IS28B OR BLANIK L-13?
tinb...@lankaster.com
Can anyone comment on the relative +/- of these ships.
The soaring directory shows the IS28 with a higher L/D, lower payload.
Do not know max. wing loading or aerobatic restrictions.
The L-13 seems to have a reputation for being fairly rugged. Having
flown the blanik only I am curious if the ships handle in simular
manner.
Have heard complaints of parts availablity, price concerning both.
Any insights would be appreciated
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John Wren
tinb...@lankaster.com wrote:
> The L-13 seems to have a reputation for being fairly rugged. Having
> flown the blanik only I am curious if the ships handle in simular
> manner.
>
> Have heard complaints of parts availablity, price concerning both.
Parts are no problem for the L13. Go to Blanik America (See ad in Soaring).
The L13 is the second most common trainer in North America (210 at peak).
JW
Bill Tisdale
We have both in our club, the L-13 is a club ship.. easier to fly well than
the IS28, the L-13 L/D is about 28/1 and I believe the IS28 is about 34/1.
The Blanik is much easier to move around on the ground as the IS28 is a very
heavy sailplane. You want a strong tow ship on 100 degree days..
The L-13 checks in at about 600lbs empty and GW at apx 1040. while the IS28
empty weight approaches 1000lbs. If you are going to trailer the IS28, make
sure you have more than 2 people to rig/derig.
As for parts and pricing... Blanik America has been available for parts when
needed. I cannot comment on the IS28, as I have not had to order parts for
it.
Both are within a few thousand dollars of each other.. I have seen the L-13
and an IS28 listed in the $17K area.
tinb...@lankaster.com wrote:
> Can anyone comment on the relative +/- of these ships.
>
> The soaring directory shows the IS28 with a higher L/D, lower payload.
> Do not know max. wing loading or aerobatic restrictions.
>
> The L-13 seems to have a reputation for being fairly rugged. Having
> flown the blanik only I am curious if the ships handle in simular
> manner.
>
> Have heard complaints of parts availablity, price concerning both.
>
Jean Richard
tinb...@lankaster.com wrote:
>
> Can anyone comment on the relative +/- of these ships.
>
> The soaring directory shows the IS28 with a higher L/D, lower payload.
The IS-28 is a better performer than the Blaník L13,
with an L/D of 33 compare to 28, and with negative
setting flaps allowing to get that performance at
higher speed.
The IS-28 has an empty mass of 330 kg and a maximum
gross of 590 while the Blaník is 292 kg empty and
500 kg at gross. Once again, the + is for the Lark.
The Blaník is somewhat easier to fly and probably more
forgiving (mostly for beginners). But the IS-28 is not
hard to fly, but only a little bit heavy on control
(not worst than the Grob Twin Astir or the Twin II
however).
And the IS-28 is more suitable for after solo training.
It spins very well and you can learn use of the flaps.
BUT...
The IS-28 lifespan is limited to 20 years only (people
are working hard to get extension and the builder doesn't
cooperate) - That could mean a rapid depreciation.
Blaník is providing a very good after sale service
while the Lark IS-28 can look like an orphean when
it's time to get parts (poor service not to say no
service at all).
Landing gear is a little bit weak on the IS-28 and
a hard landing can mean a broken gear or at least a
bent one.
The main gear is so positioned that the tail is very
heavy on the ground, making ground handling more
difficult than the Blaník (be careful with your back
when you have to lift the heavy tail of that plane).
> Do not know max. wing loading or aerobatic restrictions.
Nor the IS-28 nor the Blaník L13 are real aerobatic
sailplanes. For aerobatic training, only ASK-21,
DG-500T/505T and Grob Twin III Acro are certified.
And only the DG is certified for some inverted
manoeuvres.
> Having
> flown the blanik only I am curious if the ships handle in simular
> manner.
Take off run is longer in the IS-28, control response is
slower, you fly it faster. For landing, I prefer the
IS-28 since you can do two wheel landing (preferable with
most of the sailplane) without hearing the tailwheel
scratching the ground - I would prefer a skid on the
Blaník instead that too small and castoring wheel. The
IS-28 is easy to land smoothly but you need the right
attitude (it's better for student since the Blaník is
giving way to loosy landing methods - you can land it
at 40 knots or 60 knots without any punishment for a
poor speed control).
