Division Brantly B-2 Series Helicopters - AD/B-2/32 - Tail Rotor Gearbox - Brantly B-2 Series Helicopters

Brantly B-2 Series Helicopters

AD/B-2/32	Tail Rotor Gearbox	7/2006 TX

Applicability:	Brantly Helicopter, Inc. Model B-2, B-2A, and B-2B helicopters, serial number 2001 and larger, with a vertical shaft (shaft), part number (P/N) 249-10, or any serial-numbered helicopter with a shaft, P/N 249-10, that was purchased after 1994.
Requirement:	1. To detect fatigue cracking of the shaft and prevent failure of the shaft and subsequent loss of control of the helicopter, accomplish the following:(a) Remove the tail rotor vertical gearbox (gearbox), P/N 278- 200; shaft, P/N 249-10; vertical shaft housing (housing), P/N 249-3; and the intermediate gearbox bushing (bushing), P/N 252-4, from the helicopter.(b) Inspect the flange retainer, part number (P/N) 15-17, located at the top of the shaft housing for deformation and measure the inside diameter. Replace the flange retainer with an airworthy flange retainer if the part is deformed or if the inside diameter is not 1.5050 to 1.5060 inches, before further flight.(c) Inspect the housing, P/N 249-3, for deformation and measure the outer diameter at each end and at the centre of its span.Replace the housing with an airworthy housing, before further flight if:(i) The housing is deformed;(ii) Any outer diameter not on the flared end is not 1.497 to 1.500 inches; or(iii) The outer diameter of the flared end is not 1.844 to 1.875 inches.(d) Inspect the bushing, P/N 252-4, for nicks or scoring, and measure the bushing's length. If the length of the bushing is not .292 to .302 inch or if nicks or scoring is found, replace the bushing with an airworthy bushing, before further flight.(e) Inspect the bevel pinion gear (gear), P/N 15-8, paying particular attention to the bore, for nicks, scoring, burrs, or misalignment. Measure the diameter of the bolt hole and the bore. Replace the gear with an airworthy gear before further flight if:(i)You find misalignment,(ii) You cannot remove all nicks, scoring, or burrs with light hand polishing using Scotch Brite (maroon or white) and maintain all tolerances and a 32 root mean square (rms) finish,(iii) The diameter of the bolt hole is not .1894 to .1899 inch, or(iv) The bore diameter is not .6248 to .6250 inch.(f) Inspect the shaft attachment bolt, P/N 15-201, that inserts into the pinion, and the attachment bolt, P/N 249-11, that inserts into the male coupling, for fretting or nicks in the area where the bolts contact the shaft and measure the grip diameter. If a bolt has fretting or nicks or if the grip diameter is not .1889 to .1894 inch, replace the bolt with an airworthy bolt, before further flight.(g) Inspect the male coupling, P/N 249-9, paying particular attention to the bore for nicks, scoring, keyway elongation, burrs, or misalignment and measure the bolt hole diameter and the bore diameter. Replace the male coupling with an airworthy male coupling before further flight if:(i) You find misalignment;(ii) The keyway has elongation;(iii) You cannot remove all nicks, scoring, or burrs with light hand polishing using Scotch Brite (maroon or white) and maintain all tolerances and a 32 rms finish;(iv) The diameter of the bolt hole is not .1894 to .1899 inch; or(v) The bore diameter is not .6250 to .6260 inch.(h) Inspect the shaft, P/N 249-10, for misalignment. Measure the diameter of the bolt holes. Inspect for straightness of the shaft by placing the shaft on a flat surface plate calibrated to work surface accuracy tolerance of .001 inch, rolling the shaft, and measuring the greatest gap between the shaft and the flat surface table. Magnetic particle inspect the shaft for a crack, paying particular attention to the bolt holes. Visually inspect the shaft, paying particular attention to a circular area of .500 inch radius from the centre of the bolt holes for the following damage: nicks, scoring, fretting, burrs, or misalignment. Before further flight, replace the shaft if:(i) You find misalignment,

Applicability:

Brantly Helicopter, Inc. Model B-2, B-2A, and B-2B helicopters, serial number 2001 and larger, with a vertical shaft (shaft), part number (P/N) 249-10, or any serial-numbered helicopter with a shaft, P/N 249-10, that was purchased after 1994.

