EASA AD No.: 2013-0293R1

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EASA AIRWORTHINESS DIRECTIVE

AD No.: 2013-0293R1

Date: 17 December 2013

Note: This Airworthiness Directive (AD) is issued by EASA, acting in accordance with 

Regulation (EC) No 216/2008 on behalf of the European Community, its Member States and of 

the European third countries that participate in the activities of EASA under Article 66 of that 

Regulation.

This AD is issued in accordance with EU 748/2012, Part 21.A.3B. In accordance with EC 2042/2003 Annex I, Part M.A.301, the 

continuing airworthiness of an aircraft shall be ensured by accomplishing any applicable ADs. Consequently, no person may operate 

an aircraft to which an AD applies, except in accordance with the requirements of that AD, unless otherwise specified by the Agency 

[EC 2042/2003 Annex I, Part M.A.303] or agreed with the Authority of the State of Registry [EC 216/2008, Article 14(4) exemption].

Design Approval Holder’s Name:

BALLONBAU WÖRNER GmbH

Type/Model designation:

NL-STU gas balloons

TCDS Number: EASA.BA.009

Foreign AD: Not applicable

Revision: This AD revises EASA AD 2013-0293 dated 09 December 2013.

ATA 05 Time Limits and Maintenance Checks – Amendment

Manufacturer(s): Ballonbau Wörner GmbH

Applicability: NL-STU/280, NL-STU/380, NL-STU/510, NL-STU/640, NL-STU/840 and

NL-STU/1000 gas balloons, all serial numbers (s/n).

Note: NL-STU gas balloons with s/n 1101 or higher will be delivered with the 

new Instructions for Continued Airworthiness dated November 2013.

Reason: The results of an analysis of NL-STU maintenance data revealed that the

current inspection intervals are no longer adequate to ensure timely detection 

of deterioration or damage, which could affected the structural integrity of the 

balloon.

This condition, if not detected and corrected, could lead to failure of balloon 

components or envelope, possibly resulting in loss of the balloon.

To address this potential unsafe condition, Ballonbau Wörner developed new,

more detailed and descriptive Instructions for Continued Airworthiness (at the 

same time separated from the Flight Manual) and issued Technische 

Mitteilung/Technical Note EASA.BA.009-6 to inform all operators.

For the reasons described above, EASA issued AD 2013-0293 to require

compliance with the updated Instructions for Continued Airworthiness.

This AD is revised to extend the compliance time for the initial porosity test, for 

balloons which have already exceeded the relevant threshold.

Effective Date: Revision 01 (same as original issue): 23 December 2013
EASA AD No.: 2013-0293R1

TE.CAP.00110-003 © European Aviation Safety Agency. All rights reserved. 2/2

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Required Action(s) 

and Compliance

Time:

Required as indicated, unless accomplished previously:

(1) From the effective date of this AD, except as specified in paragraph (3) of 

this AD, accomplish all maintenance tasks within the compliance times as 

specified in Ballonbau Wörner Anweisungen zur Aufrechterhaltung der 

Lufttüchtigkeit, Gasballon Baumuster NL-STU / Instructions for Continued 

Airworthiness, Gas Balloon Model NL STU, original issue, dated 

November 2013.

Note: Ballonbau Wörner Technische Mitteilung/Technical Note EASA.BA.009-

6 (bilingual German-English document) provides further detailed information.

(2) Compliance with the requirements of paragraph (1) of this AD can be 

demonstrated by:

(2.1) Revising as follows the approved Aircraft Maintenance Programme 

(AMP) on the basis of which the operator or the owner ensures the 

continuing airworthiness of each operated balloon:

Incorporate all maintenance requirements and associated 

airworthiness limitations as specified in Ballonbau Wörner 

Anweisungen zur Aufrechterhaltung der Lufttüchtigkeit, Gasballon 

Baumuster NL-STU / Instructions for Continued Airworthiness, Gas 

Balloon Model NL STU original issue, dated November 2013,

and

(2.2) Complying with the approved AMP described in paragraph (2.1) of 

this AD.

(3) For balloons which, on the effective date of this AD, have exceeded the 

threshold compliance time for the porosity test, as defined in Chapters

5.1.1.4, 5.1.2.4 and 5.1.3.4 of Ballonbau Wörner Anweisungen zur 

Aufrechterhaltung der Lufttüchtigkeit, Gasballon Baumuster NL-STU / 

Instructions for Continued Airworthiness, Gas Balloon Model NL STU, 

original issue, dated November 2013, within 3 months after the effective 

date of this AD, accomplish the initial porosity test.

Ref. Publications: Ballonbau Wörner Anweisungen zur Aufrechterhaltung der Lufttüchtigkeit, 

Gasballon Baumuster NL-STU / Instructions for Continued Airworthiness, Gas 

Balloon Model NL STU, original issue, dated November 2013.

Ballonbau Wörner Technische Mitteilung / Technical Note EASA.BA.009-6, 

dated 7 November 2013.

The use of later approved revisions of these documents is acceptable for 

compliance with the requirements of this AD.

Remarks: 1. If requested and appropriately substantiated, EASA can approve 

Alternative Methods of Compliance for this AD.

2. Based on the required actions and the compliance time, EASA has

decided to issue a Final AD with Request for Comments, postponing the 

public consultation process until after publication.

3. Enquiries regarding this AD should be referred to the Safety Information 

Section, Executive Directorate, EASA. E-mail: ADs@easa.europa.eu.

4. For any question concerning the technical content of the requirements in 

this AD, please contact:

Ballonbau Wörner GmbH, Zirbelstraße 57c, 86154 Augsburg, Germany

Telephone: +49-(0)821-4504060, Facsimile: +49-(0)821-419641

E-mail: info@ballonbau.de; Internet: www.ballonbau.de.