Summary
We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 787-8 airplanes. This proposed AD was prompted by numerous reports of failures of the proximity sensor within the slat skew detection mechanism assembly (DMA) leading to slats up landing events. This proposed AD would require replacing the slat skew DMAs with new slat skew DMAs, and marking the existing identification plates on the slat with the new part number. We are proposing this AD to prevent failure of the proximity sensor, which could result in the slats being shut down and a slats up high speed landing. This condition, in combination with abnormal landing conditions such as a short runway or adverse weather conditions, could result in a runway excursion.