As airlines take delivery of a new generation of commercial jets, they are counting on the manufacturers’ advertised claims of enhanced performance, improved fuel-burn and greater maintenance efficiencies such as longer intervals between major checks.
“It’s a step-change in operating economics and system reliability with the new-generation jets,” says Richard Brown, a principal at ICF International in London. “As a step-change, what comes to mind are composites or complex metal alloys, bleedless engines, advanced avionics suites, connectivity, health monitoring equipment, and more electric systems, such as brakes or flight control actuation. For the MRO industry, it will be a game changer—over time.”
In order to appreciate such changes, it is necessary to view these new aircraft from the perspective of airlines’ performance expectations.
For Zurich-based Swiss International Air Lines, introduction of the Bombardier C Series will mean significant improvements over the carrier’s 18 aging Avro RJ100s slated for retirement. Swiss International has 30 on order, of which the first 10 will be the 125-passenger CS100, with the CS100 and the larger 160-seat CS300 under consideration for the remainder. Deliveries are scheduled to commence in the first half of 2016.
A CS100 at the OEM’s Mirabel factory near Montreal, in the livery of launch customer Swiss International Air Lines. Credit: Bombardier
“The C Series will consume up to 25% less fuel per passenger-kilometer than the Avro RJ100, and cut our annual carbon dioxide emissions by around 90,000 tons. This is the equivalent of the CO2 emitted by 7,000 Zurich-London City flights,” reports Peter Koch, Swiss International’s C Series project leader, commander and C Series fleet chief.In a further comparison to the RJ100, Koch says that its fleet undergoes heavy maintenance about every 1.5 years, depending on flight hours and cycles. “Since we will constantly monitor the system status of the C Series through the AHMS [aircraft health monitoring system], the on-wing time of parts and systems can be drastically increased,” he explains. “We expect that with a well-balanced maintenance program, the C Series will have to undergo heavy maintenance only after 8 years—having the aircraft in for [light] maintenance every 14 days for one night.
”The AHMS, Koch adds, will report the status of 34 main systems with about 5,000 parameters, on the ground and airborne, allowing the maintenance control technicians to start analyzing problems immediately.
“Once landed, and confirmed by the pilot, the technicians will be ready at the gate with the correct spare part and repair documentation. Through optimized access panels, the technicians will be able to remove over 70% of line replaceable units within 15 min., giving us better dispatch reliability,” reports Koch.
JetBlue’s daily utilization rate averages as much as 12.9 hr. per day. It will replace its classic Airbus A320s like these with A320neos and A320ceos starting in 2018. Credit: JetBlue
Computer-based health monitoring systems are one of the keys to greater maintenance efficiencies and cost savings that should accrue from the new Boeing 737 MAX, according to Jon Stephens, director of fleet transactions for 737 MAX launch customer Southwest Airlines in Dallas. “The aircraft is smarter, and comes with a secure, onboard network file server that will perform many of the aircraft’s self-diagnostics,” he notes.
As Stephens points out, mechanics will be able to download data onto a portable device and obtain a much more comprehensive overview of the maintenance status of the aircraft’s components. “The mechanics will be able to see more fault indications of components before an actual failure takes place,” he says.
Southwest has 200 737 MAX jets on firm order, of which 170 are the -8 series, and 30 the -7. Another 191 are option positions that can be exercised for either model.
Using the currently operated 737NG family for comparison, Stephens says capturing data from that airplane’s health monitoring system is a more time-consuming, manual process. “We’ll be able to capture more data, and generate reports on that data, much faster, on the MAX. By tracking more [line-replaceable units] and other systems, we will get considerably more trend-monitoring data, which will really increase reliability,” he explains.
Boeing 747-8s on the assembly line at Everett, Washington. Lufthansa reports that the 747-8’s technical dispatch reliability is comparable to the 747-400’s mature reliability of more than 99%. Credit: Boeing
With first deliveries starting in the third quarter of 2017, Stephens explains that the 737 MAX is part of Southwest’s modernization strategy, which includes bringing new technology and efficiency into the fleet. In fact, once the 737 MAX fleet matures, the carrier expects that it will equal the technical dispatch reliability rate of its 737NGs. That rate runs “north of 99%,” predicated on a daily system average utilization of approximately 11 hr., he says.
