Airworthiness Directive 

Pacific Aerospace 750XL Aircraft I CIVIL loVV.TION AUTHORITY 

I OF NEW ZCAIJ\ND 

Issued by the Civil Aviation Authority of New Zealand in accordance with section 721(3A) of the Civil Aviation Act. An Airworthiness Directive (AD) contains regulatory information which is mandatory. An operator of an aircraft must not operate the aircraft unless the operator complies with every applicable AD issued by the Director in accordance with section 721(3A) of the Civil Aviation Act. An AD is issued where the Director believes on reasonable grounds that an unsafe condition exists in an aircraft or aeronautical product. 

DCA/750XU18 

Applicability: 

Note: 

Requirement: 

Compliance: 

Effective Date: 

Background: 

Fin Forward Pickup - Inspection 

Model PAL 750XL aircraft, SIN all through to 193, 195 and 197. 

This AD supersedes DCA1750XU16A to introduce the requirements in Pacific Aerospace Limited 

Mandatory Service Bulletin (MSB) PACSB/XU068 issue 5, dated 29 June 2015. The revised MSB 

introduces a life limit for fin forward pickup P/N 11-10281-1 and reduces the torque setting for the fin 

forward pickup bolt to alleviate some of the loads applied to the pickup. The MSB also introduces a new 

improved replacement fin forward pickup P/N 11-03375-1 which is not life limited. 

To prevent failure of the fin forward pickup due to possible fatigue cracks, accomplish the following 

requirements per the instructions in Pacific Aerospace Limited Mandatory Service Bulletin (MSB) 

PACSB/XU068 issue 5, dated 29 June 2015: 

1. Reduce the fin forward pickup bolt torque per the instructions in PACSB/XU068 issue 5. If the fin 

has been removed, then remove the two rudder trim driveshaft grub screws and apply Loctite 222 thread 

locking compound and refit the grub screws per the instructions in PACSB/XU068 issue 5. 

2. Visual and Dye Penetrant Inspections: 

Accomplish the inspection requirements in paragraphs 2.A and 2.B of PACSB/XU068 issue 4. If any 

cracks are found, accomplish the instructions in paragraphs 2.C of PACSB/XU068 issue 5, before further 

flight. 

3. Fin forward pickup replacement: 

Remove fin forward pickup P/N 11-1 0281-1 and replace with PIN 11-03375-1 per the instructions in paragraphs 2.C or 2.D of PACSB/XU068 issue 5. 

(PACSB/XU068, occurrences 12/4698, 12/4699 and 14/1898 refer) 

1. For all aircraft affected by this AD: 

At the next 150 hour scheduled maintenance inspection. 

2. For standard category aircraft: 

At 2000 hours TTIS or the next 150 hour scheduled maintenance inspection, whichever is the later, 

unless previously accomplished, and thereafter at intervals not to exceed 600 hours TIS or annual 

inspection, whichever occurs sooner. 

For restricted category aircraft: 

At 1000 hours TTIS or the next 150 hour scheduled maintenance inspection, whichever is the later, 

unless previously accomplished, and thereafter at intervals not to exceed 600 hours TIS or annual 

inspection, whichever occurs sooner. 

3. For standard category aircraft: 

At 6000 hours TTIS or within the next 600 hours TIS, whichever occurs later. 

For restricted category aircraft: 

At 2000 hours TTIS or within the next 200 hours TIS, whichever occurs later. 

30 July 2015 

This AD with effective date 30 July 2015 supersedes DCA1750XU16A to introduce the requirements in Pacific Aerospace Limited Mandatory Service Bulletin (MSB) PACSB/XU068 issue 5, dated 29 June 

2015. The revised MSB introduces a life limit for fin forward pickup P/N 11-10281-1 and reduces the 

torque setting for the fin forward pickup bolt to alleviate some of the loads applied to the pickup. The 

MSB also introduces a new improved replacement fin forward pickup P/N 11-03375-1 which is not life 

limited. 

Owen 0//s 

Airworthiness Specialist 

Delegate of the Civil Aviation Authortiy of New Zealand 

30 July 2015 
PACIFICAEROSPACE 

Padfk: Aerosp9C8 I irnitcd 

Airpor t Read, Hamilton 

MANDATORY SERVICE 

Prlvsto Sag 3027, Hemilt.on 3240, NAW Zealand 

TEL -~o64 7 843 6144 FAX +64 7 843 6134 

EMAIL pacif\c@eercY..pace.co.m PACSB I XL I 068 

ISSUE 5 

WED www.aerospace.co.nz 

FIN FORWARD PICKUP 

1. PLANNING INFORMATION 

A. EFFECTIVITY 

B. REASON · 

C. DESCRIPTION 

D. COMPLIANCE 

All PAL 750XL aircraft up to S/N XL-193 inclusive, XL-195 and 

XL-197. 

