AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/LA -4/26 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
Consolidated Aeronautics, Colonial and LA-4 Series Aeroplanes
AD/LA-4/26
Amdt 1
Wing Upper and Lower Spar Doublers 7/2002
Applicability: Affected aircraft with wing spar part numbers incorporated as specified below:
Model | Serial Numbers |
Lake LA-4 | 246 through 421, 423 through 429, 445, and 446 |
Lake LA-4A | 244 and 245 |
Lake LA-4P | 121 |
Lake LA-4-200 | 422, 430 through 444, 446, and all subsequent serial numbers. |
Lake Model 250 | 1 through 232 |
Wing Spar Parts | Part Numbers |
Upper Spar Cap Angles | 2-1610-015 and 2-1610-016 |
Lower Spar Cap Angles | 2-1610-075 and 2-1610-076 |
Upper Spar Doublers | 2-1610-061 and 2-1610-081 and 2-1610-065 |
Lower Spar Doublers | 2-1610-063 and 2-1610-083 |
Requirement: 1. Inspect the left and right wing upper and lower spar doublers for cracks in accordance with the Inspection section of Revo Incorporated Service Bulletin B- 79 R1, Revised 5 January 2000.
Consolidated Aeronautics, Colonial and LA-4 Series Aeroplanes
AD/LA-4/26 Amdt 1 (continued)
Replace any cracked wing spar doubler, before further flight, with a new part that incorporates the same part number (or FAA-approved equivalent part number), in accordance with the applicable maintenance manual.
2A. Incorporate Modification Kit B-79 in accordance with the Kit Installation section of Revo Incorporated Service Bulletin B-79 R1.
OR
2B. Incorporate STC ASA052ML.
Note: FAA AD 2000-10-22 Amdt 39-11746 refers.
Compliance: 1. Within 50 hours time in service after 10 August 2000, or before 10 August 2001, whichever occurs first.
2. Before further flight after Requirement 1 is accomplished. Also, if 2B, inspect regularly in accordance with the STC instructions.
This amendment becomes effective on 11 July 2002.
The original issue of this Airworthiness Directive became effective on 10 August 2000.
Background: The FAA received a report of a fatigue crack found at the second most inboard wing attachment bolt hole on one of the affected aircraft. Similar fatigue cracking has since been reported on seven more of the affected aircraft, including incidents where the fatigue cracking occurred on aircraft with less than 500 hours time in service.
Such cracking could result in wing separation from the aircraft with consequent loss of control.
Amendment 1 adds an alternative modification.
David Alan Villiers
Delegate of the Civil Aviation Safety Authority 31 May 2002
The above AD is notified in the Commonwealth of Australia Gazette on 19 June 2002.
Overview
The Civil Aviation Safety Authority (CASA) introduced this Airworthiness Directive (AD) under the Civil Aviation Regulations 1998 (CAR 1998) to address a safety concern identified in the Lake LA-4 series aeroplanes. This AD, titled AD/LA-4/26 Amendment 1, specifically targets the installation of wing upper and lower spar doublers to mitigate the risk of fatigue cracking. This problem was identified after a fatigue crack was found on an affected aircraft, which could potentially result in wing separation and loss of control. The AD mandates inspections and necessary repairs or modifications within specified timeframes to ensure the continued airworthiness of the affected aircraft. The policy objective is to enhance aviation safety by ensuring the structural integrity of the aircraft is maintained.
Scope and Application
The Airworthiness Directive (AD) AD/LA-4/26 Amdt 1, issued under subregulation 39.1(1) of the Civil Aviation Regulations 1998 (CAR 1998), applies specifically to certain Lake Model 250 and Consolidated Aeronautics, Colonial, and LA-4 series aeroplanes identified by particular serial numbers and wing spar part numbers. This AD is applicable to any aircraft with the specified wing spar part numbers, including upper and lower spar cap angles, and upper and lower spar doublers. The AD mandates that inspections and modifications be carried out to address the identified safety concern related to potential fatigue cracking in the wing spar doublers. The directive requires that inspections for cracks be performed in accordance with Revo Incorporated Service Bulletin B-79 R1, Revised 5 January 2000, and any cracked wing spar doublers must be replaced with new parts of the same or an FAA-approved equivalent part number. Additionally, operators must choose either to incorporate Modification Kit B-79 or STC ASA052ML to address the issue. The directive must be complied with within 50 hours of the aircraft being in service after 10 August 2000, or before 10 August 2001, whichever comes first, and before further flight after the required actions are taken. The AD is effective from 11 July 2002, following its notification in the Commonwealth of Australia Gazette on 19 June 2002.
Key Provisions
The Airworthiness Directive (AD) AD/LA-4/26, amended by AD/LA-4/26 Amdt 1, outlines specific requirements for the maintenance and inspection of certain models of Lake LA-4 series aeroplanes to address safety concerns related to wing spar doublers. The AD specifically applies to the Lake LA-4, LA-4A, LA-4P, and LA-4-200 models, with particular attention to the serial numbers and part numbers detailed in the applicability section (section 3). The requirement section (section 4) mandates that inspections and repairs be conducted on the wing upper and lower spar doublers to prevent the risk of cracking and subsequent structural failure. Specifically, Section 4(1) requires an inspection for cracks in accordance with Revo Incorporated Service Bulletin B-79 R1, Revised 5 January 2000. If cracks are found, Section 4(2) requires the replacement of the cracked spar doublers with new parts of the same part number or an FAA-approved equivalent. Additionally, Section 4(2A) and 4(2B) provide alternative modifications: either incorporating Modification Kit B-79 or STC ASA052ML, as specified in the service bulletin.
The AD imposes several obligations on the parties governed by it, primarily focusing on compliance with the specified inspection and repair requirements. Owners and operators of the affected aircraft must ensure that the required inspections are conducted and any necessary repairs are performed in accordance with the instructions provided in the service bulletin and maintenance manuals. Compliance must be achieved within 50 hours of time in service after 10 August 2000, or before 10 August 2001, whichever occurs first (section 5(1)). Moreover, any repairs must be completed before further flight, and if the STC ASA052ML modification is chosen, regular inspections must be conducted as per the STC instructions (section 5(2)).
Failure to comply with the requirements set out in the AD can result in severe consequences. Although the AD itself does not explicitly state the penalties for non-compliance, non-adherence to ADs generally falls under the broader regulatory framework of the Civil Aviation Safety Authority (CASA). Potential penalties for non-compliance may include enforcement actions by CASA, which can range from fines to the suspension or revocation of the aircraft's certificate of airworthiness. Such actions can have significant operational and legal ramifications for the aircraft owner or operator, potentially leading to grounding of the aircraft until the required actions are taken.