Legacy Aircraft, Modern Demands: Upgrading Contactors, Relays, and Terminal Blocks

In the world of aviation, technology moves fast but aircraft fleets don’t always keep up at the same pace. Across the globe, hundreds of legacy aircraft remain in service, relied upon daily for cargo, training, charter, and regional operations. For fleet operators, the challenge isn’t just keeping these aircraft airworthy—it’s keeping them compatible with today’s demanding safety, regulatory, and performance expectations.

Nowhere is this challenge more evident than in the electrical systems. When an airline in the Southwest struggled to source a working aircraft contactor or an essential aircraft terminal block for its aging turboprop, grounded operations stretched into costly delays. The part was obsolete. OEMs had moved on. Replacement estimates climbed into the tens of thousands. And yet, grounding the aircraft long-term wasn’t an option.

This is the reality of maintaining aging fleets. But legacy doesn’t have to mean obsolete—especially when you're working with a partner like NAASCO, who understands the intricacies of out-of-production components and the operational value of certified refurbishment.

Sourcing Discontinued Components in Legacy Aircraft Fleets

One of the most pressing issues operators face is sourcing discontinued parts like an exact-match aircraft terminal block or an older-generation aircraft relay. These components may seem minor compared to engines or avionics but they’re essential for the safe distribution and control of electrical power throughout the aircraft.

As OEMs phase out older models and move toward newer digital systems, support for these components begins to disappear. What follows is a sourcing dilemma:

• Limited global supply of certified replacements
• Long lead times on re-engineered solutions
• High risk of counterfeit or non-compliant parts flooding the secondary market

In many cases, even locating a part number is difficult due to lack of documentation. And even if the part is available, it's often at a premium without the backing of FAA or EASA certification. Installing uncertified or gray-market components can jeopardize compliance and risk AOG penalties or inspection failures.

The result? Aircraft are grounded, inspections are failed, and budgets are stretched thin.

Refurbishment vs. Replacement: The Smarter Investment

The traditional fix buying a brand-new component isn’t always feasible, especially when the part is no longer produced. That’s where certified refurbishment presents a valuable, long-term alternative.

NAASCO offers FAA and EASA-approved refurbishment services that extend the operational life of core electrical components without compromising safety or reliability. In fact, many operators discover that properly overhauled contactors, relays, and terminal blocks perform as well, or better, than OEM replacements.

Consider the Benefits:

• Lower cost than new production units
• Reduced lead times through in-stock exchange inventory
• Environmentally conscious by reducing waste and material use
• Upgraded performance using modern materials and diagnostics

For one operator of an aging jet, NAASCO refurbished a discontinued aircraft terminal block using upgraded insulation materials and gold-plated contacts. The result was a part that outperformed OEM metrics in resistance and temperature tolerance, at less than half the cost.

What Goes Wrong in Aging Electrical Components?

Even high-quality electrical parts degrade over time especially under the stress of flight. Understanding how these failures happen helps reinforce the need for scheduled refurbishment.

Common Aging Patterns:

1. Aircraft contactor

• Arc burn across contact points
• Pitting and oxidation
• Coil degradation from thermal cycling

2. Aircraft relay

• Sluggish actuation due to mechanical wear
• Broken or sticking contacts
• Insulation breakdown and heat stress

3. Aircraft terminal block

• Corrosion from environmental exposure
• Loose or deformed connections
• Cracked insulation or plastic housings

These issues can lead to intermittent faults, voltage fluctuations, and most dangerously total system failure. Left unresolved, they compromise critical systems such as lighting, fuel pump control, and landing gear actuation.

NAASCO addresses each of these failure points through comprehensive inspection, testing, and reconditioning protocols restoring full functionality and extending safe service life.

From Failure to Flight: Real-World Results of Refurbishment

In a recent overhaul project, a 30-year-old aircraft required an immediate fix for a non-functional starter system. The root cause: a degraded aircraft relay with inconsistent switching under load. Rather than replacing the entire assembly, NAASCO refurbished the unit with upgraded windings and newly machined contacts.

The aircraft returned to service within 72 hours—saving over $8,000 in estimated downtime and new part procurement.

Supporting Aging Fleets with Proven Modern Expertise

Legacy aircraft are still valuable assets, but only if supported properly. That’s where NAASCO brings unmatched depth: decades of experience, specialized capabilities, and a growing catalog of certified solutions for obsolete or hard-to-source parts.

Through our in-house electro-mechanical repair division, we specialize in overhauling:

• Aircraft contactors for older DC and AC power systems
• Aircraft terminal blocks in vintage and modified panel configurations
• Aircraft relays across generations of aviation platforms

And for the truly rare cases, NAASCO provides custom reverse engineering based on performance benchmarks and historical design data—ensuring compatibility without compromise.

• We are also trusted by operators worldwide for:
• Full FAA/EASA certification
• Short turnaround times
• Extensive component exchange inventory
• Dedicated engineering support

Whether you're running a fleet of vintage jets or just a few aging airframes, our mission is to help you fly further safely and affordably.

Need Certified Components or Fast Overhaul Support?

Sourcing replacement components for older aircraft can feel like navigating a maze. But it doesn’t have to. At NAASCO, we make it easy to upgrade your aging systems with parts that are:

• FAA/EASA certified
• Performance-tested
• Sustainably restored or fabricated
• Backed by our decades-long expertise in aviation MRO

If you’re searching for a certified aircraft terminal block, a hard-to-find aircraft relay, or a fully overhauled aircraft contactor, we invite you to explore our catalog and capabilities. You can also submit a request for a custom quote or inventory check.

Don’t ground your aircraft for lack of a part partner with NAASCO and keep your legacy fleet flying strong.