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#11
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Fat boy wants to soar...
On Mar 20, 2:15*pm, bildan wrote:
On Mar 18, 2:23*pm, Guy Byars wrote: On Mar 18, 12:43*am, "BT" wrote: Knowing flying over the MTOW or out of the CG range can cause an insurance company to deny a claim. Can anyone anywhere cite a single example of an insurance company denying a claim due to flying outside MTOW or CG ranges? The insurance issue isn't getting a settlement for the first accident related to an over gross flight - you will get paid. *However, a problem may arise at renewal time. There is really no excuse for operating outside the CG envelope. *The JAR 110 Kg seat limit is a little restrictive for us chubby Americans but, hey, it's an incentive to cut back on the bacon burgers and fries. The idea that the gross weight limit isn't a hard rule is just wrong. Aircraft manufacturers gain nothing by understating load capacity. The certificated max weight is as high as can be safely allowed. It may only be my impression but it seems to me that gliders that are habitually operated over gross suffer undue wear and damage to the landing gear, seats and cockpit area. *I've noticed that some POH's call for tire pressure above the max pressure on the tire sidewall. I wouldn't think operating those gliders over gross is a good idea. You could always suggest that Mr McFarley cuts down on the Burgers, French fries and beer, and does a bit of exercise. Or is that not 'American'? Derek C |
#12
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Fat boy wants to soar...
On Mar 20, 7:41*am, delboy wrote:
On Mar 20, 2:15*pm, bildan wrote: On Mar 18, 2:23*pm, Guy Byars wrote: On Mar 18, 12:43*am, "BT" wrote: Knowing flying over the MTOW or out of the CG range can cause an insurance company to deny a claim. Can anyone anywhere cite a single example of an insurance company denying a claim due to flying outside MTOW or CG ranges? The insurance issue isn't getting a settlement for the first accident related to an over gross flight - you will get paid. *However, a problem may arise at renewal time. There is really no excuse for operating outside the CG envelope. *The JAR 110 Kg seat limit is a little restrictive for us chubby Americans but, hey, it's an incentive to cut back on the bacon burgers and fries. The idea that the gross weight limit isn't a hard rule is just wrong. Aircraft manufacturers gain nothing by understating load capacity. The certificated max weight is as high as can be safely allowed. It may only be my impression but it seems to me that gliders that are habitually operated over gross suffer undue wear and damage to the landing gear, seats and cockpit area. *I've noticed that some POH's call for tire pressure above the max pressure on the tire sidewall. I wouldn't think operating those gliders over gross is a good idea. You could always suggest that Mr McFarley cuts down on the Burgers, French fries and beer, and does a bit of exercise. Or is that not 'American'? Derek C careful................remember we have lot's of cruise missiles......... |
#13
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Fat boy wants to soar...
On Mar 20, 4:01*pm, Brad wrote:
On Mar 20, 7:41*am, delboy wrote: On Mar 20, 2:15*pm, bildan wrote: On Mar 18, 2:23*pm, Guy Byars wrote: On Mar 18, 12:43*am, "BT" wrote: Knowing flying over the MTOW or out of the CG range can cause an insurance company to deny a claim. Can anyone anywhere cite a single example of an insurance company denying a claim due to flying outside MTOW or CG ranges? The insurance issue isn't getting a settlement for the first accident related to an over gross flight - you will get paid. *However, a problem may arise at renewal time. There is really no excuse for operating outside the CG envelope. *The JAR 110 Kg seat limit is a little restrictive for us chubby Americans but, hey, it's an incentive to cut back on the bacon burgers and fries. The idea that the gross weight limit isn't a hard rule is just wrong. Aircraft manufacturers gain nothing by understating load capacity. The certificated max weight is as high as can be safely allowed. It may only be my impression but it seems to me that gliders that are habitually operated over gross suffer undue wear and damage to the landing gear, seats and cockpit area. *I've noticed that some POH's call for tire pressure above the max pressure on the tire sidewall. I wouldn't think operating those gliders over gross is a good idea. You could always suggest that Mr McFarley cuts down on the Burgers, French fries and beer, and does a bit of exercise. Or is that not 'American'? Derek C careful................remember we have lot's of cruise missiles.........- Hide quoted text - You also have a lot of very *big* people, so I guess you are right! We see some of them in the UK during the tourist season. A quick plug for our tourist industry (about all we have left) if you don't mind: Thanks to our useless 'socialist' government the pound is now worth b*gg*r all, so you will get a good exchange rate if you come over this year. We even have gliding, and a lot of sites that do winch launching if you want to give it try, or wish to learn properly. We will make you very welcome, although we would appreciate it if you weigh less than 232 lbs (105 kg) to allow for wearing a 10 lb parachute. We speak a fairly quaint old fashioned form of American called English by the way, so no need to learn another language. Derek C |
#14
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Fat boy wants to soar...
