Airworthiness Directive · Amendment 39-19584 · Powerplant/engine drains
Rolls-Royce plc Turbofan Engines
Superseded. A later AD replaced this one: AD 2025-05-04. Comply with the one in force.
This AD applies to all Rolls-Royce plc (RR) RB211-Trent 970-84 and RB211-Trent 972-84 turbofan engines with a drains mast, part number (P/N) KH31996 or FW29847, installed.
We are superseding airworthiness directive (AD) 2017-22-13 for certain Rolls-Royce plc (RR) RB211-Trent 900 turbofan engine models. AD 2017-22-13 required an inspection of the drains mast and the replacement or repair of the drains mast if a crack is found. This AD retains this requirement, but adds repetitive inspections and expands the population of affected RR RB211-Trent 900 turbofan engine models. This AD was prompted by RR in-service findings that indicated a need to include part number (P/N) FW29847 drains mast and additional RR RB211- Trent 900 turbofan engines to the affected population. We are issuing this AD to address the unsafe condition on these products.
(1) For Group 1 engines, within 24 months after November 22, 2017 (the effective date of AD 2017-22-13), or within 24 months time since new, whichever occurs later, and thereafter, at intervals not to exceed 24 months since previous inspection, visually inspect the external areas of the transition duct area of the drains mast for a crack using Accomplishment Instructions, paragraph 3.A.(1), of RR Alert Non-Modification Service Bulletin (NMSB) RB.211-71-AJ576, Revision 1, dated July 11, 2018.
If a crack is found, do one of the following before further flight:
(i) Remove and replace the drains mast with a part eligible for installation, or
(ii) Seal the crack using the Accomplishment Instructions, paragraph 3.A.(1).(c).(ii).(2), of RR Alert NMSB RB.211-71-AJ576, Revision 1, dated July 11, 2018, and within 100 flight cycles after sealing the crack, remove and replace the drains mast with a part eligible for installation.
(2) For Group 2 engines, within 24 months after the effective date of this AD, and thereafter, at intervals not to exceed 24 months since previous inspection, visually inspect the external areas of the transition duct area of the drains mast for a crack using Accomplishment Instructions, paragraph 3.A.(1), of RR Alert NMSB RB.211-71-AJ576, Revision 1, dated July 11, 2018.
If a crack is found, do one of the following before further flight:
(i) Remove and replace the drains mast with a part eligible for installation, or
(ii) Seal the crack using the Accomplishment Instructions, paragraph 3.A.(1).(c).(ii).(2), of RR Alert NMSB RB.211-71-AJ576, Revision 1, dated July 11, 2018, and within 100 flight cycles after sealing the crack, remove and replace the drains mast with a part eligible for installation.
(1) For the purposes of this AD, “Group 1” engines are those with a drains mast, P/N KH31996, installed that have installed the sub-idle ejector system introduced in RR SB RB.211-80-H632, Revision 2, dated August 11, 2015. “Group 2” engines are those engines with a drains mast, P/N FW29847, installed or have a drains mast, P/N KH31996, that have not installed the sub-idle ejector system introduced in RR SB RB.211-80-H632, Revision 2, dated August 11, 2015.
(2) For the purposes of this AD, a part eligible for installation is a drains mast with a part number not listed in this AD or a part that has passed the inspection required by this AD.
(3) For the purposes of this AD, a flight cycle is a take-off and landing.
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.
Engines