Requirement:

1. To detect fatigue cracking of the shaft and prevent failure of the shaft and subsequent loss of control of the helicopter, accomplish the following:(a) Remove the tail rotor vertical gearbox (gearbox), P/N 278- 200; shaft, P/N 249-10; vertical shaft housing (housing), P/N 249-3; and the intermediate gearbox bushing (bushing), P/N 252-4, from the helicopter.(b) Inspect the flange retainer, part number (P/N) 15-17, located at the top of the shaft housing for deformation and measure the inside diameter. Replace the flange retainer with an airworthy flange retainer if the part is deformed or if the inside diameter is not 1.5050 to 1.5060 inches, before further flight.(c) Inspect the housing, P/N 249-3, for deformation and measure the outer diameter at each end and at the centre of its span.Replace the housing with an airworthy housing, before further flight if:(i) The housing is deformed;(ii) Any outer diameter not on the flared end is not 1.497 to 1.500 inches; or(iii) The outer diameter of the flared end is not 1.844 to 1.875 inches.(d) Inspect the bushing, P/N 252-4, for nicks or scoring, and measure the bushing's length. If the length of the bushing is not .292 to .302 inch or if nicks or scoring is found, replace the bushing with an airworthy bushing, before further flight.(e) Inspect the bevel pinion gear (gear), P/N 15-8, paying particular attention to the bore, for nicks, scoring, burrs, or misalignment. Measure the diameter of the bolt hole and the bore. Replace the gear with an airworthy gear before further flight if:(i)You find misalignment,(ii) You cannot remove all nicks, scoring, or burrs with light hand polishing using Scotch Brite (maroon or white) and maintain all tolerances and a 32 root mean square (rms) finish,(iii) The diameter of the bolt hole is not .1894 to .1899 inch, or(iv) The bore diameter is not .6248 to .6250 inch.(f) Inspect the shaft attachment bolt, P/N 15-201, that inserts into the pinion, and the attachment bolt, P/N 249-11, that inserts into the male coupling, for fretting or nicks in the area where the bolts contact the shaft and measure the grip diameter. If a bolt has fretting or nicks or if the grip diameter is not .1889 to .1894 inch, replace the bolt with an airworthy bolt, before further flight.(g) Inspect the male coupling, P/N 249-9, paying particular attention to the bore for nicks, scoring, keyway elongation, burrs, or misalignment and measure the bolt hole diameter and the bore diameter. Replace the male coupling with an airworthy male coupling before further flight if:(i) You find misalignment;(ii) The keyway has elongation;(iii) You cannot remove all nicks, scoring, or burrs with light hand polishing using Scotch Brite (maroon or white) and maintain all tolerances and a 32 rms finish;(iv) The diameter of the bolt hole is not .1894 to .1899 inch; or(v) The bore diameter is not .6250 to .6260 inch.(h) Inspect the shaft, P/N 249-10, for misalignment. Measure the diameter of the bolt holes. Inspect for straightness of the shaft by placing the shaft on a flat surface plate calibrated to work surface accuracy tolerance of .001 inch, rolling the shaft, and measuring the greatest gap between the shaft and the flat surface table. Magnetic particle inspect the shaft for a crack, paying particular attention to the bolt holes. Visually inspect the shaft, paying particular attention to a circular area of .500 inch radius from the centre of the bolt holes for the following damage: nicks, scoring, fretting, burrs, or misalignment. Before further flight, replace the shaft if:(i) You find misalignment,

Brantly B-2 Series HelicoptersBrantly B-2 Series Helicopters

Get a plain-English read of Brantly B-2 Series Helicopters

Brantly B-2 Series Helicopters