Exceeding maximum gross weight
Avoid imitations
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As far as the engine and airframe are concerned, the strain on the rotor head is the same, is it not?
Note that test aircraft are wired for data logging using strain gauges etc, and are far more deeply examined than yours is, after every flight.
The real answer is, they possibly have, in the past, explored a wider performance envelope. If they could safely certify a wider performance envelope, they would do so because it makes commercial sense to do so.
But they haven't, so go figure why not.
Would you treat your car like this? Routinely exceed the rev limits, for example, just because you can get it to rev higher than the red line?
I still think you're not for real.
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Stand on a scales in a lift. You will weigh more going up than coming back down!
Max weight on a heli is directly proportional to how much strain is applied to lift it.
If you limit the amount of power to lift it with, then you are also limiting the stress to that same limit. My point is overloading a heli and flying within the power limitations is not the same as overloading a heli and then flying it normally, exceeding power limitations to get airborne, this is what causes the damage.
How often has anyone strapped a heli down and loaded it up with weight so that it will not be able to take off, in order to perform a max power check? This would be clearly over weight, but would it invalidate the C of A? I think not.
Max weight on a heli is directly proportional to how much strain is applied to lift it.
If you limit the amount of power to lift it with, then you are also limiting the stress to that same limit. My point is overloading a heli and flying within the power limitations is not the same as overloading a heli and then flying it normally, exceeding power limitations to get airborne, this is what causes the damage.
How often has anyone strapped a heli down and loaded it up with weight so that it will not be able to take off, in order to perform a max power check? This would be clearly over weight, but would it invalidate the C of A? I think not.
Stand on a scales in a lift. You will weigh more going up than coming back down!
Avoid imitations
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Stand on a scales in a lift. You will weigh more going up than coming back down!
Limits are Limits are Limits
I agree that we may have a troll looking for an argument. Only one thing needs to be understood. Limitations are just that, limitations. Why they have been identified as limitations (i.e. gross weight, airspeed, engine power or maximum certified altitude) are not for us to question. It is not ours to attempt to determine why a limit has been imposed but rather to obey it.
Once, in a former lifetime, I was assigned with the task of evaluating the autorotative performance and flying qualities of the CH-53D at the aircraft’s forward and aft CG limits. As part of my preflight preparation I contacted Sikorsky for advice when approaching the limits in this evaluation. Their advice was simple and direct. Be careful and don’t exceed the limits.
Once, in a former lifetime, I was assigned with the task of evaluating the autorotative performance and flying qualities of the CH-53D at the aircraft’s forward and aft CG limits. As part of my preflight preparation I contacted Sikorsky for advice when approaching the limits in this evaluation. Their advice was simple and direct. Be careful and don’t exceed the limits.
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Limitations are just that, limitations. Why they have been identified as limitations (i.e. gross weight, airspeed, engine power or maximum certified altitude) are not for us to question.
Saw the result of a Hughes 500 that lost it's head as a result of doing aerobatics. Unfortunately the two guys flying it at the time were not the ones who had performed the aerobatics. Manufactures don't go to the trouble of printing the AFM in order to,
(a) consume forests
(b) keep people employed
(c) move the CofG forward.
It's to keep your sorry ass in one piece.
A few things to consider (found in FAR part 27 and other sources):
Strength requirements are specified in terms of limit loads (the maximum loads to be expected in service) and ultimate loads (limit loads multiplied by prescribed factors of safety). Unless otherwise provided, prescribed loads are limit loads. A safety factor might only be 1.25 or 1.5--we don't fly tanks, we fly lightweight aircraft.
The rotorcraft must be designed for--
(a) A limit maneuvering load factor ranging from a positive limit of 3.5 to a negative limit of -1.0; or
(b) Any positive limit maneuvering load factor not less than 2.0 and any negative limit maneuvering load factor of not less than -0.5 for which--(1) The probability of being exceeded is shown by analysis and flight tests to be extremely remote; and (2) The selected values are appropriate to each weight condition between the design maximum and design minimum weights.
+2.0g!
The rotorcraft must be designed to withstand, at each critical airspeed including hovering, the loads resulting from a vertical gust of _only_ 30 feet per second.
The speed for maximum load factor capability for a helicopter is approximately 0.6 Vh--not Vne/Vdl.
As flight speed increases, a given rotor angle-of-attack change produces a larger thrust increment so that large load factors may be reached without large attitude changes. The maximum loads thus may be obtained by variation of rate of control application, magnitude of control movement, and speed.
The maximum power-off rotor speed limit is essentially the design limit of the rotor (with some reduction for a factor of safety). Thus potentially much higher rotor load factors can be generated under autorotation than powered flight.
Landing gear have limitations too.
Strength requirements are specified in terms of limit loads (the maximum loads to be expected in service) and ultimate loads (limit loads multiplied by prescribed factors of safety). Unless otherwise provided, prescribed loads are limit loads. A safety factor might only be 1.25 or 1.5--we don't fly tanks, we fly lightweight aircraft.
The rotorcraft must be designed for--
(a) A limit maneuvering load factor ranging from a positive limit of 3.5 to a negative limit of -1.0; or
(b) Any positive limit maneuvering load factor not less than 2.0 and any negative limit maneuvering load factor of not less than -0.5 for which--(1) The probability of being exceeded is shown by analysis and flight tests to be extremely remote; and (2) The selected values are appropriate to each weight condition between the design maximum and design minimum weights.
+2.0g!
The rotorcraft must be designed to withstand, at each critical airspeed including hovering, the loads resulting from a vertical gust of _only_ 30 feet per second.
The speed for maximum load factor capability for a helicopter is approximately 0.6 Vh--not Vne/Vdl.
As flight speed increases, a given rotor angle-of-attack change produces a larger thrust increment so that large load factors may be reached without large attitude changes. The maximum loads thus may be obtained by variation of rate of control application, magnitude of control movement, and speed.
The maximum power-off rotor speed limit is essentially the design limit of the rotor (with some reduction for a factor of safety). Thus potentially much higher rotor load factors can be generated under autorotation than powered flight.
Landing gear have limitations too.
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Let's see now, up up in the lift, the blood goes thin,
down down in the lift I feel a thickness near my shin.
damm it, there you are all, the same as lifting off in the ol' flying machine and getting light headed, and well - then going back down again and landing and trying not to look too thick! all with the same persistant writing in section two - Limitations - oh well.
I guess that destroys that argument there chopjock ol' son.
but I think Brian Abraham crystallized it for me when he labled Jock as Jack.
No I don't tink so Brian, Jack is still be on the way UP the hill with Jill. jock is beyond the pail and is cometh tumbling down.
all the best jock ol son.
tet
down down in the lift I feel a thickness near my shin.
damm it, there you are all, the same as lifting off in the ol' flying machine and getting light headed, and well - then going back down again and landing and trying not to look too thick! all with the same persistant writing in section two - Limitations - oh well.
I guess that destroys that argument there chopjock ol' son.
but I think Brian Abraham crystallized it for me when he labled Jock as Jack.
No I don't tink so Brian, Jack is still be on the way UP the hill with Jill. jock is beyond the pail and is cometh tumbling down.
all the best jock ol son.
tet
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The rotorcraft must be designed for--
(a) A limit maneuvering load factor ranging from a positive limit of 3.5 to a negative limit of -1.0; or
(a) A limit maneuvering load factor ranging from a positive limit of 3.5 to a negative limit of -1.0; or
Anyone fancy buying Chopjock's Enstrom..........................................R eally?
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You simply have done what you shouldn't have done......period! Lets just say that you replaced your piston engine with a turbine of the same weight but with bags more power, would you think it ok to load up the heli, well overweight as long as you weren't exceeding the "engines" limitations. If you are selling it don't advertise under chopjock or a very difficult machine to sell will become impossible.
Might be worthwhile to publish your registration so we can all follow it and be proved wrong as the years and hours go by. Haha like you would do that......I don't think so!!!!!!
Might be worthwhile to publish your registration so we can all follow it and be proved wrong as the years and hours go by. Haha like you would do that......I don't think so!!!!!!
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Chopjock:
You're way out of your league in terms of talking of limits and designs. There is a maximum weight published in the limitations. Your job is to not exceed it.
Ignorance is not excuse in a court of human law, nor in the court of physical laws.
(I was a certification test pilot for 5 years for Transport Canada, and can testify that there are a myriad of reasons for weight limitations, as well as other limitations.)
You're way out of your league in terms of talking of limits and designs. There is a maximum weight published in the limitations. Your job is to not exceed it.
Ignorance is not excuse in a court of human law, nor in the court of physical laws.
(I was a certification test pilot for 5 years for Transport Canada, and can testify that there are a myriad of reasons for weight limitations, as well as other limitations.)
