This Seat AD may set an international precedent as to Global Aircraft Certifications

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FAA Airworthiness Directive (AD) for Zodiac Seating Systems

Might set precedents about future BASAs, certifications & commercial responsibilities.

The Federal Aviation Administration has issued an “Airworthiness Directive (AD) for certain Zodiac Seats California LLC seating systems. This AD was prompted by a determination that the affected seating systems faa zodiac seatsmay cause serious injury to the occupant during forward impacts when subjected to certain inertia forces.” 82 FR 23723. Specifically, “Slim” or “Slimplus”, produced by Zodiac Seats California LLC, were found to have been unairworthy.

The basis for the AD is described in this quote from the final notice:

“The FAA and Agência Nacional de Aviação Civil (ANAC) (Brazil) reviewed seven videos from the technical standard order authorization for TSO-C127a seating systems. Based on the video, the FAA characterized the interaction of the ATD chin and the tray table into five cases: two that are normal (typical) interactions, and three that are not. In the two typical interactions, the head either slides down the seat back and tray table unimpeded, or the head crushes the tray table inward and dislodges it downward. The FAA and Zodiac Seats California agreed that two of the abnormal cases are unsafe and corrective action is required.

The original proposal, Federal Register April 20, 2016 (81 FR 23212), was reopened the period to submit comments. There were twenty requests, a high number, to modify the AD. Most were denied, but the FAA did amend some of their lists of applicability and a few standards. The entities that submitted their views to the docket included an Industry Ad Hoc Committee (Bombardier, Embraer, HAECO Cabin Solutions, Zodiac Seats California, Zodiac Seats France, Zodiac Seats UK, and Zodiac Seats US), UPS, Austrian Airlines AG, SkyWest Airlines, and Delta.

delta united seat replacement

ADs are issued routinely even though their subject matter may be an unairworthy condition. The Zodiac Slimline final rule is notable in several ways:

Technical Debate

  • Many of the 20 requests were debates about the standards being used by the FAA and ANAC to assess the risk of serious neck injury. ADs are usually based on uncontestable safety analyses. Read the comments for the debate between the FAA and those submitting technical comments.

Cost of AD Compliance

  • 10,482 seats must be removed from Boeing’s 717-200 and MD-90-30 aircraft, Bombardier’s CRJ700, CRJ900 and Q400 aircraft, and Embraer’s E170 and E190 planes.
  • FAA estimated it would cost $85 to remove each unsafe seat, for a total of $890,970 to remove 10,482 seats flying with U.S. carriers within five years.
  • SkyWest, a regional carrier for American, Delta, United and Alaska airlines, alone reports that it would cost between $250,000 and $500,000 to replace seats in its affected 120 planes.
  • If the cost of replacement is ~$2,000 @ seat and labor, then the AD full cost (passengers cannot fly without seats) would cost the industry about $17,470,000.

BASA Impact

  • The NPRM mentions that ANAC and the FAA reviewed seven videos on the seats in questions.
    • Which CAA had the responsibility to establish the airworthiness of the seat?
    • Was the initial a/w determination as to this seat made by the FAA or the CAA?
      • As part of an aircraft certification?
      • Or a later request to add these seats to aircraft?
  • Which authority first became aware of these videos and how soon was the discovery communicated?
  • The AD also mentioned the Bombardier CRJ700, CRJ900 and Q400. Those aircraft were certificated by Transport Canada Civil Aviation; yet there is no mention of TCAA’s participation in the AD. There is a BASA between the US and Canada. Same questions as above. 

Commercial Impact

  • Whether you accept the FAA’s costs for the AD compliance, the airlines will have to spend substantial sums for the replacement of the seats.
  • Will Boeing (McDonnell Douglas’ successor), Bombardier, Embraer, Zodiac or a combination thereof be involved in the recompense for the replacement? Voluntarily or through litigation?

boeing bombardier embraer seat replacement

  • The competition between aircraft manufacturers to sell their products to airlines is fierce. The only sector with greater pressure is that in which suppliers to the manufacturers, like Zodiac. Commercial power may influence the allocation of the AD compliance costs.
  • These are matters of absolutely ZERO concern to the FAA.

Sovereigns deal with their peers behind the cloak of diplomacy. How ANAC and the FAA came to this decision will not likely be revealed in any documents made available to the public. At the same time, aircraft certification is increasingly a share responsibility between CAAs. The concept of a BASA was developed to facilitate reliance between CAAs. This AD may well set precedents about future BASAs, certifications and commercial responsibilities thereof.


FAA: Airlines must remove unsafe seats from some regional planes
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1 Comment on "This Seat AD may set an international precedent as to Global Aircraft Certifications"

  1. Nice article. Great questions. It will be interesting to see the answers. Hopefully, the compliance philosophy will work itself out in this case.

    I don’t understand your two for one comment. If AD’s don’t apply to the two for one, how can it be a serious departure?

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