The underestimated danger: assembly errors in detail
Gliders have a modular design to facilitate transport and storage. Wings, tailplane, rudder - they all have to be correctly reconnected before flying. Sounds simple, but in practice it is complex, as each system has its own peculiarities. This is precisely where the risk lies: errors in the connection of control surfaces or control surfaces, incorrectly inserted securing elements or forgotten control mechanisms can lead to complete failure of the flight controls during flight.
In the Safety Information Bulletin (SIB) 2019-07 EASA has therefore specifically highlighted the problem. The bulletin highlights several real accidents and analyses how avoidable installation errors can lead to the death of pilots. It particularly emphasises that even safety cotter pins - simple, seemingly self-explanatory components - can be used incorrectly or overlooked.
Technical understanding creates safety
One of the main aims of the EASA bulletin is to promote a better understanding of how safety-relevant components work. It is not enough to know procedures "by heart". Who knows, Why a safety system also recognises faster, when it is not installed correctly.
Examples from the bulletin:
- Anti-twist devicesThese only work reliably if the bolt has been tightened correctly first. A bolt that is only hand-tightened can come loose in flight - with potentially disastrous results.
- Securing elements against displacementTo check its function, it makes sense to actively move the connected element in both directions. This is the only way to determine whether the mechanical lock is engaging correctly.
- Restricted view when assembling connections, for example through hull structures or cable runs, can easily lead to overlooked errors. A torch is an indispensable tool here.
Good practices: What every pilot can do
The good news is that many of these mistakes can be avoided through discipline, teamwork and clear processes. The following applies:
- Know and use the flight manualIn many cases, the manual describes the assembly processes and pre-flight checks in sufficient detail. If this is not the case, now is the right time to create or update a more precise checklist.
- Avoid distractionsInterruptions during assembly or checks - whether due to a conversation, a phone call or an unexpected problem - are a high risk. Once you are interrupted, it is easy to miss a step. Therefore: Concentration and a clearly structured process are crucial.
- Clear responsibilities in the teamGliding is a team sport, even on the ground. However, this does not mean that everyone can rely on the others. Who controls what should be clearly agreed in advance. Documentation in the form of checklists, signatures or entries in the flight logbook provides additional security.
- Do not make any assumptionsEach aircraft is individual. A safety mechanism on the Duo Discus works differently to an LS4. Transferring knowledge from one model to another can lead to dangerous misconceptions.
Conclusion: Safety starts on the ground
The assembly of a glider is more than just routine - it is a safety-relevant task of the highest order. Those who work precisely here create the basis for a safe flight. The EASA figures are a reminder to be careful: three to four deaths per year due to avoidable assembly errors are three to four too many.
So let's use the start of the season as an opportunity to scrutinise our processes, understand our systems better and work together to ensure greater safety in gliding. Because good flying days start with good preparation - preferably together, as a team and with the necessary respect for the technology.
Source references:
Staysafe.aero