Comment from Air T&G Pty Ltd

Docket No. FAA-2026-3863; Project Identifier AD-2024-00567-R 1.Excessive Cost Relative to Demonstrated Risk The proposed AD imposes enormous compliance costs on a small fleet (estimated at only 325 U.S.- registered helicopters). After a quick search on Registry.faa.gov, there are currently 325 N registered UH60s (far above the estimated 96 listed in the proposed AD). - Safety enhancement modification kit: roughly $300,510 per helicopter (including labor). - Split pitch horn modification: roughly $50,510 per helicopter (including labor). - Total potential cost to U.S. operators: Up to $97.7M+ if all require the more expensive kit. - If all use the lower-cost split pitch horn option: Approximately $16.4M. - Realistic mixed scenario (assuming a significant portion need the full kit): Likely $60–90M+ across the fleet. This is on top of retained daily visual/tap inspections (40 hour) and new recurring inspections of the disbond indicator. For operators of older military-surplus UH-60/EH-60/HH-60 variants (often used in utility and firefighting), these costs could threaten economic viability. Many such operators run on thin margins and cannot easily absorb hundreds of thousands of dollars per aircraft for a modification that addresses a historical issue. The original AD 2020-02-17 was prompted by only four incidents of pitch horn/torque tube disbonding. While any loss of tail rotor control is serious, expanding the applicability years later to a broader set of models without clear evidence of a continuing, widespread safety crisis suggests overreach. The FAA has not (in the NPRM summary) demonstrated a sufficient number of recent events to justify this level of mandated expenditure. 2.Questionable Necessity of Mandatory Modification The proposal requires installing either a split pitch horn or a safety enhancement kit (with visual disbond indicator stripes) and re-identifying the blades. This goes far beyond the existing inspection-based approach. - Inspections appear effective: The retained daily visual and tap-test requirements from the 2020 AD already detect disbonding before catastrophic failure. If safety is the main focus of this AD, a more frequent inspection interval (10 hours vs the current 40 hours) would identify failures sooner, reduce the risk of incidents or accidents, and not add a financial burden to operators who rely on these aircraft to service ongoing firefighting operations. The new disbond indicator is essentially a visual aid - useful, but not necessarily worth a $300k retrofit across the fleet. - Manufacturing improvements acknowledged: Sikorsky implemented process changes between 2006–2007. Blades made after that date have a lower risk profile, yet the proposal still mandates modifications within 48 months. This timeline is aggressive for older, low-utilization aircraft. - Modification failures: The number of blades being scrapped during the modification process due to the blades being damaged by the manufacture is 60%. Operators have to plan for and expect that 60% of the blades they send off will be damaged during the process, making them absorb the costs of disposal as well as additional downtime due to the lack of available replacement blades industry wide. - Excessive lead time: The lead time for Sikorsky to complete the modification of one set of blades is currently 6 months and will be significantly longer if this AD is published in its current form. - Lack of availability: There is a serious lack of availability of replacement blades. - Impact: This AD will have a significant impact on the industry and the country as a whole. UH60 type aircraft currently make up approximately 80% of the Type 1 firefighting assets in North America. This AD will effectively ground this fleet of assets causing significant economic and environmental impacts, financially burdening the operators as well as removing these aircraft from active fires. 3.Regulatory Burden and Small Entity Impact Although the FAA certifies it would not have a “significant economic impact on a substantial number of small entities”, this is dubious: - Many affected operators are small businesses running 1–5 ex-military Black Hawk derivatives. - There are currently 325 N registered aircraft that will be affected by this AD in the US, there are many more operating worldwide providing firefighting support across a wide range of countries including Australia, Indonesia, New Zealand, Philippines, and most of Europe........................... FOR OUR FULL COMMENT, PLEASE SEE THE ATTACHED PDF ................................ In summary, while tail rotor reliability is critical, this proposed AD fails a reasonable cost-benefit test, over- relies on mandatory hardware changes instead of proven inspection methods, and disproportionately burdens small operators without compelling new safety data. It should be withdrawn or significantly scaled back in favor of a less burdensome, inspection-focused solution.