On Mar 21, 3:15*am, bildan wrote:
The idea that the gross weight limit isn't a hard rule is just wrong. Aircraft manufacturers gain nothing by understating load capacity. The certificated max weight is as high as can be safely allowed. That is clearly not true. A lot of aircraft design is trading off one desirable feature against another. In the case of powered aircraft the MTOW is the weight used to establish the published takeoff run, the distance to clear a 50' obstacle, the rate of climb, the service ceiling, and probably others. If you're operating out of short strips then you want to know how much load you can carry. If you're operating a cessna off a 4 km runway at sea level with no obstructions then it will be perfectly safe to operate somewhat over MTOW, especially if the extra weight is carried in the wings. In the case of, for example, our club's DG1000 basic trainers, the aircraft is permitted to do unlimited aerobatics with a +7/-5 G rating at MTOW. If that's not a requirement on a particular flight and you're happy with the +5/-3 G like most other gliders then you could operate at some higher weight. There is really no excuse for operating outside the CG envelope. *The JAR 110 Kg seat limit is a little restrictive for us chubby Americans but, hey, it's an incentive to cut back on the bacon burgers and fries. Seat weight is one thing, CofG is quite another. With the tail ballast box full, those same DG1000's are within the published CofG limit even with two pilots well over 110 kg each. |
#15
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Fat boy wants to soar...
On Mar 21, 2:05*am, Bruce Hoult wrote:
On Mar 21, 3:15*am, bildan wrote: The idea that the gross weight limit isn't a hard rule is just wrong. Aircraft manufacturers gain nothing by understating load capacity. The certificated max weight is as high as can be safely allowed. That is clearly not true. A lot of aircraft design is trading off one desirable feature against another. We're talking gliders not airplanes. I claim it's precisely true. Trade-offs you mention were made by the engineers who signed the airworthiness documents. Estimates made on the flight line don't even remotely rise to that level of expertise. In the case of powered aircraft the MTOW is the weight used to establish the published takeoff run, the distance to clear a 50' obstacle, the rate of climb, the service ceiling, and probably others. If you're operating out of short strips then you want to know how much load you can carry. If you're operating a cessna off a 4 km runway at sea level with no obstructions then it will be perfectly safe to operate somewhat over MTOW, especially if the extra weight is carried in the wings. Although an overweight glider could make an aero tow takeoffs hazardous under some conditions for the same reasons. In the case of, for example, our club's DG1000 basic trainers, the aircraft is permitted to do unlimited aerobatics with a +7/-5 G rating at MTOW. If that's not a requirement on a particular flight and you're happy with the +5/-3 G like most other gliders then you could operate at some higher weight. Yes, you can fly an aerobatic glider at a heavier weight if flown within standard class G limits. But, we were not talking about aerobatic gliders. There is really no excuse for operating outside the CG envelope. *The JAR 110 Kg seat limit is a little restrictive for us chubby Americans but, hey, it's an incentive to cut back on the bacon burgers and fries. Seat weight is one thing, CofG is quite another. With the tail ballast box full, those same DG1000's are within the published CofG limit even with two pilots well over 110 kg each. We're not talking about 'CofG' we're talking about gross weight. The seat is primary structure just like a wing spar and is only designed to support 110 Kg. In many, if not most, gliders, if the seat structure fails, the flight controls would be jammed - just as catastrophic as a wing failure. Bottom line, if you fly outside the airworthiness certification limits, you're a fool claiming to be smarter than the engineers who designed the glider. Yes, I know the BGA allows over gross flights. |
#16
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Fat boy wants to soar...
