L-13 AD Information

[Stephen Northcraft]

#20539

AD Issued on Blanik L-13s ; 2007-25-01; control bridge.

This AD applies to Blanik L-13 gliders, all serial numbers, certificated in any category.

Inspect the front and rear control bridge attachment at the stick base for cracks with a ten power magnifier and dye penetrant inspection. Replace bridges which have any visible cracking.

Within the next three months after the effective date of this AD, make the inspection for cracking.  This AD inspection recurs annually.

This airworthiness directive (AD) becomes effective January 7, 2008.

Full text of the AD may be found at:     here .

C. Brickner, Govt. Liaison Committee

[Stephen Northcraft]

#20540

EASA has issued an emergency Airworthiness DIrective for the LET Blanik L-13.

 

For additional information see here, and here.

[Stephen Northcraft]

#20542

FAA Issues AD for Blanik L-13

The FAA has issued an Airworthiness Directive for the LET Blanik L-13 with an effective date of July 19th, which requires an inspection of the spar before further flight. This is a serious structural concern and is already an EASA (European) AD and the subject of a Mandatory Bulletin from the manufacturer. SSA urges all members who fly the affected aircraft to perform the inspections according to the FAA AD and report the results to the FAA as requested. SSA also urges all owners and operators to make any other concerns with the AD known directly to the FAA. When a final or amended FAA rule is drafted the inspections may or may not need to be repeated or performed in a different manner.

Questions or concerns should be addressed directly to the FAA contact identified in the AD, Mr. Greg Davison at the FAA Small Airplane Directorate in Kansas City at 816 329 4130.

 

The AD is here.

The reference EASA and LET documents are here and here.

[Stephen Northcraft]

#20574

The recent FAA AD (Airworthiness Directive) on the LET Blanik L-13 (2010-14-45) refers to EASA EAD 2010-0122-E.  However, if you contact LET they will refer to EASA EAD 2010-0160-E.   The FAA has not yet incorporated EASA EAD 2010-0160-E into an AD.  The SSA has been discussing with the FAA what it believes are serious problems with EASA EAD 2010-0160-E.  Specifically, the SSA has indicated that the requirements for categorizing flight hours in order to continue to fly the L-13 is not reasonable and has informed the FAA that we believe that no one logs flight hours in the manner required, nor is it called for in the L-13 flight or maintenance manuals.

The SSA wiil continue to discuss this with the FAA as we believe that the latest issuance in this series of EASA EADs on the L-13 is unreasonable and should not be issued by the FAA as an AD.

[Stephen Northcraft]

#20545

The FAA has issued AD 2010-18-05 dated August 25th.  It is available here.  The reference LET MB is here.

 

From the AD:

“Since issuance of AD 2010-0122-E, based on further information provided by the Austrian Accident Investigation Board, EASA has re-assessed the inspection method as described in Aircraft Industries a.s. Mandatory Bulletin No. L13/109a. EASA now concludes that the inspection method might not be sufficient for detecting the crack which means that the unsafe condition might still be present even if the sailplane has passed the inspection required by AD 2010-0122-E.”

 

Also stated in the AD:

"Actions and Compliance

    (f) To address this problem, before further flight after August

30, 2010 (the effective date of this AD), incorporate an FAA-

approved inspection and/or modification program developed

specifically for this AD. Corrective action is considered FAA-

approved if it is approved by the State of Design Authority (or

their delegated agent). You are required to assure the product is

airworthy before it is returned to service.

FAA AD Differences

    Note: This AD differs from the MCAI and/or service information

as follows: The MCAI requires the owner/operator to submit data

regarding certain operations including aerobatic operations, to the

European Aviation Safety Agency (EASA) and Aircraft Industries, a.s.

so they can determine whether further flight is permitted. The FAA

does not require such data to be collected for operations in the

United States. The FAA is relying on an inspection and/or

modification program approved specifically for this AD to detect and

correct cracks before further flight. Until such a program is

approved, owners/operators may apply for an alternative method of

compliance (AMOC) following 14 CFR 39.19 described in paragraph

(f)(1) of this AD. The FAA will work with EASA and Aircraft

Industries a.s. to determine if an acceptable level of safety is

achieved with the AMOC proposal."

For further information read the complete AD.

