By J.R. Wilson
WASHINGTON — Leaders of the U.S. Federal Aviation Administration (FAA) are delaying indefinitely their nationwide rollout of the new Controller-Pilot Data Link Communications (CPDLC) system, which has been undergoing tests at Miami International Airport since October 2002.
FAA officials say they are delaying the program for two reasons: the airlines are unable to make the necessary investment in the cockpit, and the FAA's new prime objective of increased security.
Critics of the decision, however, claim the real reason is to protect the agency's investment in the En Route Automation Modernization (ERAM) program, which was designed without taking the datalink capability into account.
"If they continued to deploy datalink across the U.S. now, they would have to put it [ERAM] on hold and that obviously is not a good thing," says Alex Wandels, data-link program manager for the European Organisation for the Safety of Air Navigation (EUROCONTROL) in Brussels, the FAA's European equivalent. "That looks to me to be a more credible reason than not enough airlines equipping."
Basically, the U.S. and European programs are designed to replace much of today's radio voice traffic between pilots and air controllers with wireless data transfers. This move, experts say, would reduce demand on cluttered radio frequencies, controller workload, and errors due to accent, poor reception, language skills, and distractions.
Officials of American Airlines in Fort Worth, Texas, which has been heavily involved in both efforts, prefer the original CPDLC schedule, which called for a December 2005 rollout that would have seen all 20 FAA air-route traffic-control centers equipped by the end of the decade.
By contrast, a spokesman for Northwest Airlines in St. Paul, Minn., says airline officials are not disappointed by the delay because "CPDLC involves very costly aircraft equipage issues with uncertain benefits." Northwest has been active in many new technology developments related to the Free Flight concept, of which CPDLC is a part.
AirTran, an Orlando, Fla.–based regional, is representative of many airlines, having ordered 50 new Boeing 737-700/800s with CPDLC capability. As those are delivered from mid-2004 and through the end of 2008, AirTran officials say they plan to retrofit their remaining 82 Boeing 717s with the same cockpit communications equipment.
While air travel has stagnated since Sept. 11, the problem that CPDLC is designed to fix will continue to worsen and may reach crisis level before the FAA resumes deployment, says Ira Pearl, director of flight operations technology support at Delta Airlines in Atlanta.
"We believe airspace utilization by airlines, cargo carriers, business jets, and general aviation will continue to grow and ultimately we will have failures of communications due to [frequency] oversaturation," Pearl says. "So we support developing new technologies to make better use of the frequency spectrum we do have. We believe CPDLC is a good way to do that."
Europe, already at that crisis point, made one move not in the FAA game plan by splitting the conventional 25-kHz-wide VHF analog voice channel into three 8.33-kHz-wide channels. They also are moving forward with LINK 2000+, with the first center implemented in Maastricht, The Netherlands, last June. Additional centers will become operational through 2007, covering Belgium, Germany, France, Switzerland, Austria, Spain, Portugal, and Italy.
"The two systems are very similar and interoperable," Wandels says of CPDLC and LINK 2000+. "The services are the same groups of messages used to achieve a certain objective. We have a considerably larger message set than Miami, where the FAA started their first implementation very cautiously. Our PETAL [Preliminary EUROCONTROL Test of Air/ground data Link] trials lasted from 1996 to 2001, giving us a lot of experience, and we were confident we could start with more messages."
Wandels says he shared concern that avionics designers might respond to the FAA announcement by delaying development. Despite fears, however, "they are concentrating in Europe and trying to sell as many of their radios and CMUs [communications management units] as they can."
European experts worry that the delay may have another hidden motive — to convert CPDLC from the VHF Data Link Mode 2 (VDL2) radios and LINK 2000+ to VDL3, which would merge voice and data into a common communications link. Officials of EUROCONTROL and some airlines question the wisdom of relying on only one voice and data channel. VDL2, they say, greatly reduces the volume of voice traffic, and separate modes could back each other up.
They are not alone in that concern.
ARINC of Annapolis, Md., owns and operates all VDL2 equipment from an aircraft's antenna to the connection to the FAA's National Airspace Data Interchange Network. That would not be the case with VDL3.
"We have invested a great deal of money in developing VDL Mode 2 and ATN [Aeronautical Telecommunication Network], and delaying its adoption as a full national service introduces risk into the business case," says John Burks, ARINC's CPDLC program manager. "If any of that changes, our investment would be lost."
Burks points out that the airlines have been investing heavily in VDL2 avionics. "We have not received any indication from the FAA that this is what they are planning, but three to five years is a very long time in technology and in programmatics. Things do change."
