AD 2008-14-04

We are adopting a new airworthiness directive (AD) for Eurocopter France Model AS 355 N helicopters. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The European Aviation Safety Agency (EASA), the technical agent for France, with which we have a bilateral agreement, states in the MCAI: "This Airworthiness Directive (AD) is issued because it was found that the power drawn by the starter generators from the engines is above the consumption capacity at altitudes above 3,000 meters, declared for the engines of AS 355 N helicopters. Excessive power consumption of the starter generators reduces the engine surge margin, which can result in engine failure.''

After engine start, the starter generator functions as the normal operational electrical generator. We are issuing this AD to require actions that are intended to address this unsafe condition.

Final rule.

2008-14-04 Eurocopter France: Amendment 39-15599. Docket No. FAA- 2008-0041; Directorate Identifier 2007-SW-16-AD.

Effective Date

(a) This amendment becomes effective on August 5, 2008.

Other Affected ADs

(b) None.

Applicability

(c) This AD applies to Model AS 355 N helicopters, certificated in any category.

Reason

(d) The mandatory continuing airworthiness information (MCAI) states: "This Airworthiness Directive (AD) is issued because it was found that the power drawn by the starter generators from the engines is above the consumption capacity at altitudes above 3,000 meters, declared for the engines of AS 355 N helicopters. Excessive power consumption of the starter generators reduces the engine surge margin, which can result in engine failure.''
The starter-generator is a single unit that is operated both as an engine starter generator and after starting, as an operational generator. The EASA AD and the Eurocopter service bulletin refer to this unit as a starter generator. The starter generator requires energy from the engine to generate electricity. When the electrical current exceeds 100 amps, the load on the engine reduces the engine surge margin and may cause the engine to surge and flame out.
Therefore, at altitudes above 10,000 feet, the maximum continuous current supplied by each starter generator must be limited to 100 amps to prevent engine surging.

Actions and Compliance

(e) Within 100 hours time-in-service or within 12 months, whichever occurs first, unless already done, do the following actions:
(1) Install a limitation placard (indicating the new load limitation for the starter generator) on the overhead instrument panel, immediately below the ammeter.
(2) The placard must state the following: Maximum continuous load per generator 100A If Hp>10000 ft.

Differences Between This AD and the MCAI AD

(f) None.

Other Information

(g) Alternative Methods of Compliance (AMOCs): The Manager, Safety Management Group, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Ed Cuevas, Aviation Safety Engineer, Fort Worth, Texas 76193-0111, telephone (817) 222-5355, fax (817) 222- 5961.

Related Information

(h) MCAI EASA Airworthiness Directive No. 2006-0338, dated November 7, 2006, and Eurocopter Alert Service Bulletin, Revision 1, No. 01.00.52, dated September 14, 2006, contain related information.

Air Transport Association of America (ATA) Tracking Code

(i) ATA Code 2435--Electrical Power Starter Generator, 80-- Starting.

Discussion

We issued an NPRM to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM was published in the Federal Register on January 23, 2008 (73 FR 3891). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states: "This Airworthiness Directive (AD) is issued because it was found that the power drawn by the starter generators from the engines is above the consumption capacity at altitudes above 3,000 meters, declared for the engines of AS 355 N helicopters. Excessive power consumption of the starter generators reduces the engine surge margin, which can result in engine failure.''

Comments

By publishing the NPRM, we gave the public an opportunity to participate in developing this AD. However, we received no comment on the NPRM or
on our determination of the cost to the public. Therefore, based on our review and evaluation of the available data, we have determined that air safety and the public interest require adopting the AD as proposed except for some formatting changes. These changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Relevant Service Information

Eurocopter has issued Alert Service Bulletin, Revision 1, No. 01.00.52, dated September 14, 2006. The actions described in the MCAI are intended to correct the same unsafe condition as that identified in the service information.

Differences Between This AD and the MCAI AD

There are no substantive differences between this AD and the MCAI AD.

Costs of Compliance

We estimate that this AD will affect about 17 helicopters of U.S. registry. We also estimate that it will take about 15 minutes to install the placard in each helicopter. The average labor rate is $80 per work-hour. The manufacturer states in its service bulletin that the "labels will be delivered free of charge on the Operator's order.'' Because the manufacturerhas indicated it will provide the placard free of charge, we have assumed there will be no charge for these placards. However, because we do not control warranty coverage for affected parties, some parties may incur costs higher than estimated here. Based on these figures, we estimate the cost of the AD on U.S. operators to be $340 or $20 per helicopter.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. "Subtitle VII: Aviation Programs,'' describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in "Subtitle VII, Part A, Subpart III, Section 44701: General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.
For the reasons discussed above, I certify this AD:
1. Is not a "significant regulatory action'' under Executive Order 12866;
2. Is not a "significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and
3. Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.We prepared an economic evaluation of the estimated costs to comply with this AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. The FAA amends Sec. 39.13 by adding the following new AD: