Goodwood Ec120 spinning..... Anyone see it
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on the saturday morning i had two phone calls,
one from a fellow pilot asking if it was me, explaining it was very serious as the heli spun not once but moved away and did it again..... thought it was me as didnt know my reg......
the second call was from (.......) lets not point the finger........
he also thought it was me, telling me that i should have had an engineer take a look at the heli before i took off again in the afternoon as both these people knew that it was most definatly overtorqued........
after he calmed down a bit when i said it wasnt me - he babbled on about reporting it to the powers that be..... as this is very serious......
again...... it wasnt me !!!!!
one from a fellow pilot asking if it was me, explaining it was very serious as the heli spun not once but moved away and did it again..... thought it was me as didnt know my reg......
the second call was from (.......) lets not point the finger........
he also thought it was me, telling me that i should have had an engineer take a look at the heli before i took off again in the afternoon as both these people knew that it was most definatly overtorqued........
after he calmed down a bit when i said it wasnt me - he babbled on about reporting it to the powers that be..... as this is very serious......
again...... it wasnt me !!!!!
I don't think we need to get into a witch hunt do we ?? Luckily most of the really daft things I have done have been well away from you lot !!
I think the pilot did well to keep it together but IF he isn't aware of what he did wrong how will he ensure it doesn't happen again . If it was me I would be straight onto someone like JJ and go out on the first windy day and repeat it .
Ps why does it have to be over torqued ? If the fenestron has stalled it will not be pulling lots of power .....and if collective is left alone what would produce such a spike ? ( just asking and not saying it couldn't happen )
I think the pilot did well to keep it together but IF he isn't aware of what he did wrong how will he ensure it doesn't happen again . If it was me I would be straight onto someone like JJ and go out on the first windy day and repeat it .
Ps why does it have to be over torqued ? If the fenestron has stalled it will not be pulling lots of power .....and if collective is left alone what would produce such a spike ? ( just asking and not saying it couldn't happen )
Nigel
Having not seen the incident myself, it's difficult to speak with any certainty. However, what 'usually' occurs in these circumstances is that the rate of left yaw is so rapid that it requires full right pedal to stop it. In an EC120 (and Gazelle) that will almost certainly result in overtorque. An exacerbating factor is that the pilot usually panics (quite naturally) and wants to get away from the ground (again, quite naturally). The collective is raised and the yaw rate increases further still as does the torque.
As an aside, the EC120 will record any Torque exceedance on the VEMD so the engineers (and pilot if he knows the button presses required to access the data) will know for sure whether, and by how much, the torque (or Ng / T4) was exceeded.
JJ
Edited for typo.
Having not seen the incident myself, it's difficult to speak with any certainty. However, what 'usually' occurs in these circumstances is that the rate of left yaw is so rapid that it requires full right pedal to stop it. In an EC120 (and Gazelle) that will almost certainly result in overtorque. An exacerbating factor is that the pilot usually panics (quite naturally) and wants to get away from the ground (again, quite naturally). The collective is raised and the yaw rate increases further still as does the torque.
As an aside, the EC120 will record any Torque exceedance on the VEMD so the engineers (and pilot if he knows the button presses required to access the data) will know for sure whether, and by how much, the torque (or Ng / T4) was exceeded.
JJ
Edited for typo.
Last edited by jellycopter; 4th Jul 2012 at 05:56.
Did someone mention over-torque? Surely not..
Luckily most of the really daft things I have done have been well away from you lot!
Even in Italy we have drivers who are not immune to that most annoying of syndromes .. 'non-concentration-itus'!
Even Italians are not immune.
No excuses for the pilot, who doesn't need to press any buttons to find out if there's been an over torque; he'll get one of these in his face when he's powered down...
A bit like seeing a flashing blue light in your rear-view mirror after speeding on a motorway - you're nicked pal!
A bit like seeing a flashing blue light in your rear-view mirror after speeding on a motorway - you're nicked pal!
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Have been following this post with interest, and am intrigued as to which EC120 it was, but as I wasn't there, I guess I will never know!
However does anyone who was there know if this was a private flight or an AOC flight with paying pax in the back?
However does anyone who was there know if this was a private flight or an AOC flight with paying pax in the back?
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and am intrigued as to which EC120 it was, but as I wasn't there, I guess I will never know!
