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AS 350: "Hold my beer son and watch this!"

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AS 350: "Hold my beer son and watch this!"

Old 16th Jul 2018, 21:59
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Crab , you say


that happened with many military helicopters as their use and hours matured, they were being used for military sortie profiles and not civilian ones

then the next moment you are advocating military style manoeuvres as being fine ( if the pilot is capable ...) and maintaining those manoeuvres have no effect on maintenance etc !! Make your mind up !

No TC , rather worryingly I am agreeing with you !
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Old 17th Jul 2018, 09:36
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nigelh, if I read it properly I think Crab is talking about the fact that a military aircraft is designed against an agreed predicted usage spectrum. At various points this spectrum is revisited with the experience of how the airframe is actually being used. It is rarely about "military manouevres" more about the relative percentage of time the airframe spends in particular flight conditions, weights, cycles. Everything in the spectrum should be within the RFM/RTS.
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Old 17th Jul 2018, 09:55
  #143 (permalink)  
 
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So what percentage do you think the manufacturer allows for unapproved aerobatic manoeuvres then ?
is it fine if the pilot just does this once a month ? Once a week or every day ? By the time the ship is 30 years old she may have spent a long time almost upside down !!
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Old 17th Jul 2018, 11:18
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What "unapproved aerobatic manouevre"?

If it is within the limits of the RFM / RTS then it's being used within the constraints of the manufacturer. After that it is about determining loads and lifing.
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Old 17th Jul 2018, 11:39
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C'mon Nige, stop reading things into statements that aren't there - you don't appear to understand military flying and how tactics and techniques constantly evolve to meet or counter the threat from the enemy. Heli vs Heli and Heli vs fighter manoeuvring evolved out of exactly such a situation - something that wouldn't have been considered when the aircraft was designed and manufactured.
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Old 17th Jul 2018, 12:24
  #146 (permalink)  
 
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How did the antics of some bored guy in the land of holy cheese end up as a military contest?
He wasn't flying a lynx and definitely wasn't having a dogfight.
It's a common, garden variety French can, the manufacturer thereof is fairly particular about how it should be treated.

It is good to know the military professionals (some of them anyway) can spend as much time inverted/semi/quasi-inverted as they like, though that could really make drinking the hot cuppa a bit more challenging.
Back to beating the dead horse.
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Old 17th Jul 2018, 12:28
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Originally Posted by [email protected]
... tactics and techniques constantly evolve to meet or counter the threat from the enemy...
sometimes it is more mundane than that Crab. Helicopters are very versatile and people find different ways of using them. So the fleet may be spending more time hovering than expected, or flying sideways, or may be there are more landings per flying hour. So the numbers get re-crunched.
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Old 17th Jul 2018, 12:38
  #148 (permalink)  
 
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The issue for me Bell_ringer is that this thread appeared to be a trial by social media.

While the original video looks spectacular the more I looked the more I found I couldn't interpret the severity of the manouevre due to the point of view. I know nothing of the pilot or the situation under which they choose to perform it. I find it strange therefore that some pilots have leveled severe allegations here on this thread, they can obviously see something I can't.
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Old 17th Jul 2018, 12:53
  #149 (permalink)  
 
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dCa, that is what social media is for isn't it?
I think most, if not all, have managed to agree that the actual severity can't be judged from the perspective of a mobile phone video.
The point of view, as I interpret it, is that in the civilian world that style of flying is unnecessary and not representative of good judgement (irrespective of how far along in the 50 shades of flying grey the manoeuvre may actually be).

The military have different.rules for a very different role and what may be perfectly acceptable in that environment could be career limiting in another.
When the elastomeric bearings have to be replaced before their time that may not be a concern for Johnny taxpayer but for the owner of a civilian aircraft trying to eek out as much margin as possible, it will not sit as well.
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Old 17th Jul 2018, 13:17
  #150 (permalink)  
 
