AMM34
SL 20-043 (链接:https://pan.baidu.com/s/1NkE3OZw1UTUfuwyY-9lpZA 提取码:6666)
The purpose of sealant application on leading edge skin of wing or stabilizer is to:
1. Fill the gap btw the skin and other structures.
2. Maintain the aerodynamic smoothness requirements - The 737 airplane must have an aerodynamically clean shape and a smooth external surface to give high performance. It is important to keep the initial contour and smoothness of the external surfaces of the airplane.
According to SRM 51-10-01, Leading Edge of Wing and Stabilizer has been identified as the Extra Critical Area – extra high level of Aerodynamic Smoothness is necessary for these areas.
Besides, the unfilled gap btw the leading edge skin and other structures could cause ice to accumulate. This will further change the wing or stabilizer contour to reduce the airplane performance or result in premature stalling. The accumulated ice may also depart from the airplane and further damage other structures.
Our database also indicates several special approvals for the deferment of sealant application. But those are on case-by-case basis and will require additional procedure to avoid the risk mentioned above.