Hi Bill
I agree on the - fly within the limits. But I must disagree on your view that seats are designed for 110kg. There is no rule that says you have to limit it to 110kg. Read CS 22.25(a)(2)- the a minimum assumed single seat load is 110kg - and all the force multipliers work fomr that assumption. Effectively - For JAR-22/EASA CS-22 they are designed to withstand 110kg*40g - that's 4400kg... So - no - a fat guy sitting on one is not going to break it. Although some of them might deform enough to be a problem at reachable G levels. This is the "test pilot" part of exceeding the design limits. It's all here if you feel like reading. http://www.easa.europa.eu/ws_prod/g/rg_certspecs.php CS 22.625 Fitting factors - Says you have to multiply by 1.33 for seat loads. CS 22.561 CS 22.785 Seats and safety harnesses says it has to be strong enough to handle the force multipliers specified for emergency landings and crash resistance with the designed seat load. The minimum load for calculation of strength required being 110kg. Practically the force multipliers are so high the they design for 110kg. Practically - the size of the cockpit naturally limits the amount of load you can put on the seat pan. I sincerely doubt anyone is going to manage a 200kg load on a single seat... Of more interest structurally is the total mass of non-lifting components. That puts bending load into the main spar - so it does matter. Although - again the multipliers used are very high. You are unlikely to exceed safe strength margins unless you are executing aerobatic manoeuvres. Bruce bildan wrote: On Mar 21, 2:05 am, Bruce Hoult wrote: On Mar 21, 3:15 am, bildan wrote: The idea that the gross weight limit isn't a hard rule is just wrong. Aircraft manufacturers gain nothing by understating load capacity. The certificated max weight is as high as can be safely allowed. That is clearly not true. A lot of aircraft design is trading off one desirable feature against another. We're talking gliders not airplanes. I claim it's precisely true. Trade-offs you mention were made by the engineers who signed the airworthiness documents. Estimates made on the flight line don't even remotely rise to that level of expertise. In the case of powered aircraft the MTOW is the weight used to establish the published takeoff run, the distance to clear a 50' obstacle, the rate of climb, the service ceiling, and probably others. If you're operating out of short strips then you want to know how much load you can carry. If you're operating a cessna off a 4 km runway at sea level with no obstructions then it will be perfectly safe to operate somewhat over MTOW, especially if the extra weight is carried in the wings. Although an overweight glider could make an aero tow takeoffs hazardous under some conditions for the same reasons. In the case of, for example, our club's DG1000 basic trainers, the aircraft is permitted to do unlimited aerobatics with a +7/-5 G rating at MTOW. If that's not a requirement on a particular flight and you're happy with the +5/-3 G like most other gliders then you could operate at some higher weight. Yes, you can fly an aerobatic glider at a heavier weight if flown within standard class G limits. But, we were not talking about aerobatic gliders. There is really no excuse for operating outside the CG envelope. The JAR 110 Kg seat limit is a little restrictive for us chubby Americans but, hey, it's an incentive to cut back on the bacon burgers and fries. Seat weight is one thing, CofG is quite another. With the tail ballast box full, those same DG1000's are within the published CofG limit even with two pilots well over 110 kg each. We're not talking about 'CofG' we're talking about gross weight. The seat is primary structure just like a wing spar and is only designed to support 110 Kg. In many, if not most, gliders, if the seat structure fails, the flight controls would be jammed - just as catastrophic as a wing failure. Bottom line, if you fly outside the airworthiness certification limits, you're a fool claiming to be smarter than the engineers who designed the glider. Yes, I know the BGA allows over gross flights. --- news://freenews.netfront.net/ - complaints: --- |
#17
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Fat boy wants to soar...
