# AD 78-23-14 R1: Tow Release System

- Type: Airworthiness directive
- Status: Current
- Products: BLANIK Blanik L-13 and Blanik L-13 AC
- Effective: August 17, 1984
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Glider
- Amendment: 39-4894
- Registered aircraft: 38 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/93FC5F3528133A8C86256A38006395AE.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/78-23-14-R1

## The airworthiness directive

78-23-14 R1 LET BLANIK: Amendment 38-3349 as amended by Amendment 39-4894. Applies to Model L-13 gliders, Serial Numbers 170101 through 174730, certificated in all categories.

Compliance is required as indicated, unless already accomplished.

To prevent tow release malfunction due to structural cracks at the attach point of the tow release system countershaft bracket, accomplish the following:

  (a) Within the next 10 hours time in service after the effective date of this AD, inspect the No. 1 bulkhead for cracks at the attach points of the tow release system countershaft brackets in accordance with Let Mandatory Bulletin No. L13/047 dated January 11, 1978, and Note 2 in Bulletin No. L13/047 (Supplement), dated April 1, 1978, or an equivalent procedure approved by the Manager, Aircraft Certification Staff, Europe, Africa and Middle East Office.

  (b) If cracks are found during inspection in accordance with paragraph (a) of this AD, before further flight:

  (1) Where cracks do not exceed 6 mm in length, repair and reinforce the No. 1 bulkhead in accordance with paragraph A, "Reinforcement of bulkhead No. 1" of Let Mandatory Bulletin No. L13/047 dated January 11, 1978, and Bulletin L13/047 (Supplement) dated April 1, 1978, or equivalent approved by the Manager, Aircraft Certification Staff, Europe, Africa and Middle East Office; or,

  (2) Where cracks exceed 6 mm in length, repair and reinforce the No. 1 bulkhead in accordance with the metal repair procedures, Section 3 of FAA Advisory Circular 43.13-1A, or equivalent approved by the Manager, Aircraft Certification Staff, Europe, Africa, and Middle East Office.

  (c) If no cracks are found during the inspection required by paragraph (a) of this AD, within the next 100 hours time in service after the effective date of this AD, reinspect, repair, and reinforce the No. 1 bulkhead as follows:

  (1) If no cracks have developed, in accordance with the method specified in paragraph (b)(1) ofthis AD; or

  (2) If cracks have developed, in accordance with the applicable method specified in paragraph (b) of this AD.

Amendment 38-3349 became effective November 27, 1978. This Amendment 39-4894 becomes effective August 17, 1984.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS G24EU](https://openairdocs.org/tcds/G24EU): Blanik Aircraft CZ s.r.o.; names 2 of 2 models: Blanik L-13, Blanik L-13 AC

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 38 (38 by airframe model, 0 by engine model)
- Makers: Let 38

Models with the most aircraft:

- [Let BLANIK L-13](https://openairdocs.org/model/let-blanik-l-13): 38 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/78-23-14-R1/models.md
Every aircraft: https://openairdocs.org/ad/78-23-14-R1/aircraft.md

## Related documents

- [AC 43.13-1B CHG 1 Ed Update](https://openairdocs.org/ac/43.13-1): Acceptable Methods, Techniques, and Practices—Aircraft Inspection and Repair. Cited as AC 43.13-1A in the AD's requirements

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