ALL OPERATORS TELEX – ALL OPERATORS TELEX SUBJECT: ATA 34 - PITOT PROBE 0851HL - LOOSE PNEUMATIC QUICK-DISCONNECT UNION
OUR REF: AOT A340-34A5074 REV 02 dated 01 MARCH 2010 OUR PREV/REF: AOT A340-34A5074 dated 10 SEPT 2009 AOT A340-34A5074 REV 01 dated 21 SEPT 2009
0. REASON FOR REVISION The aim of this AOT revision is to inform operators about the terminating action for affected probes held as spares. This AOT revision includes instructions to identify a Goodrich Pitot probe that has already had the torque check performed and therefore requires no further action under this AOT. The revised paragraphs are indicated by: **BEG REV** and **END REV**.
1. AIRCRAFT AFFECTED **BEG REV** All A340-500/600 fitted with Goodrich Sensors Integrated Systems (Rosemount) Pitot probes P/N 0851HL with Serial Numbers from 267328 THRU 270714 (inclusive). Pitot probes currently fitted on aircraft, which have already been checked per the previous revision of this AOT, do not need re-checking. **END REV**
2. REFERENCED DOCUMENTATION Ref 1 SB A340-34-5071 Ref 2 AMM TASK 34-11-15-000-801 Ref 3 AMM TASK 34-11-15-400-801 Ref 4 RIL SEOT2 916.0253/09 **BEG REV** Ref 5 CMM GOODRICH 34-11-09, Revision 3, OCT 2009. Ref 6 AD 2009-0202-E **END REV**
3. REASONS
3.1 FACTSSeveral operators have reported loose pneumatic quick disconnect unions on Goodrich Pitot probes P/N 0851HL, as per SB Ref 1 and RIL Ref 4. Airbus suspects a batch quality issue due to increased production rate.
3.2 CONSEQUENCES A loose pneumatic quick-disconnect union could lead to an air leak and potentially incorrect total pressure measurement. **BEG REV** However, further investigations have shown that an under-torqued probe would not leak (torque value lower than the one specified in CMM Ref 5).
3.3 AIM The aim of this AOT revision is to provide operators with the updated procedure to apply to Pitot probes P/N 0851HL with Serial Numbers from 267328 THRU 270714 (inclusive) that are still held in stock as spares.
4. SHORT-TERM ACTION Category A: Pitot probes P/N 0851HL in the effectivity of this AOT and installed on aircraft have been checked as per AOT A340-34A5074Revision 1 dated 21 SEPT 2009. No further action is required for these probes as long as they remain installed on aircraft. Once removed from aircraft, pitot probes shall be treated as indicated in category B prior to re-installation on aircraft. Category B: For Pitot probes P/N 0851HL in the effectivity of this AOT that are still held as spares or have been removed from aircraft, as per category A, check the interface of the quick disconnect union and the union mount for red torque check indicating mark: - If a torque check indicating mark is present and intact, the pitot probe may be installed on aircraft with no further action required. - If no torque check indicating mark is present or if it is compromised, either: * Apply CMM Ref 5 instructions to check and adjust (if necessary) the torque of the quick-disconnect union and apply (or re-apply) a red torque check indicating mark as per the Check Section of Goodrich CMM Ref 5. Or * Install the pitot probe on aircraft as per AMM Ref 3 and perform a torque check of the pneumatic quick-disconnect union (in accordance with the procedure in para 4.2 of this AOT) just after installation on aircraft and before next flight.
4.1 PLANNING AND MANPOWER
4.1.1 ACCOMPLISHMENT TIMESCALE The torque check of the pneumatic quick-disconnect union should have been done within 5 days of reception of the original issue of this AOT dated 10 SEPT for those Pitot probes fitted on aircraft. For those Pitot probes held as spares: - Ref 5 CMM application shall be done before installation on aircraft Or- Pitot probes shall be installed provided the procedure described in para 4.2 of this AOT is done before next flight after installation on aircraft.
4.1.2 MANPOWER The elapsed time necessary to check the quick disconnect coupling connection as required by par 4.2 of this AOT is: - 30 minutes for one person to check 3 Pitot probe on one aircraft plus 5 minutes for another person for visual check of quick-disconnect coupling connection. - 10 minutes for 1 person to check in shop 1 Pitot probe held as spare.
4.2 DESCRIPTION 4.2.1 TORQUE CHECK For each Pitot probe that needs to be checked on aircraft (no torque check mark present or AOT rev 1 not applied), apply the following procedure: - Disconnect the quick-disconnect coupling from each Goodrich probe (as per Ref 2) - Gradually torque the quick-disconnect union fitted on the probe to 4.9 ft-lbs / 0.66 daN.m while using a restraining wrench on the mating hex to oppose the applied torque. - If the connector nut does not rotate for a torque lower or equal to 4.9 ft-lbs / 0.66 daN.m, it is correctly torqued and no further action is required. - If the connector nut does rotate for a torque lower or equal to 4.9 ft-lbs / 0.66 daN.m, it is not sufficiently torqued. In this case, continue applying torque to reach 6 ft.lbs / 0.81 daN.m, again using a restraining wrench on the mating hex to oppose the applied torque. - Re-connect the quick-disconnect coupling to the Pitot probe. - Make sure that you can see the blue ring on the quick-disconnect coupling (as per Ref 3) - Pull the quick-disconnect coupling to make sure that it is correctly installed. - Make sure that a second qualified mechanic does a visual inspection of the quick disconnect coupling connection. The two mechanics must sign off the job.
4.2.2 RED TORQUE CHECK INDICATING MARK APPLICATION A torque check indicating mark can be applied as per the following procedure: - apply a small amount of marking paint (colour: red) to the interface of the air fitting and the air-fitting mount - air dry for one hour.
5. FURTHER ACTION N/A
6. AOT APPROVAL The technical content of this AOT has been approved under EASA Design Organisation Approval EASA.21J.031. It is anticipated that corresponding EASA Airworthiness Directive (AD Ref 6) will be modified accordingly. **END REV**7. RECORDING/ACKNOWLEDGMENT Operators are requested to acknowledge receipt of this AOT revision to: Mr. R. LASCOURS, SEE E-mail: richard.lascours@airbus.com Fax number: +33/(0)5 61 93 32 73 Within 10 days after receipt. This acknowledgement can be made through the Airbus RCSR office when available. Questions about the technical content of this AOT are to be addressed to: Mr Antoine BOUYER Phone: +33/(0)5 67 19 73 65 Fax: +33/(0)5 61 93 44 25 E-mail: antoine.bouyer@airbus.com Best regards,
John GROTHER VICE PRESIDENT A330/A340 PROGRAMME CUSTOMER SERVICES DIRECTORATE If you receive this message via e-mail/internet, we draw your attention to the fact that it may be monitored and/or intercepted. Further, whilst Airbus has taken reasonable measures to ensure the integrity of this message and its contents, no warranty, whether express or implied is given that the contents hereof conform to the original. In case of any doubt, please, retrieve this document from your SITA address or the AirbusWorld or request that it be retransmitted by fax or telex.