[Stephen Northcraft]

#20546

9-1-10

The continuing airworthiness issues, manufacturer’s (LET / Aircraft Industries) Mandatory Bulletins, European Aviation Safety Administration (EASA) Airworthiness Directives and the Federal Aviation Administration (FAA) ADs are of concern to SSA as well as to the owners and operators of the affected L-13 and L-13A Blaniks.  It is likely that most of the Blanik fleet in the United States and around the world will be affected and/or grounded before the manufacturer and the European agencies issue appropriate methods to inspect and modify the aircraft to prevent recurrence of the problems that have led to structural failure and death.

The SSA has worked with FAA since the beginning of the current problems and has attempted to offer suggested resolutions to the FAA,  For the moment, there is little the SSA can do to directly impact the situation.

At this point the manufacturer and EASA have not developed or approved an effective inspection or modification program to ensure safe continued flight of the affected aircraft.

However, the FAA’s latest AD states that the flight-hour record-keeping requirements of the manufacturer do not apply to American operators and that the FAA will review Alternative Methods of Compliance (AMOC’s) presented to them. These statements are encouraging for American operators.

SSA does not have the expertise to engineer solutions, but some of our members may. SSA encourages qualified members who work on aircraft inspection and repair methods to contact Greg Davison, Aerospace Engineer at FAA’s Small Airplane Directorate in Kansas City at (816) 329-4130. Also please send copies of correspondence with the FAA to SSA and we will summarize and publish relevant information about the situation on this page on a regular basis.

SSA will also use this page to publish other written reports of developments or offers of assistance. In particular, FAA is working on an informational statement that it hopes to forward to SSA for publication in the next few days. At the moment SSA believes that acting as an information clearinghouse is its most appropriate course of action while it encourages its members and the owners / operators of Blaniks to work together to develop technical solutions.

Finally, SSA also believes that owners and operators of affected Blaniks should make the manufacturer (LET / Aircraft Industries) and its American representative (Blanik America) aware of their concerns and the need for their help and timely solutions. Meanwhile, owners with valid questions and suggestions continue to be invited to contact the FAA as stated in the ADs.

SSA Airworthiness Certification Committee

[Stephen Northcraft]

#20547

Report of Gregg Heer and George Wacker:

Greg Heer, IA, who has worked on improving N125DW for many years, got a return call from Greg Davison of the FAA.  This is a summary of the points made during that discussion:

Blanik L-13s are grounded until the factory adequately addresses the wing spar fatigue crack issues.  This could be accomplished by an inspection and/or modification program.

During the conversation, Mr. Davison, discussed the issues that concern him (no significance to the order of listing):

• EASA AD 2010-160-E says “EASA now concludes that the inspection method (of Mandatory Bulletin No. L13/109a) might not be sufficient for detecting the crack which means that the unsafe condition might still be present even if the sailplane has passed the inspection required by EASA AD 2010-0122-E.” Apparently cracks were discovered during the subsequent investigation of the failed spar that cannot be detected by the inspection detailed by the MB and previous AD.
• The most likely place for cracks to begin (the outer surface of the spar cap) cannot be seen without removing the outer skin.
• The design of a steel tapered spar cap sandwiched between two aluminum members and fastened by rivets.
• The skin is fastened to the spar cap by drilling into the rivet heads holding the spar cap together and then rivets installed to hold the skin to the spar cap rivet heads which potentially further compromises the rivets holding the spar cap sandwich together.
• Knowledge, or lack thereof, of the corrosion and fatigue characteristics of the materials involved.

Mr. Davison said that the reason a US DER may have trouble proposing a satisfactory solution is that the material details and characteristics are not known within the US. He also said two other things which will likely happen:

• The FAA will likely issue a document which is intended to clarify some of the confusion.
• A delegation of folks from the US may go to Europe to discuss these issues and what to do about them.  Participants and date of visit unknown.

I’m willing to help in any way that I can but don’t know what would be helpful at this moment.  It does appear that the FAA is waiting for the factory and EASA to come up with something.  Due to the concerns and unknowns listed above, the FAA will likely be looking to the factory and EASA to approve any proposals received in the US.

Pass this along to anyone as I am interested if anyone else has received any information that would shed new light or open up a new avenue allowing us to resume flying more quickly.

– – – – –   – – – –     – – – –     – – – –     – – – –

Members wishing to participate in a group discussion of the topic may send their email contact information to  feedback@ssa.org, subject line Blanik Wing Spar AD.  Please include a description of your role: owner, A&P or A.I., DER, or structures engineer or metallurgist.  SSA will create a group email listing from these respondents to facilitate communications.

[Stephen Northcraft]

#20548

SSA has just received this EASA AD and wants to pass it on. Please remember that an EASA AD is not an FAA AD although it may be indicative of what may lie in  the future. We will try to post additional information in the next few days.