J. Richard
Walt Konecny
Bill Tisdale wrote in message <34AB1B76...@ix.netcom.com>...snip
>The L-13 checks in at about 600lbs empty and GW at apx 1040. while the IS28
>empty weight approaches 1000lbs. If you are going to trailer the IS28, make
>sure you have more than 2 people to rig/derig.
The published numbers are: Blanik 644 empty, 1102 max, Lark 794 empty, 1300
max. This gives the Lark approx 50 pounds more payload. The Lark however,
"feels" like it weighs 1000 pounds when groundhandling it. Part of the
problem is the relatively forward location of the main wheel, which makes
the tail VERY heavy. Our club had a Lark for approx 10 years, during which
time I flew it just under 200 hours. Loved it! Great for all soaring
conditions. (At least in the Western U.S.) If you have one, you will hate
it when groundhandling, but will love it as soon as the towplane starts
moving.
>
>As for parts and pricing... Blanik America has been available for parts
when
>needed. I cannot comment on the IS28, as I have not had to order parts for
>it.
Blanik America provides good support, because that is what Vitek Siroky does
for a living. Howard Allman (sp?) who is the Lark distributor in the U.S.
does something else for a living (737 jock, I believe) and when you call his
number, you get either his answering machine or his wife. I don't know
about other people's experiences with Howard, but as for me, I have placed
several orders and received nothing. One of those orders was for a new
IS28B2. A partner and I wanted one because we enjoyed flying our club's
Lark. After I called Howard to order it, he never called me back. After
leaving more messages for him over a period of a month and not getting any
return calls, we "settled" for a Duo Discus.
>
>Both are within a few thousand dollars of each other.. I have seen the L-13
>and an IS28 listed in the $17K area.
L-13 usually sell for around $13,500 to $15,500, IS28B2 for $15,000 to
$18,000. For rigging / de-rigging the Lark, have at least 3 healthy people
available. Another issue with the Lark is the 20 year airframe life
limitation. I'm not sure what has been done about that.
As far as actual flying is concerned, I would choose the Lark over the L-13
or L-23 any day.
Walt Konecny
ASW-27 "1WK"
Wings and Wheels // Tim Mara
Our club has operated Both (2)L-13's and (1) IS28b2. We sold one Blanik a
few years ago to buy the IS28 so we could have a transition fleet which also
included (1) SGS-233......then unfortunately had one of our students total
the last remaining L-13..
The SGS-233 was OK for basic instruction up to solo as it was simple enough
and very forgiving and allowed the students to gain confidence
quickly......sort of like soloing a Buick! However, the 233 was not good for
training most pilots for what they might encounter later on....The L-13 was
up to the task of basic training up to training for most semi-modern single
seaters (something I personally don't think the SGS-233 can accomplish) but
takes a bit longer to solo new students.
The Lark could be used for basic training up to solo but is better suited
for teaching transition to more complex and high performance sailplanes..The
Lark is still nothing like flying a modern Glass single seater but does
teach energy management due to it's higher weights, Higher performance and
additional required "Touch" to make it perform at it's best.. The Lark is
still very easy to fly and ideal for High Performance training and ride
giving..it's roomier than the Blanik and from seat visibility is superb,
back seat is so-so but not as poor as the Blanik and a huge improvement over
visibility in the 233!
We actually considered buying Blanik L-23's before we purchased the Lark new
in 1995 but almost everyone we spoke to about the L23 who had also owner
L13's told us that the preferred the L-13 over the L-23 for several
reasons. The Lark even new was cheaper than the Blanik (Ours was under
$25,000.00 NEW ((Less instruments)) delivered!)
The Quality of the Lark is excellent, possibly even Better than the Blanik,
the Lark is stronger, Higher performance, and quite modern looking which
helps to attract new prospects to soaring and better for selling rides which
we also do to help support the club...The Lark is also much easier to
enter/exit as the fuselage sides are much lower than the L-13.
The Lark is heavy to move on the ground (empty weight is about 900 pounds)
as it is a tail-dragger and does not have a swivel tailwheel.....a simple
device can be made for ground handling to eliminate this problem.
