DAT E 

### ALERT SERVICE BULLETIN

REVISION NOTICE

A Subsid iar y of T e xtron Inc.

AN APPRO P RIA T E ENTRY S H OULD BE MADE I N TH E AIRCRAFT LOG B O O K UP O N ACCO MPLIS H MENT

IF O W NE RSHIP O F AIRCRAFT HAS CHANG E D P L EASE FO RWA RD TO NEW OWNER MAR 18, 2005

TO: All O w ners/Operators of Bell 212 Helicopters

SUBJ ECT: REVISION “D” TO ALERT SERV ICE BULL E TIN 212-00-111 (TAIL

ROTOR BLADE 212- 010-750-009 THROUGH -129 TIP BLOCK MODIFICATION)

Revision “A” to this bulletin adds additional seri al num bered prefix blades ATR-xxx

and A3-xxx. All blades with serial number prefix ATR or A3 must also comply with the bulletin requirements.

Revision “B” to this bulletin adds a number of se rial numbered blades for the tip block

modification. All blades with serial num ber A or A-FS-11530 to 13594, 13603 to 13618 are now subject to PART B of this ASB.

This revision also adds the procedure fo r removal of the tip closure rivets.

Revision “C” to this bulletin changes the effectivit y of the Tail Rot o r Blades affected by

this ASB.

Revision “ D ” to this bulletin provides an alter nate fastener for the tail rotor blade tip

closure rivets installation.

This alternate rivet P/N NAS9307M-4-01 has a monel sleeve which is more erosionresistant. Installation of this rivet wit h sealant MIL-PRF-81733 in lieu of adhesive 299-

947-100 T Y 2 CL 2 will offer a better prot ection against wat e r contamination and

corrosion. An oversiz e rivet P/N NAS9310M -4-01 is also added to the material list.

Tip closure rivets installations accomplished pr ior to this revision are acceptable as is.NO.

DATE

PAGE DATE

REV 

### ALERT SERVICE BULLETIN

A Subsidiary of Textron Inc.

AN APPROPRIATE ENTRY SHOULD BE MADE IN TH E AIRCRAFT LOGBOOK UPON ACCOMPLISHMENT

IF OWNERSHIP OF AIRCRAFT HAS CHANGED PLEASE FORWARD TO NEW OWNER 212-00-111

MAR 18, 05 NOV 10, 00

D 1 of 8

MODEL AFFECTED: 212

SUBJECT: TAIL ROTOR BLADE P/N 212-010-750-009 THROUGH –129, TIP BLOCK RETENTION

MODIFICATION

HELICOPTERS AFFECTED: All Model 212 He licopters with Tail Rotor Blades

P/N 212-010-750-009 thr ough -129, (All serial numbers) installed require accomplishment of

this bulletin.

PART A of this bulletin is requi red only if any of the

countersunk screws are installed below the surface of the abrasion strip. Refer to the inspection procedure.

PART B of this bulletin is required on all tail rotor blades P/N 212-010-750-009 through –129.

PART C of this bulletin provides instruction for the removal of the tip closure rivets if required.

[Tail rotor blade S/N A or AFS-11926, 13351, 13367,
13393, 13400, 13402, 13515, 13540, 13568, 13595 to 13602 and 13619 and subseq uent will have the intent of this bulletin accomplished prior to delivery.]

COMPLIANCE: Within the next 100 hours afte r receipt of this bulletin but no later than Dec 31, 2004

.ASB 212-00-111 Page 2 of 8

DESCRIPTION:

Bell Helicopter has recently investigated t he in-flight loss of a 212-010-750-105 tail rotor blade tip block. Investigation has rev ealed that the countersunk screws retaining the tip block were installed incorrectly resu lting in little or no tip block retention. Additionally reports have been submitted of the loss of the tail rotor tip closure. Investigation revealed that t here is a possibility of a poor adhesive bond in this area allowing for voiding and eventual closure loss.

This bulletin addresses these two issues by incorporating additional fasteners in the tip area to prevent future loss of ei ther the tip block or tip closure.

