendix. The stick force must vary with speed so that any substantial speed change results in a stick force clearly perceptible to the pilot. The airspeed must return to within 10% of the trim speed when the control force is slowly released for each trim condition specified
(d) Slow cruise.
Stability must be shown throughout the speed range from 0.9 VMINI to 1.3 VMINI or 37 km/h (20 knots) above trim speed, whichever is greater, with:
(1) The helicopter trimmed and power adjusted for level flight at 1.1 VMINI; and
(2) Landing gear retracted (if retractable).
What's the point you're making, or should we guess
From CS-29
VMINI means instrument flight minimum speed, utilised in complying with minimum limit speed requirements for instrument flight.
It relates to;
Static longitudinal stability
(a) General. The helicopter must possess positive static longitudinal control force stability at critical combinations of weight and centre of gravity at the conditions specified in sub* paragraphs IV (b) to (f) of this appendix. The stick force must vary with speed so that any substantial speed change results in a stick force clearly perceptible to the pilot. The airspeed must return to within 10% of the trim speed when the control force is slowly released for each trim condition specified
(d) Slow cruise.
Stability must be shown throughout the speed range from 0.9 VMINI to 1.3 VMINI or 37 km/h (20 knots) above trim speed, whichever is greater, with:
(1) The helicopter trimmed and power adjusted for level flight at 1.1 VMINI; and
(2) Landing gear retracted (if retractable).
What's the point you're making, or should we guess