The reason for the concern is the confluence of timing between the FAA's presumed CPDLC resumption in 2008 and another agency program called Next Generation Communications (NEXCOM), in which VDL3 is a centerpiece.
FAA officials insist that their long-term objective is to switch domestic air-to-ground communications to NEXCOM technology, which enables four independent channels within the 25-kHz-wide frequency to handle voice and data. Under the original plan, that would not have happened until sometime in the next decade. At the same time, the officials in the FAA's Communications, Navigation & Surveillance Systems (CNSS) Directorate, which is responsible for NEXCOM, now says they hope to have VDL3 radios available and certified by 2005.
"We want to be able to develop VDL3 and prove that it works, then we will reassess the timing for completing the program," says CNSS deputy director James Link. "That probably will be around 2005, so we are moving to a more phased approach. Assuming a positive decision to move forward, we can start upgrading the infrastructure, slowing switching the FAA system over to VDL3. As we start to do that, we would gradually transition the users to this new system. We will have made a decision on this before ERAM is fully deployed, so anything that needs to be done will be incorporated into it."
Mike Gouth, a former controller who is now the FAA's deputy director for Free Flight, says deployment of any system must be based on compelling need and best timing for the FAA.
ERAM involved a hardware replacement; the host is still running the original software, which is programmed in the 1960s-vintage U.S. Air Force JOVIAL computer language. "So our pressing need is to modernize the software for the automation capability for our ground systems," Gouth says. "The smart thing for us is to let that happen, which will make the implementation and integration of new technologies easier, then roll in CPDLC right after that software upgrade. The ERAM schedule now calls for deployment in 2008, so that is the smart time for us to deploy CPDLC in a perfect world."
Officials of Geneva-based SITA, ARINC's European counterpart, also question the official FAA arguments.
"The FAA has an almost religious belief that a digital system is needed to improve the voice system rather than reducing channel spacing in the analog spectrum, as Europe did because it couldn't wait for the more challenging change that VDL3 implies," says Philip Clinch, SITA's director of aircraft operations and navigation services.
"One of the recent arguments is that VDL3 would be cheaper in the long run, but the logic behind that sounds to me like scare tactics." He says the FAA signed research and development contracts with two companies at $20 million each to develop prototype VDL3 ground stations to demonstrate the system. "For that much money, SITA or ARINC could deploy a complete VDL2 network covering the entire U.S. and meeting all FAA requirements for the next 15 years," he says.
Avionics companies are responding by trying to cover all possible bases with multimode radios capable of talking to VDL2, 8.33 kHz, and VDL3. But they and the airlines have voiced concerns about that approach, as well.
"We, the manufacturers, can put multimode inside a single box, but is it cost-effective to add additional technology to the same box when we haven't resolved all the interoperability issues?" asks Richard Heinrich, director of strategic initiatives at radio designer Rockwell Collins in Cedar Rapids, Iowa. "Our goal is to serve the community by offering them one product with multiple functionality; the community needs to decide what that functionality needs to be."
Airlines typically take a long time to upgrade radios and navigation aids, so a five- or six-year delay in a core technology is unlikely to see much change, Heinrich says. "The hard part now is to make sure, as we move the program forward, that we keep the operational training requirement between the U.S. and Europe similar. How messages are structured and how the controllers and pilots react to them have to be commonized for all elements. You don't what to train a pilot in the U.S. and have him have to react differently in Europe."
Delta's Pearl says the FAA is missing the point: "It is somewhat specious to say the airlines haven't invested in the equipment. All of the next-generation aircraft we have bought since 1998 are VDL2 capable; it's just a matter of loading the software.
At the same time the FAA supports VDL3, and U.S. airlines support VDL2. "I wouldn't place a bet on any one technology prevailing," Pearl says. "I know what our preference is, what the European preference is, what nearly every air carrier in the U.S. would prefer. But we don't know where the FAA is going."
Whatever the FAA ultimately decides, almost everyone outside the agency agrees it should offer some form of incentives to the airlines as Europe has done to hasten the necessary equipment conversion, something the FAA, to date, has not indicated it plans to do.
"Intelligent people can have differences of opinion on what is the best technology," Pearl says. "Everybody makes their case and places their bets, but we, as an industry, don't want to have to bet on the outcome. We want to know which technology is going to prevail. If we make the investment in VDL2 and VDL3 prevails, there will be a lot of very sorry people at a lot of airlines who bet on the wrong horse. We want a decision made, a technology selected and we hope our input will be considered in making that decision so we can move forward with a single program, well defined, to make that happen."