APPROVAL:

The engineering design aspects of th is bulletin are FAA/DER approved.

MANPOWER:

Approximately 3 man-hours are required to complete this bulletin. Man-hours are based on hands-on time, and may vary wit h personnel and facilities available.

MATERIAL:

Required Material: The following material is required for the ac complishment of this bulletin and may be obtained through your Bell Helico pter Textron Supply Center.

PART A

Part Number Nomenclature Quantity

100-159-6-2 Titanium Hi-lok Pin 2 per bladeASB 212-0 0 -111 Page 3 of 8

PART B

Part Number Nomenclature Quantity

M7885/2-4-01 Blind Rivet 4 per blade

A l t e r n a t e NAS9307M -4-01 Blind Rivet 4 per blade

M7885/6-4-01 Blind Rivet NOTE 1

A L T E R N A T E

NAS9310M -4-01 Blind Rivet NOTE 1 D

NOTE 1: Oversize rivet if required.

Consumable Material:

The following material is required to acco mplish this bulletin, but may not require ordering, depending on t he operator’s consumable mat e rial stock levels. T h is material may be obtained through your Bell He licopter Textron Supply Center.

Part Number Nomenclature Quantity Reference

2 9 9

- 9 4 7

- 1 0 0 T Y 2 C L 2 A dhesiv e Magnobond 6398

or EA934 A / R C

- 3 1 7

Denatured Solox Denat ured Alcohol A/R C-326

2 9 9

- 9 4 7

- 1 0 0 T Y 2 C L 3 P T A dhesiv e Magnobond or

EA956 A / R C

- 3 6 3

180 GRIT CLOTH Abrasive Cloth 180/220 A/R C-423 TT-N-95,TYII 1GAL Alip hatic Naptha A/R C-305 MIL-PRF-81733 (4 OZ) Corrosion- Inhibiting Sealant A/R C-392 D

SPECIAL TOOLS:

None required

ELECTRICAL LOAD DATA:

Not affecte d

REFE RE NCES:

BHT-212-IPB Illustra ted Parts BreakdownASB 212-00-111 Page 4 of 8

BHT-212-MM Maintenance Manual BHT-212-CR&O Component Repair and Overhaul Manual

PUBLICATIONS AFFECTED:

BHT-212-IPB Illustra ted Parts Breakdown BHT-212-CR&O Component Repair and Overhaul Manual

ACCOMPLISHMENT INSTRUCTIONS

- NOTE -

Removal of the hub assembly fr om the output shaft is not required to remove the T/R blades. Note location and quantity of span balance washers for reinstallation. Remove any defective tail rotor blades fr om the T/R hub assembly in

accordance with 212 CR&O.

Inspection Procedures

1. Deleted

2. Inspect forward tip weight retention blo ck and aft tip closure for voids. Remove any

blade from service that exhibits vo ids in excess of CR&O limitations.

3. Inspect forward tip block attachment count ersink screws. 4 locations. See Figure 1. Inspect to insure that the head of the counters unk screw is flush with the surface of the abrasion strip.

4. T/R blades that have the scr ews flush with the surface of the abrasion strip in all 4 locations do not require shear pin installation. T/R blades with one or more of the

screws that are set below the surface of the abrasion strip or are covered with filler material may not provide acceptable retent ion of the tip block in the event of

adhesive failure and will require shear pin installation. The limit is flush to 0.010 inch (0.0254 mm) high.

5. The aft tip closure rivet installation must be accomplished on all tail rotor blades.ASB 212-0 0 -111 Page 5 of 8

PART A

Shear Pin Installation

- NOTE -

Only those blades identified wi th countersink screws below

the surface of the abrasion strip require the shear pin

installation. Do not use cutting oil during drilling operation. Do not drill th rough opposite side of blade.

1. Using a clean, sharp No. 7 drill bit, drill a .50 inch deep shear pin installation hole as shown on Figure 1. The upper surface of the blade can be identified as the curved side of the blade and is same side as the data plate. Likewise the lower

surface of the blade is the most flat side of the blade. The shear pin installation holes are located at 2.0 inches (proje cted) aft of the leading edge on the upper surface and 1.5 inches (projected) aft of the leading edge on the lower surface.