There have been reported instances of cracking in the aft plate 

of the forward Fin Pickup Lug located at fuselage STN 337.00 

on 750XL aircraft operated in agricultural and survey roles. 

Over tightening of the pickup bolt will result in additional loads 

being applied to the pickup, which is designed to allow rotation 

about the aircraft longitudinal axis. 

An inspection of the fin forward pickup assembly {consisting of 

P/N 11-1 0281-1, Qty 2 bonded together) is required to 

determine if there is any evidence of cracking. 

If cracking is found the plates are to be replaced. 

This issue of the bulletin introduces a reduced torque setting for 

Fin Forward Pickup bolt to alleviate some of the loads being 

applied to the pickup. 

Current Fin Forward Pickups (PIN 11-10281-1) are now Life 

Limited items and are to be replaced by new improved, nonlifed parts (P/N 11-03375-1) lAW Accomplishment instructions 

(also refer to modification PAC/XU0629). 

Fin Forward Pickup replacement is a terminating action for this 

bulletin. 

A. For all effective PAL 750XL aircraft: 

At Next 150 Hour scheduled maintenance: 

1) Reduce Fin forward pickup bolt torque to 45- 55 

in.lb. and re-lockwire. 

2) If the Fin has been removed lAW any issue of this 

bulletin, remove Qty 2 Rudder Trim Driveshaft grub 

screws, apply Loctite 222 thread locker and refit. 

B. For PAL 750XL aircraft with a Standard Category 

Airworthiness Certificate and greater than 2000 Hours 

TIS: 

1) Carry out inspection lAW accomplishment 

instructions (Para. 2.A. & 2.8.) at next 150 Hour 

scheduled maintenance and thereafter at 600 Hour 

intervals, or annual inspection (whichever occurs 

first). 

B 

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E 

T 

I 

N 

Issued: 29 June 2015 Page 1 of 9 
P A CIFICAEROSPACE PACSB I XL I 068 

E. TOOLING 

F. WEIGHT AND BALANCE 

G. REFERENCE 

H. HOURS REQUIRED 

Page 2 of9 

ISSUE 5 

2) At 6000 hours TTIS or within the next 600 hours 

TIS, whichever is later, retire and scrap Fin 

Forward Pickup P/N 11-10281-1 and replace with 

PIN 11-03375-1, lAW accomplishment instructions 

(Para 2.C. or 2.D.). 

C. For PAL 750XL aircraft with a Restricted Category 

Airworthiness Certificate and greater than 1000 Hours 

TIS: 

1) Carry out inspection lAW accomplishment 

instructions (Para. 2A & 2.8.) at next 150 Hour 

scheduled maintenance and thereafter at 600 

Hour intervals, or annual inspection (whichever 

occurs first). 

2) At 2000 hours TTIS or within the next 200 hours 

TIS, whichever is later, retire and scrap Fin 

Forward Pickup P/N 11-10281-1 and replace with 

P/N 11-03375-1 lAW accomplishment instructions 

(Para 2.C. or 2.0.). 

As required to perform liquid penetrant Inspection. 

No change. 

Maintenance Manual Chapters 04-00-00 & 55-30-00. 

Modification PAC/XL/0629. 

A. 

B. 

C. 

2 Hours. 

1) 6 Hours 

1) 6 Hours 

2) 4 Hours. 

2) 4 Hours. 

Issued: 29 June 2015 
PACIFICAEAOSPACE 

2. ACCOMPLISHMENT INSTRUCTIONS 

INSPECTION 

A Visuallnspection: 

1) Jack/trestle aircraft. 

PACSB I XL I 068 

ISSUE 5 

2) Remove the fin (vertical stabilizer) lAW Maintenance Manual chapter 55-30-00. 

3) Carry out a detailed visual inspection of both the forward fin pickup plates for any 

evidence of cracking (refer to Figure 1 below for example). 

4) If there is visual evidence of cracking in either of the two fin forward pickup plates then 

both plates must be replaced (refer to para C. below}. 

5} If no visual evidence of cracking is found carry out liquid penetrant inspection as per 

para B. below. 

Issued: 29 June 2015 

FIN FORWARD PICKUP 

(11-10281-1) 

FIGURE 1 11-10281-1 FIN FORWARD PICKUP 

Page 3 of9 
PACIFICAEROSPACE PACSB I XL I 068 

ISSUE 5 

B. Liquid Penetrant Inspection: 

1) Prepare for a liquid penetrant inspection by removing paint from the external surfaces 

of the fin forward pickup plates extending above the fuselage. 

