Metrojet crash Eygpt

[Data Guy]

Yet Another AD

AD 2015-23-13. All A-318, 319, 320, and A321 series airplanes. Allowable load limits on the vertical tail plane could be reached and possibly exceeded. Exceeding allowable load could result in detachment of the vertical tail plane.

SUMMARY: “This AD was prompted by a determination that, in specific flight conditions, the allowable load limits on the vertical tail plane could be reached and possibly exceeded. Exceeding allowable load could result in detachment of the vertical tail plane. This AD requires modification of the pin programming flight warning computer (FWC) to activate the stop rudder input warning (SRIW) logic; and an inspection to determine the part numbers of the FWC and the flight augmentation computer (FAC), and replacement of the FWC and FAC if necessary. We are issuing this AD to prevent detachment of the vertical tail plane and consequent loss of control of the airplane.Effective December 29, 2015.” Compliance within 48 months.

“We estimate that this AD affects 953 airplanes of U.S. registry. We also estimate that it will take about 3 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this AD on U.S. operators to be $243,015, or $255 per product.”

FAA AD Link > http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/41103a24e0131b2286257f0700529ecf/$FILE/2015-23-13.pdf

ALSO REFERENCED IN THIS AD.

“EASA Airworthiness Directive 2014-0217R1, dated February 26, 2015 (referred to after this as the Mandatory Continuing Airworthiness Information, or ''the MCAI''), to correct an unsafe condition.The MCAI states: During design reviews that were conducted following safety recommendations related to in-service incidents and one accident on another aircraft type, it has been determined that, in specific flight conditions, the allowable load limits on the vertical tail plane could be reached and possibly exceeded.This condition, if not corrected, could lead, in the worst case, to detachment of the vertical tail plane in flight and consequent loss of the aeroplane.To prevent such a possibility, Airbus has developed modifications within the flight augmentation computer (FAC) to reduce the vertical tail plane stress and to activate a conditional aural warning within the flight warning computer (FWC) to further protect against pilot induced rudder doublets.”

“Consequently, EASA issued AD 2014-0217 to require installation and activation of the stop rudder input warning (SRIW) logic. In addition, that [EASA] AD required, prior to or concurrent with modification of an aeroplane with the activation of the SRIW, upgrades of the FAC and FWC, to introduce the SRIW logic and SRIW aural capability, respectively. After modification, the [EASA] AD prohibited installation of certain Part Number (P/N) FWC and FAC.”

“Since that [EASA] AD was issued, an additional previously-published Airbus Service Bulletin (SB) was identified, and a new SB was published, for the concurrent requirement to replace the FAC with a unit having a P/N as listed in Table 3 of Appendix 1 of the AD.”

NTSB SAFETY RECCOMMENDATIONS A-04-56 through -62.
See Letter to FAA Administrator Marion C. Blakey, November 10, 2004 which addressed the loss of American Airlines Flight 587 on Nov 12, 2001.
NTSB Letter Link > http://www.ntsb.gov/safety/safety-recs/recletters/A04_56_62.pdf