2. When drilling, it is acceptable to hav e contact with brass master balance weights installed in the tip block. Once drilling is completed insure that the hole is thoroughly deburred and the depth and fit of the shear pin is verified.

3. Clean shear pins 100-159-6- 2 and drilled holes in blade with denatured alcohol or naphtha. Mix adhesive 299-94 7-100 TY 2 CL 2 (Hysol EA 934 or Magnobond 6398) in accordance with manufactures inst ructions. Coat shear pin shanks and

drilled hole with adhesive. Inse rt shear pin into hole insu ring that head of shear pin is seated firmly with the surface of abr asion strip. Clean off excess adhesive leaving a small filet of adhesive squeeze-out around shear pin head to insure blade

is sealed. Allow to cure at room te mperature for 24 hours at 70-80 degrees F.

PART B

Aft Tip Closure Rivet Installation

- NOTE -

All tail rotor blades must hav e the following accomplished. Do not use cutting oil during drilling operation. Do not drill through opposite side of blade.

1. Using a clean, sharp no.30 drill bit, drill two rivet inst allation holes on both the upper and lower surface of the blade tip as shown in Figure 1. It is not necessary to remove the paint in the area.ASB 212-00-111 Page 6 of 8

2. De-burr drilled holes and verify ri vet fit. Clean M7885/2-4-01 or NAS 9 307M-4-01

rivets and drille d hole s with Aliph a tic N aphth a . Wipe dry before solvent evaporates.

D 3. Obtain a kit of sealant per MIL-PRF-81733. Thoroughly mix the accelerator, add it to the base product, then thoroug hly mix the mixture until a uniform color, dev o id of streaks, is achieved.

4. Coat rivet-shanks with MIL-PRF-81733 seal ant and install verifyi ng that rivet heads are seated firmly with blade sk in. Allow a f illet of adhesive to squeeze out ar ound

rivet heads to insure blade is sealed.

5. Allow sealant to cure for 24 hours at r oom temperature. Refi nish rivet heads in

accordanc e with 212 MM for bl ade refinis h i ng. Re-identify the modified blade by

the addition of "FM" after t he part number (i.e., 212-010-750-109F M).

6. Reinstall T / R blades ont o the T/R hub ass e mbly in accordance with 212 CR&O. Note the location of the span balance wa shers removed and reinstall in exact

location where removed.

7. Dynamically balance T/R in accor dance with 212 MM and annotate historical

records to i ndicate compli ance with this bulletin.ASB 212-0 0 -111 Page 7 of 8ASB 212-00-111 Page 8 of 8

PART C

Removal of tip closure rivets

1. Remove pa int and filler from around ri vets using 180/220 -grit sandpaper witho ut damaging t he skin.

2. Using a sanding disk, carefully remove approximately half the rivet head(s) (in height).

3. Using a 3/32-inch paralle l punch, tap the stem(s) insi de the tip closure area.

4. Using the same punch, pry out the remainder of the st em locking ring(s).

5. Using a cle an sharp #30 drill bit, drill near ly t h rough the remainder of the rivet head(s) to weaken them.

6. Break the head(s) off, using a small chis el or the parallel punch.

7. Using a 1/8-inch parallel punch, carefully driv e the rivet shank(s) inside the tip

closure area.

8. Clean area to receive new rivet(s).

9. Inspect hole(s) for size. The hole di ameter should be 0.129 to 0.132-inch. If any hole is elongated but no larger than 0.146-inch di ameter, oversize rivets

P/N M7885/6-4-01 or P/N NAS9 3 10M-4-01 are permissible. Drill h o le(s) usin g a clean sha r p #27 drill bit and deb urr.

Note

It is recommended that the loos e stem(s) and shank( s ) be glued inside the closure area to prevent rattling. Inject a small quantity of C-363 adhesive through one rivet hole and move the blade in all directions until all loose parts stop rattling. A llow adhesive to

cure. D

10. Refer to P A RT B for r i vet installation.