2) Carry out a liquid penetrant inspection lAW ASTM E1417 (or equivalent approved· 

standard) of the fin forward pickup plates extending above the fuselage for any 

evidence of cracking. 

3) If there is evidence of cracking in either of the two fin forward pickup plates then both 

plates must be replaced (refer to para C. below). 

4) If no evidence of cracking is found, protect the assembly with paint lAW approved 

maintenance procedures and install the fin (vertical stabilizer) lAW Maintenance 

Manual chapter 55-30-00. 

REPLACEMENT 

NOTE: If replacement is being carried out as result of cracking found 

during inspection lAW Para's A. and B., then proceed lAW with 

Para C. 

Optionally, replacement can be carried out at any time without 

removing Fin Assembly, in which case proceed lAW with 

Para D. 

C. Replacement of Fin Forward Pickup Plates {with Fin removed): 

(Refer to Figures 1, 2 & 3) 

1) Gain access to the interior of the rear fuselage section. 

2) Remove roll pins from rudder trim drive tube connecting sleeve (aft of Frame @ 

STN 221.67) and from forward end of rudder trim dr.ive tube universal (aft of Frame@ 

STN 337 .00) (refer to Figure 1). ' 

FIGURE 1 RUDDER TRIM DRIVE 

3) Uncouple rudder trim drive tube se~t on and draw tube forward to clear the frame and 

fin pickup at Frame@ STN 337.00. Remove the nylon bushing from fin forward pickup. 

4) Carefully drill and remove the attachment rivets securing the forward fin attachment 

assembly and remove assembly from Frame @ STN 337.00. 

----------- - .. - - - Page 4 of 9 Issued: 29 June 2015 
PACIFICAEROSPACE PACSB I XL I 068 

ISSUE 5 

NOTE: Check for corrosion on the frame. If any is found, remove, treat 

the area and repaint lAW approved maintenance procedures. 

5) Using existing pickup assembly as a template, place over the new fin forward pickup 

assembly P/N 11-03375-1, install bolt through the fin attachment bolt hole and clamp 

both assemblies securely with the rivet holes correctly aligned. 

6) Drill through the old pickup assembly into the new at the existing hole size. 

7) Position new fin forward pickup assembly P/N 11-03375-1, and pin on existing holes in 

Frame @ STN 337.00. 

NOTE: Qty 3 MS20470AD4 rivets installed through P/N 11-45775 

angle and skin may be uninstalled to facilitate installation of the 

Hi-Loks through fin pickup in the vicinity of PIN 11-45771 pulley 

bracket. 

Reinstall the angle using Qty 3 CR3213-4-01 rivets (Refer to 

Figure 3 for detail). 

8) Drill and ream holes (10 places) through the new fin forward pickup assembly and 

fuselage frame to 0.1890/0.1895. 

9) Remove new pickup assembly, apply Duralac Jointing Compound on mating surfaces 

of the frame and pickup, and place back In position. 

10) Install the new fin pickup plate to the frame assembly at STN 337.00 with HI-LOK pins, 

collars and washers. 

11) Protect the assembly with paint JAW approved maintenance procedures. 

12) Install nylon bushing in fin forward pickup with jointing compound. 

13) Install rudder trim drive tube section through the frame and fin pickup at Frame@ 

STN 337.00. 

14) Reconnect rudder trim drive tube connecting sleeve (aft of Frame@ STN 221.67) and 

forward end of rudder trim drive tube universal (aft of Frame@ STN 337.00). Secure 

with roll pins and lockwire roll pins. 

NOTE: There is a Bonding Strap (P/N BON-5-1) fitted between the fin 

and the fuselage located in close proximity to the forward fin 

pickup. This bonding strap must be refitted when installing the 

fin. 

15) Install the fin (vertical stabilizer) lAW Maintenance Manual chapter 55-30-00. 

NOTE: When installing the fin: 

a) Prior to installation, apply Duralac Jointing Compound on 

mating surfaces of the fin forward attachment lug and pickup. 

b) Torque bolt through forward pickup to 45- 55 in.lb. and 

lockwire bolt. 

c) \Nhen reconnecting the Rudder Trim system, ensure the 

driveshaft grub screws are secure, with Loctite 222 thread 

locker applied. 

16) Carry out Rudder Trim Tab rigging checks and duplicate Inspection. 

----~~ Issued: 29 June 2015 -------------------------------------------------------- Page 5 of 9 
PACIFICAEROSPACE PACSB I XL I 068 

ISSUE 5 

D. Replacement of Fin Forward Pickup Plates (with Fin installed): 

(Refer to Figures 1, 2 & 3) 

1) Jack/trestle aircraft. 

