AD 2000-11-01 Airworthiness Directives; McDonnell Douglas Model DC-9-80 and MD-90-30 Series Airplanes, and Model MD-88 Airplanes

Models named: MD-90-30 series, MD-88. Read the applicability below — it usually turns on serial or part numbers too.

Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87) series airplanes; Model MD-90-30 series airplanes; and Model MD-88 airplanes; manufacturer's fuselage numbers 995 through 2243 inclusive; certificated in any category. Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Required as indicated, unless accomplished previously. To ensure that insulation blankets constructed of metallized polyethyleneteraphthalate (MPET) are removed from the fuselage, accomplish the following: Inspection (a) Within 5 years after the effective date of this AD, determine whether, and at what locations, insulation blankets constructed of MPET, are installed. When markings are not visible, the determination shall be made by using known MPET material as a comparison sample to assist in the identification. Note 2: Insulation blankets that are marked with “DMS 2072, Type 2, Class 1, Grade A;” “DMS 2072, Type 2, Class 1;” or “DMS 1996, Type 1;” are constructed of MPET. Corrective Actions (b) For insulation blankets that are determined not to be constructed of MPET, no further action is required by this AD. (c) For insulation blankets that are determined to be constructed of MPET, within 5 years after the effective date of this AD, replace the MPET insulation blankets with new insulation blankets that have been approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. The blankets shall be replaced in accordance with the Accomplishment Instructions of McDonnell Douglas Service Bulletin MD-90-25-015, Revision 01, dated November 5, 1997 (for Model MD-90-30 series airplanes); or McDonnell Douglas Service Bulletin MD80-25-355, Revision 01, dated November 5, 1997 (for Model DC-9-80 series airplanes and Model MD-88 airplanes); as applicable. The replacement insulation blankets must be constructed of materials tested in accordance with Appendix 1 of this AD, or in accordance with a method approved by the Manager, Los Angeles ACO. Note 3: Although this paragraph allows up to 5 years for the required replacement, the FAA anticipates that operators will comply at the earliest practicable maintenance opportunity. Note 4: Only one of the two metallized Tedlar TM covers specified in the service bulletins has been shown to have successfully passed the testing of the American Society for Testing and Materials (ASTM) flammability standard and is considered acceptable for compliance with the requirements of paragraph (c) of this AD. Spares (d) As of the effective date of this AD, no person shall install an MPET insulation blanket on any airplane. Alternative Methods of Compliance (e) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles ACO. Operators shall submit their requests through an appropriate FAA PMI, who may add comments and then send it to the Manager, Los Angeles ACO. Note 5: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. Special Flight Permits (f) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. Incorporation by Reference (g) The blankets shall be replaced in accordance with the Accomplishment Instructions of McDonnell Douglas Service Bulletin MD-90-25-015, Revision 01, dated November 5, 1997; or McDonnell Douglas Service Bulletin MD80-25-355, Revision 01, dated November 5, 1997; as applicable. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Technical Publications Business Administration, Dept. C1-L51 (2-60). Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California; or at the Office of the Federal Register , 800 North Capitol Street, NW., suite 700, Washington, DC. (h) This amendment becomes effective on June 30, 2000. Appendix 1.