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but thats the whole argument right?
whether this manoeuvre actually creates any added stress on the parts like the elastomers is a hard fought debate. Some think total aircraft destruction is imminent. Some think who cares. Others sit on the fence. I can tell you after seeing an EC120 Main and Epi Module with Rotor Head, all decked out in Airbus' stress monitors, I can assure you, they have every single component wired up to gather the data they need to know they have built a component capable of the flight envelope they tested the design at. with a healthy safety margin I imagine.
The frequency adapters and the spherical bearings react on the rotor head the same way no matter the attitude. The gearbox doesn't care if it's flat and level or 45 degrees. The tailrotor and drive is oblivious as to whether its doing a hard pedal turn, or lifting a max gross external load.
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Old 17th Jul 2018, 13:51
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Don't disagree technically Bell_ringer but without any data trace it's hard to say whether any excessive lifing has occurred. Certainly impossible to claim there's been damage. I don't know what was the pilot's motivation so can't even comment on whether it was necessary. We see worse manoeuvres in films and on TV all the time, they're civil but the manouevre is justified for the purpose of entertainment?
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Old 17th Jul 2018, 15:31
  #152 (permalink)  
 
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Bellringer - you would do more damage to the elastomeric bearings by not releasing the collective lock after shutdown - keeps them in a deformed condition.

You would also hammer the bearings much harder with constant high AuM and high speed ops - you need to keep this 'damage' idea in perspective and remember what the aircraft spends 99% of it's life doing (and that is never going to be wingovers).
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Old 17th Jul 2018, 19:13
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Indeed Crab but I was trying to be more metaphorical than literal.
If you've ever had the pleasure of seeing some of the unexpected failings of aircraft operated in modern day Africa then perhaps that would put it into better context.
It isn't up to any of us to decide when it is or isn't appropriate to deviate from the flight manual or standard ops, as none of us are metallurgists, and few are engineers. Can't we all agree that sticking to the same script is a good idea for longevity?
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Old 17th Jul 2018, 20:54
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But presumably those aircraft in Africa have been operated in accordance with the RFM and haven't been wingovered so I don't clearly see your argument.

If you mean that the aircraft in Africa are being abused and not serviced properly then I understand the 'unexpected failings'.
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Old 17th Jul 2018, 21:32
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my dealings with African aircraft fall squarely on overloading, and poor maintenance
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Old 18th Jul 2018, 06:35
  #156 (permalink)  
 
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When you end up having to replace parts before they are due and owners complain about the manufacturer, no one has a record of every time someone has pushed the aircraft whether it be weight or unnecessary flying (whilst not exceeding the flight manual). While one wingover may not cause noticeable decreases in service times, a culture of doing so will.
There is no way to empirically measure that apart from looking at the maintenance history over a period of time.
Maintenance deviations aren't only a result of exceeding the FM, how an aircraft is used within it's operational limits is a contributing factor.
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Old 18th Jul 2018, 07:48
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Originally Posted by Bell_ringer
...
Maintenance deviations aren't only a result of exceeding the FM, how an aircraft is used within it's operational limits is a contributing factor.
Absolutely true, but there are far more punishing flight conditions than a well executed wingover. They aren't spectacular so don't draw immediate criticism - if it was all about maintenance burden then all need to be monitored.

Last edited by dClbydalpha; 18th Jul 2018 at 08:03.
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Old 18th Jul 2018, 08:15
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Maintenance deviations aren't only a result of exceeding the FM, how an aircraft is used within it's operational limits is a contributing factor.
So you have a culture of overloading the aircraft and poor maintenance (99% of the use) and you are worried about the odd wingover (less than 1% of the use) even if they did one every sortie - hmmm perspective adjustment required.

Sounds like they all need HUMS and CVFDR installed if you are really worried about early component failure.
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Old 18th Jul 2018, 08:28
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Not talking about overloading. Remaining within the letter of the FM does not mean you will make component times, the manual does not tell you how to operate just sets limits.
Components rarely fail, they just don't last. If you have ever had to maintain your own aircraft you will understand that is an unnecessary expense.
Wingovers are an indication of an overall culture the results of which will have a greater than 1% effect.

Nonetheless the argument from some seems to be that since the aircraft can do aerobatics and test pilots have shown that it can be done safely then it is ok in the bigger picture.
With that logic they also test aircraft well beyond VNE quite safely, so let's also do that from time to time. It is also unlikely to contribute more than 1%.
But why stop there. If you are a good, capable pilot let's just push all the boundaries every now and then.
Eventually all those 1% add up.
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Old 18th Jul 2018, 09:26
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Wingovers are an indication of an overall culture the results of which will have a greater than 1% effect.
I don't think that's a true statement at all - do you have any evidence to support that?

As for extrapolating the wingover argument into exceeding all limitations, that seems a very black and white position to take ie 'If you are going to break one rule you may as well break them all' and not representative of any pilots I have ever flown with.
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