ATM Modernization

Perspective: IFALPA View: Emerging Technologies

By Capt. Edward R Hanson, Jr. | April 1, 2003
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The hottest ticket for "right now" avionics applications has to be reduced vertical separation minima (RVSM) for domestic U.S. and Canadian airspace. The opening of the extra flight levels above 290 will add spot capacity at choke points in upper airspace strata. Air traffic controllers will be able to run more traffic much more efficiently. The fuel usage rate and en-route delays will decrease. So far, the European experience of the International Federation of Airline Pilot Associations (IFALPA) with RVSM has been quite positive.

The airlines will be ready for early 2005 domestic RVSM implementation. Corporate aviation also must install RVSM packages and train crews in RVSM procedures or risk being denied access to RVSM airspace. The RVSM rule also states that aircraft with TCAS II must upgrade to Version 7 logic. The IFALPA ATS Committee, however, supports a more inclusive RVSM rule: ACAS II (TCAS II, Version 7 logic) should be mandated for RVSM operations; freighters, corporate aircraft and state aircraft should have ACAS II "on and operating."


Many good things can come from a robust expansion of automatic dependent surveillance-broadcast (ADS-B) to a full-up application. ADS-B surveillance fused with advanced airport surface detection equipment (ASDE), powering both a cockpit display of traffic information (CDTI) and the controller’s workstation screen, can put a stop to most runway incursion accidents. The same data can increase capacity in low visibility, when used in conjunction with a high-accuracy airport layout on the CDTI. If pilots are absolutely assured that traffic displayed on their CDTIs conforms to all actual traffic in the aerodrome, airports can expect to achieve near visual meteorological conditions (VMC) capacity throughput.

ADS-B surveillance, fused with terminal radar inputs and displayed on the CDTI, will allow structured, "follow me" procedures to be designed. The industry eventually will achieve increased capacity as well as enhanced safety through electronic "visual" procedures. The key to successful implementation will be the active involvement of all of the stakeholders.

But the IFALPA’s Air Traffic Service Committee’s position is that ADS-B will supplement, not replace, ACAS II. ADS-B could be considered a deconfliction tool used in automating air traffic management, but that it should not be relied upon as an anti-collision device.

Required navigation performance- (RNP) based instrument procedures offer capacity and safety enhancements in the terminal area. Top-line avionics suites of the future will include GPS inputs to a flight management system that also includes scanning DME/DME, VOR/DME, inertial navigation systems and Loran C inputs. This redundancy assures graceful degradation, permitting continued safe operations despite the failure of individual elements of the navigation system.

RNP procedures will foster much more predictable flight paths, so that terminal controllers will intervene less and can plan more to safely sequence and separate the traffic. Equipped aircraft will be able to make efficient descents and approaches while complying with tighter noise abatement profiles. The best thing about RNP instrument procedures is that most glass cockpit aircraft already can meet many of the envisioned design criteria. Aircraft that cannot meet the RNP challenge can be upgraded to allow participation. RNP-based departures, descents and approaches will increase efficiency, capacity and safety.


The airlines are installing VHF data link Mode 2 (VDL-2) radios for air operations communications. Pilots will use the VDL-2 radios to access weather databases, load planners, dispatchers and maintenance coordinators. We will get our predeparture clearances and make oceanic clearance requests using these radios, which add several layers of message reliability.

Europe and the United States are deeply involved with controller-pilot data link communication (CPDLC) trials and partial implementation. IFALPA also participates in ATS data link development on a global basis.

But digital data link is not the end state for radio communication. IFALPA’s long-term position is that voice communication must always be provided. But the current voice system creaks with age and cries for improvement.

Europe uses an 8.33-KHz frequency separation scheme to create more usable channels for voice communication. But the air traffic community fears that voice channels in the European core nevertheless will become capacity-restrictive. We need a different means of assuring controller and pilot dialog–CPDLC backed by digital voice.

Edward R. Hanson Jr. is vice chairman of the International Federation of Airline Pilot Associations’ Air Traffic Service Committee.

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