Its quite likely to have been one of these though ..
G-CBNB, G-COML, G-CONN, G-DEVL, G-EIZO, G-ETIM, G-FCKD, G-GTJM, G-GTJM, G-HVRZ, G-IGPW, G-ISSY, G-JJFB, G-KLNP, G-LHMS, G-MODE, G-OLDO, G-OMEM, G-OTFL, G-PDGE, G-PWAD, G-RCNB, G-SKPP, G-TBLY, G-TGGR, G-VIPR, G-WZRD, G-ZZOE, G-ZZZSThe best comment I've read so far is ....
perhaps you could outline the circumstances and actions that led to this event - it would be useful for novice 120 drivers to be aware of control limitations. Also as this pilot recovered, mentioning the actions he took and the consequences might also be helpful.
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Ok for clarification....
I own G GTJM and I was not there on Friday....
I went on Saturday... As previously stated...... So you can cross that one off your list....
I was accused of operating illegally.......
As the people at goodwood had got the booking mixed up.
I received in the post the other guys reciept for his booking on Friday,
Instead of my receipt for MY Saturday booking so can see why they rang me up moaning at me......
Nelly..
I own G GTJM and I was not there on Friday....
I went on Saturday... As previously stated...... So you can cross that one off your list....
I was accused of operating illegally.......
As the people at goodwood had got the booking mixed up.
I received in the post the other guys reciept for his booking on Friday,
Instead of my receipt for MY Saturday booking so can see why they rang me up moaning at me......
Nelly..
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My thoughts - open to correction / debate
The EC120 is a wonderful craft BECAUSE it records every mistake that you make.
Hence if there was an overtorque the "Over Limit" yellow warning comes up and the Pilot cannot remove the evidence. Scrolling through to the relevant screen, the over-limit parameter is displayed, and so it enables a very precise conversation with the engineer to understand if the machine is now grounded or whether it can be flown back. There are tables for this so the machine is different from (say) a Jet Ranger in that on the telephone I would hop that an engineer could clear / ground the machine.
An EC120 that develops a spin does not have to be over-torqued to recover - not in every case. It depends, not suprisingly, on the amount of power that you are using before you react, how far you stick your foot in, and how fast you go from current pedle setting to [wherever you end up]. If you are light weight and hovering with plenty of reserve then the spike (from rapid movement to high-right-foot) and the power requirement (eg flooring your right boot) may not exhaust your reserve.
If you are closer to the limit, and you have the time to act more steadily, and the presence of mind to do so, you might apply "full right boot" in a controlled fashion to reduce the potential impact of the anticipator dumping Jet A1 into the engine and giving an over-torque. It is possible that (with appropriate loading / power usage before you reacted) you might not over-torque.
============
I did not see this event, I was not there. Spins can start by getting the wind onto the wrong side of that BIG, BIG sail. Theycan also develop simply from not recognising the flight characteristics of the machine.
The EC120 has a big tail which is aerodynamically shaped and, into wind at speed, this "wing" gives a very large anti-torque effect. When the peddles are level in the cab you are actually holding the tail fan in a "left foot forward" position, so to go to "full power peddle" you have a big distance to move, and the poewr change is not linear (I think). This is a significant difference to heli's without such a Fenestron tail. As you bleed speed on approach in a 120 the anti-torque effect from that "big wing" tail reduces and you need to replace it with fan-induced anti-torque; increasing the right boot steadily on approach as you slow. If you don't control the left-yaw as you reduce speed (being slow on your feet, or not being used to the amount of boot required (eg used to flying a Robinson 44)) then the rate of yaw will increase as you bleed speed - requiring even faster feet / more feet at an increasing rate. The rate of change in yaw accelaration is not linear with speed loss; this means "stay ahead of the aircraft, as playing catch-up can be "interesting").
If you think you are behind the curve in yaw control as you approach then the guaranteed safe sloution - if there is such a thing in aviation - is to "go around". Nose down and increase speed so that wind over the tail increases and brings the anti-torque component from the "big wing" tail back up to add to the fan-effect and the problem goes away. If you are behind the curve in yaw control as you approach then you need to get ahead of the yaw very quickly because the rate change of yaw acceplaration will change dramatically as you continue the approach. Once youre tail passes through 90 degrees to the wind, then reducing sail effect works against you, and once the wind gets on to the left-side of the tail you are going to rapidly spin-up.
