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2017-17-09: We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-300, -400, and -500 series airplanes. This AD was prompted by a manufacturer's review that showed that the fuel tank access door at a certain wing buttock line did not have an engineered ground path with the mating wing structure. This AD requires replacing the fuel tank access door, doing a check of the electrical bond, doing related investigative and corrective actions if necessary, and revising the maintenance or inspection program by incorporating an airworthiness limitation (AWL). We are issuing this AD to address the unsafe condition on these products.
55-14-02: 55-14-02 PIPER: Applies to Model PA-23 Serial Numbers 23-1 to 23-208 Inclusive. Compliance required by August 1, 1955. Because of possible damage to the hydraulic actuating cylinders for the landing gear system and flap system of the two end plug retaining pins, as a result of excessive pressures caused by thermal expansion, it is necessary that these cylinders be inspected and replaced or modified as follows: 1. If the cylinder housing is upset or fractured, it must be replaced by a new reinforced cylinder P/N 455927. (Piper Service Bulletin No. 138 dated May 9, 1955, covers this same subject.) 2. If the cylinder housing is not upset or fractured, it must either be replaced by P/N 455927, or reinforced by adding two retaining plugs in accordance with Piper Service Letter No. 250 dated June 8, 1955. This supersedes AD 55-12-01.
2017-16-04: We are adopting a new airworthiness directive (AD) for Romtex torso restraint systems (restraint systems) installed on but not limited to Airbus Helicopters Model AS350B2, AS350B3, EC130B4, EC130T2, and AS355NP helicopters. This AD requires replacing certain restraint system buckles. This AD was prompted by a report of several restraint system buckle knobs breaking. The actions of this AD are intended to correct an unsafe condition on these products.
54-14-01: 54-14-01 CURTISS-WRIGHT: Applies to all Model C-46 Series aircraft. Compliance required as indicated. A. Inspection. 1. Carefully inspect the outboard horizontal stabilizer rib, which supports the outboard elevator hinge, left and right, P/N 20-110-5014-2 and angles, P/N 20-110-5014-4 for cracks in the area from the rib end to a point at least 6 inches forward of the trailing edge of the stabilizer. (a) On aircraft which do not have the modification described in paragraphs B1 and B2 below, this inspection is required every 100 hours. (b) On aircraft which do have the modification described in paragraphs B1 and B2 below, this inspection is required every 800 hours. (c) Deleted, March 28, 1955. B. Replacement. 1. If cracks are found in the angles, P/N 20-110-5014-4, remove and replace with a similar angle fabricated from 0.040 24ST or 0.040 24SO aluminum allow sheet. Specification No. AN A-13, condition A, heat treat in accordance with Specification AN 01-1A- 1. 2. If cracks are found in the rib, P/N 20-110-5014-2, reinforce each rib as follows: (a) Fabricate (per airplane) four angles, P/N 20-110-5014-1201 from 0.051 24STAL sheet, 15 inches long with 0.62 x 0.71 inch leg, and install at top and bottom on outboard side of rib and extending forward from the forward edge of hinge block assembly, P/N 20-110-5112-3 or 20-110-5070-502. 24ST aluminum alloy extrusion, Alcoa Die No. 12883, may be used as an alternate material if desired. Pick up existing rivets in the rib and skin. (b) Fabricate (per airplane) four angles, P/N 20-110-5014-1202 from 0.051 24STAL sheet, 8.80 inches long with 0.62 x 0.71 inch legs and install angles on inboard side of rib at top and bottom, picking up the six bolts in the hinge block assembly P/N 20-110-5112-3 or 20-110-5020-502, and extending forward 8.80 inches from the end of the rib. 24ST aluminum alloy extrusion Alcoa Die No. 12883 may be used as an alternate materialif desired. In addition to picking up the existing rivets, add three additional rivets at top and bottom between the existing rivets through the web of the rib assembly, and add four rivets, both top and bottom through the flange of the rib and leg of the angle. (c) To assemble reinforcement angles called for in parts (a) and (b), the following modifications to the existing structure are necessary: (1) Cut clip, P/N 20-110-5033-1 to clear angles - 1201 and install. (2) Cut angle P/N 20-110-5014-5 to clear angles - 1202 and install. (3) Cut skin, P/N 20-110-5001-66, to clear angles - 1202 and replace rivets. (Army Technical Order 01-25L-103 or Curtiss-Wright Service Information Letters: SBS:ASF:asf-7195, dated October 26, 1946, and its enclosures, cover this same subject.) This supersedes AD 47-51-1.
