canaero - Canadian aviation history

Maintaining the ATR

Report by Raymon J. Kaduck

First Air ATR42 at Carp, ON

Mike Bernard, Yellowknife Maintenance Manager, has just over a year of experience on the new ATR42. The company deployed the type at its Yellowknife base first, where it will be evaluated before purchasing more airframes and converting its Baffin hub in Iqaluit.


The first two aircraft (FIQU, FIQR) entered service in the original factory configuration that had smaller and less functional cargo compartments in late 2001. The first combi version, FTCP, entered service in November 2002 with FHCP following in December.


After four seasons of operation, Bernard is impressed with the performance: “They have done really well. I thought we would see a lot more skin damage. The airplane doesn’t look that tough, but it’s surprisingly durable.”


“We’re just starting to develop an understanding of the maintenance rates. The plan was three quarters of the person-hours of the Hawkers, because there’s a learning curve, but I don’t think we’re going to need that much. The first two airplanes had been parked for two years, but they came to us virtually snag-free, which is incredible.”


The new-generation aircraft are designed using a modular approach and built-in trend-monitoring equipment. The engines are linked to an Engine Parameter Recording System (EPRS) that allows maintenance requirements to be predicted. The system includes automatic trend monitoring and recording of engine parameter exceedences, and storage of engine operating times and cycles. EPRS data are automatically collected and can be downloaded for analysis by means of a notebook PC on the ground. The data are also available in flight through the Aircraft Communication Addressing and Reporting System (ACARS).


One of the key considerations when purchasing the aircraft was the operating history that came with them. Don Orr explains: “With the operating data from Inter-Canadien, we were able to incorporate some of its maintenance material into our programs, as well as continue the ‘on condition’ program. The manufacturer has stipulated overhaul periods for some components, but an operator can apply, after demonstrating suitable controls to Transport Canada, and with experience, that the components can be monitored and replaced when required, rather than on some rigid timetable.


“These engines originally had an 8,000-hour overhaul period. ‘On condition’ allows the operator to run the engine beyond that time and overhaul when required. TBO is 12,000 hours, with regular inspections in between. A basic overhaul would be about US$350,000 plus life-limited components. For example, some internal parts may have a life of 15,000 cycles.”

This pre-existing maintenance history has helped First Air reduce operating costs and learn more quickly, but the new aircraft technology changes the nature of maintenance, so First Air staff has had to adjust.


“It’s a new way of thinking–less maintenance intense,” says Bernard. “The ATR concept is very straightforward. The modular approach means you’re changing components based on performance information. With the high-time engines, mostly you’re monitoring trends, not doing inspections–a lot more soft time downloading information and less hard time changing engines.”


The ATR42 was previously certified to –40°C, but First Air’s certification is to –54°C. How well the aircraft adapted to the cold pleasantly surprised Bernard: “The HS 748 is extremely labour intensive in the cold–a lot of preheating, a lot of leaks and constant work to keep it going. The ATR is more like the jets.”


“The mechanical reliability of the aircraft is 98% which, for a small fleet, is amazing,” says Orr. He is less candid about the exact reliability of the Hawker, but concedes that the improvement is in the order of 20%.


One of the tradeoffs required by the C Class compartment was that “recons” become solely a maintenance function. The Hawker’s simple system allowed it to be reconfigured in the field. This was often by aircrew, who are not sorry to see an end to it. Asked about the ease of the operation, Bernard points out that the cost of reconfiguration is a key factor: “We haven’t done too many. Some are in excess of 35 person-hours. A lot are only 10 hours, but you can’t be casual about it. It’s a question of worth. Everybody has to take that into account, operations, sales … everybody.


“Everything that is disturbed has to be perfect again; move a bulkhead and it has to be resealed. And you can’t have 10 guys working. If the change will use 35 person-hours, it’s not possible to put a dozen people on it and finish in three hours. It’s practical to have only two or three doing the job.”


While each aircraft can be reconned to any of six configurations, it is likely that each one will be operated in only one or two configurations over a given period. The complete flexibility of the Hawker will be replaced by a portfolio approach in which the most useful configurations on a route will dominate. First Air is still learning how best to accomplish this.


“Should a major change in passenger load be required, another aircraft with the appropriate configuration will be substituted on the route,” explains Orr. “Using that approach, the number of recons will be kept to a minimum.”


It is only in the last few months that the newly certified combis have started to take over. “It’s getting exciting now,” says Bernard. “On this base, we’re down to two Hawkers; soon we’ll have four ATRs and one Hawker. Now, the Hawker is just filling in. The crews are excited and everybody is happy about it.”


Bernard is old enough to remember the period in which the Hawker displaced the DC-3. “Some people said you couldn’t replace the Douglas. Now, guys are saying the same about the Hawker. But I don’t see anybody wanting to return to the past. This is a nice aircraft.”


And will he be sad to see the Hawker go? “We can’t wait. The new aircraft is what First Air will grow with. In some ways, when you work on any aircraft for 15 years, there’s a feeling of nostalgia for the older type. But the ATR is just a lot better.” |