Data increasingly drives smart maintenance and will drive it much sooner in the near future. Greater quantities of data transferred inflight from an aircraft is a major next step in improving MRO on the ground. But what has to happen to make that step practical, and when will it be taken?
John Schmidt, Accenture’s managing director for North American aerospace, sees ample benefits in inflight data transfer, including predictive maintenance, optimizing spare-part inventories and minimizing disruptions. Benefits will be especially important for new aircraft such as Boeing 787s, Airbus A350s and new 737s and A320s.
Access to data inflight is better than downloading data when aircraft land. “Avoiding disruptions is a big deal—excessive turnaround time costs airlines money,” Schmidt stresses. “If mechanics are prepared to fix a problem before it pulls up to a gate, aircraft can stay on schedule.”
Carriers now send “bits and pieces” of operating data over ACARS or early satellite links. Schmidt sees the ultimate goal as nose-to-tail connectivity that includes inflight entertainment and communications for passengers as well as operating data for airlines.
Several hurdles to inflight connectivity will ease steadily. For example, monitoring equipment on older aircraft does not offer much benefit, but this limit will diminish as new aircraft come into fleets.
Satellite links are not yet available for all portions of all flights for instance in polar regions. But satellite coverage is expanding, and carriers do not need data during entire flights as long as it’s available in sufficient time to prepare for problems on landing. “Small gaps will not hold it back,” Schmidt says, as long as the data can be sent in time to stage parts, for example.
There are challenges in getting licenses for data transfers over some countries, but Schmidt thinks “licensing is a workable issue” and sees steady progress on this front.
Then there are bandwidth limits and data-transfer costs. “Data costs will come down.” Schmidt estimates costs at $6 per megabyte and declining. And airlines do not need all 500-600 GB on a 787 flight to reap MRO benefits. “They can be more selective.”
Communications are shifting from ACARS to satellite links, as more aircraft are equipped for satellite communication. Schmidt predicts carriers will eventually use the same communications links for aircraft operations and passenger data. “If the airline has a satellite connection, it might use that connection when passengers are not using it.”
Data will be analyzed mostly on the ground, in operations centers or in the cloud. Analysis will take into account passenger rerouting and crew schedules as well as maintenance options.
How soon will inflight data come? An Accenture report this autumn will attempt to answer that question. Schmidt expects the decisive factor will be the proportion of fleets with new, data-rich aircraft. “If airlines have too few such aircraft, then they have to run dual systems, and that can be very expensive.” He predicts some airlines will use inflight data in five years and the movement will be general within 10 years.
The majority of airline operational and MRO data is still transferred on the ground and manually. GE Aviation Product Manager Mark Thomson says manual data transfer typically misses 10-20% of desired data.
Digital flight data acquisition units submit only a small subset of data via ACARS. More modern systems transmit larger data subsets via satellite. Thomson thinks systems now used on business jets, such as aircraft health management systems on Gulfstream G650s, G500s and G600s, would be valuable to airlines.
GE’s onboard maintenance system on the Comac C919 incorporates a similar capability. Users define algorithms, parameters and data, and the system stores up to a gigabyte per flight. As little as 30 KB may need downloading inflight; most can be downloaded on landing.
Thompson sees airlines beginning to add wireless capabilities. Next-generation monitoring systems will store more than 100 GB and let airlines define algorithms and configure data flows in rate, resolution, links, transmittal triggers and priorities. Airlines can choose among satellite and ACARS inflight and Wi-Fi and cellular on the ground based on criticality, bandwidth, coverage and timeliness.
Thomson stresses configuration tools will be critical to economic exploitation of data. These tools allow airlines to choose which communication links to use when.
Furthermore, recording flight data in a database, rather than in monolithic files by flight, enables airlines to download key data in transit, without transmitting the “entire haystack to find the needle.”
Thomson says analytics markedly improves when given better data. GE and its joint venture with Accenture, Taleris, strongly favor increasing data range and frequency, while minimizing efforts necessary to clean up transmitted data.
