EASA AD No.: 2009-0037-E 

EASA Form 111 Page 1/2 

EASA EMERGENCY AIRWORTHINESS DIRECTIVE 

AD No.: 2009-0037-E 

Date: 19 February 2009 

Note: This Emergency Airworthiness Directive (AD) is issued by EASA, acting in accordance 

with Regulation (EC) No 216/2008 on behalf of the European Community, its Member States 

and of the European third countries that participate in the activities of EASA under Article 66 

of that Regulation.

This AD is issued in accordance with EC 1702/2003, Part 21A.3B. In accordance with EC 2042/2003 Annex I, Part M.A.301, the 

continuing airworthiness of an aircraft shall be ensured by accomplishing any applicable ADs. Consequently, no person may operate 

an aircraft to which an AD applies, except in accordance with the requirements of that AD unless otherwise specified by the Agency 

[EC 2042/2003 Annex I, Part M.A.303] or agreed with the Authority of the State of Registry [EC 216/2008, Article 14(4) exemption]. 

Type Approval Holder’s Name : 

Agusta S.p.A. 

Type/Model designation(s) : 

A109A, A109AII and A109C helicopters 

TCDS Number : EASA.R.005 

Foreign AD : Not applicable 

Supersedure : None 

ATA 72 Engine – Power Turbine Speed – Operational Limitation 

Manufacturer(s): Agusta S.p.A. 

Applicability: A109A, A109AII and A109C helicopters, all serial numbers if equipped with 

Rolls-Royce Corporation (formerly Allison) engine model 250-C20B or 250-

C20R/1 with the third stage turbine wheel part number (P/N) 23065833 

installed. 

Reason: Following several third stage turbine wheel failures, the engine Type 

Certificate holder, Rolls-Royce Corporation, issued Commercial Engine 

Bulletin (CEB) A-1400 Rev. 3 to introduce an operational limitation on the 

power turbine N2 speed range (95% - 97%) for more than 60 seconds in 

single or cumulative events for engines with the third stage turbine wheel 

P/N 23065833 installed. 

Thereafter, Agusta issued Bollettino Tecnico (BT) 109-129 to introduce the 

same operating limitation, which is also required by this AD, on the affected 

helicopters. 

Effective Date: 20 February 2009 

Required action(s) and 

Compliance Time(s): 

Required as indicated, unless accomplished previously: 

Within the next 5 flight hours after the effective date of this directive but no 

later than 28 February 2009, whichever occurs first, accomplish the tasks 

specified below in accordance with the instructions of Agusta BT 109-129: 
EASA AD No.: 2009-0037-E 

EASA Form 111 Page 2/2 

 

1. Avoid steady-state operation in the 95-97% N2 range for more than 60 

seconds in single or cumulative events. If steady-state operation in the 

95-97% N2 range exceeds 60 seconds in single or cumulative events, 

before further flight perform specific corrective actions as per RollsRoyce CEB A-1400 Rev. 3. 

Note: Steady-state operation is defined as any manoeuvre during which an 

attempt is being made to maintain a constant engine speed within 2% 

N2. 

2. Install on the instruments panel below or near the “ENGINE & ROTOR 

RPM POWER TURBINE (N2)” indicator, in an area visible by the pilot(s), 

one of the two decals (depending on the applicable instruments panel 

configuration) shown in figure 1 of Agusta BT 109-129 reporting the 

following text: 

“MIN. CONT. 97% N2 – MIN. TRANS. 95% N2” 

3. A109A and A109AII helicopters: 

 Insert page 5 or 6, as applicable depending on the helicopter model, of 

Agusta BT 109-129 in the Flight Manual, Section I – OPERATING 

LIMITATIONS, paragraph “POWER PLANT LIMITATIONS”. 

4. A109C helicopters: 

 Insert page 7 of Agusta BT 109-129 in the Flight Manual, Section I - 

LIMITATIONS, paragraph “POWER PLANT AND TRANSMISSION 

LIMITATIONS”. 

Ref. Publications: Agusta Bollettino Tecnico 109-129 dated 16 February 2009. 

The use of later approved revisions of this document is acceptable for 

compliance with the requirements of this AD. 

Remarks: 1. If requested and appropriately substantiated, EASA can approve 

Alternative Methods of Compliance for this AD. 

2. The safety assessment has requested not to implement the full 

consultation process and an immediate publication and notification. 

3. Enquiries regarding this AD should be referred to the Airworthiness 

Directives, Safety Management & Research Section, Certification 

Directorate, EASA. E-mail ADs@easa.europa.eu . 

4. For any question concerning the technical content of the requirements in 

this AD, please contact: Agusta S.p.A. Customer Support – 

Via per Tornavento, 15 21019 Somma Lombardo (VA) – Italy; 

Phone: + 39 0331 940396; Fax: + 39 0331 711180; 

E-mail: custserv@agustawestland.com .