By Rob Finfrock
The business aviation community is counting down with a mixture of anticipation and – well, dread – towards the FAA’s mandate for aircraft to be equipped with Automatic Dependent Surveillance-Broadcast “Out” (ADS-B Out) systems. While that date may still seem to be in the distant future, it will almost certainly come sooner than you think if you have not yet determined how your airplane will meet this requirement.
The FAA has determined that by January 1, 2020 any aircraft operating in Class B or Class C airspace, or above 10,000 feet MSL, will be required to have ADS-B Out equipment onboard. A fundamental part of the agency’s planned “NextGen” air traffic control system, ADS-B Out is projected to eventually supersede the use of primary radar systems for tracking aircraft movements.
Revised equipage requirements for operators flying throughout Europe are similar, with a deadline of June 8, 2016 to have ADS-B Out onboard for new aircraft, and June 7, 2020 for equipment to be retrofitted to legacy aircraft. European authorities amended their initial deadlines last summer to more closely-align European timetables with the U.S. ADS-B mandate.
What Is It?
ADS-B Out functions exactly as its name implies. Utilizing onboard navigational data broadcast through the aircraft’s transponder, ADS-Out automatically broadcasts an aircraft’s identifying information, as well as position and ground speed based on GPS data, to ground-based relay stations at a rate of one reading per second. This information is then transmitted to the appropriate air traffic control stations, and may be transmitted to other aircraft in the area as well.
The speed and precision offered by GPS-linked position reporting benefits ATC in determining an aircraft’s location and capabilities, allowing for improved handling of traffic particularly in busy sectors. The technology may also be scaled down for ground operations; due to the accuracy and reliability of this data, airports may also opt to equip ground vehicles with ADS-B Out capabilities to reduce ramp accidents, and prevent runway incursions.
Two Systems Available to U.S. Operators
Two types of equipment may be used to comply with the ADS-B Out requirement, though CJP Members will undoubtedly focus on the one to be utilized by most business aviation operators. Anyone operating in the flight levels above 17,999 feet will be required to utilize a transponder with 1090 Extended Squitter (1090ES) capability. The “extended” part of that name refers to the extra data transmitted on the same frequencies already used by Mode-S transponders throughout the world.
(The second option for compliance with ADS-B Out in the United States is intended for smaller general aviation aircraft operating below 18,000 feet. Instead of utilizing existing Mode-S transponder frequencies, a Universal Access Transceiver (UAT) uses a dedicated 978 MHz frequency reserved for ADS-B transmissions in the U.S. This may be provided through a UAT-equipped transponder, or a separate interface between in-cockpit systems and an existing transponder.)
As you might expect with two different forms of similar technology – think Mac versus PC – 1090ES and UAT are not inherently compatible with each other. In order for both systems to be used safely within the same airspace, ground stations re-transmit information on the opposite link so that all aircraft can be seen on cockpit traffic displays. This is known as ADS-R, for “rebroadcast.”
From a practical standpoint, most business aircraft operators have little choice about which system to use. 1090ES has already been adopted as the global interoperability standard for ADS-B Out, while UAT is limited only to the United States.
Operators shouldn’t dismiss fitting their aircraft with UAT, however, if they operate at lower altitudes and don’t plan to leave the country, as UAT does offer significantly greater bandwidth over the 1090ES signal. This added benefit is important when considering in-cockpit uses for ADS-B, or ADS-B “In.”
Having an ADS-B In receiver and display onboard allows pilots to see the same position information displayed on ATC screens, as well as in-cockpit weather and other advisories. This added level of information gives pilots greater ability to maintain “self-separation” with other aircraft; UAT was first deployed 11 years ago in Alaska, as part of the Capstone program, for precisely this reason.
Opt “In,” or Stay “Out?”
ADS-B In is available with both 1090ES and UAT systems, and both technologies are compatible with Traffic Information Service-Broadcast (TIS-B) information. TIS-B uses ground-based surveillance radar to identify aircraft without ADS-B systems onboard, and transmits that data to an in-cockpit traffic display.
As previously stated, 1090ES will represent the most cost-effective solution for many operators. In fact, newer aircraft may only need to be equipped with a 1090ES transponder, as well as the necessary equipment to interface with onboard navigational systems, in order to comply with ADS-B Out mandates. Older avionics may need to be replaced with more modern equipment compatible with ADS-B, however.
No international mandate to equip aircraft with ADS-B In capability exists at the moment, and if one does come to pass it will almost certainly come well past the January 2020 deadline for ADS-B Out. Pilots should research for themselves whether it’s worth the added cost to equip with ADS-B In, particularly if they operate primarily away from high traffic airspace and airports.
CJP Working to Address Equipage Costs for Members
Much of the equipment that will be required for CJP Members with legacy aircraft to comply with ADS-B Out is still in development, which makes exact costs difficult to pinpoint. At current pricing and equipment availability, it may cost over $100,000 to upgrade an older aircraft with diversity transponders and other new equipment.
This steep cost factor is the primary reason why CJP has opted to form committees to address these issues for CJP Members. The Association is also actively working with Cessna and avionics manufacturers including Garmin, Rockwell Collins, and Bendix-King to address concerns about the upcoming 2020 mandate. CJP Members may expect additional updates and information about this critical issue in upcoming editions of Flight Levels. Discussions will also be held through educational sessions at CJP events, including the upcoming Annual Convention in Colorado Springs later this year.
(Portions of this article were previously published by the National Business Aviation Association)