—Test for Materials Replacing Metallized PET Thermal Acoustical Insulation, Film February 16, 2000 This test method is used to evaluate the flammability and flame propagation characteristics of thermal/acoustic insulation when exposed to both a radiant heat source and a flame. (a) Definitions. (1) Thermal/Acoustic Insulation. Thermal/acoustic insulation is defined as a material or system of materials used to provide thermal and/or acoustic protection. Examples include a film-covering material encapsulating a core material such as fiberglass or other batting material and foams. (2) Radiant Heat Source. The radiant heat source is an air/gas fueled radiant heat energy panel. (b) Test Apparatus (as schematically shown in figure 1). (1) Radiant Panel Test Chamber. Tests will be conducted in the radiant panel test chamber as used in ASTM—Designation: E 648. It is suggested that the test chamber be located under an exhaust hood to facilitate clearing the chamber of smoke after each test. The radiant panel test chamber shall consist of an enclosure 55 inches (1400 mm) long by 19 1/2 inches (500 mm) deep by 28 inches (710 mm) above the test specimen. The sides, ends, and top shall be insulated with a fibrous ceramic insulation such as Kaowool TM board. One side shall be provided with an approximately 48 by 6 inch (1219 by 152mm) draft tight, high temperature, heat resistant glass observation window, to facilitate viewing the sample during testing. On the same side and below the window is a door which, when open, allows the specimen platform to be moved out for mounting or removal of test specimens. The bottom of the test chamber shall consist of a sliding steel platform, which has provisions for securing the test specimen holder in a fixed and level position. The top of the chamber shall have an exhaust stack with interior dimensions of 4 inches (102mm) wide by 15 inches (380 mm) deep by 12.5 inches (318mm) high at the opposite end of the chamber from the radiant energy source. (2) Radiant Heat Source. The radiant heat energy source will be a panel of porous refractory material mounted in a cast iron frame, with a radiation surface of 12 by 18 inches (305 by 457mm). It shall be capable of operating at temperatures up to 1500°F (816°C (Figure 1). ER26MY00.023 (i) Radiant Panel Fuel System. The radiant panel fuel will be propane (liquid petroleum gas—2.1 UN 1075). The panel fuel system shall consist of a venturi-type aspirator for mixing gas and air at approximately atmospheric pressure. Suitable instrumentation will be necessary for monitoring and controlling the flow of fuel and air to the panel. Instrumentation will include an air flow gauge, an air flow regulator, a gas pressure gauge, and a rotameter for measuring gas flow. (ii) Radiant Panel Placement. The panel will be mounted in the chamber at 30 degrees to the horizontal specimen plane. (3) Specimen Holding System. (i) The sliding platform serves as the housing for test specimen placement. A 1/4 inch (6.35mm) sheet of Duraroc κ a , or other non-combustible base, measuring 43 1/4 inches by 12 1/2 inches (1098 by 317.5mm) will be placed in the open bottom (base) of the sliding platform. It is necessary to cut the non-combustible base into two pieces for placement in the bottom of the platform, since it will be supported by a 3/4 -inch (19.1mm) lip that extends around the bottom of the platform base. It is suggested that the shortest piece be placed at the end furthest from the radiant panel (figure 2). A 1/2 inch (13mm) piece of Kaowooλ TM board or other high temperature material measuring 41 1/2 by 8 1/4 inches (1054 by 210mm) will be attached to the back side of the platform. This board will serve as a heat retainer and will protect the test specimen from excessive preheating. The height of this board must not be too high such that it will impede the sliding platform movement (in and out) of the test chamber. ER26MY00.024 (ii) The test specimen will be placed horizontally on the non-combustible base. A stainless steel retaining frame (AISI Type 300 UNA-NO8330), or equivalent, having a thickness of 0.078 inches (1.98mm) and overall dimensions of 44 3/4 by 12 3/4 inches (1137 by 320mm) with a specimen opening of 40 by 7 7/8 (1016 by 140mm) will be placed on top of the test specimen. The retaining frame will have two 1/2 inch (12.7mm) holes drilled at each end for positioning the frame to the two stud bolts at each end of the sliding platform (figure 3). ER26MY00.025 (iii) A securing frame (acting as a clamping mechanism) constructed of mild steel will be placed over the test specimen. The securing frame overall dimensions are 42 1/2 by 10 1/2 inches (1080 by 267mm) with a specimen opening of 39 1/2 by 7 1/2 inches (1003 by 190mm). Hence, the exposed area of test specimen exposed to the radiant panel is 39 1/4 by 7 1/4 inches (996 by 184mm). See figure 4. It is not necessary to physically fasten the securing frame over the test specimen due to the weight of the frame itself. (4) Pilot Burner. The pilot burner used to ignite the specimen is a commercial propane venturi torch with an axially symmetric burner tip having a propane supply tube with an orifice