The Glenair Series 806 Mil-Aero and MIL-DTL-38999 Series III are both designed for demanding military, aerospace and harsh-environment interconnect systems. They offer threaded coupling, environmental sealing, EMI protection and support for signal, power, high-speed and fiber-optic contacts.

The main difference is that Series 806 delivers comparable environmental and mechanical performance in a smaller, lighter and higher-density Glenair-specific interface. MIL-DTL-38999, by contrast, is an established military standard with standardized dimensions, broad multi-manufacturer availability and extensive installed-system compatibility.

Series 806 is generally the stronger choice for new designs where SWaP—size, weight and power—is critical. MIL-DTL-38999 remains preferable when a program requires QPL parts, standardized interchangeability or compatibility with existing D38999 equipment.

Quick Comparison

What Is Glenair Series 806?

The Series 806 Mil-Aero is a micro-miniature circular connector developed for high-density aerospace applications. It retains the rugged threaded form and environmental design principles associated with MIL-DTL-38999 Series III while reducing the connector envelope and weight.

Key features include:

• High-density #22HD and #20HD contacts

• Reduced-pitch triple-start ACME coupling

• Integrated anti-decoupling mechanism

• Rear-release removable crimp contacts

• Metal contact-retention clips

• Triple-ripple wire-sealing grommet

• Integral Nano-Band shield-termination platform

• Signal, power, RF and high-speed arrangements

• Environmental and hermetic versions

• Fiber-optic configurations

• Factory-terminated cable assemblies

Glenair states that independent testing demonstrated compliance with every MIL-DTL-38999 performance requirement, with some tests exceeding the standard. However, meeting the performance requirements does not make Series 806 mechanically interchangeable with D38999 or automatically give it a D38999 QPL part number.

What Is MIL-DTL-38999 Series III?

MIL-DTL-38999 Series III defines a family of high-density, scoop-proof circular connectors with triple-start threaded coupling and rear-release crimp contacts. It is one of the most established connector standards for military aircraft, avionics, ground vehicles, naval systems and space equipment.

Typical Series III product forms include:

• D38999/26 cable plugs

• D38999/20 wall-mount receptacles

• D38999/24 jam-nut receptacles

• Hermetic receptacles

• PCB receptacles

• Filter connectors

• Fiber-optic connectors

• High-speed and RF arrangements

Standardization is one of its main advantages. Qualified products from different manufacturers can be intermateable when their shell size, insert arrangement, contact type, polarization and specification class match.

Glenair supplies both DLA-qualified MIL-DTL-38999 products and its enhanced SuperNine Series 23 D38999 Series III-type connectors.

Selection Recommendations

Choose Glenair Series 806 when:

• Reducing connector size and weight is a primary objective.

• The design requires very high signal density.

• A new connector interface can be introduced.

• The system needs compact high-speed or hybrid arrangements.

• The application requires harsh-environment performance.

• A Glenair-specific mating interface is acceptable.

• UAV, satellite or compact avionics packaging is involved.

Choose MIL-DTL-38999 when:

• The specification explicitly requires a D38999 part number.

• DLA QPL qualification is mandatory.

• Multi-manufacturer sourcing is required.

• The connector must mate with existing D38999 equipment.

• Standard MIL-STD-1560 arrangements are already defined.

• Established contacts, tooling and maintenance procedures must be retained.

• Redesigning the panel and cable harness is impractical.

Frequently Asked Questions

Does Series 806 mate with MIL-DTL-38999 connectors?

No. Series 806 uses a smaller Glenair-specific interface and does not mechanically mate with standard MIL-DTL-38999 connectors.

Does Series 806 meet MIL-DTL-38999 performance requirements?

Glenair states that Series 806 has been independently tested to meet—and in some cases exceed—the performance requirements of MIL-DTL-38999. This does not make it a standard D38999 QPL connector.

How much smaller is Series 806 than D38999?

Glenair describes applicable Series 806 configurations as nearly half the size and weight of comparable D38999 solutions. Exact savings depend on shell size, contact arrangement, material and accessories.

Which connector is better for high-speed or fiber-optic systems?

Series 806 offers greater density and lower installed weight, while D38999 provides standardized contacts and broader support infrastructure. The best choice depends on protocol performance, channel count, qualification and compatibility requirements.

Which connector provides better supply-chain flexibility?

MIL-DTL-38999 generally offers greater sourcing flexibility because qualified products are available from multiple manufacturers. Series 806 is a Glenair-specific platform.