The Blanik (IMHO) was the very best trainer we ever had, it offered good
performance, reasonable ease of flight for training and also was perfectly
honest in that it would spin, stall and soar much like sailplanes our
students might encounter later on in soaring. The Blanik is somewhat fragile
in some areas so it needs to be inspected carefully by prospective buyers.
The area behind the rear seat bulkhead has been found to have be a weak area
on many L-13's and it's not uncommon to find this bulkhead damaged even on
flying Blaniks! Inspect this area carefully! Our Blanik that was totaled was
basically due to damage in this area due to a student catching the wing in
high grass and brush and ground-looping, I've also seen similar damage to
other "Totaled" Blanks from similar accidents.We found cracks in ours (both
of them) around the base of the Vertical fins, Damage in the landing gear
steel structures area due to corrosion (Ours were stored in hangers for much
of their life) and damage in the landing gear area where the gear was
attached due to hard landings. We also found loose and working rivets on the
wings which had to be replaced. These were all on 1976 vintage Blaniks with
less than 1000 hours total time. The tailwheels(or skids) on the Blaniks are
a constant problem and we typically had to re-build these at least 2-3 times
a year (the Lar uses a conventional 210x65 Pneumatic tire for a tailwheel).
As far as assembly, neither the L-13 or IS28b2 are hard to assemble or
disassemble, both will require about 4-5 people due to the size and weight
of the structures. I actually think the Lark is easier to assemble than the
L-13 due to the expanding main wing pin and access to control hook-ups but
the wings are slightly heavier on the Lark. Both are quite straight forward
as 2 seat trainers go.
Summary: I like Both the L-13 and IS28b2 for use in clubs, they however
probably suit different purposes. If you are looking for something is a
Basic trainer the Blanik is hard to beat. The cost is low, performance is OK
for a trainer and it really does do a much better job the SGS-233 at
preparing students for more modern sailplanes.
If however you already have a Basic trainer and you want to use this as a
Step-Up to modern sailplanes, or if it's for personal use, or for rides the
Lark is excellent.
Both have some aerobatics capability (Loops, 1/2 roll-1/2 Loop, spins, stall
turns ect)
Both are quite good and reasonably low cost...
tim
tinb...@lankaster.com wrote in message
<883609490....@dejanews.com>...
>Can anyone comment on the relative +/- of these ships.
>
>The soaring directory shows the IS28 with a higher L/D, lower payload.
>Do not know max. wing loading or aerobatic restrictions.
>
>The L-13 seems to have a reputation for being fairly rugged. Having
>flown the blanik only I am curious if the ships handle in simular
>manner.
>
F.L. Whiteley
In recent years, more of the L-13's have been showing up with cracked
frames in the tail.
----------
> From: tinb...@lankaster.com
> Newsgroups: rec.aviation.soaring
> Subject: IS28B OR BLANIK L-13?
> Date: Wednesday, December 31, 1997 4:11 PM
>
> Can anyone comment on the relative +/- of these ships.
>
> The soaring directory shows the IS28 with a higher L/D, lower payload.
> Do not know max. wing loading or aerobatic restrictions.
>
Unlikely an IS-28B2 weighs 1000lbs empty unless it's had extensive repair
or is heavily overpainted.
> The L-13 seems to have a reputation for being fairly rugged. Having
> flown the blanik only I am curious if the ships handle in simular
> manner.
>
http://www.nwinternet.com/~blanikam/ba/home.htm
The L-23 compares very closely with the L-13, except for the missing flaps
and T-tail. Weights and capacities are very close. The Acro L-13 is a bit
different.
Both are very good trainers. They are somewhat different aircraft in
concept.