diameter of 0.003 inches (0.076mm). The propane flow is adjusted to produce a pencil flame blue inner cone length of 1/2 inch (13mm). There will be a means provided to move the burner out of the ignition position so that the flame is horizontal and at least 2 inches (50mm) above the specimen plane. (5) Thermocouples. Three 24 American Wire Gauge (AWG) Type K (Chromel-Alumel) thermocouples will be installed in the test chamber for temperature monitoring. All three are inserted into the chamber through three small holes drilled through the top of the chamber. One thermocouple is placed 2 inches (51mm) from the end of the radiant panel and approximately 16 inches (406mm) above the test specimen. The second thermocouple is placed 5 inches (127mm) from the first thermocouple and approximately 16 inches (406mm) from the sample. The third thermocouple is located in the chimney approximately 38 inches (965mm) above the specimen. (6) Calorimeter. The calorimeter will be a one inch cylindrical water-cooled, total heat flux density, foil type Gardon Gage that has a range of 0 to 5 BTU/ft 2 -second (0 to 5.6 Watts/cm 2 ). (7) Calorimeter Calibration Specification and Procedure. (i) Calorimeter Specification. (A) Foil diameter will be 0.25±0.005 inches (6.35±0.13mm). (B) Foil thickness will be 0.0005±0.0001 inches (0.013±0.0025mm). (C) Foil material will be thermocouple grade Constantan. (D) Temperature measurement will be a Copper Constantan thermocouple. (E) The copper center wire diameter will be 0.0005 inches (0.013mm). (F) The entire face of the calorimeter will be lightly coated with “Black Velvet” paint having an emissivity of 96 or greater. (ii) Calorimeter Calibration. (A) The calibration method will be by comparison to a like standardized transducer. (B) The standardized transducer will meet the specification given in paragraph (6). (C) It will be calibrated against a primary standard by the National Institute of Standards and Technology (NIST). (D) The method of transfer will be a heated graphite plate. (E) The graphite plate will be electrically heated, have a clear surface area on each side of the plate of at least 2 by 2 inches (51 by 51mm), and be 1/8 inch ± 1/16 inch thick (3.2 ±1.6mm). (F) The 2 transducers will be centered on opposite sides of the plates at equal distances from the plate. (G) The distance of the calorimeter to the plate will be no less than 0.0625 inches (1.6mm), nor greater than 0.375 inches (9.5mm). (H) The range used in calibration will be at least 0-3.5 BTUs/ft 2 second (0-3.9 Watts/cm 2 ) and no greater than 0-5.6 BTUs/ft 2 second (0-5 Watts/cm 2 ). (I) The recording device used must record the 2 transducers simultaneously or at least within 1/10 second of each other. (8) Calorimeter Fixture. With the sliding platform pulled out of the chamber, install a 2-rail fixture that has a travel range of 40 1/4 inches (1022mm) over the sliding platform. The dimension between the 2 rails is 2 11/16 inches (68mm). The rail fixture is screwed into the sliding panel, such that it is always directly under the geometric center of the radiant panel (figure 4). Push the platform into the chamber and insert the calorimeter. The calorimeter, which is mounted in an insulated housing, fits in the rail opening but has enough clearance such that it may be moved along the rail for heat flux readings. The top surface of the calorimeter must be level with the rails. ER26MY00.026 (9) Instrumentation. A calibrated recording device with an appropriate range or a computerized data acquisition system will be provided to measure and record the outputs of the calorimeter and the thermocouples. The data acquisition system must be capable of recording the calorimeter output every second. (10) Timing Device. A stopwatch or other device, accurate to ±1second/hour, will be provided to measure the time of application of the pilot burner flame. (c) Test Specimens. (1) Specimen Preparation. A minimum of three test specimens will be prepared and tested. (2) Construction. Cut a piece of core material such as foam or fiberglass. If fiberglass is used, cut the material 43 1/2 (± 1/4 ) inches long (1093mm) (±6.3mm) by 12 1/2 inches (305.1mm) wide. If using foam, cut the material 41 1/4 inches (1039mm) by 11 inches wide (279mm) by 1 1/2 inches (381mm) high. Cut a piece of film cover material (if used) large enough to cover the core material. It is permissible to staple the film cover at the ends, as they are not exposed to the radiant heat source. A