Can't leave home without the phone

USB charging systems are an important element for the office aloft.

True Blue Power TA102 dual USB charging port (pictured) is a modern addition to any cockpit and interior cabin which protects itself and the devices being charged from short-circuit, power surges and overcurrent potential. Its successor, the TA202 offers both USB type A and type C configurations.

An important characteristic of a USB is the ability to deliver DC power and, hence, charge batteries or power devices. This transmission is 1 directional and always flows from the host device to the receiver, meaning you can charge a phone from a USB port on a computer but not vice versa. When considering only the ability to deliver power, not all USB chargers are equal. Identical looking hardware can deliver disparate amperage levels and for that reason it's important to denote it in some way.

Charging ports on a computer typically range from 0.5 to 3 amps and those with the highest amperage dedicated to charging are identified with a lightning bolt icon. For comparison, the average wall outlet 110V USB adapter (technically a transformer/rectifier) delivers from 1 to 2.4 amps; the exact specifications should be printed on the unit.

In terms of how fast a battery charges, one would think higher numbers are better. In most cases yes, but other variables can play a role. The "more must be better" theory became popular among Apple owners when they suggested that attaching an iPad charger to an iPhone could shorten charging time. It's true that the former produces greater amperage than the later.

However, earlier models of the phone are only capable of accepting 1 amp of current, so anything more than that is superfluous and won't help the cause. The takeaway is that sometimes the device receiving the charge has known design limits. A far more serious situation is one in which the limitations are unknown or untested.

Charging devices are frequently counterfeited or not manufactured to standards suitable for airborne use. It's one thing to make an impulse purchase of a replacement charger at a store checkout and have it burst into flames on the drive home, but it's far different when the failure happens at FL390 somewhere near 30W longitude on the North Atlantic tracks.

USB charging ports are a safe, cost-effective solution to charging PEDs in the air
Surveys indicate that passengers prefer to use their own PEDs when traveling by air. It's a given that those devices will eventually need to be recharged. Flight departments were quick to realize that lack of Wi-Fi to support PED connectivity was a significant disadvantage, and the same holds true when it comes to USB charging capability.

The reliance on PEDs is so important that it's influencing design decisions on production aircraft and inducing owners of classic airframes to retrofit. Demand rapidly spiked in the last decade and a little history can explain why. The 1st dedicated USB charging system for corporate aircraft dates back to1999. At that time, Esoteric LLC developed a single slot charger for the Bombardier Global 6000. It was known as the SmartDock. The irony was that there were few portable devices to charge using the USB format at the time.

A cockpit USB charging port eliminates the need for an alternate current adapter. And heavy duty cords like the ones made by Lone Star Aviation (at right) resist fraying and failure, and make a good complement for airborne PED powering systems.

In September of 2016, the Esoteric cabin power product line was acquired by Elite Aerospace Group. Elite currently sells 9 USB charging products branded under the name SkyDock and SmartDock. Robert Pecanic, director of operations for the technology division at Elite – and one of the original designers of USB for the aerospace industry – offers cogent arguments for using DC voltage charging stations in lieu of 110V AC: convenience, smaller footprint, reduced weight, and safety. He points out that wiring a DC system in an aircraft cabin is less logistically complex than AC and reminds users that, "As technology continues to advance, so will the amperage requirements. Increased output comes with flight safety issues."

Esoteric sole source for Dassault Falcons

Dassault released its specifications for a USB charging device 6 years ago in a 145-page document. It included QTP sectional testing in excess of the DO160G – the standard for environmental conditions and test procedures for airborne equipment. One of the most challenging was a voltage spike test. As described by Pecanic, the testing process involved shocking the USB chargers with 3 successive 600 volt bursts.

To be successful, the unit had to resist smoke, fire, and terminate power at the input source (not the end the user interacts with) within a microsecond. The Esoteric design passed all the tests and now the company is the sole source provider of USB charging systems for the Falcon jet series, although they also sell across the industry from props to jets. A myriad of designs, installation parameters, and finish cosmetics allows clients to select the option that works best for the mission, whether that's an office-in-the-sky concept or the recreational flyer that needs power for a portable GPS.

When looking to retrofit a strictly AC system or add USB charging capability to an aircraft that lacks any system at all, it's important to find a product that's FAA certified. The popularity of USB has prompted electronics manufacturers to flood the market with devices. Even automobile manufacturers have gotten onboard and now it's normal to find USB charging stations as standard in new vehicles. Unfortunately some generic products lack the safety features needed for airborne use.

One of the most desirable benefits is the ability to reduce or eliminate current to the battery as it reaches full capacity – is essence, a safeguard against thermal runaway. The Esoteric charger uses a microprocessor to fluctuate power input as a function of battery status and visually identifies when the unit is powered via a green LED on the face.

Risk of electromagnetic interference

Fire is always a major concern but electromagnetic interference (EMI) is another potential problem. Rick Slater of True Blue Power, a division of Mid-Continent Instrument, echoes the value of formal TSO certification. True Blue, well known for its main ship and emergency aviation batteries, got into the USB charging business in 2013. The True Blue Power chargers exhibit low EMI and interference with other aircraft electronics. A unique feature of the True Blue TA202 is that it provides a type C input – the latest in USB technology. Data transfers enormously faster using type C format and the plugs are thinner, symmetrical and reversible.

Right now there are only a few laptop computer models that charge using USB C, but more are expected enter the market in the near future.

Each certified USB charging system has a niche to it and buyers will have to ultimately decide what's best based on their needs and wants. Flight Display Systems, a maker of airborne LCD screens, adds an internal fan to their dual USB charger, touting the cooler operating temperature provides for a consistent power supply. There's even an option for a "ruggedized" version if a standard USB is not tough enough. Lone Star Aviation Corporation produces a lightweight aluminum chassis FAA TSO MIL STD panel mount USB charging receptacle that comes with silicone cap that is dust and splash resistant.

Don't forget the need for a good cord

Regardless of which design or manufacturer a buyer decides to purchase, Jim Mantos of Lone Star makes an important point: The Achilles heel is often the cord that runs between the charging port and the device. We've all been there; the cord is too short, becomes frayed, or constantly pulls out of the socket.

To combat this, Lone Star offers a "ruggedized" iPad cord that's longer, thicker, and more insulated than the one supplied with the tablet – a nice-to-have accessory even if it's never used in an airplane. Best of all is that the price point for this USB charging system places them within reach of all operators.

One thing is for sure – USB is here to stay. Adding or upgrading a USB charging system will pay off in the long run from the standpoint of safety, utility and convenience.

Shannon Forrest is a current line pilot, CRM facilitator and aviation safety consultant. He has over 10,000 hours and holds a degree in behavioral psychology.


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