AD A330/A340

During the overhaul of two different Nose Landing Gears (NLG), cracks were
found on the main fitting of one and the sliding tube of the other. Investigations
concluded that the cracks initiated as a result of residual stress in the parts
following damage due to impact during towing incidents.
A subsequent review of the reported incidents has led to conclude that an
inspection of the main fitting and sliding tube is required on 10 NLG that have
sustained impacts as results of towing incident.
The failure of the main fitting or sliding tube could lead to NLG collapse.
To prevent above unsafe condition, this AD requires a one- time
inspection followed by repetitive inspections of the main fitting and sliding
tube of the 10 NLG’s listed above:
- One time Magnetic Particle Inspection (MPI) of the affected areas to
detect any crack,
- Repetitive Detailed Visual Inspections (DVI) of the affected areas to
detect any damage of the surface protections or corrosion.
This AD also requires the accomplishment of the associated corrective
actions, as necessary.

Required as indicated:
(1) In accordance with instructions defined in Airbus Service Bulletin (SB)
A330-32-3233 or SB A340-32-4275 or SB A340-32-5095, as
applicable, unless already accomplished, within 900 Flight Hours (FH)
after the effective date of this AD, and depending on impacted areas:
(1.1) perform a detailed visual inspection of the main fitting and/or
sliding tube of the NLG, and
(1.2) perform MPI inspection of the main fitting and/or sliding tube of
the NLG.
(2) If any crack is detected during the MPI inspection defined in
paragraph (1.2) of this AD, before next flight, replace the damaged
part in accordance with the instructions defined in SB A330-32-3233
or SB A340-32-4275 or SB A340-32-5095, as applicable.
(3) If NO crack is detected during the MPI inspection defined in paragraph
(1.2) of this AD :
(3.1) do flap peening to introduce compressive residual stress and
corrosion protection, in accordance with the instructions of SB
A330-32-3233 or SB A340-32-4275 or SB A340-32-5095, as
applicable, and
(3.2) repeat the inspection defined in paragraph (1.1) of this AD at
intervals not exceeding 900 FH from the last inspection and
apply the associated corrective actions.

EASA Orders Checks Of Thales AoA Probe

Feb 11, 2010



By Frances Fiorino fiorino@aviationweek.com
WASHINGTON


By April 30, Airbus A330 and A340 operators will be required to make a detailed visual inspection of aircraft equipped with a Thales Avionics AoA (angle of attack) probe with part no. C16291AA.

The inspections are necessary to identify and replace parts suspected of causing inaccurate AoA indications. The requirement comes from a Feb. 9 airworthiness directive issued by the European Aviation Safety Agency (EASA) after final assembly line testing revealed that AoA data from two different aircraft were incorrect. Flight data analysis confirmed the inaccuracies.

Thales, in its examination of the suspect probes, discovered oil residue between the stator and rotor parts of the AoA vane position resolvers. The residue, according to EASA, was the result of improperly cleaned machine oil used in manufacturing the resolvers.

The oil residue becomes viscous at low temperatures, especially at cruise altitudes, and can cause a lag in AoA vane movement. This, in turn, can lead to erroneous measurement of the aircraft’s angle of attack. Should two or three probes become simultaneously affected and provide incorrect indications, the aircraft’s AoA protection would be late to activate, which, when combined with flight at a high angle of attack, creates an unsafe condition.

Operators of Airbus A330 and A340s must inspect rudders for defects and correct any degraded areas as mandated by an EASA airworthiness directive that is effective July 7.

EASA issued this AD today because "surface defects were visually detected on the rudder of one A319 and one A321" during scheduled maintenance. Airbus has reworked both areas during production.

"The investigation confirmed that the surface defects were a result of de-bonding between the skin and honeycomb core," EASA says in the AD.

Failure of the auxiliary power unit (APU) bleed leak detection system could result in overheat of the fuel tank located in the horizontal stabilizer and ignition of the fuel vapors in that tank, which could result in a fuel tank explosion and consequent loss of the airplane.

(g) Within 6 months after the effective date of this AD, do the applicable actions specified in paragraphs (g)(1) and (g)(2) of this AD.
(1) For Model A330-201, -202, -203, -223, -243, -301, -302, -303, -321, -322, -323, -341, -342 and -343 airplanes: Install flight warning computer (FWC) software standard T3 (part number (P/N) LA2E20202T30000) on both FWCs, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A330-31-3146, including Appendix 01, Revision 01, dated May 5, 2010.
(2) For Model A340-211, -212, -213, -311, -312, and -313 airplanes: Install FWC software standard L11 (P/N LA2E0060D110000) on both FWCs, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A340-31-4125, Revision 01, dated December 9, 2008.
(h) Prior to or concurrently with accomplishing the corresponding requirements of paragraph (g) of this AD, install FWC software standard T2-0 in accordance with the Accomplishment Instructions of Airbus Service Bulletin A330-31-3125, dated December 31, 2008 (for Model A330-201, -202, -203, -223, -243, -301, -302, -303, -321, -322, -323, -341, -342 and -343 airplanes).
(i) Prior to or concurrently with accomplishing the corresponding requirements of paragraph (g) of this AD, install FWC software standard L10-1 in accordance with the Accomplishment Instructions of Airbus Service Bulletin A340-31-4111, dated February 5, 2007 (for Model A340-211, -212, -213, -311, -312, and -313 airplanes).
(j) Actions done before the effective date of this AD in accordance with Airbus Service Bulletin A330-31-3146, dated February 2, 2010; or A340-31-4125, dated October 27, 2008; are acceptable for compliance with the corresponding requirements of paragraph (g) of this AD.