1.General This AMC does not apply to flight deck display panels. A display panel should be considered large if its diagonal is greater than 51 cm (20 in.). Any large display panel should be shown not to be a hazard during events such as emergency landing and cabin depressurisation. It should meet the following requirements:
(a)the large display panel should withstand the differential pressures caused by a worst-case cabin depressurisation event without having any adverse effect (for instance no substances should be released through cracks or openings, no sharp edges should be created);
(b)the large display panel should be subjected to, and pass, abuse load testing (see paragraph 3 below);
(c)the installation should withstand the inertia loads outlined in CS 25.561(b)(3) without any adverse effect; and
(d)if the large display panel incorporates glass, it should be subjected to, and pass, ball impact testing (see paragraph 2 below). With the exception of the ball impact testing, large display panels incorporating any glass element should withstand the above-defined loads with no more than minor cracks (i.e. no parts released nor the surface becoming a hazard) and without becoming dislodged from their mounts. Alternatively, the installation may still be found acceptable if some means, such as a protective cover, are provided to shield the passenger cabin from the glass monitor. The installation including its protective cover should meet all the relevant criteria identified in this AMC. Furthermore, the cover should not introduce additional hazardous characteristics of its own and should comply with all pertinent aeroplane certification requirements, e.g. flammability. Unless it has been shown that the display panel withstands all the mechanical tests in paragraphs 1.(a) to (d) above without any damage that would result in the release of chemical substances into the cabin, documentation should be provided from medical authorities which substantiates that the type and amount of chemical substances released into the cabin in case of failure would not result in adverse health effects on cabin occupants. The specific cabin volume may be considered. Alternatively, it is acceptable to show that each installed glass screen complies with A 4(1) of Directive 2002/95/EC ‘on the restriction of the use of certain hazardous substances in electrical and electronic equipment’ (RoHS).
2.Ball Impact Testing (only for display panels containing glass) The test procedure and pass/fail criteria of the Underwriters Laboratories standard UL 61965, Mechanical safety for cathode ray tubes, Edition 2, 27 July 2004 or former UL 1418, Standard for safety cathode ray tubes, Edition 5, 31 December 1992, or other equivalent approved method, are the basis of the ball impact strength and no-hole tests described in this paragraph. The large display panel should be installed in a test fixture representative of the actual installation in the cabin.
2.1. Strength Test The large display panel should be subjected to a single impact applied in accordance with the test conditions of paragraph 2.3 below. The impact energy should be 7 J, caused by a 51-mm diameter ball or, alternatively, 5.5 J, caused by a 40-mm diameter ball, as specified in paragraph 2.3.2 below. The test is passed if the expulsion of glass within a 1-min period after the initial impact satisfies the following criteria:
(a)there is no glass particle (a single piece of glass having a mass greater than 0.025 g) between the 0.90 and 1.50-m barriers (see paragraph 2.3.1);
(b)the total mass of all pieces of glass between the 0.90 and 1.50-m barriers (see paragraph 2.3.1) does not exceed 0.1 g; and
(c)there is no glass expelled beyond the 1.50-m barrier (see paragraph 2.3.1).
2.2 No-Hole Test The large display panel should be subjected to a single impact applied in accordance with the test conditions of paragraph 2.3 below. The impact energy should be 3.5 J, caused by a 51-mm diameter ball as specified in P 2.3.2 below. The test is passed if the large display panel does not develop any opening that may allow a 3-mm diameter rod to enter. Cracking of the panel is permitted. Note: If the large display panel does not develop any opening that would allow a 3-mm rod to enter when subjected to the strength test defined in paragraph 2.1 above, the no-hole test defined in this paragraph does not need to be performed.
2.3 Test Conditions
2.3.1 Test Apparatus and Setup The centre of the large glass item should be 1.00 ± 0.05 m above the floor. For the strength test (see paragraph 2.1 above), two barriers, each one made of material 10–20 mm thick, 250 mm high, and 2.00 m long, should be placed on the floor in front of the test item (or on both sides in case of a glass partition) at the specified location, measured horizontally from the front surface of the large glass item to the near surface of the barrier. The barriers may be less than 2.00 m long, provided that they extend to the walls of the test room. A non-skid surface such as a blanket or rug may be placed on the floor. A solid, smooth, steel ball of the size specified in paragraph 2.3.2 below should be suspended by suitable means such as a fine wire or chain and allowed to fall freely as a pendulum and strike the large glass item with the specified impact energy. The large glass item should be placed in a way that its surface is vertical and in the same vertical plane as the suspension point of the pendulum. A single impact should be applied to any point on the surface of the large glass item at a distance of at least 25 mm from the edge of the surface.
2.3.2 Impact Objects The 51-mm diameter steel ball used as an impact object should have a mass of approximately 0.5 kg and a minimum Scale C Rockwell Hardness of 60. The 40-mm diameter steel ball used as an impact object should have a mass of approximately 0.23 kg and a minimum Scale C Rockwell Hardness of 60.
3.Abuse Load Tests (all large display panels) Large display panels should withstand a 133 daN (300 lbf) static abuse load applied, in separate tests, in 5 different locations: in the centre, at the opposite corners (two separate tests), along the perimeter, at the midpoints of the short and long sides (two separate tests), or at an equivalent set of locations acceptable to EASA (see Figure 2 below). For all the tests to be performed, the display panels should be mounted in a test fixture representative of the actual installation in the cabin. For the above-mentioned load applications, it is acceptable to use any loading pad with a shape and dimensions that fit into a 15.24-cm (6-in.) diameter circle. The display panels should withstand the applied loads without any adverse effect (e.g. glass elements, if present, cracking or breaking, the unit becoming dislodged from its mounts, substances released through cracks or openings, or sharp edges created).
1 2 3 4 5
Large display panel Area of load application
1 2 3 4 5
Large display panel Area of load application During the test, it is acceptable for the display to suffer minor failures, such as minor cracks, provided that no parts are detached and the surface does not become a hazard to occupants.
Figure 2 — Load Cases 1) centre loading; 2) corner loading; 3) opposite-corner loading; 4) short-side-midpoint perimeter loading; and 5) long-side-midpoint perimeter loading.
[Amdt 25/19]