Check your POH - it will say 110KG max in each seat. The POH is part
of the airworthiness certification documents and is the legal, and engineering, standard. The operator of an aircraft is given no latitude in interpreting this. To say a glider seat is designed to withstand 4400 G positive is ridiculous. It shows the danger of trying to 'out-engineer' the people who designed the glider. I don't know what part of the world you live in but I know one FAA Operations Inspector who has a bathroom scale in his car. I know he has zero tolerance for violations of POH limits like gross weight and seat limits. On Mar 21, 3:16*pm, Bruce wrote: Hi Bill I agree on the - fly within the limits. But I must disagree on your view that seats are designed for 110kg. There is no rule that says you have to limit it to 110kg. Read CS 22.25(a)(2)- the a minimum assumed single seat load is 110kg - and all the force multipliers work fomr that assumption. Effectively - For JAR-22/EASA CS-22 they are designed to withstand 110kg*40g - that's 4400kg... So - no - a fat guy sitting on one is not going to break it. Although some of them might deform enough to be a problem at reachable G levels. This is the "test pilot" part of exceeding the design limits. It's all here if you feel like reading.http://www.easa.europa.eu/ws_prod/g/rg_certspecs.php CS 22.625 Fitting factors - Says you have to multiply by 1.33 for seat loads. CS 22.561 CS 22.785 Seats and safety harnesses says it has to be strong enough to handle the force multipliers specified for emergency landings and crash resistance with the designed seat load. The minimum load for calculation of strength required being 110kg. Practically the force multipliers are so high the they design for 110kg. Practically - the size of the cockpit naturally limits the amount of load you can put on the seat pan. I sincerely doubt anyone is going to manage a 200kg load on a single seat... Of more interest structurally is the total mass of non-lifting components. That puts bending load into the main spar - so it does matter. Although - again the multipliers used are very high. You are unlikely to exceed safe strength margins unless you are executing aerobatic manoeuvres. Bruce bildan wrote: On Mar 21, 2:05 am, Bruce Hoult wrote: On Mar 21, 3:15 am, bildan wrote: The idea that the gross weight limit isn't a hard rule is just wrong. Aircraft manufacturers gain nothing by understating load capacity. The certificated max weight is as high as can be safely allowed. That is clearly not true. A lot of aircraft design is trading off one desirable feature against another. We're talking gliders not airplanes. *I claim it's precisely true. Trade-offs you mention were made by the engineers who signed the airworthiness documents. *Estimates made on the flight line don't even remotely rise to that level of expertise. In the case of powered aircraft the MTOW is the weight used to establish the published takeoff run, the distance to clear a 50' obstacle, the rate of climb, the service ceiling, and probably others. If you're operating out of short strips then you want to know how much load you can carry. If you're operating a cessna off a 4 km runway at sea level with no obstructions then it will be perfectly safe to operate somewhat over MTOW, especially if the extra weight is carried in the wings. Although an overweight glider could make an aero tow takeoffs hazardous under some conditions for the same reasons. In the case of, for example, our club's DG1000 basic trainers, the aircraft is permitted to do unlimited aerobatics with a +7/-5 G rating at MTOW. If that's not a requirement on a particular flight and you're happy with the +5/-3 G like most other gliders then you could operate at some higher weight. Yes, you can fly an aerobatic glider at a heavier weight if flown within standard class G limits. *But, we were not talking about aerobatic gliders. There is really no excuse for operating outside the CG envelope. *The JAR 110 Kg seat limit is a little restrictive for us chubby Americans but, hey, it's an incentive to cut back on the bacon burgers and fries. Seat weight is one thing, CofG is quite another. With the tail ballast box full, those same DG1000's are within the published CofG limit even with two pilots well over 110 kg each. We're not talking about 'CofG' we're talking about gross weight. *The seat is primary structure just like a wing spar and is only designed to support 110 Kg. *In many, if not most, gliders, if the seat structure fails, the flight controls would be jammed - just as catastrophic as a wing failure. Bottom line, if you fly outside the airworthiness certification limits, you're a fool claiming to be smarter than the engineers who designed the glider. *Yes, I know the BGA allows over gross flights. --- news://freenews.netfront.net/ - complaints: --- |
#18
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Fat boy wants to soar...
On Mar 22, 11:23*am, bildan wrote:
To say a glider seat is designed to withstand 4400 G positive is ridiculous. *It shows the danger of trying to 'out-engineer' the people who designed the glider. That's like trying to say that people who slow below the posted speed limit for corners on a mountain road and go a bit faster on the straights are trying to "out engineer" the people who designed the road. If you think doing things precisely according to book and never exercising any judgement will keep you safe you are likely to find yourself in big trouble. Judgement is properly exercised in BOTH directions -- knowing when you need to modify the book numbers downward is no more and no less valid than knowing when and why you can modify them upwards. Think! I don't know what part of the world you live in but I know one FAA Operations Inspector who has a bathroom scale in his car. *I know he has zero tolerance for violations of POH limits like gross weight and seat limits. I don't doubt it. There are brainless Jobsworths everywhere. |
#19
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Fat boy wants to soar...
