Meaning of 6,000 hr service life

[saddletramp]

I'm in the process of trying to purchase a two-place sailplane. I plan to give glider rides & instruction.

One on my choices for a glider is a Blanik L-23. I leased one in the early 90's when I had a operation back then & felt it was a great machine for instruction & scenic rides.

The info on the L-23 says it has a 6,000 hr service life. The ship I'm looking at has 4,800 hrs.

I've searched every site I could to the relevance of this service life.

Anybody? Bueller?

 

[BillTIZ]

The Maintenance Manual should have instructions for the required inspection to extend the service life.
I am not to familiar with the L23. I know the Grob 103 has service life extension inspections at 3000, 6000, 9000 and 10,000, 11,000 and at 12,000 it is done flying. Most of the inspections require extensive review/replacement of control rod ends and sealed bearings.

Blanik should be able to help you. I'm not sure if their US Rep is still around. But parts (skins) are hard to get.

 

[saddletramp]

Thanks. I've never flown a Grob but have considered one of them too. If you have time in the Grob I'd appreciate your perspective.

 

[Let'sgoflying!]

I asked a very knowledgeable (I think the ultimate source, actually) and he says:
"from a former Blanik L-23 owner": (he is also rather humble)

Information regarding the 6,000 hour service limitation on Blanik L-23 Gliders:
Note that the FAA Type Certificate G60EU is listed under
Aircraft Industries a.s. (not “Blanik” nor “LET.”) The “S7” company in Russia may be supplying new Blanik L-23 and parts soon.

Address: 686 04 Kunovice 1177 Czech Republic

Previous Type Certificate Holder LETECKÉ ZÁVODY a.s. transferred TC G60EU to Aircraft Industries a.s. on September 26, 2005 LET Aeronautical Works transferred TC G60EU to LETECKÉ ZÁVODY a.s. on October 15, 2002

From the FAA Type Certificate Data Sheet (TCDS) G60EU:
"Information essential to the continued airworthiness,proper maintenance, inspection and repair is contained in the LET L 23 SUPER-BLANIK Maintenance Manual (Books 1 and 2).
Time Limits/Maintenance Checks are listed in Chapter 5."
The owner must read the Maintenance Manuals (not just the Flight Manual) to find the service limitations and required inspection checklists.
Per the L-23 Flight Manual, the glider logbook must also record the number of aerotows, ground (winch) launches, acrobatic flight time and the flights with the extended wingtips (an option offered approximately at L-23 serial # 81.)
These logged flights might change the 6,000 hour service limit but read the Maintenance Manuals (chapter 5.)
Note that you do not need to ground the L-23 permanently (like the L-13) but have a comprehensive inspection (more than an Annual Inspection per the inspection checklist in the Maintenance Manual(s).
Do your own research! The above is just from my experience . . .readers of my comments must look up these details in the actual manuals.
My manuals were sold with the sale of my two L-23’s in 2010. At the sale they each had about 2,000 hours logged.
Vitek at Blanik America may be able to advise further. Website: http://home.nwi.net/~blanikam/ba/blanik.htm
Also see this recent news release: http://www.let.cz/clanek_380_obnoveni-vyroby-blaniku-v-kunovicich.html?lang=2
A Russian company called “S7” may restart production of the L-23 and offer a fix for the L-13 world-wide grounding due to wing failure.
An alternative: I replaced my Blanik L-23’s with a new Schleicher ASK-21, a superior two-seat sailplane with excellent factory support (Poppenhausen, Germany.)
Website: http://www.alexander-schleicher.de/en/flugzeuge/ask-21/
The ASK-21 is relatively expensive but with a much higher service life. Divide the cost of a new ASK-21 glider by 25 years and it is a bargain.
It is rare to find used ASK-21’s in the USA as they are extremely popular, stronger than the L-23 and easier to fly.
Research all aircraft Airworthiness Directives at www.faa.gov
On the FAA.gov webpages, the AD’s for the ASK-21 glider are listed under “A” for “Alexander Schleicher.”
AD’s for the BlanIk L-23 are under “BLANIK LIMITED”.

 

[BillTIZ]

Thanks. I've never flown a Grob but have considered one of them too. If you have time in the Grob I'd appreciate your perspective.

It is difficult to find a good Grob 103 that has not been broken and repaired. Most Grob's get their tailbooms broken from PIO landings. Watch the total useful load, if should be around 400# or better. I know there is (was) a Grob 103 that was essentially a single seat glider because the useful load was so low. Also some 103's may have speed limitations. Ours was not affected so I am not too familiar with the final outcome of that AD.

Look at the Soaring Safety Foundation article on Grob PIO. They need to be landed on speed, low energy, not forced. Forcing the landing catches the nose wheel first and that starts the PIO. Check for repairs where the nose gear may have been pushed up.

The 103 has a side hinged rudder on the left, so the left rudder is more effective than right rudder. More exposed surface area with left rudder. Right rudder, some of the surface area slides into the vertical fin, less exposed surface area.

Most pilots new to the 103 have problems with yaw dance. If they just put positive pressure on the rudder pedals the yaw dance will stop. Long wings with effective ailerons, always moving the stick left and right creates adverse yaw and the yaw dance starts. Stop moving the stick!

Many clubs use the 103 as the primary trainer. I tell my students, if you can master the Grob 103, you can fly most any 2 seat glider, ASK-21 or DG500.