## 3 UAV Specification and Wind Farm Specification
### Typical Defects on Wind Turbine Blades  
Wind farm operators can reduce the underperformance of wind energy facilities by being proactive in identifying, repairing, or replacing wind turbine blades using best prac  
Figure 1: Overview of the complete UAV-based system for inspections at the wind farm.  
tice preventative maintenance measures. Wind turbine blades of various types experience both similar and dissimilar types of defects. The commonly visible defects of wind turbine blades are investigated in this article. The part that follows discusses some of these wind turbine blade flaws in greater detail, and Figure 2 illustrates the typical defects more clearly:  
1. Blade Cracks (along the suction or leading edge): Minor issues (cracks and chips), and crucial problems that can seriously harm the blade exterior, can both cause blade damage. Cracks can form as a result of a variety of factors, including high temperatures or extreme weather conditions. Nevertheless, they are typically found during routine inspections and are simple to fix. The same cannot be said for web cracks, which may not be visible at first. High blade stress causes internal cracks to form, necessitating a complex repair by highly qualified engineers.
2. Delamination: Delamination can be caused by structural damage, blade stress, or a manufacturing defect. This entails splitting laminate layers and, at times, bending the blades 2 to 5 m at the tips. Blade cracks can also be caused by glue line delamination, most commonly on the trailing edge. This can have an effect on variables like blade strength and stability [11; 12; 13].
3. Leading Edge Erosion: This is perhaps the most prevalent and frequently discussed problem that has a significant impact on WTG performance and, as a result, energy output. Initially, turbines were not protected, and they began to deteriorate early in their warranty period. Leading edge protection (LEP) is now installed during the manufacturing stage, a practice which has recently changed. Before this, asset owners had to be aware of and plan for leading edge erosion prevention. In order to protect their investment, they can use blade protection tape, paint, or longer-lasting polyurethane shells [11; 14].
4. Lightning strike damage: Lightning strikes may be the most harmful blade problems. This is usually due to the remote locations and unstable environments in which WTGs operate. They are extremely vulnerable to problems caused by extreme weather conditions. The impact on the structure of the blade is noticeable, and repairs are very expensive, frequently resulting in long turbine downtime. It is critical that lightning protection systems (LPS) function properly and are inspected on a regular basis [11; 12].
5. Fatigue Damage: The word \"fatigue\" refers to the inability of a material to withstand cyclic applied loads that are fully tolerable when applied just once or a few times. A wind turbine is subjected to repetitive loads throughout its operational lifetime, which adds to the overall structure's fatigue. These loads are primarily caused by wind and can be steady loads, transient loads brought on by sudden events like gusts, periodic loads brought on by wind shear, or stochastic loads brought on by turbulence. The cyclic starts and stops of the turbine, yaw error, yaw motion, resonance-induced loads from structure vibration, and gravity can all result in additional loads.