top of page

Installation of a modified nozzle thrust reverser controller (NTRC) to Concorde G-BOAE


CAA NOTE: G-BOAE – Installation of a modified nozzle thrust reverser controller






AIRCRAFT TYPE: Concorde Type 1 Variant 102




OPERATOR: British Airways


INSTALLER: British Airways








MODIFICATION TITLE: Installation of Modified Nozzle Thrust Reverser


Controller (NTRC)


1. Introduction


1.1 The basic AAN was raised to approve associated modifications 2326 and 2328,


27 Degree Bucket Position Switch Isolation for ASOV test and provision of LVDT


Bucket Position Circuit Malfunction Detection/Indication respectively.


1.2 Addendum 1 was raised to cover the introduction of Airbus Mod 2330 to Concorde, to reduce the number of in-flight engine shut-downs. It affects the


Secondary Nozzles on each engine, which on Concorde are fully modulating, to


ensure optimum engine performance in both the subsonic and supersonic flight regimes.


1.3 This addendum covers the introduction of Airbus modification 2376. It affects the


Secondary Nozzles on each engine, which on Concorde are fully modulating, to ensure optimum engine performance in both the subsonic and supersonic flight regimes.


1.4 Two recent failures of NTRC (121562-9) at BA have been confirmed by


SNECMA and Honeywell to be isolated failures of the internal –15 Volt DC supply.


During the course of the investigation for these reported failures it was found that some of the units being converted from –8 to –9 configuration experienced over heating during Bench testing


Investigation of the cause of the overheating has lead to a Vendor Modification to raise the part number to a –10 version.


2. Modification Definition


2.1 This modification installs the modified NTRC’s Part Number 121562-10 at Panels


10-215 (Eng 1 & 2), and 1-216 (Eng 3 & 4). In addition it also energises the associated Flight Deck Indicators located at the Flight Engineers Panel provisionally installed under Modification 2328.


2.2 The following modification has been applied to the subject aircraft:


• Modification 2376 – Installation of Modified (-10) Nozzle Thrust Reverser Controller (NTRC).


2.3 To reduce the number of in-flight engine shut-downs, the Honeywell Nozzle and


Thrust Reverser Controller (NTRC) is modified internally to enable detection of a circuit malfunction associated with the Bucket Pneumatic Drive Actuator (BPDA) Linear Variable Displacement Transducer (LVDT) position feedback signal. This results in the Secondary Nozzle being frozen, or commanded towards zero degrees (fully open).


3. Approval Procedures


This modification approval/validation has been carried out in accordance with Concorde Airworthiness Procedures Edition 5, July 2002.


4. Basis of Validation/Approval


4.1 CAA Certification / Validation / Approval Basis for the modification Concorde TSS Standards.


4.2 CAA Design Requirements for Certificate Of Airworthiness


Not applicable.


4.3 Environmental Requirements


Not applicable.


4.4 Design Requirements Associated with Operational Approvals


Not applicable.


5. Compliance with the basis of Certification / Validation / Approval


5.1 Compliance with the Certification / Validation Basis for the Modification


Evidence of compliance with the requirements of 4.1 above:


a. Design reports / drawings / data Mod Proposal PM No. 11021, Mod 2376.


b. Ground / Rig Test Reports


Ground Test Report contained in Certification Document ref.


CON/71/UL/P/SS/004 Issue 1


c. Flight Testing


For Mod 2376, no specific flight testing is required, see statement in Compliance


Plan ref. CON/71/UL/P/SS/001 Issue 4


d. Compliance Checklist.


Compliance plan / Checklist provided in Certification Document ref.


CON/71/UL/P/SS/001 Issue 4


5.2 Compliance with Design Requirements for Certificate of Airworthiness


Not applicable.


5.3 Compliance with Environmental Requirements


Not applicable.


5.4 Compliance with Design Requirements Associated With Operational Approvals


Not applicable.


5.5 Required (Amendments To) Manuals and Other Documents Including Mandatory Placards


a. Flight Manual Temporary Revisions 373 to 378 incl. are relevant to the operation of this Modification. These have been supplied to the CAA for approval.


b. Placard standard is defined in the associated Service Bulletin ref. 78-019


c. Electrical Load Analysis – Not Affected


d. The Maintenance Manual is updated to reflect the equipment Part Number change


e. The Maintenance Schedule is not affected


f. The MMEL is not affected


g. The Weight and balance Manual is not affected


h. The Type Certificate Data Sheet does not need amending


6. Conditions Affecting This Approval


All placards specified by the manufacturer/modification must be installed. Limitations, and conditions defined in the modification/manufacturer’s documentation, and the Flight Manual Temporary Revisions must be observed.


The compatibility of this modification with other previously approved modifications (2326 & 2328), installed on the particular aircraft, must be verified by the installer. Where the potential for interactions between modifications exists, the advice of the CAA shall be sought.


Certain operational approvals require that the aircraft and/or systems comply with specified design requirements. Where this AAN records compliance with those design requirements this shall not be taken as acceptance by the CAA of compliance with the relevant operational requirements, for which further justification may be required.


7. Continued Airworthiness


The influence of the modification on Airworthiness Directive, Service Bulletin eligibility and other data must be considered and the publications monitored accordingly. The maintenance schedule for the aircraft should include reference to this material additional to the original design.


8. Survey


“This aircraft G-BOAE being the first to embody the modification to be approved under this AAN, has been surveyed by the CAA”.


In the particular areas examined during the survey the modified aircraft was found to conform to the standard recorded by this AAN.


9. Authorisation of Release to Service


In addition to the actions required by the procedures for release to service following maintenance or modification, the following actions must be completed prior to signing the Certificate of Release to Service:


a. All actions and ground test procedures specified by the modification instructions must be completed satisfactorily.


b. It must be verified that the documents or amendments to documents, and the placards defined under Section 5.5 above are as specified, including any changes specified under Section 8 above.


10. Approval


Subject to the conditions of Section 6 above Airbus modification No. 2376 is approved for embodiment on any Concorde aircraft certificated in the Transport Category (Passenger), provided that it conforms with the contents of this AAN, and is operated in accordance with the Flight Manual.


D J Clement




For the Civil Aviation Authority


Date 30 January 2003


bottom of page