2) Remove forward fin pickup access panel. Remove lockwire, bolt and washer from 

forward fin attachment fitting. 

3} Gain access to the interior of the rear fuselage section. 

4) Remove roll pins from rudder trim drive tube connecting sleeve (aft of Frame @ 

STN 221.67) and from forward end of rudder trim drive tube universal (aft of Frame @ 

STN 337.00) (refer to Figure 1). 

5) Uncouple rudder trim drive tube section and draw tube forward to clear the frame and 

fin pickup at Frame@ STN 337.00. Remove the nylon bushing from fin forward pickup. 

6) Carefully drill and remove the attachment rivets securing the forward fin attachment 

assembly and remove assembly from Frame @ STN 337.00. 

NOTE: Check for corrosion on the frame. If any is found, remove, treat 

the area and repaint lAW approved maintenance procedures. 

7) Using existing pickup assembly as a template, place over the new fin forward pickup 

assembly PIN 11-03375-1, Install bolt through the fin attachment bolt hole and clamp 

both assemblies securely with the rivet holes correctly aligned. 

8) Drill through the old pickup assembty into the new at the existing hole size. 

9) Position new fin forward pickup assembly PIN 11-03375-1 , and pin on existing holes in 

Frame@ STN 337.00. 

NOTE: Qty 3 MS20470AD4 rivets installed through P/N 1'3-45775 

angle and skin may be uninstalled to facilitate installation of the 

Hi-Loks through fin pickup in the vicinity of P/N 11-45771 pulley 

bracket. 

Reinstall the angle using Qty 3 CR3213-4-01 rivets (Refer to 

Figure 3 for detail). 

10) Insert the fin attachment bolt through the new pickup assembly and fin and tighten. 

11) Drill and ream holes (10 places) through the new fin forward pickup assembly and 

fuselage frame to 0.1890/0.1895. 

12) Remove new pickup assembly, apply Duralac Jointing Compound on mating surfaces 

of the frame and pickup, and the fin forward attachment lug and pickup, and place back 

in position. 

13) Install the new fin pickup plate on the Frame@ STN 337.00 with HI-LOK pins, collars 

and washers. 

14) Protect the assembly with paint lAW approved maintenance procedures. 

15) Install nylon bushing in fin forward pickup with jointing compound. 

16) Install rudder trim drive tube section through the frame and fin pickup at Frame 

STN 337.00. 

17} Reconnect rudder trim drive tube connecting sleeve (aft of Frame @ STN 221.67) and 

forward end of rudder trim drive tube universal (aft of Frame@ STN 337.00). Secure 

with roll pins and lockwire roll pins. 

18) Install the fin forward pickup bolt, torque to 45 - 55 in.lb. and secure with lockwire. 

19) Install forward fin pickup access panel and secure. 

20) Carry out Rudder Trim Tab rigging checks and duplicate inspection. 

Page 6 of 9 Issued: 29 June 2015 
PACIFICAEROSPACE 

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FIGURE2 FIN FORWARD PICKUP INSTALLATION 

Issued: 29 June 2015 

PACSB I XL I 068 

ISSUE 5 

Page 7 of9 
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11-45771 

PULLEY BRACKET 

11-45775 

ANGLE 

View Looking Aft on Frame at STN 337 

CR3213-4-01 

RIVET 

11-45771 

PULLEY BRACKET 

11-033

FIN PIC

Detail of Pickup faste

(Skin removed for cla
PACIFICAEROSPACE 

3. CERTIFICATION 

Record compliance with this bulletin in the aircraft Log Book. 

4. MATERIAL REQUIRED: 

PACSB I XL I 068 

ISSUE 5 

If the forward fin pickup is to be replaced then the following parts are required. Contact PAL for 

parts availability. 

Descri!;!tion Part Number Qt~ Reguired 

FIN PICKUP - FORWARD- STN 337.00 11-03375-1 1 

PIN (HI-LOK) HL 18PB-6-5 10 

ALTERNATE PART 

PIN (HI-LOK) HL 18-6-5 10 

COLLAR AND WASHER HL94W-6 10 

ALTERNATE PART 

COLLAR (HI-LOK) HL94-6 10 

DURALAC DTD 369 8 1305-1 AIR 

(JOINTING COMPOUND) 

THREAD LOCKER LOCTITE 222 AIR 

ROLL PIN MS171496 3 

ALTERNATE PART 

ROLL PIN 9048-069 3 

RIVET CR3213-4-01 3 

Issued: 29 June 2015 Page 9 of9