The original L-13's had a 3650 hour life, as I recall. I believe this was
extended in
1000 hour blocks through special inspections. I don't think it was ever an
AD, so compliance may be spotty. Shipping the glider back to the factory
for rework extended the life to 6000 hours. New L-23's have a 6000 hour
service life if ground launched. 10,000 hours, if aerotowed. You'll have
to contact Vitek for details. The flaps make slow thermaling a treat and
1/2 flap improve ground launch performance. L-13's are a bit delicate in
the aft end. The tail skid/wheel fittings
fail periodically. Good maintenance prevents service interruptions. I've
known one Blanik to lose it's rudder in flight and another to have the
elevator rigging fail while being wheeled to the launch point. My former
English club lost a Blanik on winch launch entirely due to instructor
error, stalling at low altitude as the winch lost power. FWIW, both
wingtips ended up on the ground and several fuselage frames were buckled.
Fortunately both student and instructor were only badly bruised in the
lower back. It could have been much worse. We lost a second L-13 in a
landing accident when the instructor, in avoiding a post in an unused part
of the airfield put the glider into a cyclone fence. The glider was
written off, but both occupants were unscathed. The only reason I mention
this is that reasonable cost of repair was higher than the value of the
glider, thus neither were rebuilt but scrapped for parts. Since the Czech
Republic has joined the capitalists, parts are more easily procured, but
much more expensive. Damaged Blaniks pretty much require use of factory
frames, ribs, and fittings. Sheet aluminum is less costly through a local
source. Undercarriages are semi-retract. Most clubs lock these
permanently in the down position to prevent gear collapse and damage to the
locking mechanism and frame damage. They can land gear up okay with a
small amount of wheel
protruding. Most in the US have bridle fittings for ground launching.
I've heard of two release failures with this mechanism. It requires more
turn around time between launch to configure the bridle. I prefer
retro-fitting a CG hook. This costs ~$1000US. Overall the L-13 thermals
well and gets good soaring from winch launching. It's okay for cross
country flying except on windy days. They aerobat well and are good for
spin training. The may be flown inverted, but clean out the mud first.
The IS-28B2 is heavier and like the Blanik, needs a lifting bar to hoist
the tail around properly. The Lark tail is best hoisted by two. This is
designed in to keep the nose from pitching down on tow. The IS-28B2 was
imported into the US in two types. The earlier S/N's, it's either 1-49, or
1-79, are placarded differently than later S/N's. It's on the STC, but my
copy is filed away at the moment. Unlike the Blanik, the Lark structure is
glued as well as riveted. This reduces the amount of oil canning to a
minimum. It's non-existent on many. Generally speaking, you'd think you
were in glass rather than metal. Both fore and aft seats will accomodate
taller pilots than the Blanik. The seating position is more supine and
suited to longer legs. The rear pilot's head is behind the edge of the
fuselage, but perspex panels give very good visibility.
The front seat joysticks of both the Blanik and Lark are quite tall to
accomodate high stick loads during aerobatics. The Lark is also aerobatic.
Not sure, but I think tail slides are prohibited in both. The Lark has a
reputation of spinning unexpectedly. If you study the wing prior to
flying, you'll find that the ailerons are very large chordwise. I'm
convinced that those who've themselves in unexpected spins have used poor
pilot technique in the incipient stage, forgetting or neglecting the
secondary effects of controls. This is a semi-aerobatic aircraft, not a
G-103,
nor a K-21. Yet, properly handled, it is suitable for basic glider pilot
training. The L/D gives reasonable cross country performance. It's a bit
prone to falling out in weak conditions. In a region where thermals are
strong and winds common, it gives the pilot a lot more performance than
other two seaters. It's flapped and runs well into wind, something a lot
of this range of two seaters doesn't do as well. The L/D remains low
enough
for an insurance break. Since the fuselage is a semi-monocoque structure,
repairs may require highly specialized skill. The undercarriage frames
will not take too many hard cross wind landings, but neither will a Blanik.
Neither glider will take rough field pounding like a 2-33. IMHO, they
wear best on a nice turf strip. The undercarriage is semi-retract like the
Blanik and it can be landed wheel up without damge. Both the Blanik and
Lark require several hands to rig. Both need about the same amount of
effort.
I wouldn't buy either with the expectation to tie them outside. I know
this is a US standard, but it's my experience that this is a false economy
in the long run. Both the Blanik and Lark have fabric covered controls.
Hail stones will dent them. Dust causes bearing and control deterioration.
UV and dust damage the finish and canopy. They corrode faster. They
become subject
to squall, wind, or nuisance damage. Just not worth it.
