Electric Aircraft Design Considerations
The Lectromec Podcast
Electrical energy storage has reached a point where it is possible for the manned vehicle propulsion to use non-petroleum based energy. To achieve this goal, it has required a lot of research, design, and innovation that has pushed these vehicles to depend on high voltage electrical power systems and forego the use of hydraulics and pneumatics. If electrical aircraft are the aircraft of the future, what are the design factors that the EWIS community will have to address?
info_outline
Is my Aircraft Wiring Serviceable?
The Lectromec Podcast
This idea of serviceability is applicable to other engineering disciplines and is undoubtedly applicable to aerospace vehicles. From our perspective at Lectromec, understanding the serviceability of aircraft wiring is critical. However, to determine an aircraft wiring system serviceability state requires the limit state to be defined and assessed. Here we propose three such properties of a serviceable aircraft wiring system.
info_outline
International Test Standards for Aircraft Wire
The Lectromec Podcast
Frequently, Lectromec's articles and podcasts have focused on wire and cable testing from US-focused standards such as the SAE and US military (MIL) documents. While these are standards frequently cited, there are other standards organizations that support the aerospace wiring community.
info_outline
Replacing Old Aircraft Wire
The Lectromec Podcast
As aircraft age, it is natural to contemplate the aircraft condition as to how much longer the equipment can be maintained. Typically, after the engines, structures, environmental control system (ECS), navigation, landing gear, interiors, flight controls, and fuel system are considered, the question will ultimately appear, “do I need to replace my wires that are 15/20/25/30 years old?” While it would be nice if there were a simple answer, like all engineering, it comes down to the evaluation of the syst
info_outline
Selecting Coaxial Cables for Aircraft Application
The Lectromec Podcast
The transmission of electrical energy is, surprisingly, not a trivial task. At low frequencies and low power, a very primitive wire construction is possible and can be successful for extended applications. As frequencies increase, the need for focused attention becomes ever more apparent.
info_outline
EWIS and Instructions and Continued Airworthiness
The Lectromec Podcast
Aircraft are delicate creatures. They can be very finicky when not treated right and the design of an aircraft can only go so far to ensuring that the aircraft has a long, successful life. Without a doubt, many of Lectromec’s articles address the design and manufacturing phases of an aircraft’s life. As highlighted in the last article, technological and engineering hurdles must be overcome for aircraft electrical wiring interconnect system (EWIS) to achieving a fault-free life.
info_outline
Cold Testing of Wires
The Lectromec Podcast
The environmental extremes under which wiring exists in aircraft can rapidly degrade materials that are not prepared or designed for those conditions. Without a doubt, high-temperature ranges that are typically considered for aircraft wiring eliminate most wire insulation types that are suitable for ground-based home applications.
info_outline
Should Polyimide Insulated Wire be Trusted?
The Lectromec Podcast
The history of polyimide insulated wire is one that has numerous opinions and a lot of misconceptions. After several incidents involving polyimide wire in military and commercial aircraft, many within the aerospace industry refused to put any polyimide insulated wire/cable onto the aircraft they design/maintain. As is often the case with components involved in incidents, a lot of facts and myths get jumbled together.
info_outline
25.981 is Not a Barrier
The Lectromec Podcast
The certification of an aircraft requires the expertise of dozens of disciplines coming together for a single effort. Certainly, as the electrical wiring interconnect system (EWIS) has developed over the last couple of decades, the interaction with other systems and components is becoming better understood as the requirements are becoming more pronounced.
info_outline
DO-160, EWIS, and EMI
The Lectromec Podcast
From an implementation perspective, it cannot be understated how much EMI can impact system performance ranging from degraded performance to make a system completely inoperable. Thankfully, there are test methods to evaluate the susceptibility of electromagnetic interference of a wire harness design.
info_outlineAny concept that has earned the word “plague” in its name is certain to be an infamous hassle. The “Red Plague” of the aerospace industry is no exception. For decades, the plague has been identified with corrosion impacting the performance of silver-plated copper conductors.
Some have brushed the issue aside saying that they have never seen it, thus it is not a problem. To put the issue of red plague into perspective, a worst-case estimate suggests as much as 3% of braided silver-plated copper shields have some degree of red plague. Across the aerospace industry, this equates to millions of dollars each year in scraped products, rewiring, and maintenance actions