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
> 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
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" <flyhi...@aol.com> wrote in message
news:20040103114908...@mb-m04.aol.com...
BT
"Flyhighdave" <flyhi...@aol.com> wrote in message
news:20040103114908...@mb-m04.aol.com...
> 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?
- max weight of non-lifting parts (think: strength of the fuselage
mountings)
- seat and seatbelt mounting point strength
- C of G out of limits, possibly meaning not enough up elevator
available at low speeds (e.g. landing round-out)
> 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.
The day I'm 242 lbs, including parachute, will be a minor miracle.
Right now I'm 260. Several months ago, around the beginning of spring,
I was over 270. Several years ago when I was dotcommed for a while and
bicycled 30 - 50 km every day during a Chicago summer I got down to
about 250 briefly.
I've flown quite a few gliders, at quite a few places in NZ and the USA,
and no one has *ever* suggested that I shouldn't be flying their gliders
due to weight. Sometimes I've had a conversation with an engineer or
instructor and we've agreed that I'll mentally knock 5 or 10 knots off
the placarded rough air/manouvering speeds and keep the G loading down.
I do that anyway. It's probably not necessary.
Just because it's easy to do, here's a logbook dump of the types I've
flown. Not a lot of experience, I know, but more than zero...
Glider Type Flights Total PIC Avg
=============== ======= ====== ====== ===
Club Libelle 36 56:55 56:55 95
Blanik 110 46:56 27:38 26
Janus 43 36:55 30:02 52
Ka6CR 21 26:26 26:26 76
PW-5 19 20:04 20:04 63
Twin Astir 27 14:42 12:08 33
Std Libelle 9 9:32 9:32 64
Grob 103 3 3:13 3:13 64
ASK21 6 2:42 2:42 27
Ka7 16 1:52 0:14 7
ASK13 3 1:32 1:15 31
Duo Discus 1 1:07 0:00 67
Puchacz 1 1:02 0:00 62
T53 1 0:37 0:00 37
Phoebus C 1 0:33 0:33 33
Pirat 1 0:19 0:19 19
I haven't had problems with any of the above types, although I'm
probably over the placarded weight for all of them (and some, such as
the K6 and the Std Libelle are a bit of a squeeze).
People flying marginal powered aircraft are, rightly, quite a bit more
concerned about weights. Put full tanks and two big people in a Cessna
152 and it probably won't climb at *all*.
-- Bruce
At 06:30 12 January 2004, Bruce Hoult wrote:
>In article ,
> flyhi...@aol.com (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?
>
>- max weight of non-lifting parts (think: strength
>of the fuselage
>mountings)
>
>- seat and seatbelt mounting point strength
>
>- C of G out of limits, possibly meaning not enough
>up elevator
>available at low speeds (e.g. landing round-out)
>
>
>> 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.
>
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
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
so you'd have to try to find specific individuals that would report it
BT
"Andy Durbin" <a.du...@netzero.net> wrote in message
news:f8509ec7.04011...@posting.google.com...
> 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.
Not unless it's a cause of the incident leading to the claim.
Every plane crash ever probably violates at least one regulation, but
insurance companies don't decline them all, do they?
-- Bruce
> NTSB database is well populated with aircraft accident reports that
> list flying over max certificated gross weight as a contributing, or
> primary, accident cause.
I'm sure that's the case for lots of Cezznas, a lot of which have very
marginal climb at gross weight in hot/high conditions. But are there
any such entries for gliders?
> 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.
I think it's extremely thin. I'll pay a *lot* more attention to "you'll
kill yourself and here's why".
-- Bruce