55-08-04: 55-08-04 PIPER: Applies to Model PA-22 Serial Numbers 22-1621 Through 22-1625, 22-1627, 22-1630, 22-1633, 22-1634, 22-1637. Compliance required as soon as possible but not later than July 1, 1955. The Hypass No. 48P6 ignition filters should be removed from the magnetos and replaced with magneto filter, Piper No. 63149 (Lear) obtainable from the Piper Service Department. It has been found that the Hypass No. 48P6 filters short and ground out the magnetos when subjected to a temperature which has been reported to be equal to the engine accessory temperature after a series of takeoffs have been performed.
55-08-01: 55-08-01 BEECH SAFETY BELT BUCKLES: Applies to All Beech Safety Belt Buckles, P/N 113652. Compliance required as soon as possible but not later than September 1, 1955. Inspect Beech safety buckles by checking the buckle lever attachment pin for snap ring retainers installed at each end. All Beech buckles with buckle lever dowel type attaching pin retainers in lieu of buckle lever attaching pins with snap ring retainers should be retired from service by replacement with the newer improved safety buckle with through pin and snap ring retainers. (Beech Service Bulletin No. OS-55-1 issued January 25, 1955, covers this same subject.)
55-09-01: 55-09-01 BOEING: Applies to all Model 377 aircraft with Hamilton Standard Propellers. To be accomplished as soon as practicable but not later than June 30, 1955. Loss of manual r.p.m. control can occur as a result of tripping of the fast-acting magnetic circuit breaker before the slow-acting fuse is blown on a faulted branch. Improved circuit protective coordination and resultant reliability in the manual control function should be provided by replacing the "Manual" 10-ampere magnetic circuit breaker with a 5-ampere thermal type breaker, and replacing the four 5-ampere fuses in the synchronizer unit with 2 ampere Slo-Blo fuses. (Hamilton Standard Service Bulletin No. 283 dated December 21, 1953, covers this same subject.)
2017-15-08: We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc., Model CL-600-2E25 (Regional Jet Series 1000) airplanes. This AD requires modifying the bleed-air duct and detection system; and revising the maintenance or inspection program, as applicable. This AD was prompted by a report of a possibility that the shrouds of the high pressure bleed air ducts could deteriorate and their maximum permitted leakage rate could be exceeded. We are issuing this AD to address the unsafe condition on these products.
67-03-01: 67-03-01 CESSNA: Amdt. 39-338 Part 39 Federal Register January 14, 1967. Applies to Model 150 Series Airplanes, Serial Numbers 17001 through 15061328, Equipped With Right- Hand Exhaust Gas Cabin Heat Exchanger (Muffler). Compliance required within the next 50 hours' time in service after the effective date of this AD, unless already accomplished within the last 50 hours' time in service, and thereafter at intervals not to exceed 100 hours' time in service from the last inspection, until the exhaust system is modified in accordance with Cessna Service Letter No. 65-72 dated July 27, 1965, or later FAA-approved revision, or an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA Central Region. Several cases of exhaust gas cabin heat exchanger cracking have occurred, allowing carbon monoxide to enter the cabin with cabin heat "ON." To minimize the possibility of carbon monoxide contamination of cabin air, accomplish either of the following or an FAA approved equivalent: (a) Inspect right-hand exhaust gas cabin heat exchanger (muffler) for cracks by conducting a pressure test of 1 1/2 p.s.i. in accordance with paragraph 12-93 of Cessna 100 Series Service Manual dated November 1962. Replace cracked exhaust gas cabin heat exchanger before further flight with an exchanger inspected in accordance with this AD and found free of cracks. (b) Conduct a ground test with a carbon monoxide indicator by heading the airplane into the wind, warming the engine on the ground, advancing throttle to full static r.p.m. with cabin heater "ON", and taking carbon monoxide readings of the heated air stream at the cabin heater deflector, P/N 0411824, on the firewall inside the cabin and another reading immediately thereafter in free air 15 feet in front of the propeller, with engine shut down. If carbon monoxide indication in the cabin is greater than in free air, comply with (a) before further flight. This supersedes AD 64-17-03.This directive effective January 14, 1967.
2017-14-12: We are superseding Airworthiness Directive (AD) 2015-22-06 which applied to all Airbus Model A318, A319, A320, and A321 series airplanes. AD 2015-22-06 required revising the After Start Normal Procedures section of the airplane flight manual (AFM) to provide procedures that address latent failures in the spoiler and elevator computer (SEC). This AD requires installing new updated SEC software. This AD was prompted by reports that certain maintenance messages indicated the loss of elevator servo control monitoring performed by SEC 1, SEC 2, or both, during the engine start. We are issuing this AD to address the unsafe condition on these products.