Airworthiness Directive · Amendment 39-17100 · Turbomeca S.A. Turboshaft Engines
Turbomeca S.A. Turboshaft Engines
This AD applies to Turbomeca S.A. Arriel 2C1, 2C2, and 2S2 turboshaft engines with any of the digital engine control units (DECUs) listed in Table 1 of this AD installed.
| 529 | 558 | 560 | 655 |
| 696 | 869 | 878 | 939 |
| 983 | 1039 | 1050 | 1052 |
| 1150 | 1195 | 1208 | 1236 |
| 1302 | 1304 | 1329 | 1330 |
| 1350 | 1384 | 1408 | 1412 |
| 1416 | 1429 | 1430 | 1440 |
| 1464 | 1468 | 1472 | 1499 |
| 1508 | 1528 | 1557 | 1558 |
| 1560 | 1567 | 1578 | 1615 |
| 1616 | 1656 | 1689 | N/A |
We are adopting a new airworthiness directive (AD) for Turbomeca S.A. Arriel 2C1, 2C2, and 2S2 turboshaft engines. This AD requires replacement of affected digital engine control units (DECUs). This AD was prompted by a report of a helicopter experiencing a DECU malfunction during flight. We are issuing this AD to prevent loss of automatic control on one or both engines installed on the same helicopter, which could result in an uncommanded in-flight engine shutdown, forced autorotation landing, or accident.
Unless already done, do the following actions.
(1) For any helicopter fitted with two DECUs listed in Table 1 of this AD:
(i) Within 50 engine hours after the effective date of this AD, replace one of the two DECUs with a DECU that is not listed in Table 1 of this AD.
(ii) Within 1,000 engine hours or 12 months after the effective date of this AD, whichever occurs first, replace the other DECU with a DECU that is not listed in Table 1 of this AD.
(2) For any helicopter fitted with one DECU listed in Table 1 of this AD, within 1,000 engine hours or 12 months after the effective date of this AD, whichever occurs first, replace the DECU with a DECU that is not listed in Table 1 of this AD.
From the effective date of this AD, do not install a DECU listed in Table 1 of this AD onto any engine, and do not install any engine having a DECU listed in Table 1 of this AD, onto a helicopter.
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.
