AD/DA42/6 - Aircraft Flight Manual - Lightning Strike Procedures

The Directive operationalises three core concepts.

First, mandatory AFM amendment. The AD requires incorporation of Diamond Aircraft Industries’ Temporary Revision TR‑MÄM‑42‑270 (dated 31 May 2008) into the AFM for every DA 42 and DA 42 M aircraft, all serial numbers (Requirement; Applicability). That is a textual amendment to the aircraft’s flight manual rather than a physical modification to the airframe. The AD also provides a clear exit mechanism for the TR, permitting its removal when a normal AFM revision includes or supersedes the TR (Requirement, removal provision).

Second, risk‑mitigation through operational limitation language. The Background explains why the TR was developed: some aircraft experienced lightning strikes of unusual high levels over the design requirement with resulting damage that may not be visible to the pilot (Background). The TR contains procedures intended to reduce the likelihood of additional structural loading after a strike, specifically including an airspeed limitation and “certain procedures to avoid additional loads to the structure” (Background). The AD therefore supplements an existing AFM prohibition on intentional flights into known thunderstorms (AFM Section 2.13 already specifies “Flights into known thunderstorms are prohibited”) with post‑strike procedures intended to limit further harm (Background).

Third, inspection and harmonisation signals. The AD directs inspection after any lightning strike in accordance with the DA 42 Aircraft Maintenance Manual, Chapter 05‑50, paragraph 5.D (Note 1). It also cross‑refers EASA AD 2008‑0136 (Note 2), indicating that the matter is not solely domestic and that equivalent or related regulatory action exists or is referenced elsewhere. Mechanically this AD therefore ties AFM content, maintenance inspection practice, and international regulatory references into a single compliance package.

The AD does not specify training requirements, record‑keeping formalities, or penalties. Nor does it mandate physical structural modification beyond inspection requirements after a lightning strike. The AD’s enforcement text is limited to a compliance deadline and an effective date, together creating an immediate obligation to alter the AFM. All of these points are recorded verbatim in the AD’s Requirement, Notes, Background and Compliance lines.

The AD affects several discrete categories of persons and entities connected to DA 42 and DA 42 M aeroplanes.

Aircraft operators and owners: Every owner or operator of a DA 42 or DA 42 M aeroplane, irrespective of serial number, is directly affected because the AD mandates that the applicable AFM be amended to include the specified Temporary Revision (Applicability; Requirement). The obligation to amend the AFM is an operational compliance task that rests with the party responsible for the aircraft’s documents and operations.

Pilots and flight crews: Pilots must operate in accordance with the AFM. Incorporating TR‑MÄM‑42‑270 will change the AFM procedures that pilots are required to follow after a lightning strike, specifically imposing an airspeed limitation and other steps to avoid additional structural loading (Background). Pilots are therefore affected in how they respond to lightning strikes and in any in‑flight decision making that references AFM‑required limitations.

Maintenance organisations and engineers: The AD requires that after any lightning strike the aircraft be inspected in accordance with the DA 42 Aircraft Maintenance Manual, Chapter 05‑50, paragraph 5.D (Note 1). Maintenance organisations performing post‑strike inspections and records must therefore follow that section of the maintenance manual. The maintenance manual reference makes engineers a principal point of compliance for structural assessment tasks.

Flight manual custodians and continuing airworthiness personnel: The duty to amend the AFM within the 30‑day compliance window places a logistical task on those controlling AFM revisions. They must obtain TR‑MÄM‑42‑270 dated 31 May 2008 and insert it into the AFM, then track subsequent normal AFM revisions that may supersede the TR (Requirement; removal provision).

Regulator and delegations: The AD was issued by the Civil Aviation Safety Authority via its delegate, James Coyne (signature block). That identifies the regulator as the decision maker and enforcer for the directive’s application (signature line, 24 July 2008).

