MIL-HDBK-17-3F Volume 3,Chapter 8 Supportability carbon-epoxy and metal patches (see Figure 8.2.1(a)),while all the metal parts of the center box were replaced due to permanent deformations.One aircraft exhibited erosion of the outer ply at the leading edge of the upper skin,and a chamfer was introduce in the design,and no other problems have been reported. a)Damaged ATR 72 carbon outer wingbox:carbon front spar and carbon wing skins b)Repaired carbon spar before repair of wing skins FIGURE 8.2.1(a)Repairs to badly damaged ATR 72 wing. Production carbon-epoxy sandwich parts,such as trailing edge panels,cowls,landing gear doors, and fairings have demonstrated weight reduction,delamination resistance,fatigue improvement and cor- rosion prevention.The poor service records of some parts can be attributed to fragility,the inclusion of non-durable design details,poor processing quality,porous face sheets(insufficient thickness),and badly installed or poorly sealed fasteners.Many of the design problems were a result of insufficient technology 8-4MIL-HDBK-17-3F Volume 3, Chapter 8 Supportability 8-4 carbon-epoxy and metal patches (see Figure 8.2.1(a)), while all the metal parts of the center box were replaced due to permanent deformations. One aircraft exhibited erosion of the outer ply at the leading edge of the upper skin, and a chamfer was introduce in the design, and no other problems have been reported. a) Damaged ATR 72 carbon outer wingbox: carbon front spar and carbon wing skins b) Repaired carbon spar before repair of wing skins FIGURE 8.2.1(a) Repairs to badly damaged ATR 72 wing. Production carbon-epoxy sandwich parts, such as trailing edge panels, cowls, landing gear doors, and fairings have demonstrated weight reduction, delamination resistance, fatigue improvement and cor￾rosion prevention. The poor service records of some parts can be attributed to fragility, the inclusion of non-durable design details, poor processing quality, porous face sheets (insufficient thickness), and badly installed or poorly sealed fasteners. Many of the design problems were a result of insufficient technology