In terms of data range, GE sees additional value in several new data types such as high-speed electrical control signals, voltage and current measurements and faster data acquisition generally to diagnose transient problems.
Potential benefits of inflight data include faster turn-times and alerting some station teams that inspections will be due on retasked aircraft before the next day. Managers will be able to see an up-to-date operational picture of their airline as a complex system through a “single pane of glass,” Thompson says.
All systems to collect and transmit data for maintenance must meet ROI criteria. So GE adds to health management other utility functions that provide additional monetary benefits or cost savings. These utilities include file servers, data load servers, configuration reporting, plane-side data and analysis on embedded webservers. These utilities may be expanded to an entire onboard maintenance system, which could generate further monetary benefits.
Rockwell Collins intends to be a major player in connecting aircraft inflight for all purposes, says Joel Otto, vice president strategy for information management systems. The company makes onboard communications equipment, has a major communications network through its acquisition of Arinc and uses data extensively to support its own repair and overhaul business. “Arinc also connects to other players in the aviation ecosystem, support, reservations and interlining,” Otto says
Otto notes most inflight data still flows over ACARS, older satellite systems and the newer, more capacious SwiftBroadband, on satellites run by Inmarsat and Iridium. Business jets are using SwiftBroadband, but mostly for passenger and crew purposes, not aircraft monitoring. Otto predicts high-speed links will first come to airline passengers, then airlines will figure out how to exploit them for MRO. Security will be a major challenge in sharing public, high-speed communication among passengers and operators.
Rockwell expects much more capacity at lower costs per unit to be available from Internet links such as SwiftBroadband and is prepared to use them. But carriers also will have to build out ground systems to use inflight data: to clean and interpret it and then transmit resulting instructions reliably across networks. Otto argues back-office capabilities and absolutely reliable ground communication will be as critical as satellite downlinks.
But faster links are certainly coming. Inmarsat and Honeywell have proven the performance of Honeywell’s JetWave MCS 8200 hardware on Inmarsat’s Global Xpress (GX) satellite network. Two GX satellites are already up, the third is set for launch in the second quarter of this year, and the entire network is expected to be operational in the third quarter.
Kurt Weidemeyer, vice president for business aviation at Inmarsat, says 14,000 aircraft are now connected to Inmarsat’s classic and SwiftBroadband networks. SwiftBroadband transmits up to 432 kilobits per second, per channel. Inmarsat’s new GX network will handle up to 50 megabits per second.
The GX network is primarily designed to deliver passenger-cabin connectivity. Aircraft might use it for operational and maintenance data in the future, Weidemeyer says. “But major OEMs like Boeing and Airbus are still very concerned about network security and segregating passenger data from flight-critical data,” he says.
Ground infrastructure is being added to SwiftBroadband, and a dedicated, secure service, SB Safety, is being tested for safety and traffic control communications. Weidemeyer expects SB will be certified for safety-related data by 2016. He thinks the two major OEMs will first choose this link, faster than earlier networks but not as fast as GX, for operational data. He expects business aircraft will use multiple links, adding GX to SwiftBroadband for flight-critical and passenger data.
Moving from ACARS to SwiftBroadband decreases cost per megabit, and using GX will drop costs even more. More data transmitted saves money in other ways. “If the airline gets data down during flight, it might get a discount on engine services,” Weidemeyer notes. Trend data on APUs would similarly be useful in flight.
Another use might be updating navigation data by inflight transmission rather than taking disks out to the aircraft periodically. Weather and wind data transmitted among aircraft inflight would be more accurate than the same data forecast before flights. Honeywell offers radar data to aircraft without radar over SwiftBroadband, to improve situational awareness. And Cobham is now testing safety service over SwiftBroadband on Hawaiian Airlines’ Boeing 767-300s.
Weidemeyer, too, sees great benefits in gathering operating and MRO data during flights, especially for newer aircraft. The 787 produces 500 gigabytes of data for its central maintenance computer during a typical 6-hr. flight. “You can’t get it all off, but you can transmit critical data that improves operational efficiency,” he says.