Airworthiness Directive · Amendment 39-16929 · Honeywell International Inc. TPE331-10 and TPE331-11 Series Turboprop Engines
Honeywell International Inc. TPE331-10 and TPE331-11 Series Turboprop Engines
Honeywell International Inc. TPE331-10, -10AV, -10GP, -10GT, -10N, -10P, -10R, -10T, -10U, -10UA, -10UF, -10UG, -10UGR, -10UR, and TPE331-11U model turboprop engines with a first stage turbine disk, part number (P/N) 3101520-1 or 3107079-1, with a serial number (S/N) listed in Table 2 of Honeywell International Inc. Alert Service Bulletin (ASB) TPE331-72-A2156, dated December 2, 2008, installed.
We are adopting a new airworthiness directive (AD) for the products listed above. This AD was prompted by a report of an uncontained failure of a first stage turbine disk that had a metallurgical defect. This AD requires inspecting certain serial number (S/N) first stage turbine disks, part number (P/N) 3101520-1 and P/N 3107079-1. We are issuing this AD to prevent uncontained failure of the first stage turbine disk and damage to the airplane.
(1) For first stage turbine disks, P/N 3101520-1 or 3107079-1, that have an S/N listed in Table 2 of Honeywell International Inc. ASB TPE331-72-A2156, dated December 2, 2008, inspect the disks as follows:
(i) For turbine disks with 4,100 or fewer cycles-since-new (CSN) on the effective date of this AD, perform an initial fluorescent penetrant inspection (FPI) by using paragraph 3.B.(2) through 3.B.(5) of Honeywell International Inc. ASB TPE331-72-A2156, dated December 2, 2008, within 4,500 CSN or at the next access, whichever occurs first.
(ii) For turbine disks with more than 4,100 CSN on the effective date of this AD, perform an initial FPI by using paragraph 3.B.(2) through 3.B.(5) of Honeywell International Inc. ASB TPE331-72-A2156, dated December 2, 2008, within 400 cycles-in-service (CIS) after the effective date of this AD or at the next access, whichever occurs first.
(iii) If the disk passes the FPI inspection, perform a special eddy current inspection (ECI) by using paragraph 3.B.(6) of Honeywell International Inc. ASB TPE331-72-A2156, dated December 2, 2008, before returning the disk to service.
(2) If you find a crack in the disk, remove the disk from service.
(1) Thereafter, for first stage turbine disks, P/N 3101520-1 or 3107079-1, that have an S/N listed in Table 2 of Honeywell International Inc. ASB TPE331-72-A2156, dated December 2, 2008, inspect the disks as follows:
(i) Perform a repetitive inspection at each scheduled hot section inspection, but not to exceed 3,600 hours-since-last inspection. Use paragraph 3.B.(2) through 3.B.(5) of Honeywell International Inc. ASB TPE331-72-A2156, dated December 2, 2008.
(ii) If the disk passes the FPI inspection, perform a special ECI by using paragraph 3.B.(6) of Honeywell International Inc. ASB TPE331-72-A2156, dated December 2, 2008, before returning the disk to service.
(2) If you find a crack in the disk, remove the disk from service.
For the purpose of this AD, “next access to the first stage turbine disk” is defined as the removal of the second stage turbine nozzle from the turbine stator housing.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