The Lark has a life of 10000 hours, 30000 landing, or 20 years. Yes,
according the Romanian Air Authority, 20 years. Tom Knauff coined this
'shelf-life'. IAR Brasov has a proposed life extension before the RAA the
last I heard. Benone Costea, IAR Brasov chief of R&D, has been
working on lifting the life restriction since 1995. Several IS-28B2's will
hit their 20th this year. It's
possible the owners will lose their STC. The gliders can then be
relicensed experimental which is okay for club or private use, but of no
use to FBO's or for rides. Until this is resolved, I wouldn't give over
$12,000 for a Lark with a trailer if it was over 15 years old. Okay, maybe
$14K with chutes and oxygen. About the same for a Blanik, only because of
easier resale due to acceptance. A Blanik is really worth about $2-3K less
than a Lark, again IMHO.
Some Aussies did an OSTIV paper in 1994 (I think) on fatigue life testing
of
the IS28B2. It was published in Technical Soaring. Hopefully, these
papers will some day be republished on the web or on CD-ROM. Mr. Costea
had never seen this paper and I faxed him a copy when I was in the UK
(USAF). They concluded that the Lark should continue in unrestricted
flight to about 14,500 hours, then restrict from aerobatics. One of the
Australian clubs had a fleet of six Larks and had amassed 32000 hours, with
one airframe over 12000 hours, I think. The did crack testing, crack creep
analysis, and loaded strain gauges on the airframe during their work. I
think Mr. Costea may have used this analysis in building his current life
extension case to the RAA. Be advised that the 10K hour/30K landing/20year
limit is the
second extension on the initial lifing.
Hope this helps. If you hear anything different or new, please keep me
informed.
Frank Whiteley
Colorado Soaring Association
p.s.: check http://www.gfa.org.au/adreg.htm and do a search for the
IS-28B2
ADs. There is a life limit from 96.8.26. Don't know the contents.
Also, on approach, the Lark will do much better with a +1 flap setting.
Neutral is too slick.
Bill Tisdale
Cracked frames (fuselage formers) come from landing with the tail first..
striking the tail wheel on the runway.. before the mainwheel touches.. usually
from landing with no flaps... landing with flaps.. lowers the nose and landing
attitude at the same airspeed..
wonder if the L-23 has the same problem.. I understand it is a flapless ship..
Jean Richard
>
> > The IS-28 lifespan is limited to 20 years only (people
> > are working hard to get extension and the builder doesn't
> > cooperate) - That could mean a rapid depreciation.
> >
>
> of airworthiness?
Exactly. There's at least one IS-28 grounded in Canada because
certification time has expired.
> I didn't know there was such a thing. Ship all those
> old unairworthy, 20 year old, IS-28 to the USA. We may be able to find
> a use for them. :-)
But there's some hope in the air. TC is preparing an AD concerning
a special inspection and maintenance program for those planes.
Everybody is hoping they will be back in the air in next summer.
J. Richard
F.L. Whiteley
From what I recall, there were problems with the first two L-23's imported
into the US. I spoke with Vitek about this at the SSA convention. A
factory repair was designed and incorporated into later L-23's. I believe
the earlier numbers were repaired though I not sure an AD was issued.
Of course, pilot technique has a lot to do with cumulative damage. So do
field conditions. None the less, it is very common to find problems with
the skid/tail wheel of Blaniks, requiring frequent maintenance. Likewise,
it is not uncommon to find the cracked frames over a long period of
training use. Our inspector found this in the UK where many glider fields
are turf and two point landings are the rule. Many of our club members
feel our field here in Colorado is too rough for a Blanik L-13 to stand up
to 'normal' training use. I tend to agree, but I'd still like one to get
better results from our winching capabilities.
Frank Whiteley
Bill Tisdale <btis...@ix.netcom.com> wrote in article
<34AC8572...@ix.netcom.com>...
> Cracked frames (fuselage formers) come from landing with the tail first..
> striking the tail wheel on the runway.. before the mainwheel touches..
usually
> from landing with no flaps... landing with flaps.. lowers the nose and
landing
> attitude at the same airspeed..
