AIRWORTHINESS DIRECTIVE

CAA-AD-040/2001

Date of issue: May 10, 2001

AIRCRAFT – STRUCTURE - INSPECTION

Applicability: ATR 72 models -101, -102, -201, -202, -211, -212 aircraft.

Effective date: June 14, 2001

Compliance: Required as indicated in DGAC AD 2001-142-056(B).

Remarks: The compliance of this AD must be recorded in Aircraft Logbook, where applicable the requirements of this AD must be integrated into Aircraft Technical Documentation. Address inquiries concerning this AD to: Civil Aviation Authority, Airworthiness Division, Ruzyne Airport, 160 08 Prague 6, Czech Republic, tel: 420 2 33320922, fax: 420 2 20562270.

Ing. Pavel MATOUŠEK

Director of Airworthiness Division

CAA CZ

DGAC AD No.: 2001-142-056(B)

EADS ATR

ATR 72 aircraft

Structure - Result of fatigue tests (ATA 52, 53)

1. APPLICABILITY:

This Airworthiness Directive applies to ATR 72 models -101, -102, -201, -202, -211, -212 aircraft.

2. REASONS:

AD 92-046-012 (B) was issued further to damage discovered during fatigue tests.

On some aircraft, embodiment of modification 3184 led to a bore oversizing which must be corrected by the implementation of ATR Service Bulletin 72-52-1018 Revision 1.

This AD replaces AD 92-046-012 (B), to which requirements are recovered, and, in its section "COMPLIANCE 1", it mandates the embodiment of SB 72-52-1018 Revision 1.

3. COMPLIANCE:

The following measures are made mandatory from the effective date of this AD.

3.1. Cargo door outer skin

Applies to ATR 72 models -102, -202 and -212 aircraft on which modification 3191 has not been embodied.

In order to prevent the initiation and the growth of cracks in the cargo compartment door outer skin at the hinge fitting, the following measures are made mandatory:

- Before the aircraft has accumulated 27,000 flights, applies SB ATR 72-52-1018 Revision 1.

3.2. Fuselage - Main frames (lower part)

Applies to ATR 72 models -101, -102, -201, -202, -211, -212 aircraft, serial numbers: 108 to 210 inclusive.

In order to check that the positioning holes of the lower part of the main frames have been properly blanked off with rivets during production, the following measures are made mandatory:

- Before the aircraft has accumulated 36,000 flights, check that the positioning holes of the lower part of the main frames have been property blanked off, and, if necessary, blank off the holes according to the instructions in SB ATR 72-53-1013.

3.3. Fuselage -Typical frames and upper part of main frames

Applies to ATR 72 models -101, -102, -201, -202, -211, -212 aircraft, serial numbers 108 to 207 inclusive.

In order to check that the positioning holes of the typical frames and of the upper part of the main frames have been properly blanked off with rivets during production, the following measures are made mandatory :

- Before the aircraft has accumulated 36,000 flights, check that the positioning holes of the typical frames and of the upper part of the main frames have been properly blanked off, and, if necessary, blank off the holes according to the instructions in SB ATR 72-53-1019.

3.4. Plug type doors

Applies to ATR 72-101, -201, -211 aircraft on which neither modification 3775 nor modification 3776 has been embodied.

In order to prevent the initiation and the growth of cracks in the stops of forward and aft LH passenger doors, and of forward and aft RH service doors, the following measures are rendered mandatory:

a) Before the aircraft has accumulated 12,000 flights, inspect the stops of forward and aft LH passenger doors, and of forward and aft RH service doors according to the instructions in SB ATR 72-52-1028. Then repeat this inspection within an interval of 6,000 flights.

b) Before the aircraft has accumulated 18,000 flights, modify the stops of forward and aft LH passenger doors, and of forward and aft RH service doors according to the instructions in SB ATR 72-52-1029 or in SB ATR 72-52-1033.

Note: The embodiment of the modifications listed in b) of this paragraph cancels the inspection requirements listed in a) of this same paragraph.

3.5. Plug type doors

Applies to ATR 72-101, -201, -211 aircraft on which modification 2986 has not been embodied.

In order to prevent the initiation and the growth of cracks in the skin of the upper frame of forward and aft LH passenger doors, and of forward and aft RH service doors, the following measures are made mandatory:

- Before the aircraft has accumulated 18,000 flights, modify the frame of forward and aft LH passenger doors, and of forward and aft RH service doors according to the instructions in SB ATR 72-53-1021.

3.6. Frames 24 and 28 - Outboard stringer 4

Applies to ATR 72 -101, -102, -201, -202, -211, -212 aircraft on which modification 2397 has not been embodied.

In order to prevent the initiation and the growth of cracks in outboard stringer No. 4, at frame 28, the following measures are made mandatory:

- Before the aircraft has accumulated 12,000 flights, add a reinforcement angle on outboard stringer No. 4, at frames 24 and 28 according to the instructions in SB ATR 72-53-1014 R1.

3.7. Frame 26 at cut out at level of stringer 11

Applies to ATR 72 -101, -102, -201, -202, -211, -212 aircraft on which modification 3185 has not been embodied.

In order to prevent the initiation and the growth of cracks in frame 26 at cut out at level of stringer 11, the following measures are made mandatory:

- Before the aircraft has accumulated 12,000 flights, reinforce frame 26 with two doublers according to the instructions in SB ATR 72-53-1020.

REF.: Service Bulletins ATR 72-52-1018 R1, 72-53-1013, 72-53-1019, 72-52-1028, 72-52-1029, 72-52-1033, 72-53-1021, 72-53-1014 R1, 72-53-1020

Any further approved revision of these SB is acceptable.

This AD replaces the AD 92-046-012(B) R4 dated November 05, 1997 which is cancelled by its Revision 5.

EFFECTIVE DATE: APRIL 28, 2001