ATA 55

Horizontal Stabilizer Aft Fitting inspection: Worthington Aviation has requested and has received an Alternate Method Of Compliance (AMOC) for Airworthiness Directive (AD) 89-12-08. This AD concerns the inspection criteria for the horizontal stabilizer splice (aluminum). The AD states, (paragraph C) “if cracks are found, replace the splice fitting prior to further flight, in accordance with the following IAI Service Bulletin entitled “Horizontal Stabilizer Assembly –Inspection, Repair and Improvement (AFC 2037), as appropriate”. The Service Bulletins listed do no reference the replacement of the fitting with the titanium fitting (453005-509) hence the continued inspection criteria remains in the body of the AD (paragraph B).
Since then IAI has come out with the -509 titanium fitting and had changed the AMM Ch 5 to reflect the changed times for inspection for this part.
This AMOC references the -509 titanium fitting and the changed inspection times for this fitting.

Please refer to the IAI AMM 5-20-06 pg 202
Contact Worthington for a copy of the AMOC for your records (ANM-116-08-212)

ATA 24

Aircraft Grounding Points
Several instances have been reported of failing electrical grounding points. These connections have developed significant arcing, enough so that the cables have eroded a hole completely through the bulkhead frames. Compliance with the Service Bulletins 1124-24-120 will help minimize this. The areas to pay special attention to are the grounding cable GND 87, 88, 89 and 90, these are the attached at frame station 383 on the ceiling. Also the external power connection to the airframe, this is located at frame station 402.810. Holes in the frame may not be visible until the cables are removed.

AD-AMOC

Worthington has pursued and recieved the following Alternate Method Of Compliance (AMOC)
AD 92-12-02 AMOC ANM-116-08-182. This terminates the repetitive inspection of the 513506 push pull tube. (ANM-116-08-182).
AD 89-12-08 AMOC ANM-119-08-212. This extends the repetitive inspection of the Horizontal Stabilizer Titanium Splice. (ANM-116-08-212).

ATA 24

Several instances have been reported of electrical grounding points failing. These connections have developed significant arcing, enough so that the cables have eroded a hole completely through the bulkhead frames. Compliance with the Service Bulletins 1124-24-120 will help minimize this. Pay special attention to the grounding cable GND 87, 88, 89 and 90. These are the attached at frame station 383 on the ceiling. Also, pay attention to the external power connection to the airframe. This is located at frame station 402.810. Holes in the frame may not be visible until the cables are removed.

ATA 78

When loose rivets are found in the “5000” series engine inlets, please refer to Chapter 54-30-00 page 802 for instructions on replacement. Pay CAREFUL attention to the little detail that tells you that the rivet will STAKE high. The rivet head will NOT be flush so do not try to make it flush. The skin is not thick enough to do that, so in a few hours the rivets are loose again, with no material left in the “D” ring to replace them.

ATA 76

When DEECs are installed, sometimes the operating switch in the throttle quadrant (#12) for the ground bypass valve will have to be adjusted. This is because of the revised fuel scheduling in the DEEC. It can cause the ground valve to remain open when the engine speed is well above the 52% N1 speed cutoff due to actual throttle arm position. This will show up as a “BLEED AIR OVERPRESSURE” light or a large increase in airflow from the gaspers due to increased bleed air supply.
The easiest way we have found to adjust the switch position is to run the R/H engine and mark the throttle quadrant at 52% N1. Next, shutdown the engine. Remove the electrical connector from the valve (P348) and run a test lead from pin “A” to the cockpit. Move the switch until 28VDC is not present @ pin “A” with the throttle @ 52% position or greater.

ATA 56

Next time you are looking at your outer windshields, pay close attention to the little fiberglass pad bonded to the front lower surface of the glass. It is the static bonding strap for the windshield surface; and if it is eroded and missing, static can build up on the surface. When a windshield is replaced, cover the pad up with the same sealant used during windshield installation to protect it.

ATA 53

The inspection criteria will be changing for the fuselage in the areas of the chem. milled skins. The preliminary change will be to add the following: Removal of all sound deadening / insulation above floor level and accomplish a visual inspection in the areas of the chemically milled skins for corrosion. Then reinstallation of new insulation that will be adhered to the outer skin. This insulation will be easier to remove for subsequent inspections.

ATA 35

During an operational check of an aircraft oxygen system, it was determined that a passenger oxygen drop down mask would not let oxygen flow. The fault was in the connection between the smaller tube and the larger tube attached to the barbed fitting on the oxygen drop down box. There is supposed to be clearance for oxygen to flow, in this case the smaller line was squeezed shut and would not allow oxygen to flow to the mask. The part number in question is a 174080-31 Rev “K”. The, Batch was LC0526K. This lot had been shipped around July of 2005. A thorough inspection of the masks that are installed in your aircraft is recommended. This inspection should include a functional test of the mask as well as the aircraft system.

Please refer to the IAI AMM 35-00-00 Oxygen system adjustment and test paragraph 1, Steps (1) thru (36).

ATA 29

Hydraulic leaks in the lines in the pressurized cabin area have proven to be a recurring problem. There will be a session and training for the perma-swedging of hydraulic lines at our M&O in Las Vegas. This would be a good time to have certified training from the manufacturer so that if needed, you may accomplish your own perma-swedging.

ATA 27

When accomplishing the inspection on the flexible flap drive cable, look at the attaching hardware for the cables to the actuators. We have had several instances of the hardware splitting and the cables becoming loose.

ATA 27

During routine inspections, carefully look at the elevator torque tube in the inboard bearing areas. There is a steel bushing on the tube that is supposed to be tight on the tube. This is the wear surface for the support bearings. We are finding that they may be loose enough to move by hand. If left uncorrected the bushing can move out of position causing excessive movement on the torque tube and no surface for the bearing to ride on.