Chopjock .....you are not giving the EOGOC a good name you know I think the point is ....going slightly overweight as a genuine mistake is one thing , ( we have all asked for 150 ltrs only to find 200 put in or a girl turns up with a handbag the size of a suitcase ) , intentionally going over is another . What happens when you allow yourself that extra 100lb you shouldnt have ....and then you "just" go say 25lb past that new limit you have set ?? Where does it stop ? It is pointless saying most of us never do it , ever ...but it is a bad thing to get into a habit and equally bad to flaunt it !!
ps I used to consistently massively overload Bell 47,s spraying but they have all crashed now so part life not so much of a problem . ( also people were not mostly v sensible 30 yrs ago !! )
pps EOGOC Enstroms Old Git Owners Club.
I think the point is ....going slightly overweight as a genuine mistake is one thing , ( we have all asked for 150 ltrs only to find 200 put in or a girl turns up with a handbag the size of a suitcase ) , intentionally going over is another . What happens when you allow yourself that extra 100lb you shouldnt have ....and then you "just" go say 25lb past that new limit you have set ?? Where does it stop ? It is pointless saying most of us never do it , ever ...but it is a bad thing to get into a habit and equally bad to flaunt it !!ps I used to consistently massively overload Bell 47,s spraying but they have all crashed now so part life not so much of a problem . ( also people were not mostly v sensible 30 yrs ago !! )
pps EOGOC Enstroms Old Git Owners Club.
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You again miss the point. What about your landing gear, for just one thing? You have stated you've operated your machine outside its design limits. Period.
I'm making a point, and that is if you load up to max weight and climb at max power, it's no different than loading 5% over weight and climbing at the same power. (this doesn't mean I've done it though)Your climb rate will be lower, but the strain on the airframe will be the same. I'm not asking for approval or even your agreement. Just stating a point of view. Jeez
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You are "putting words into my mouth" again. Read my posts, I never stated that.
You can still overload the aircraft and then fly it gently and not have any ill effects, in my experience.
how could I possibly translate "in my experience" differently as "I have done it"?
Definition:
experience |ikˈspi(ə)rēəns|
noun
practical contact with and observation of facts or events
• the knowledge or skill acquired by such means over a period of time, esp. that gained in a particular profession by someone at work
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If I may pitch in, with english not beeing my first language and all...
how could I possibly translate "in my experience" differently as "I have done it"?
how could I possibly translate "in my experience" differently as "I have done it"?
Nuff Said
It is not approval that is required to argue this position. I also submit that to operate a flying machine outside of its certified envelope is arrogance and with no malice intended, stupid. Like many on this site I have many years of rotary wing flight experience in many machines, including flight test and certification work. This knowledge and experience has provided me with a solid understanding of the design and certification of rotary wing aircraft. The only way that the longevity and safety of a vehicle can be assured is to operate and maintain it within the guide lines out lined in the appropriate manuals. To do otherwise is not smart. I can state this with confidence as one that signs my name to the posts on this site.
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chopjock
Why do you consider its acceptable to exceed weight limitations but not acceptable to exceed engine limitations ?
Why do you consider its acceptable to exceed weight limitations but not acceptable to exceed engine limitations ?
Last edited by chopjock; 13th Feb 2010 at 09:38.
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Chopjock, you obviously misunderstand some issues.
Helicopter critical component and airframe fatigue life is calculated in cycles, at no more than the certified max weight. If you routinely exceed the maximum weight, there is a cumulative effect, an unknown and possibly very serious one, and we're not talking about engine life here.
I strongly suggest that you fly the aircraft in accordance with the manufacturer's limits because from what you have written here you are compromising yourself, and others, in more ways than one. Speaking as someone who has been flying for a living for over thirty years I, for one, would not now fly in your helicopter at any cost. Unfortunately, because I don't know who you are, I would now be very cautious of ANY Enstrom, in case it has been flown by you.
Helicopter critical component and airframe fatigue life is calculated in cycles, at no more than the certified max weight. If you routinely exceed the maximum weight, there is a cumulative effect, an unknown and possibly very serious one, and we're not talking about engine life here.
I strongly suggest that you fly the aircraft in accordance with the manufacturer's limits because from what you have written here you are compromising yourself, and others, in more ways than one. Speaking as someone who has been flying for a living for over thirty years I, for one, would not now fly in your helicopter at any cost. Unfortunately, because I don't know who you are, I would now be very cautious of ANY Enstrom, in case it has been flown by you.