International stakeholders: The AD’s explicit reference to EASA AD 2008‑0136 (Note 2) signals relevance for operators or registrants who must satisfy multiple jurisdictions. Foreign operators of DA 42 aircraft who are subject to EASA obligations will need to coordinate compliance across EASA and CASA directions.

Who pays. The AD implies costs fall on operators and maintenance providers: time and administrative effort to insert the TR into the AFM, possible pilot rebriefing, and inspections after any lightning strike. The AD text does not allocate funding or provide compensation; those are responsibilities for the operator or owner to manage.

Duties specified by the AD are explicit and narrow.

Amend the AFM: The primary duty is to amend the applicable Aircraft Flight Manual to incorporate the Temporary Revision TR‑MÄM‑42‑270 dated 31 May 2008, unless that action has already been accomplished (Requirement; TR reference). This duty is subject to the AD’s compliance timeframe, which requires amendment within 30 days after the AD’s effective date of 8 August 2008 (Compliance; Effective date).

Follow post‑strike inspection procedure: After any lightning strike, the aircraft must be inspected in accordance with the DA 42 Aircraft Maintenance Manual, Chapter 05‑50, paragraph 5.D (Note 1). That inspection requirement is set out as advisory language in the AD but refers directly to the maintenance manual procedure, thereby making adherence to that maintenance manual procedure the operative maintenance duty upon a lightning event.

Retain or remove TR according to AFM revision state: The Temporary Revision may be removed from the AFM only when the AFM is amended by a normal revision that includes or supersedes TR‑MÄM‑42‑270 (Requirement, removal provision). That creates an operational duty to monitor later AFM revisions and, when appropriate, remove the TR rather than leaving a temporary insertion in place indefinitely.

Operate consistent with AFM prohibitions: The AD reiterates that the AFM already specifies that flights into known thunderstorms are prohibited (Background, AFM Section 2.13). That existing AFM obligation remains in force and is part of the flight manual regime operators must follow.

Rights and limited discretion in the text.

Right to remove TR when superseded: Operators have the right to delete the Temporary Revision from the AFM once a normal revision of the AFM includes or supersedes it (Requirement, removal provision). That prevents the TR from becoming a permanent, unmanaged insertion.

No explicit mitigations, exemptions or penalty provisions: The AD does not state that operators may seek exemptions, nor does it stipulate administrative or criminal penalties in the text. It provides a compliance window and an effective date, but no explicit dispute resolution or exemption mechanism is provided in the wording of the AD itself.

Delegated regulatory decision: The AD is signed by a delegate of the regulator (James Coyne), which reflects that the legislative or regulatory authority has been exercised through delegation. The text does not describe further appeal or review rights, therefore any operational rights to challenge or seek relief are not specified in the AD document itself.

All duties and rights above are drawn from the AD’s labelled sections: Requirement; Applicability; Notes; Background; Compliance; signature. The AD does not specify ancillary duties such as pilot retraining, recordkeeping modalities, or notification requirements; any such measures would need to be inferred and implemented by operators as practical compliance steps, but they are not expressly required in the AD text.

The AD specifies an effective date and a compliance timeframe, but it does not set out penalty provisions, enforcement mechanisms or administrative processes within the text supplied.

Specifically, the AD states: “Compliance: Within 30 days after the effective date of this Directive. This Airworthiness Directive becomes effective on 8 August 2008.” Those are the only explicit enforcement‑adjacent statements in the AD. The directive is issued and signed by a CASA delegate, James Coyne, which identifies the issuing authority (signature block, 24 July 2008), but the AD text does not include provisions describing how non‑compliance will be handled, what sanctions may attach to breaches, or what processes an operator should use to report compliance.

Because the supplied source is the AD text only, the document does not itself enumerate administrative penalties, certificate actions, fines, or criminal sanctions. It also does not describe monitoring procedures, audit cycles, or the circumstances under which CASA would take regulatory action for non‑compliance. The absence of such language in the AD creates an operational uncertainty: the AD imposes a clear duty and deadline but leaves the specific enforcement response unarticulated in the published text.