“Although there are some basic differences, such as the engine and avionics, the 737 MAX is the same airplane as the 737NG from a structural and design standpoint,” Stephens notes. “Southwest, and other 737NG operators, regularly work withto improve the efficiency of maintenance intervals on component and airframe- related tasks as the reliability of these systems continues to improve. Any changes to maintenance intervals that Boeing will be able to certify for the 737NG should automatically roll over to the 737 MAX.”
Based on Stephens reports that what Boeing has told Southwest, component and airframe maintenance scheduling will be essentially identical for both 737 families. However, he adds that he has not yet seen the OEM maintenance planning documents to confirm that.
also looks forward to experiencing a similar high level of reliability with its coming fleet as it has with its current A320ceo (current engine option) aircraft. With 25 and 45 A321neos on order, deliveries will run from 2018 through 2023, to cover lease returns and expansion plans.
“Our technical dispatch reliability rate for our classic A320 fleet is globally competitive,” says Tony Lowery, JetBlue’s vice president of technical operations. Daily fleet utilization at JetBlue, he reports, normally averages as much as 12.5-12.9 hr. in July, the airline’s peak flying month.
According to Airbus data, the global technical dispatch reliability rate for the A320neo family averaged 99.4% in 2014. For July 2014, the global average was 99.38%. Lowery declines to give the specific JetBlue technical dispatch reliability rate due to variable underlying assumptions, but he expects to see an improvement with the -A320-neos, as with any new-generation aircraft.
Among the contributors to a higher reliability rate, Lowery cites the Pratt & Whitney-JM geared turbofan engine, which, he notes, is fabricated using the latest manufacturing techniques and has fewer moving parts that can fail. “That engine, in combination with the aircraft’s wingtip-mounted sharklets, is expected to provide a conservative 11-14% fuel savings.”
Another major reliability enhancement will be to the bleed air system, which, according to Lowery, has historically not been trouble-free between scheduled maintenance intervals. “Because of the high amount of usage, components can fail at any time, based on reports we receive from technicians in the field,” he says. “Airbus has told us that they have made enhancements to the bleed air components to improve reliability.”
Lowery says that a more robust main and nose landing gear has been designed to allow longer intervals between overhauls. “It’s about a 10-year calendar limit between overhauls on the A320 classics, but Airbus has extended that to 12 years on the NEO,” he explains. “Airbus is also seeking approval to extend the period between major airframe checks to 36 months, from the current 24-month calendar limit on the A320 classics. That will give us another year of utilization between base maintenance events.”
Germany’sis finding levels of reliability with its 19 -8s that are similar to its 747-400s, which are being replaced. According to Nico Buchholz, Lufthansa’s executive vice president of group fleet management, the airline took “a low-risk approach” when it selected the , and it has paid off.
“It is very similar to, and fits the support infrastructure established for, the 747-400,” he explains. “In fact, Boeing didn’t make any great changes unless they yielded significant benefits, such as the new wing’s greater aerodynamic efficiency and the newengines. The result is the 747-8’s technical dispatch reliability is comparable to the 747-400’s mature reliability—which is in excess of 99%.”
He adds that one of the major differences between the two aircraft types is the engine. The 747-8 and 747-400 are powered by the GE GEnx2B-67 and-80C2, respectively. “But the life-cycle costs for the two engine models are very similar in terms of inspection intervals and materials, even though the is much more fuel-efficient and quieter,” says Buchholz. “If there is any concern, it’s the fact that since the CF6 is a very mature program, there is a lot more MRO competition available—to keep costs down—than for the GEnx.”
Lufthansa, Buchholz points out, follows the airframe inspection intervals recommended by the OEM whenever a new aircraft type enters service. Then, as experience is gained, the carrier works with the OEM to modify those intervals.
