McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters

AD/HU 369/82 Rotor Blades  2/91 DM

Applicability: All model 369D, 369E, 369F, 369HE and 369HS with main rotor blades P/N 369A1100-501, -501M, -503, -503A, 503M; 369D21100, -501, -501M, -505, -509, -

509M, -513, -513M; 369D21600-505, -505M; 369D21613-11 and/or tail rotor blades P/N 369A1613-3, -3M, -501, -501M, -503M, -505; 369D21613, -505, -505M;

369D21613-11 and/or tail rotor blades P/N 369A1613-3, -3M, -501, -501M, -503M, - 505; 369D21613, -1M, -11, -11M, -41, -51, with the S/Nos listed in the AD Requirement.

Requirement:  Pending completion of an investigation currently being undertaken to confirm the airworthiness of certain overhauled/repaired main/tail rotor blades with P/Nos and S/Nos detailed herein, accomplishment of the following is required:

1. Main and tail rotor blades. Inspect and determine whether installed blades have affected P/N and S/N. Blades not affected require no further action.

Main rotor blade P/N 369A1100-501, -501M Serial numbers:

1991 20-2380 20Z406 2217 2218 29B075 49B936 7888 7964 88-7008 AC10 AD59 AD68 AD74 AD98 AE55 AF47 AF57 AG66 AH28 AH82 AH92 AJ72 AK49 AL07 AL12 AL34 AL41 AL49 AM10 BC84 BC86 DC97 N579 N701 T667 U537 U762 V129 V297 V305 W314 W705 Y249 WW784 Y268 Y607 Y608 Y641 Y653 Y666 Y681 Y734 Y845.

Main rotor blade P/N 369A1100-503, -503A, -503M Serial numbers:

0321 1991 7845 AB81 AC10 AC52 AC70 AH97 AK28 AL34 AL43 AM10 AM11 AM74 AM76 AN24 AN90 AP64 AS81 AV03 AV51 AV81 AV85 AY25 B214 BB43 BC84 BC86 BC97 BD52 BE42 BE74 BE92 BN27 BN88 BS25 BS64 BT36 BT79 BY24 BY76 BY88 CB04 CF14 CF31 CH19 CH25 D850 T655 T661 T705 T716 U546 V673 VB08 W673 Y249 Y268 Y845 YO29.

Main rotor blade P/N 369D21100 Serial numbers:

M1858 M1949 M1954 M2568 M2842 M3668 M3819 M3901 M4137 M4240 M4369 M4499.

Main rotor blade P/N 369D21100-501, -501M Serial numbers:

3799  3863  3929  5303  AL12  AL41  Y641.

Main rotor blade P/N 396D21600-505, 505M Serial numbers:

0278  0321  0693  1949  1954  3679  3787  3789  4889  5076  5303  5932

6059  6537  6705  8539  M3461  M3615  M3846  M4119  M42  M4377.

Main rotor blade P/N 369D21100-505 Serial numbers:

3010  3289  3799  3829  3863  3929  3985  4411  4711  4794  5930  5933

5938  6111  6782  7906  8019  AL12  AL41  Y641.

Main rotor blade P/N 369D21100-509, -509M Serial numbers:

Main rotor blade P/N 369D21100-513, -513M Serial numbers:

Main rotor blade P/N 369D21613-11

Serial number:

2070

Tail rotor blade P/N 369D21613, -1M, -11, -11M, -41, and -51 Serial numbers:

Tail rotor blade P/N 369A1613-3, -3M, -501, -501M, -503M and -505 Serial numbers:

Tail rotor blade P/N 369A1100-501, -503 Serial numbers: AC10 AM10 Y249 Y268.

2.    Affected main rotor blades

Visually inspect leading edge abrasion strip attachment integrity. Any blisters, bubbling or lifting of the strip is cause for removal before further flight.

3.    Affected tail rotor blades

(a)     Dye-penetrant inspect and tap test per Part 1 of MDHC SI Nos DN-130.2, EN- 19.2, FN-17.1 or HN-197.2 as applicable.

(b)     Visually inspect each tail rotor blade abrasion strip for any evidence of bond failure along the abrasion strip/airfoil bond line.

Note: If evidence of separation along the abrasion strip/airfoil bond line is suspected; using a 10X magnifying glass, closely check along abrasion strip/airfoil bond line and at blade tip for any separation between epoxy adhesive and abrasion strip.

Any blade with void or bond separation beyond prescribed limits must be removed from service before further flight.

Compliance: 1. Within next 5 hours time in service after 14 December 1990.

2.    Within next 5 hours time in service after 14 December 1990 and thereafter at intervals not exceeding 50 hours time in service. Also prior to the first flight of each day the helicopter is to be operated.

3.    (a) Within next 5 hours time in service after 14 December 1990 and thereafter at intervals not exceeding 50 hours time in service.

(b) Within next 5 hours time in service after 14 December 1990 and thereafter prior to the first flight of each day the helicopter is to be operated.

Note: This Directive shall be entered on the Maintenance Release as maintenance required. The visual inspection required by Para 2 and 3 may be performed by the pilot in command in which case certification is to be made by entering AD/HU 369/82 against the daily inspection certification of the Maintenance Release. A copy of this Airworthiness Directive is to be kept in the aircraft.

Background:  An investigation in New Zealand has revealed that certain main and tail rotor blades repaired in that country had not been repaired in accordance with proper procedures (eg time expired adhesives etc).

The New Zealand CAA believe this to be a potentially serious safety of flight issue and that some of these blades are in Australia.