Once a spin starts it will usually take a number of rotations to stop it. The spin will be fast (30 rpm+) and diorientating; the spin is about the mast and you are sitting quite some way ahead of that. You will be thrown forward against the seatbelt and to the right right - physically pushed against the door. However, if you can keep your right foot in AND you can stay away from other objects it will come under control.
=========
I have not (yet) got into an accidental "violent" spin in the EC120. I do, however, regularly practice spinning on the spot, spinning whilst travelling, and spin control. I did once allow the aircraft to complete a single 360 spin because to prevent it would have over-torqued. As we came around into wind I pushed the nose slightly forward and increased speed to recover. It was a non-event as I was prepared for it.
The EC120 is a wonderful craft BECAUSE it records every mistake that you make.
Hence if there was an overtorque the "Over Limit" yellow warning comes up and the Pilot cannot remove the evidence. Scrolling through to the relevant screen, the over-limit parameter is displayed, and so it enables a very precise conversation with the engineer to understand if the machine is now grounded or whether it can be flown back. There are tables for this so the machine is different from (say) a Jet Ranger in that on the telephone I would hop that an engineer could clear / ground the machine.
An EC120 that develops a spin does not have to be over-torqued to recover - not in every case. It depends, not suprisingly, on the amount of power that you are using before you react, how far you stick your foot in, and how fast you go from current pedle setting to [wherever you end up]. If you are light weight and hovering with plenty of reserve then the spike (from rapid movement to high-right-foot) and the power requirement (eg flooring your right boot) may not exhaust your reserve.
If you are closer to the limit, and you have the time to act more steadily, and the presence of mind to do so, you might apply "full right boot" in a controlled fashion to reduce the potential impact of the anticipator dumping Jet A1 into the engine and giving an over-torque. It is possible that (with appropriate loading / power usage before you reacted) you might not over-torque.
============
I did not see this event, I was not there. Spins can start by getting the wind onto the wrong side of that BIG, BIG sail. Theycan also develop simply from not recognising the flight characteristics of the machine.
The EC120 has a big tail which is aerodynamically shaped and, into wind at speed, this "wing" gives a very large anti-torque effect. When the peddles are level in the cab you are actually holding the tail fan in a "left foot forward" position, so to go to "full power peddle" you have a big distance to move, and the poewr change is not linear (I think). This is a significant difference to heli's without such a Fenestron tail. As you bleed speed on approach in a 120 the anti-torque effect from that "big wing" tail reduces and you need to replace it with fan-induced anti-torque; increasing the right boot steadily on approach as you slow. If you don't control the left-yaw as you reduce speed (being slow on your feet, or not being used to the amount of boot required (eg used to flying a Robinson 44)) then the rate of yaw will increase as you bleed speed - requiring even faster feet / more feet at an increasing rate. The rate of change in yaw accelaration is not linear with speed loss; this means "stay ahead of the aircraft, as playing catch-up can be "interesting").
If you think you are behind the curve in yaw control as you approach then the guaranteed safe sloution - if there is such a thing in aviation - is to "go around". Nose down and increase speed so that wind over the tail increases and brings the anti-torque component from the "big wing" tail back up to add to the fan-effect and the problem goes away. If you are behind the curve in yaw control as you approach then you need to get ahead of the yaw very quickly because the rate change of yaw acceplaration will change dramatically as you continue the approach. Once youre tail passes through 90 degrees to the wind, then reducing sail effect works against you, and once the wind gets on to the left-side of the tail you are going to rapidly spin-up.
Once a spin starts it will usually take a number of rotations to stop it. The spin will be fast (30 rpm+) and diorientating; the spin is about the mast and you are sitting quite some way ahead of that. You will be thrown forward against the seatbelt and to the right right - physically pushed against the door. However, if you can keep your right foot in AND you can stay away from other objects it will come under control.
=========
I have not (yet) got into an accidental "violent" spin in the EC120. I do, however, regularly practice spinning on the spot, spinning whilst travelling, and spin control. I did once allow the aircraft to complete a single 360 spin because to prevent it would have over-torqued. As we came around into wind I pushed the nose slightly forward and increased speed to recover. It was a non-event as I was prepared for it.
