By: Britt Bochiardy

Abstract

The following article provides a private sector perspective of the maintenance/sustainment challenges faced by the USAF MX community that affect Mission Capable rates of legacy aircraft, citing examples of work done to simplify maintenance activities.

Safety wire done right is an art…but it’s also tedious, time-consuming, prone to error, can draw blood, and is one of the biggest FOD dangers on aircraft. Since the early days of aviation, keeping aircraft fasteners secure has been a challenge. Little was known about aerodynamic stresses or vibration isolation created by the simplistic engines of the time. Many aircraft crashes and incidents were attributed to mechanical damage because of fastener failure.

Over the years, mechanics learned that wrapping bailing wire around the exposed thread of the fasteners minimized this potential. In the years since, this wire, now made of materials with higher tensile strength, and more secure means to attach to the fastener, are becoming the standard to ensure fastener security.

Moeller Aerospace has been manufacturing parts for the aerospace and defense industry since 1949, including many of today’s largest companies. With this history, Moeller understands metallurgical stress and machining, as well as any manufacturer.

In the early 90s, the F-16 was being re-engined to the F110 engine. In the first two operational years of this aircraft with this engine, it experienced two catastrophic failures and both aircraft were lost. The culprit was safety wire, which could not handle the stress of the increased level of performance.

About this time, Mr. Kurt Bynum, a Moeller engineer developed a concept for a sleeve that encompasses a fluid fitting that provided a 360-degree anti-rotational hold. Originally conceived for his race car, it was presented to the USAF as a solution. After more than a year of research and testing by both USAF Cambridge Research (which is now AFRL) and GE, this prototype was chosen as the solution, and Click-Loc was born.

Since 1994, all F110 and F118 engines produced have these fuel nozzle sleeves on them. Numerous other F101, F110, and F118 engines were also retrofit. An AFMC TTO/TechTIP published in 1996 stated, “The Air Force estimates a lifecycle savings of nearly $2M!” with Click-Loc

Over the years, many of the same companies that Moeller makes air foils and other components for asked Moeller to help solve other retention problems in critical areas of multiple military and commercial aircraft. Today, Click-Loc can be found on numerous aircraft, including the F-15, F-16, F-22, F-35, U-2, B-1, B-2, and CH-53K, with 41 NSNs. Click-Loc has never experienced a failed part or had a maintenance issue bulletin published.

In 2000, a chance discussion with Maj Gen Jeffrey R. King (Director of Logistics, Deputy Chief of Staff for Logistics, Engineering and Force Protection) about these systems led to a challenge being issued, i.e., take the technology Moeller designed for production aircraft and adapt it to legacy aircraft. With this challenge, the Click-Loc team started engaging with users, mechanics, and engineers to learn where the biggest challenges were with aircraft maintenance and fasteners, such as the KC-135, F-16, F-15, and B-52.

Along the way, we established tools to help us understand and prioritize these challenges to determine how we can best help the maintainers get the aircraft mission ready.

If you have taken the Click-Loc challenge at one of the Logistics Officer Association events or competed in the Aerospace Maintenance Competition at MRO or VERTICON, you have helped us with this understanding. On average, participants spent 22% of the time installing and torquing the six fasteners (three standard safety-wire fasteners/three Click-Loc safety-wireless fasteners). The remaining 78% of the time was used to secure the three standard fasteners.

Further, we conducted a time study at a commercial engine overhaul shop in South Florida with three seasoned mechanics. Utilizing a CFM56 engine, the commercial equivalent of the F108, the mechanics were tasked with removing the OEM borescope plugs with safety wire and then reinstalling and securing with safety wire. Then the same mechanics, on the same engine, removed and reinstalled Click-Loc safety-wireless plugs. The average time savings with Click-Loc were 1 hour and 52 minutes.

 

Both examples are considered a benchmark, and it is believed that time savings on wing would be greater than the results stated here.

Today we have several parts in various approval reviews and stock listings. They include borescope plugs, fluid fittings sleeves, fuel line sleeves, engine mount sleeves, actuator sleeves, and turnbuckle sleeves. Most were initiated by mechanics in the field, and those mechanics were provided with the opportunity for feedback prior to design submittal. Safety wire is very prevalent on today’s aircraft, but there are alternatives.

MC rates on legacy platforms are continually decreasing. It is easy to blame the lack of parts as the culprit as there is a lot of truth in the statement. Legacy parts are a topic for another discussion but there are other actions that can improve mission ready status! Click-Loc is just one such example.

The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Air Force, the Department of War, or the US Government. 

About the Author

Britt Bochiardy is a LOA member associated with the MacDill – Lightning Chapter. He is currently serving as Strategic Advisor to Moeller Aerospace on the Click-Loc system. He has more than 35 years of experience in forward-leaning technology and policy development, as well as sourcing. Leading innovative research of both solicited and unsolicited solutions, spanning aerospace, defense, transportation, energy, and medical industries, that are in use today. With two start-ups underway, repurposing seasoned products to serve a new mission and currently advising three seasoned companies on strategic growth, his efforts have resulted in 22 corporate patents and copyrights. BBochiardy@gmail.com; 386-679-2813

Work Cited

Moeller Aerospace. (n.d.). Click-Loc safety-wireless fastening technology and company history.

United States Air Force. (1996). Air Force Materiel Command (AFMC) TTO/TechTIP publication.

Air Force Research Laboratory. (n.d.). Evaluation and testing of Click-Loc prototype (formerly USAF Cambridge Research).

General Electric Aviation. (n.d.). Testing and validation of Click-Loc system for F110/F118 engines.

Logistics Officer Association. (n.d.). Maintenance challenge participation data and feedback.

Aerospace Maintenance Competition. (n.d.). Time-study benchmark data (MRO/VERTICON).

Bynum, K. (n.d.). Development of Click-Loc fastening concept. Moeller Aerospace.

King, J. R. (2000). Discussion on adapting Click-Loc technology to legacy aircraft platforms. United States Air Force.