Link to EASA AD here.

[Stephen Northcraft]

#20549

The FAA has issued a letter clarifiying their position on the recent L-13 Ariworthiness Directives.

The letter (updated on 9/14) is located here.

The SSA wishes to thank the FAA Small Aircraft Directorate for taking the time to provide this clarification to the SSA, and our members, and for thier continuing efforts to resolve this issue.

[Stephen Northcraft]

#20550

Aircraft Industries has released an opinion on returning the Blanik L-13 to service.

The opinion is located here.

Gerard Robertson of New Zealand has drafted an analysis of the Blanik situation for publication in the NZ soaring magazine.  A copy is located here.

[Stephen Northcraft]

#20551

As of April 11th

An STC has been applied for to modify the L-13 to return it to flight.  However, it has not yet been approved by EASA or the FAA.

https://www.aircraftdc.de/ENG/visionen_blanik.htm
https://www.aircraftdc.de/ENG/images/Blanik/Customerinfo_ADxC-DC-39-00…

 

As of march 21st

https://www.let.cz/files//File/standpoint_BLANIKgliders_march2011.pdf

“CURRENT SITUATION IN ACTIVITIES OF AIRCRAFT INDUSTRIES, A.S. AIMED TO
THE RENEWAL OF
AIRWORTHINESS OF L-13 AND L-13A GLIDERS

In connection with the crash of the L 13 glider S/N 175117 in Austria
on 12th June 2010, EASA issued
the Airworthiness Directive No. AD 2010-0185, which mandates grounding
the whole fleet of gliders
L 13 and L 13A.
In previous statement of Aircraft Industries, a. s. from 30th
September 2010, our company announced
taking steps to the gliders airworthiness renewal, consisting of
development in cooperation with
Research and Testing Aviation Institute in Prague the Eddy current
inspection of wing critical area
focused on detection of potential occurrence of fatigue damage. With
regards to our intention to
avoid the modification of wing critical area and due to the demand for
highest reliability of inspection
method and necessity its thorough verification on number of testing
samples, it was technically and
time-consuming very demanding development. At this moment the
inspection method is practically
developed and we will present the results to EASA to receive approval
for the use of inspection for the
purpose of releasing L 13 gliders into operation.
In parallel, an independent design company is developing design
modification consisting
of strengthening of the L 13 glider wing critical area. As soon as the
organization receives EASA STC
approval and we get consent to publish more detailed information we
will post them on our website
http://www.let.cz.

[Stephen Northcraft]

#20552

The SSA Leadership has contacted the Small Aircraft Directorate (SAD) several times regarding the status of issuing an AD for the L-13.  As a result of discussions at the recent Board of Directors meeting, the SSA expressed their concern over the pace of progress of approving a US version of the European AD and requested an update on the status from the Director of the SAD.  The SAD plans to provide an update prior to the Convention.

[Stephen Northcraft]

#20553

At the request of the SSA, the FAA provided a status update on their review of the STC submitted by AD&C to provide a means of compliance with Airworthiness Directive (AD) 2010-18-05.  Their update is available here.

Information on the (not FAA approved) STC is available here:

https://www.aircraftdc.de/ENG/images/Blanik/Customerinfo_ADxC-DC-39-001.pdf

[Stephen Northcraft]

#20554

Blanik Update  – October 22nd

The SSA contacted the FAA over the last several months to obtain updates on the status of approving the Blanik L-13 STC approved by EASA last year.  A summary of the FAA’s response (September) to the latest request is as follows:

Six issue papers were generated for the Blanik L-13 STC:

G-1 Certification Basis
G-2, Determination of Compliance
A-1 Structural Substantiation
M-1,  ICA / Maintenance Manual Supplement Review
M-2 Non Destructive Test Procedures
M-3 Review of Preparation, Modification and Installation Instructions

The A-1, M-2 and M-3 papers are currently with EASA
The M-1 paper is in the AEG office (these are the folks that review manuals for maintenance and pilots operation,. they are a Flight Standards office) (Update 9/28, This paper is now with EASA)
The G-1 and G-2 were sent to EASA in September.

Once EASA has reviewed the papers the FAA and EASA will have a teleconference to review.

Short answer is no change for the current owners/operators.

The FAA is not planning on taking any action on the existing AD and or the STC until they get responses back from EASA.

[Stephen Northcraft]

#20555

See attached letter from FAA to SSA.

[Author]

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