If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Empty/Gross weight Vs. Max. Pilot weight
Hi All!
I'm confused by the weight restrictions on most gliders. As an example the Lak-12 specs show the following: Empty weight: 794lbs. Gross weight: 1433lbs. Payload: 693lbs. Max. Water 416lbs. Max. Pilot: 242lbs.(110KG) Why is the pilot weight restricted to a max. of 242lbs? It seems to me like the difference between the empty & gross weights could be made up of any combination of pilot, equipment & ballast as long as the gross weight is not exceeded & the C.G. remains within limits. What am I not understanding here? As any of you know who have read my numerous recent questions to this group I am a new and BIG pilot trying to figure out which ships will work for me & learn a little more about this endeavor. I could weigh as much as 250lbs fully equipped in the winter. That appears to exceed the limits of almost all gliders. Again the generous information that I've gotten from you all is just great! Thanks! David Roth |
#2
|
|||
|
|||
maybe max weight of none lifting parts
|
#3
|
|||
|
|||
Flyhighdave wrote:
Hi All! I'm confused by the weight restrictions on most gliders. As an example the Lak-12 specs show the following: Empty weight: 794lbs. Gross weight: 1433lbs. Payload: 693lbs. Max. Water 416lbs. Max. Pilot: 242lbs.(110KG) Why is the pilot weight restricted to a max. of 242lbs? It seems to me like the difference between the empty & gross weights could be made up of any combination of pilot, equipment & ballast as long as the gross weight is not exceeded & the C.G. remains within limits. What am I not understanding here? The difference is where the weight is carried: - in the wings, it reduces the load on the wing spars, especially at the root. That's why it's carried there. - in the cockpit, it increases the load on the wig spares, especially at the root. This is why there is a "non-lifting" parts (basically, the fuselage) load limit, in addition to an overall limit. The actual limit may also be set by things like seat and belt attachment strength, not just the wing strength. You don't know, unless the designer tells you. -- ----- change "netto" to "net" to email me directly Eric Greenwell Washington State USA |
#4
|
|||
|
|||
See JAR 22
http://www.jaa.nl/section1/jars/445499.pdf Sections 22.25 and 22.785 for details. 110kg is minimum maximum under the above, but also an upper limit in many cases. Older sailplanes built under OSTIV may have all a max weight of non-flying parts that allows 250lb+ pilot weights and a safe CG range far above that, like 350lbs. Frank Whiteley "Flyhighdave" wrote in message ... Hi All! I'm confused by the weight restrictions on most gliders. As an example the Lak-12 specs show the following: Empty weight: 794lbs. Gross weight: 1433lbs. Payload: 693lbs. Max. Water 416lbs. Max. Pilot: 242lbs.(110KG) Why is the pilot weight restricted to a max. of 242lbs? It seems to me like the difference between the empty & gross weights could be made up of any combination of pilot, equipment & ballast as long as the gross weight is not exceeded & the C.G. remains within limits. What am I not understanding here? As any of you know who have read my numerous recent questions to this group I am a new and BIG pilot trying to figure out which ships will work for me & learn a little more about this endeavor. I could weigh as much as 250lbs fully equipped in the winter. That appears to exceed the limits of almost all gliders. Again the generous information that I've gotten from you all is just great! Thanks! David Roth |
#5
|
|||
|
|||
Dear David,
the reason for the max pilot weight of 110 kg is rather simple: The (old) European certification specifications for gliders, JAR22, request, that the center of gravity stays within its limits at pilot weights from 70 kg to 110 kg with parachute (!!) without ballast, and that at least a pilot of 110 kg must be carried (see JAR22.23-22.25). For a two seater, the value is 180 kg. So other calculations, e.g. seat strength, belt fixpoints and so on are based on this minimum value for the max. pilot weight of 110 kg, and this 110 kg are printed in the glider specs. This has nothing to do with the max. weight of 'not lifting parts' or with the payload. So for pilots above 110 kg, it will not be easy to find a glider, which they can fly legally. Anyhow, you should contact the manufacturer of your glider. It might well be he knows a solution. Best regards Walter |
#6
|
|||
|
|||
Why is pilot weight restricted?.... because that is the weight limit it was
certified to. BT "Flyhighdave" wrote in message ... Hi All! I'm confused by the weight restrictions on most gliders. As an example the Lak-12 specs show the following: Empty weight: 794lbs. Gross weight: 1433lbs. Payload: 693lbs. Max. Water 416lbs. Max. Pilot: 242lbs.(110KG) Why is the pilot weight restricted to a max. of 242lbs? It seems to me like the difference between the empty & gross weights could be made up of any combination of pilot, equipment & ballast as long as the gross weight is not exceeded & the C.G. remains within limits. What am I not understanding here? As any of you know who have read my numerous recent questions to this group I am a new and BIG pilot trying to figure out which ships will work for me & learn a little more about this endeavor. I could weigh as much as 250lbs fully equipped in the winter. That appears to exceed the limits of almost all gliders. Again the generous information that I've gotten from you all is just great! Thanks! David Roth |
#7
|
|||
|
|||
|
#9
|
|||
|
|||
"Robert John" wrote in
message ... Bruce, I don't know what the insurance arrangements are in the places you fly, but what would worry me here in the UK is this: Flight outside placarded limits is outside CofA. Flight without CofA is uninsured. Are you sure you're covered in the event of a prang? It's an easy get-out for an insurance company faced with a potentially big claim. Rob I believe the same would apply here in the USofA.. obvious flight over max weight limitations.. no insurance coverage.. don't forget that some of those gliders also have, max weight for non lifting parts you may be within the Max GW, but not the max of the non lifting parts BT |
#10
|
|||
|
|||
Robert John wrote in message ...
Bruce, I don't know what the insurance arrangements are in the places you fly, but what would worry me here in the UK is this: Flight outside placarded limits is outside CofA. Flight without CofA is uninsured. Are you sure you're covered in the event of a prang? It's an easy get-out for an insurance company faced with a potentially big claim. Rob NTSB database is well populated with aircraft accident reports that list flying over max certificated gross weight as a contributing, or primary, accident cause. Can anyone cite a single case where insurance payout was refused on that basis. Please note that I am NOT advocating flying over any weight limit, I just think the "you won't be insured" argument is a bit thin. Andy |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
AOPA Stall/Spin Study -- Stowell's Review (8,000 words) | Rich Stowell | Aerobatics | 28 | January 2nd 09 02:26 PM |
Diamond DA-40 with G-1000 pirep | C J Campbell | Instrument Flight Rules | 117 | July 22nd 04 05:40 PM |
RV-7a baggage area | David Smith | Home Built | 32 | December 15th 03 04:08 AM |
Moving violation..NASA form? | Nasir | Piloting | 47 | November 5th 03 07:56 PM |
Effect of Light Sport on General Aviation | Gilan | Home Built | 17 | September 24th 03 06:11 AM |