>
> wonder if the L-23 has the same problem.. I understand it is a flapless
ship..
>
> F.L. Whiteley wrote:
>
Jean Richard
Bill Tisdale wrote:
>
> Cracked frames (fuselage formers) come from landing with the tail first..
> striking the tail wheel on the runway.. before the mainwheel touches.. usually
> from landing with no flaps... landing with flaps.. lowers the nose and landing
> attitude at the same airspeed..
>
> wonder if the L-23 has the same problem.. I understand it is a flapless ship..
We had some cracks in the rear fuselage of one 2500 hours
Blaník. We had some discussions about that. Examination of
the location of those cracks suggest that it's not landing
tail first that can make those cracks (anyway, more than
99 % of landings are done on mainwheel in our club). It
seems more evident that it can be caused by the tail falling
on the ground (mostly after wheel braking with heavy pilots
in the front seat - nose touching the ground before the tail
start to fall heavily).
The cracks were found in an area where fin and rudder may
have induced fatigue, but not the tailwheel. So, keeping the
tail low is what we recommand to pilots. That doesn't mean
landing tail first, but only avoiding to keep the tail
1 metre high, and mostly, bringing the tail to the ground
before it falls by itself.
J. Richard
Fred Steadman
Jean Richard wrote:
> BUT...
>
> The IS-28 lifespan is limited to 20 years only (people
> are working hard to get extension and the builder doesn't
> cooperate) - That could mean a rapid depreciation.
>
Beg pardon? Are you saying the airplane is built with a "doomsday" loss
of airworthiness? I didn't know there was such a thing. Ship all those
Tomasz Sielicki
Fred,
It is true for several wooden glider types we use here in Poland, too. They
have 25 years lifespan and then it can only be prolonged (after a capital
repair) for 100 hours repeatedly . As most of Polish clubs cannot afford
this capital repair, many nice old gliders like Foka 4, Foka 5, Bocian and
Mucha just stay in hangars and wait (what for?).
Tomasz Sielicki
Bill Tisdale
As I was told.. the U.S. FAA was working on extending the "20 yr lifespan" but
was getting no help from the manufacturer.. have to wait and see.. I have seen
nothing official in writing.
If you check the new PW-5 stats.. you see that it was designed for a 20yr life
span.. but I do not know.. if this means it has an in-service experation.. I
do not know..
F.L. Whiteley wrote:
> Fred Steadman <fst...@fastlane.net> wrote in article
> <34AE71...@fastlane.net>...
> > Jean Richard wrote:
> > > BUT...
> > >
> > > The IS-28 lifespan is limited to 20 years only (people
> > > are working hard to get extension and the builder doesn't
> > > cooperate) - That could mean a rapid depreciation.
> > >
> >
> > Beg pardon? Are you saying the airplane is built with a "doomsday" loss
> > of airworthiness? I didn't know there was such a thing. Ship all those
> > old unairworthy, 20 year old, IS-28 to the USA. We may be able to find
> > a use for them. :-)
> >
> Experimental(ly), which is okay for clubs and private owners. There was a
> post in a while back that the factory had an extension up before the
> Romanian Air Authority. No details yet.
>
> F. Whiteley
F.L. Whiteley
James H. Hogue
> If you check the new PW-5 stats.. you see that it was designed for a 20yr life
> span.. but I do not know.. if this means it has an in-service experation.. I
> do not know..
The PW-5 does not have a 20 year limit to its service life. Here is the
text regarding the PW-5 Service and Operational Life, taken directly from
"Technical Requirements for the PW-5 "Smyk" Sailplane", Document
PW-5/WT/II/94, dated March 1994 (this document is part of the PW-5 Type
Design description):
>3.2 Designed service life of the sailplane: 9000 flight hours. Fatigue
test >of the sailplane is required to prove the designed service life.
>
>3.3 Assumed operational life of the sailplane: not less that 20 years.
This >operational life will be confirmed by technical condition of the
oldest >sailplanes.
The engineers at the Warsaw University of Technology are conducting an
ongoing fatigue test on the PW-5 under the monitoring of the Polish
Airworthiness Authorities to prove the 9000 hours service life. I saw the
test rig about a year ago. The test should be nearing completion for a
9000 hour life, and the WUT engineers intended to continue it to prove if
a life extension is possible.