John
On the whole an interesting and helpful post. As you offered it up for correction in your opening sentence, here's a correction:
"you might apply "full right boot" in a controlled fashion to reduce the potential impact of the anticipator dumping Jet A1 into the engine and giving an over-torque"
The Anticipator isn't connected to the yaw controls; it's only connected to the collective. The torque 'spike' associated with right boot in an EC120 is simply the extra aerodynamic load of the fenestron causing the rotors to (momentarily) slow down thus the governor responds by dumping in more fuel. I suppose if you substitute 'governor' for 'anticipator' in your sentence that would be correct.
As an aside, assuming that the aircraft is on an into-wind approach, the rate of yaw increases when the relative airflow to the fin gets beyond its critical alpha (just like an aeroplane wing stalling). This will occur after only about 20 degs (very approx) of left yaw.
JJ
On the whole an interesting and helpful post. As you offered it up for correction in your opening sentence, here's a correction:
"you might apply "full right boot" in a controlled fashion to reduce the potential impact of the anticipator dumping Jet A1 into the engine and giving an over-torque"
The Anticipator isn't connected to the yaw controls; it's only connected to the collective. The torque 'spike' associated with right boot in an EC120 is simply the extra aerodynamic load of the fenestron causing the rotors to (momentarily) slow down thus the governor responds by dumping in more fuel. I suppose if you substitute 'governor' for 'anticipator' in your sentence that would be correct.
As an aside, assuming that the aircraft is on an into-wind approach, the rate of yaw increases when the relative airflow to the fin gets beyond its critical alpha (just like an aeroplane wing stalling). This will occur after only about 20 degs (very approx) of left yaw.
JJ
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So, in summary, the EC120 is a descendant of the SA341 and is vulnerable to loss of tail rotor effectiveness - especially in certain medium to high wind conditions and at certain profiles involving a relation between the tail rotor/fin and the prevailing wind/slipstream?
And - because the EC120 is relatively low powered - this vulnerability becomes more of an issue than if say the heli had an extra 600shp?
And - as Friday was blowing a mild gale is it fair to assume that there is a probability that while manoeuvering about Goowood, the 120 in question may have gotten his tail in a twist?
And - because the EC120 is relatively low powered - this vulnerability becomes more of an issue than if say the heli had an extra 600shp?
And - as Friday was blowing a mild gale is it fair to assume that there is a probability that while manoeuvering about Goowood, the 120 in question may have gotten his tail in a twist?
AS: ...there is a probability that while manoeuvering about Goowood, the 120 in question may have gotten his tail in a twist?
And as for '...an extra 600shp'?! Good grief..
Not a good beginners\ low hours machine then. Feet allways seemed to be the hardest part to get correct, when training & in overload I would have cooked a fair No. of engines
Talking to other pilots the consensus seems to be feet are the first thing that seize up.
Talking to other pilots the consensus seems to be feet are the first thing that seize up.
Not a good beginners\low hours machine then
I'd bet a week's wages that 'the 120 at Goodwood' was over-torqued. The really scary bit however, is that nobody I spoke to saw a technician go anywhere near the aircraft before it flew off again in the afternoon...
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And you are sure that the pilot did not clear the machine with a mechanic by telephone?
The parameters of the over torque are recorded on the V Med. The details can be given on the telephone to a qualified mechanic. They look up the details in the Eurocopter bible of bad and expensive things, and give you the answer.
It's not like over torque in a More basic, older machine design where all you know until a physical inspection is that you had an over torque
The parameters of the over torque are recorded on the V Med. The details can be given on the telephone to a qualified mechanic. They look up the details in the Eurocopter bible of bad and expensive things, and give you the answer.
It's not like over torque in a More basic, older machine design where all you know until a physical inspection is that you had an over torque
Last edited by John R81; 4th Jul 2012 at 19:45.
John - I admire your generous optimism, but this wasn't a 'phone call to a techy, just to check' over-torque. This was a 'how badly melted is it?' over-torque... I'm surprised the vid hasn't surfaced on YouTube yet.
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Didn't see the Friday event, but on Saturday did see a R44 yawing through about 60 degrees as it started to lift from spot 3, with the skids still on the ground. Interesting to say the least. Also quite alarmed when a boy got out of a rotors running Jetranger and started to walk towards the tail to get around the other side. Luckily the ground staff noticed in time.