For practitioners this means two points. First, compliance cannot be treated as optional merely because penalties are not stated in the AD; the Directive imposes a mandated change to the AFM and references applicable maintenance inspections. Second, the AD’s silence on enforcement procedures implies that operators who require certainty about enforcement consequences or who seek relief should consult CASA guidance, the relevant civil aviation regulatory framework outside this AD, or obtain formal advice, because enforcement mechanisms and penalty structures are typically set out elsewhere in CASA instruments or legislation, not in the AD text itself. None of those external instruments are included within the supplied source, and therefore they are not described here.

All descriptive statements in this section are grounded in the AD text’s Compliance, Effective date and signature lines, and in the AD’s omission of penalties or enforcement mechanics.

The AD explicitly references and interacts with several existing documents and regimes, as set out in its text.

Aircraft Flight Manual (AFM) baseline: The AD requires amending the AFM, and it references an existing AFM prohibition in Section 2.13 that states “Flights into known thunderstorms are prohibited” (Background). The AD therefore operates as an amendment to the AFM content for DA 42 aeroplanes; that ties this AD directly into the pre‑existing AFM regulatory framework that governs pilot procedures and limitations.

DA 42 Aircraft Maintenance Manual: The AD instructs that after any lightning strike the aircraft should be inspected in accordance with the DA 42 Aircraft Maintenance Manual, Chapter 05‑50, paragraph 5.D (Note 1). That cross‑reference creates an operational interface between AFM content and the maintenance manual’s structural inspection regime. Compliance therefore implicates both the flight operations document regime (AFM) and the continued airworthiness/maintenance manual regime.

Manufacturer Temporary Revision process: The AD requires the incorporation of a manufacturer’s Temporary Revision, TR‑MÄM‑42‑270 (dated 31 May 2008), into the AFM. It also allows the TR to be removed when a normal AFM revision incorporates or supersedes it (Requirement, removal provision). This constructs an interaction between temporary manufacturer revisions and the normal AFM revision cycle, and it delegates to the normal revision process the responsibility for making the TR permanent or superseded.

European Aviation Safety Agency reference: The AD notes that EASA AD 2008‑0136 refers (Note 2). That explicit cross‑reference indicates that equivalent or related regulatory action exists at the EASA level. Practically, operators who are subject to EASA oversight, or who operate internationally, will need to consider both CASA’s AD and the referenced EASA AD; the AD therefore functions in tandem with international airworthiness directives. The AD does not, however, specify how conflicts between directives would be resolved should they arise.

No statutory penalty provisions in the AD text: The AD does not itself set out interaction with penalty regimes in other legislation. Since the AD is an instrument of CASA, enforcement and penalty actions, if pursued, would be governed by the broader civil aviation legislative framework and CASA enforcement policy, which are not contained within this AD text.

In short, the AD operates as an operationally binding amendment to AFM content, links directly to maintenance manual inspection obligations, fits within the manufacturer’s TR and AFM revision process, and references related EASA action. All interactions described here are drawn from the AD’s Requirement, Notes, Background and the EASA reference.

The AD text provides a concise but explicit record of the immediate amendment history relevant to the Directive.

Temporary Revision origin: The AD requires incorporation of Diamond Aircraft Industries Temporary Revision TR‑MÄM‑42‑270, which is dated 31 May 2008 (Requirement; TR reference). That is the document the AD requires be inserted into the AFM.

AD issuance and dates: The AD is dated 10/2008 DM and carries the identifier AD/DA42/6 (document header). The signature block records the date 24 July 2008, with the AD stating it “becomes effective on 8 August 2008” and that compliance is required within 30 days after the effective date (Compliance; Effective date; signature). These dates create the AD’s effective amendment window and show the sequence: TR dated 31 May 2008, AD signed 24 July 2008, AD effective 8 August 2008, compliance within 30 days of effective date.