Note that the assumed service life is NOT LESS THAN 20 years. There is no
in-service expiration like there is for the IS28. "...confirmed by
technical condition of the oldest sailplanes" means that if a glider has
been abused or not properly maintained then the operational life may be
reduced (no surprise).
Hope this clarifies.....
--
James H. Hogue
NH Aviation
5374 Whitehall Place
Mableton, Georgia 30126 USA
Phone: (770)819-9748
Voice Mail: (770)948-8126
Fax: (770)948-5286
Email: nhavi...@mindspring.com
Jean Richard
Tomasz Sielicki wrote:
>
> Fred,
> It is true for several wooden glider types we use here in Poland, too. They
> have 25 years lifespan and then it can only be prolonged (after a capital
> repair) for 100 hours repeatedly .
It seems that European and mostly Eastern European builders
are very conservative with the lifespan of their planes.
Some examples :
- the Polish Jantar (I and II) has a very short lifespan ;
in several countries, there's an AD to extend lifetime from
1500 hours to 3000 hours (I don't know after 3000 hours) ;
- the Wilga airplane has a very short lifespan ;
- the 3750 hours lifespan of the Blaník L13 is based on
a typical operation of the worst case (95 % of the clubs
probably have an easier use of them) ;
- in France, a Lycoming engine on a towplane will have
its TBO reduced by 50 % for all towing hours (if the plane
is only used for towing, then a O-360 will have a TBO of
only 1000 hours).
But there's exceptions. Some wooden sailplanes from Germany
don't have lifespan limits (after all, there's wooden
buildings in Europe that has been built 1000 years ago and
even more and they are still very strong, but there's no
medieval composite churches or palaces...).
J. Richard
Jean Richard
Bill Tisdale wrote:
>
> As I was told.. the U.S. FAA was working on extending the "20 yr lifespan" but
> was getting no help from the manufacturer.. have to wait and see.. I have seen
> nothing official in writing.
I'm very happy to read « the U.S. FAA » here. It seems that
there's too many people in USA who don't know that newsgroups
are spreading over the entire World and read by people of
many different countries. Or maybe those people want to
believe that US organisations or rules are universal, which
is not the case.
Suppose one day we read that kind of information :
« Wearing a parachute is mandatory for both the pilot
and the passenger in a glider and flying a glider without
wearing a parachute is illegal. »
You will surely see people replying that it's not true.
But it's true in many countries, but not in USA.
Giving information, mostly information concerning air
regulation, can lead to bad information if you don't
specify the country where regulation applies. I suggest
you make it part of the netiquette.
J. Richard
F.L. Whiteley
Jean Richard <j.ri...@sympatico.ca> wrote in article
<34B05F...@sympatico.ca>...
Bill Tisdale wrote:
>
> As I was told.. the U.S. FAA was working on extending the "20 yr
lifespan" but
> was getting no help from the manufacturer.. have to wait and see.. I have
seen
> nothing official in writing.
I'm very happy to read « the U.S. FAA » here. It seems that
there's too many people in USA who don't know that newsgroups
are spreading over the entire World and read by people of
many different countries. Or maybe those people want to
believe that US organisations or rules are universal, which
is not the case.
No one suggested US rules are universally applied or that this is US
centric, we have an SSA list for that. The BGA often looks to what the US
is doing under the Experimental category as justification for the way their
Technical Committee evaluates gliders. Perhaps a few other countries
follow the BGA's lead? I don't think we're so far apart on some of these
issues.
The problem with the IS-28B2 is that the Romanian rules apply to the STC
and Export C of A, that affects everyone. Most would probably agree that
the 20 year 'shelf life' is completely arbitrary, I would. Over 18 months
ago, IAR Brasov requested (via the Internet and soaring publications) that
owners and operators supply the factory with damage and maintenance
information so that a case for removing the 20-year limit could be built
and argued to the RAA. Hopefully some owners took heed. I've seen one
post via the FAI list that such a proposal was before the RAA.
FWIW, as of 1995 the US FAA had no information whatsoever other than the
original STC, including two life subsequent extensions since the original
STC. The social upheaval in Romania (remember that?) coupled with normal
bureaucratic drag, transfer of responsibilities, and reorganizations meant
a lot of things fell through the cracks. One key item was notification of
owners of these changes. It wasn't happening. Thus answers have been slow
in coming. AFAIK, the Romanians are probably reassessing all of the
decisions of the prior regime's bureaucracies. I found out quite by
accident, via this newsgroup. At the time I was considering a purchase. I
found the applicable documents in the glider's logbook, after I knew what I
was looking for. I then passed the issue along to Herman Beldarok (now
retired) at the US FAA glider desk for resolution. My larger concern is
not that the IS-28B2 somehow becomes 'lifed' at 20 years, but that it gives
insurance underwriters a huge loophole to jump through in the event of a
mishap to one that was 'lifed'. Not only could the FBO/club and pilot be
affected, but the inspector who signed the ticket. During the first couple
of rounds on this issue on r.a.s. there were several replies that this
20-year life issue didn't even exist. Hopefully, soon it won't. It would
be both beneficial and enlightening to know what other countries have done
about this.
F. Whiteley
Mike Cleaver
F.L. Whiteley wrote in message <01bd1a19$d97a08c0$31f292d0@greeley>...
>
>
>Jean Richard <j.ri...@sympatico.ca> wrote in article
><34B05F...@sympatico.ca>...
>Bill Tisdale wrote:
>>
>> As I was told.. the U.S. FAA was working on extending the "20 yr
>lifespan"
maybe those people want to believe that US organisations or rules are
universal, which
>is not the case.
>
>No one suggested US rules are universally applied or that this is US
>centric, we have an SSA list for that. The BGA often looks to what the US
>is doing under the Experimental category as justification for the way their
>Technical Committee evaluates gliders. Perhaps a few other countries
>follow the BGA's lead
>The problem with the IS-28B2 is that the Romanian rules apply to the STC
>and Export C of A, that affects everyone. Most would probably agree that
>the 20 year 'shelf life' is completely arbitrary, I would. Over 18 months
>ago, IAR Brasov requested (via the Internet and soaring publications) that
>owners and operators supply the factory with damage and maintenance
>information so that a case for removing the 20-year limit could be built
>and argued to the RAA. Hopefully some owners took heed. I've seen one
>post via the FAI list that such a proposal was before the RAA.
I then passed the issue along to Herman Beldarok (now
>retired) at the US FAA glider desk for resolution. My larger concern is
>not that the IS-28B2 somehow becomes 'lifed' at 20 years
It would be both beneficial and enlightening to know what other countries
have done
>about this.
>
>F. Whiteley
For some reason - probably something to do with our weather - we seem to
regularly find that an Australian exaple of the type is the leader for
time-in-service: the first IS-28s reached their original 'design' life
(4000 hours if I recall correctly) in about 5 years from new and a life
extension modification was developed to give a life of 12,000 hours with
inspections at certain points in that life.
I am not sure whether this also affects the 20 year problem (we used to have
a 20-year limit on certificate of airworthiness of all gliders, but now do
not provided a condition inspection is performed at 20 years and every 10
years thereafter), but you could probably find out what ADs affect IS-28s
(and Blaniks - we have a couple of life-extension mods for them) from the
GFA web page http://www.gfa.org.au .
Frank says that Herman has now retired from the FAA, but they are still
putting out NPRMs with his name on them as of three weeks ago - and mostly
for ADs that Australia introduced some years ago - or are they just
releasing Herman's work after his retirement?? :-)
One of the clubs I fly with has the original high-time Blanik which was
grounded 20 years or so ago when they discovered the 3750 hour life limit -
at that time it had 7300 hrs and now has been modified and has about 9500
hours. My other club has a Jantar Std 2 with 3500 hrs on in the 21 years
they have owned it: it fles the first 750 km in a club glider a week ago -
congratulations Alan Wilson - so it still goes OK! It also set an
Australian height gain and absolute altitude record of 33,000 ft a couple of
years ago. (Pity about the cockpit ergonomics - many pilots find it very
uncomfortable for a long flight!)
Mike Cleaver Canberra, Australia