Depending on the operation and location, glider pilots may be required to assemble their aircraft before every flight, and disassemble it after every flight. It seems too obvious to say, but an incorrectly or incompletely assembled glider is unsafe and unairworthy. An unacceptable number of **entirely preventable** accidents occur each year due to improper assembly procedures, so learning to perform this task correctly, **every time**, is critical to safe flight. ### Legality Normal assembly/disassembly of the glider is **NOT** considered "maintenance", but is considered an operational function of normal flight activities to be performed by pilots. As such, normal assembly/disassembly of the glider does **NOT** need to be recorded in the aircraft maintenance record. For more information, see Amdt. 43-27, 52 FR 17277, May 6, 1987. ### Setup Considerations - Adequate space is available to assemble the glider - If assembling outside, weather conditions (especially wind) are suitable - Enough crewmembers are available - Correct tools and equipment are available - Glider assembly checklist is available - Setup area is free from distractions, and adequate time is available ### Performing Assembly **ALWAYS** use the manufacturer's instructions to assemble the glider. These instructions can be found in the GFM/POH, or may be copied and printed as a separate checklist by the owner/operator. ![[SGS 2-33 assembly.png]] \[SGS 2-33 assembly in progress, showing wing attach points with hardware installed, and aileron and dive brake rigging] When assembly is complete, check the part and tool inventory. All components and hardware should have been installed, and all tools should have been removed from the aircraft. Some methods for tracking this include an inventory list, additional checklist, or a mat/sheet with all parts and tools visually outlined. ![[2-33 assembly.png]] ### Critical Assembly Checklist A Critical Assembly Checklist (CAC) is the most straightforward means of verifying correct and complete assembly of the glider. If possible, another qualified individual should perform this as a "second set of eyes" after the pilot and crewmember/assistant complete the assembly process. If this is not possible, the pilot should run through the CAC with the crewmember/assistant, explaining how to perform each step along the way, effectively checking the work done. ![[Standard Cirrus After Assembly.png]] The CAC is required if provided by the manufacturer, but not every manufacturer or glider has one. A generic CAC can be found in the Soaring Safety Foundation's Safety Advisory 00-1, *Glider Critical Assembly Procedures*. ### Positive Control Check In addition to the CAC, a Positive Control Check (PCC) should be performed after assembly to verify correct operation of all flight controls. This requires a crewmember/assistant to firmly hold flight control surfaces as they are checked; avoid any pinch points, and if possible, use a flattened hand over a structural member (ie rib) in the control surface to evenly distribute the force. This process should be repeated for **ALL** flight control surfaces: - First, the pilot will fully deflect the flight control to be checked using the cockpit controls; which control, and which direction should be verbalized - The crewmember/assistant should provide light resistance as the pilot moves the control, and verbalize the direction of the control surface motion - At full deflection, the crewmember/assistant will then firmly hold the control surface to resist movement, as the pilot attempts to deflect the control in the other direction - If the cockpit control can be moved while the control surface is held, the flight control is not properly connected - Check both directions of movement for each control, and avoid excessive forces ### Risk Management The Soaring Safety Foundation recognizes 4 causal factors frequently associated with accidents resulting from improper glider assembly: **Use of checklists** to follow **manufacturer assembly procedures** are critical to ensuring correct and complete assembly. Checklists are the only way to systematically confirm proper assembly every time, and are required to be used by practical test standards. After assembly, performing a **Critical Assembly Checklist** and **Positive Control Check** verifies correct and complete assembly. **Distractions** can lead to incorrect or incomplete assembly. Select an area free from distractions, and brief your crewmember/assistant to not allow any outside interference during the assembly process. If a distraction does occur, go back and recheck previous steps in the assembly checklist before moving on. **Rushing** assembly procedures greatly increases the likelihood of incorrect or incomplete assembly. Allow adequate time for glider assembly, and realize that the risk of improper assembly will always outweigh the inconvenience of starting a few minutes later than expected. ### Additional Resources [[The Soaring Page - SGS233 Assembly Photos](http://thesoaringpage.com/233assembly.html)] [<iframe width="560" height="315" src="https://www.youtube.com/embed/8qqNLz6wBf0?si=SDhZg2BjyrFP1KGq" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>] ### References - FAA, *Glider Flying Handbook* - FAA, *Practical Test Standards for Glider Category* - Soaring Safety Foundation, Safety Advisory 00-1 *Glider Critical Assembly Procedures*, [[Soaring Safety Foundation](https://www.soaringsafety.org/accidentprev/advisory.html)]() - Soaring Safety Foundation, *Assisting the Pilot with Pre-Flight Preparations*, [[Wing Runner Course-Preflight](https://www.soaringsafety.org/learning/wingrunner/preflight.html)]()