Removal rule: The AD contains a provision that TR‑MÄM‑42‑270 “may be removed from the AFM when the AFM is amended by a normal revision which includes or supersedes the TR‑MÄM‑42‑270 lightning strike procedure” (Requirement, removal provision). That stipulation is an explicit, forward‑looking amendment control that governs how the temporary insertion should be treated when a permanent revision to the AFM occurs.

No later amendments recorded in this source: The supplied AD text does not record subsequent amendments or superseding ADs. No other revision history entries, rescissions, or follow‑up directives are included in the document provided.

Reference to international AD: The AD notes that EASA AD 2008‑0136 refers (Note 2). The AD does not state that the EASA AD amends or supersedes this AD, but the cross‑reference is part of the historical and regulatory context.

All dates, document identifiers and procedural instructions in this section are taken directly from the AD text: the TR date, the AD number, the signature block date, the stated effective date, the compliance timeframe and the TR removal rule.

The AD text supplied does not contain any information about litigation, judicial review, administrative appeals, or court proceedings connected to AD/DA42/6. There are no cases, proceedings, or litigation references in the document.

Because the AD itself is a regulatory instrument, affected parties may have legal pathways outside this document to seek review, such as statutory appeal or administrative review processes in the aviation regulatory framework, but those pathways and their outcomes are not described in the AD text provided. The AD does not supply any record of disputes, challenges, or adjudicated outcomes related to this Directive.

Practically, therefore, the document presents no litigation history to analyse. Any consideration of past or prospective disputes, enforcement challenges, or judicial interpretations would require reference to external records, judgments or CASA enforcement actions that are outside the supplied source. The absence of litigation entries in the AD is a factual point recorded directly from the absence of such material in the text.

All statements in this section reflect the AD’s silence on litigation and use only the supplied AD document as the source.

The AD contains concise obligations and a number of practical traps for the unwary operator; these are matters of implementation and timing grounded in the AD text.

Timing and compliance window: The AD requires the AFM amendment within 30 days after the effective date of 8 August 2008 (Compliance; Effective date). Operators who do not track the effective date precisely risk missing the mandatory insertion window. The AD does not provide a grace period or phased compliance schedule in the text.

Scope by serial number: The Applicability clause covers “DA 42 and DA 42 M aircraft, all serial numbers.” The “all serial numbers” language eliminates arguments based on selective applicability; if an operator is responsible for any DA 42 or DA 42 M, the AD applies.

Temporary Revision identification: The AD requires insertion of a specific document, TR‑MÄM‑42‑270 dated 31 May 2008 (Requirement; TR reference). Using the wrong TR number or date would not satisfy the textual requirement. Operators must ensure they obtain and insert the precise TR cited by the AD.

Removal conditions: The AD permits the TR to be removed from the AFM only when a normal AFM revision includes or supersedes the TR (Requirement, removal provision). That requires operators to monitor subsequent AFM normal revisions and confirm that the content either includes or supersedes the TR before removing it. Removing the TR prematurely could leave the aircraft out of compliance.

Post‑strike inspections: The AD directs that after any lightning strike the aircraft “should be inspected in accordance with the DA 42 Aircraft Maintenance Manual, Chapter 05‑50, paragraph 5.D” (Note 1). The use of “should” is advisory in tone within the AD, but it references a specific maintenance manual paragraph. Operators need to exercise care: although the AD frames it as a note, the practical effect is that the maintenance manual procedure becomes the specified inspection route after a lightning strike. Failure to follow the detailed maintenance manual paragraph may leave structural issues undetected because the AD’s Background warns that damage “may not be visible to the pilot”.

Contents of the TR: The Background states that the TR includes an airspeed limitation and “certain procedures to avoid additional loads to the structure.” That means pilots and operators need to review the TR carefully for specific numerical limits and procedural steps. The AD does not reproduce those numbers; they are in the TR. Operators who do not read and communicate the TR content to flight crews may fail to adopt the required airspeed limitations and load‑avoidance steps.

