2011-14-05: Main Rotor Head
FAA order 2011-14-05 is an airworthiness directive in force since August 1, 2011. The FAA's subject line: Main Rotor Head. It names Md Helicopters Inc MD 900: about 11 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: rotorcraft systems.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- MD Helicopter Inc.
- Models
- MD900
- On this site
- Md Helicopters Inc MD 900 11 registered
Dates and paperwork
- In force since
- August 1, 2011
- Published
- July 15, 2011 (signed June 21, 2011)
- Docket
- FAA-2011-0695
- Replaces
- 2010-18-52
- Replaced by
- 2012-21-01
- Status
- Historical
- The FAA's document
- Read the order on the FAA's site
The FAA's summary their words, unchanged
This amendment supersedes an existing airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) Model MD900 helicopters. That AD currently requires visually inspecting the main rotor lower hub assembly (lower hub) for a crack, and if you find a crack, before further flight, replacing the unairworthy lower hub with an airworthy lower hub. Additionally, within 10 days of finding a cracked lower hub, the existing AD requires reporting the finding to the Los Angeles Aircraft Certification Office (LAACO). That AD was prompted by two reports of cracks detected in the hub in the area near the flex beam bolt hole locations during maintenance on two MDHI Model MD900 helicopters. Since we issued that AD, we determined that one manufacturer had incorrectly inserted flanged bushings into the lower hub bore that resulted in local corrosion, leading to fatigue cracking. Examination of lower hubs from the other manufacturer shows correct bushing installation. Therefore, this amendment limits the applicability to the affected lower hubs; retains the visual inspection but at a different compliance time; adds an eddy current inspection; retains the requirement to replace a cracked lower hub with an airworthy lower hub before further flight; and removes the requirement to report to the LAACO. The actions specified by this AD are intended to detect a crack in the lower hub and prevent failure of the lower hub and subsequent loss of control of the helicopter.
The order itself the regulatory text, as published
Show the full text (4,769 characters)
Related safety bulletins advice on the same designs, not orders
Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 5, 2026. Connections as data: /graph/directive/2011-14-05.json · aircraft systems.