piece or pieces of an inorganic/inert material such as Kaowoo λ TM or Marinit ε TM board may be placed in the bottom of the sliding platform holder if the sample is not thick enough to be level with the top of the sliding platform. The specimen thickness must be of the same thickness as installed in the airplane. (d) Specimen Conditioning. The specimens will be conditioned at 70 ±5°F (21 ±2°C) and 55%±10% relative humidity for a minimum of 24 hours prior to testing. (e) Calibration. (1) With the sliding platform out of the chamber, install the rail fixture. Push the platform back into the chamber, install the calorimeter (in its housing), and move the calorimeter to the “zero” position (figure 5). Close the bottom door located below the sliding platform. The centerline of the calorimeter is 1 7/8 inches (46mm) from the end of the sliding platform. This will be the “zero” position. The distance from the center of the calorimeter to the radiant panel surface at this point is 7.5 inches ± 1/8 (191 mm ±3). (i) Prior to igniting the radiant panel, ensure that the calorimeter face is clean and that there is water running through the calorimeter. (2) Ignite the panel. Adjust the fuel/air mixture to achieve 1.5 BTUs/ft 2 -second ±0.025 BTUs/ft 2 -second (1.9 Watts/cm 2 ±0.025 Watts/cm 2 ) at the “zero” position. Allow the unit to reach steady state (this may take up to 1 hour). The pilot burner is off during this time. The temperature as measured by the thermocouple closest to the panel (forward) is approximately 1100°F (600°C). The temperatures recorded by thermocouples 2 and 3 ( thermocouple 3 located in chimney) are approximately 430°F (230°C) and 300°F (135°C), respectively. ER26MY00.027 (3) After steady-state conditions have been reached, move the calorimeter 2 inches (51mm) from the “zero” position and record the heat flux. Allow a minimum of 30 seconds at each position for the calorimeter to stablize. Record at least 10 positions. (Figure 6 depicts a calibration profile.) ER26MY00.028 (4) It is not necessary to run a full heat flux calibration (minimum of 10 positions) each time the chamber is powered on. It is required that a heat flux measurement be taken at the “zero” position at the start of the test period ( e.g., each morning) to ensure that the 1.5 BTU/ft 2 -second (1.9 Watts/cm 2 ) requirement be met. A full calibration should be run periodically. (5) Open the bottom door, pull out the sliding platform, and remove the calorimeter and rail fixture. (f) Test Procedure. (1) Ignite the pilot burner. Ensure that it is at least 2 inches (51mm) above the top of the platform. The burner must not contact the specimen until the test begins. (2) Place the test specimen in the sliding platform holder. Ensure that the test sample surface is level with the top of the platform. At “zero” point, the specimen surface is 7 1/2 inches ±1/8 (191mm ±3) below the radiant panel. (3) With film/fiberglass assemblies, it may be necessary to puncture small holes in the film cover to purge any air inside. This allows the operator to maintain the proper test specimen position (level with the top of the platform). The holes should be made in the sides and/or the corners of the test specimen using a needle-like tool. (4) Place the retaining frame and the securing frame over the test specimen. (5) A small mark should be placed on the “zero” point. (6) Immediately push the sliding platform into the chamber and close the bottom door. (7) Bring the pilot burner flame into contact with the center of the specimen such that the center line of the flame impinges on the “zero” point and simultaneously start the timer. The burner flame impinges the sample at an angle of approximately 20 degrees with the horizontal (front of the sliding platform). (8) Leave the burner in position for 15 seconds and then remove to a position at least 2 inches (51mm) above the specimen. (g) Report. (1) Identify and describe the specimen being tested. (2) Report any shrinkage or melting of the test specimen. (3) Report the Burn length (4) Report Extinguishing Time (h) Requirements. (1) During burner application, no flaming is allowed to propagate more than 2 inches (50.8mm) along the sample (to the left in figure 1) of the centerline of the flame. (2) There shall be no flaming of the test sample after pilot burner removal. Issued in Renton, Washington, on May 19, 2000. John J. Hickey, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 00-13149 Filed 5-25-00; 8:45 am] BILLING CODE 4910-13-P