Comment from Anonymous

To: Federal Aviation Administration Docket No.: FAA-2026-4630 Subject: Comment on Proposed Airworthiness Directive - Hélicoptères Guimbal Cabri G2 Helicopters Date: 05/08/2026 Introduction I am submitting this comment in response to the Federal Aviation Administration's (FAA) Notice of Proposed Rulemaking (NPRM), published May 7, 2026, proposing a new airworthiness directive (AD) for certain Hélicoptères Guimbal (HG) Model Cabri G2 helicopters (serial numbers 1003–1389, excluding S/N 1383 and 1388). The proposed AD addresses a safety risk posed by improperly installed emergency locator transmitter (ELT) antennas that produce weak signals on the 121.5 MHz and 406 MHz frequencies. Position I support the proposed AD and agree that the FAA's intervention is warranted. However, I recommend that the FAA strengthen the rule by requiring a mandatory timeline for the optional ELT antenna modification, rather than allowing the current RFM-only revision to remain the sole compliance pathway indefinitely. Supporting Arguments The safety rationale for this AD is compelling. A weak or degraded ELT signal directly undermines the device's core purpose, enabling rapid detection and rescue of helicopter occupants in an emergency. The FAA correctly notes that failure to address this condition could delay rescue efforts and deny injured survivors timely medical care. Given that the Cabri G2 is widely used for flight training, where pilots may have limited emergency experience, a reliable ELT function is especially critical. The proposed required action, revising the rotorcraft flight manual (RFM) to prohibit overwater operations under 14 CFR part 135 for aircraft lacking an external ELT antenna, is a reasonable interim measure. It reduces exposure to the highest-risk scenarios while a physical fix is performed. The FAA's estimate of just one work-hour and $85 per aircraft for the RFM revision confirms this is a minimally burdensome initial step. That said, the RFM limitation treats the symptom rather than the cause. The underlying issue, an improperly located antenna inside the cockpit, persists until the optional modification under Guimbal Mandatory Service Bulletin SB 25-006 B is completed. The European Aviation Safety Agency's original AD (EASA AD 2025-0282) required this physical modification within six months. The FAA's proposed AD omits this deadline entirely, leaving open the possibility that affected aircraft fly indefinitely with a degraded ELT, provided they avoid overwater Part 135 operations. Recommendation I recommend the FAA adopt a compliance deadline consistent with the EASA standard of six months for completing the ELT antenna relocation described in Guimbal SB 25-006 B. This would convert the "optional terminating action" into a required one within a defined timeframe. The estimated per-aircraft cost of up to $1,298 for the modification is modest relative to the life-safety benefit it provides. Operators should not be permitted to rely on an RFM operational restriction as a permanent substitute for correcting a known hardware defect. Conclusion The FAA is right to address this unsafe condition, and I commend the agency for its responsiveness to the EASA MCAI. I urge the FAA to go one step further and establish a firm compliance deadline for the physical ELT antenna modification, ensuring that all 70 affected U.S.-registered Cabri G2 helicopters are ultimately brought to a fully corrected standard — not merely restricted from specific operations.