USA: April 26, 2010 Blanik L-23's grounded

USA / as of April 26, 2010:

Your Blanik L-23 is grounded unless you have complied with FAA AD
2010-08-01, which refers to the work specified in LET/Aircraft
Industries Mandatory Bulletin MB L23/052a.

This bulletin describes the non-destructive testing for cracks in the
inner elevator hinge.

So far, 7 hinges were reportedly found cracked on L-23's.
The Soaring Safety Foundation would be very interested to hear of your
discovery of cracks, in order to possibly comment on any revised FAA
AD forthcoming on the time interval for further inspections of this
hinge.

Send your report to:

Any issues regarding the actual work to comply with this AD would also
be appreciated.

Here's the LET factory bulletin:

http://www.let.cz/files//bulletines/...23_English.pdf

Here's the EASA airworthiness directive:

http://www.let.cz/files//bulletines/...lanik_2010.pdf

Here's the US FAA airworthiness directive:

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/0/949f77e0ac989a2b862576fd004785c9/$FILE/2010-08-01.pdf

Thanks, Bob K.

Our club just complied with the AD mandating the inspection of the inner elevator hinges. No cracks were found. We were lucky in that we had spent the winter striping and repainting the wings and horizontal tail (next year for the fuselage). We also recovered the ailerons and elevator. The elevator was about ready to be put back on the tail when the AD came out. The inspection IAW the AD was complied with the elevator off, I think it would be really tough to do it without disassembly.

- Barry Muhlenberg, Cloudniners, Morgantown, PA

Originally Posted by Bob Kuykendall

Here's the LET factory bulletin:

http://www.let.cz/files//bulletines/...23_English.pdf

Here's the EASA airworthiness directive:

http://www.let.cz/files//bulletines/...lanik_2010.pdf

Here's the US FAA airworthiness directive:

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/0/949f77e0ac989a2b862576fd004785c9/$FILE/2010-08-01.pdf

Thanks, Bob K.

re. The April 2010 Blanik L-23 Airworthiness Directive (USA)

Any new reports of cracks found in the L-23 elevator hinge, other than
the initial 7 ships?
The Soaring Safety Foundation would like to know.

Burt,

I know you asked for reports of cracks but...we testing our two L-23's
and found no cracks. However, we did find that both the elevator
bearings on the newer ship had slipped out of deformed races and
needed to be replaced. We got them from Blanik America quite quickly.

The bearings are a bitch to press out due to their location (unless
you disassemble the trim cables which is ever a worse bitch). So we
found that a small gear puller pushing against a nickle (US $0.05) was
just the right size to press out the old bearing and a penny (US
$0.01) was just the right size to press the new bearing back in.
Didn't do the coins much good but it worked.

My $0.02.

- John

On May 31, 9:22*pm, ContestID67 wrote:
Burt,

I know you asked for reports of cracks but...we testing our two L-23's
and found no cracks. *However, we did find that both the elevator
bearings on the newer ship had slipped out of deformed races and
needed to be replaced. *We got them from Blanik America quite quickly.

The bearings are a bitch to press out due to their location (unless
you disassemble the trim cables which is ever a worse bitch). *So we
found that a small gear puller pushing against a nickle (US $0.05) was
just the right size to press out the old bearing and a penny (US
$0.01) was just the right size to press the new bearing back in.
Didn't do the coins much good but it worked.

My $0.02.

- John

Actually, $0.06

"bildan" wrote Actually, $0.06

Actually, two bearings mean it would be his $0.12 worth. If you count both
ships, then his $0.24 worth!

sORry all, but you know you were thinking it! g
--
Jim in NC

OK, I was reminded by others that it was a dime (US $0.10) to press
the bearing out and a nickle (US $0.05) to press it back in. Any fool
knows that the presser-outer-coin needs to be smaller than the presser-
inner coin. This all adds up to $0.30 worth per tail. No wait, we
reused the coins so we are back down to $0.15 worth. Glad we got that
settled.

g

"Presser" John

On 6/4/2010 8:20 PM, ContestID67 wrote:
Snip...

"Presser" John

Cowabunga...now THERE's an historically obscure reference!

Bob W.