On 21 mar, 22:16, Bruce wrote:
Hi Bill I agree on the - fly within the limits. But I must disagree on your view that seats are designed for 110kg. There is no rule that says you have to limit it to 110kg. Read CS 22.25(a)(2)- the a minimum assumed single seat load is 110kg - and all the force multipliers work fomr that assumption. Effectively - For JAR-22/EASA CS-22 they are designed to withstand 110kg*40g - that's 4400kg... So - no - a fat guy sitting on one is not going to break it. Although some of them might deform enough to be a problem at reachable G levels. This is the "test pilot" part of exceeding the design limits. It's all here if you feel like reading.http://www.easa.europa.eu/ws_prod/g/rg_certspecs.php CS 22.625 Fitting factors - Says you have to multiply by 1.33 for seat loads. CS 22.561 CS 22.785 Seats and safety harnesses says it has to be strong enough to handle the force multipliers specified for emergency landings and crash resistance with the designed seat load. The minimum load for calculation of strength required being 110kg. Practically the force multipliers are so high the they design for 110kg. Practically - the size of the cockpit naturally limits the amount of load you can put on the seat pan. I sincerely doubt anyone is going to manage a 200kg load on a single seat... Of more interest structurally is the total mass of non-lifting components. That puts bending load into the main spar - so it does matter. Although - again the multipliers used are very high. You are unlikely to exceed safe strength margins unless you are executing aerobatic manoeuvres. Bruce bildan wrote: On Mar 21, 2:05 am, Bruce Hoult wrote: On Mar 21, 3:15 am, bildan wrote: The idea that the gross weight limit isn't a hard rule is just wrong. Aircraft manufacturers gain nothing by understating load capacity. The certificated max weight is as high as can be safely allowed. That is clearly not true. A lot of aircraft design is trading off one desirable feature against another. We're talking gliders not airplanes. *I claim it's precisely true. Trade-offs you mention were made by the engineers who signed the airworthiness documents. *Estimates made on the flight line don't even remotely rise to that level of expertise. In the case of powered aircraft the MTOW is the weight used to establish the published takeoff run, the distance to clear a 50' obstacle, the rate of climb, the service ceiling, and probably others. If you're operating out of short strips then you want to know how much load you can carry. If you're operating a cessna off a 4 km runway at sea level with no obstructions then it will be perfectly safe to operate somewhat over MTOW, especially if the extra weight is carried in the wings. Although an overweight glider could make an aero tow takeoffs hazardous under some conditions for the same reasons. In the case of, for example, our club's DG1000 basic trainers, the aircraft is permitted to do unlimited aerobatics with a +7/-5 G rating at MTOW. If that's not a requirement on a particular flight and you're happy with the +5/-3 G like most other gliders then you could operate at some higher weight. Yes, you can fly an aerobatic glider at a heavier weight if flown within standard class G limits. *But, we were not talking about aerobatic gliders. There is really no excuse for operating outside the CG envelope. *The JAR 110 Kg seat limit is a little restrictive for us chubby Americans but, hey, it's an incentive to cut back on the bacon burgers and fries. Seat weight is one thing, CofG is quite another. With the tail ballast box full, those same DG1000's are within the published CofG limit even with two pilots well over 110 kg each. We're not talking about 'CofG' we're talking about gross weight. *The seat is primary structure just like a wing spar and is only designed to support 110 Kg. *In many, if not most, gliders, if the seat structure fails, the flight controls would be jammed - just as catastrophic as a wing failure. Bottom line, if you fly outside the airworthiness certification limits, you're a fool claiming to be smarter than the engineers who designed the glider. *Yes, I know the BGA allows over gross flights. --- news://freenews.netfront.net/ - complaints: ---- Ocultar texto de la cita - - Mostrar texto de la cita - Apart from any structural considerations, many gliders handle and perform like pigs if you have somebody really heavy in the front seat. The BGA will generally permit a 10% cockpit overload, but the glider then becomes non-aerobatic above the manufacturer´s original recommended figure. EASA may well stop this pracice at some point in the future. Derek C |
#20
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Fat boy wants to soar...
I flew a L-33 with max pilot weight of 287#. The POH of my Kestrel 19
limits pilot weight through CoG limitations and MTOW (dry). As for the BGA allowance, I thought it was 3% -- at least that's what's I've seen on the BGA Data Certificates. |
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