International reference: The AD notes EASA AD 2008‑0136 refers (Note 2). Operators that fly, register, or maintain aircraft across jurisdictions must check whether that EASA AD imposes additional or differing requirements. The AD itself does not state how conflicts are to be resolved.

No penalty language in the AD: The AD does not specify enforcement or penalty mechanisms. That absence can create uncertainty about the practical consequences of non‑compliance and should not be read as permission to ignore the directive. Operators should ensure compliance and document actions, because enforcement mechanisms may be located in other regulatory instruments.

Document control and records: The AD requires an AFM amendment but does not stipulate how the amendment must be recorded in aircraft records. Removing ambiguity requires operators to adopt recordkeeping practices consistent with maintenance and flight operations requirements, even though the AD does not describe those procedures.

All “gotchas” above derive from the AD’s Requirement, Applicability, Notes, Background, and Compliance text and the interplay between those clauses.

The AD sets out a short, specific compliance pathway; operators and maintainers will need to follow those steps and fill any operational gaps with standard organisational procedures.

1. Confirm applicability. Verify that the AD applies to the aircraft in your fleet. The AD’s Applicability states it covers “DA 42 and DA 42 M aircraft, all serial numbers.” If you operate DA 42 or DA 42 M aircraft, the AD applies (Applicability).

2. Obtain the Temporary Revision. Acquire Diamond Aircraft Industries Temporary Revision TR‑MÄM‑42‑270 dated 31 May 2008. The AD requires incorporation of that specific TR into the applicable AFM (Requirement; TR reference).

3. Insert the TR into the AFM. Amend the AFM to incorporate TR‑MÄM‑42‑270. The AD requires that the AFM be amended, and that the TR may remain until a normal AFM revision includes or supersedes the TR (Requirement; removal provision). Make sure the TR text and date match the AD’s citation.

4. Meet the deadline. Complete the AFM amendment within the AD’s compliance window, which is “within 30 days after the effective date of this Directive.” The AD states the Directive becomes effective on 8 August 2008 (Compliance; Effective date). Operators should calculate the 30‑day window from that effective date and document completion.

5. Communicate to flight crews. Ensure pilots and relevant operational staff are briefed on the new procedures in the TR, particularly the airspeed limitation and procedures to avoid additional structural loads indicated in the AD’s Background. The AD does not mandate a specific form of briefing, but pilots must operate in accordance with the AFM once the TR is incorporated.

6. Record the amendment. While the AD does not prescribe detailed recordkeeping, best practice and good regulatory hygiene require recording the AFM amendment in the aircraft’s document control and continuing airworthiness records so that the change is auditable and traceable during inspections or audits.

7. Post‑strike inspections. After any lightning strike, ensure the aircraft is inspected in accordance with the DA 42 Aircraft Maintenance Manual, Chapter 05‑50, paragraph 5.D (Note 1). That paragraph contains the maintenance procedures the AD directs be followed after a lightning strike.

8. Track AFM normal revisions. The AD permits removal of the TR only when the AFM is amended by a normal revision that includes or supersedes the TR. Maintain a process to review manufacturer AFM normal revisions and remove the TR only when the content has been incorporated or superseded (Requirement, removal provision).

9. Consider international harmonisation. If the aircraft operate under or interact with EASA regimes, consult EASA AD 2008‑0136 as referenced in the AD (Note 2). Coordinate compliance where multiple directives apply.

10. Address organisational gaps. The AD does not set out training, enforcement, or documentation standards beyond the AFM amendment and the maintenance manual inspection reference. Organisations should therefore adopt internal procedures to ensure pilots and maintainers are aware of the new AFM content and that post‑strike inspections are scheduled and performed in accordance with the maintenance manual paragraph.

Every compliance step above follows from the AD’s Applicability, Requirement, Notes, Background and Compliance entries. The AD imposes a narrow set of obligations , insert the TR into the AFM within the specified timeframe and follow the specified maintenance manual paragraph after lightning strikes , and operators should design organisational processes to implement those obligations and produce auditable records.