Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier, Inc., Model BD-100-1A10 airplanes. This proposed AD was prompted by reports of cracks found in the tailcone upper firewall where the auxiliary power unit (APU) muffler electrical bonding strap is attached. This proposed AD would require a detailed visual inspection of the tailcone upper firewall for defects, rework by replacement of the APU electrical bonding strap, and repair if necessary. The FAA is proposing this AD to address the unsafe condition on these products.