Having operated the 747-8 since 2012, Lufthansa has found a trip-cost advantage of slightly above 10%—per seat—for the 747-8. “We predicated the trip costs of the two types on their longest non-stop runs,” Buchholz explains. “These are about 13,000 km [8,077 mi.], such as Frankfurt to Buenos Aires, or Frankfurt to Hong Kong or Singapore. Our takeoff weights have been determined to carry the combined load of passengers and belly freight with cabin configuration tailored to the specific markets.”
While offering carriers a number of operational cost advantages, the new- generation aircraft will change the MRO dynamics as they move into the world commercial fleet. ICF International’s Richard Brown cites increased airframe maintenance intervals among the reasons.
“The [Boeing] 787, for example, will undergo a D Check at 12 years compared to every six on a 767,” Brown says. “The question is, will it make sense for airlines to perform maintenance in-house and keep skilled staff for events further in the future, or should the tasks be outsourced to the third-party market?”
The same issue arises on the engine side, according to Ken Herbert, a Canaccord Genuity aerospace analyst in San Francisco. To illustrate, Herbert explains that 20 years ago, the then-state-of-the-art engines would have undergone four or five major shop visits over their lifetimes. Once those engines went out of warranty, which ran about 10 years, the airlines would put the work out for bid. “Today, a modern jet engine may have as little as two to four such visits over its lifetime, which means it will be difficult for independent MRO shops to make a business case for post-warranty servicing,” Herbert explains.
Deepak Sharma, director and chief technical officer for AJW Group in London, predicts that as new aircraft enter service, it will be harder for independent MROs to obtain the capability to service the new equipment.
“I’m seeing a stronger drive on the part of the OEMs to keep most repairs in house, with the exception of the airframe itself,” he notes. “That will be the most challenging aspect of new-generation aircraft aftermarket service for the MROs, and it will be an even greater challenge than it was in the past.”
As a case in point, Sharma reports that the technical manuals for the 787 and Airbussystems available to third-party facilities are minimal. “The OEMs are not providing comprehensive support to third-party MROs. The idea is for the airlines to become more reliant on the OEMs for repair and servicing. What I don’t see happening—to counter that—is the independent MROs trying to provide a more innovative level of service, which would be the big differentiator regarding the new platforms,” he says.
The main focus of the MRO industry is shifting more toward software-related issues, not only in the development of inflight entertainment but also in more proactive maintenance approaches, according to Volkhard Metzner, 747 fleet manager of key account management and aircraft engineering, atin Germany. “The ‘aircraft will tell you’ is a huge game-changer for the MRO industry,” he says.
Also, the new materials being used on the latest aircraft entering the market will significantly affect their size and structure. “Increasing use of carbon-fiber reinforced plastic will require further developments in repair and overhaul,” adds Metzner.
But does the increasing complexity and strong software focus of the new-generation aircraft mean that independent MROs will be at a major disadvantage compared to the OEMs in the repair market? Not necessarily, says Lufthansa Technik’sfleet manager, Christian Rieckborn.
“Although the OEMs are making very strong efforts to gain market share, they are experiencing difficulties due to the lack of their own in-service experience. However, they have an advantage when it comes to intellectual property,” Rieckborn argues.
Jim Sokol, Haeco America’s president of MRO services in Greensboro, North Carolina, cautions that as the new generation of airplanes enters the fleet, the MRO industry needs to “see the technical content to help us understand what is needed to support these aircraft.
“For instance, the 787, with its composite fuselage, has not gone into heavy maintenance yet, and consequently, the MROs have not yet had the opportunity to understand the technical issues with working on the new material,” Sokol says. “Composites are going to drive a whole new approach to repair, and as an industry, we will have to acquire the technical information needed to perform the repairs on a large scale.”
This, says Sokol, will involve not only investments in new equipment but entirely new training regimes—which will be critical. “The big parts of a major maintenance visit are inspection and non-destructive testing. In the past, we’ve trained people to work on metal. Now we’re going to be doing the same types of inspections, but with a much different kind of material.”