MAX KINGSLEY-JONES / LONDON & COPENHAGEN & ANDREW DOYLE / SINGAPORE Despite the Q400 high-speed turboprop's superior economics, efforts to challenge regional jets have been hampered by a troublesome introduction.

Bombardier may have been the manufacturer that drove the regional airlines into the jet business with its CRJ family, but the Canadian manufacturer remains at the forefront of the propeller-driven marketplace with its 70-seat Q400 high-speed turboprop.


The Q400 was conceived by de Havilland in the early 1990s as a major new stretched derivative of the successful Dash 8 family, offering new technology and higher speeds to compete with emerging regional jets. In 1992, Bombardier acquired de Havilland, bringing the manufacturer under the same umbrella as Canadair, which itself was looking to build on the success of its pioneering 50-seat CRJ with a larger 70-seat model.

Despite the potential conflict between jet and turboprop models of almost identical sizes, both derivatives would eventually be given the go-ahead. Bombardier said it saw a need to have a foot in both the jet and turboprop camps as the latter would remain the most economic solution for short-haul and low-yield operations.

Conceived to meet the twin requirements of offering turboprop operators a growth path as well as providing an affordable replacement for older jets on short sectors, the Q400 was designed to offer a 350kt (650km/h) cruise speed.

The company's brave decision in 1995 to launch and persevere with the Q400 has been fraught with difficulties. The turboprop market has been in rapid decline since the Q400 was given the green light, and despite being cheaper to operate, turboprops are seen as yesterday's technology.

With a break-even target of 400 aircraft, sales of the 70-seater have remained sluggish - only 71 orders have been notched up in six years. The type's sales fortunes have not been helped by programme delays and a painful introduction into service. Last month, Bombardier took a third-quarter charge of C$264 million ($166 million) related to the non-recurring costs of the Q400 programme.

Compared to the 50-seat Dash 8-300 from which it evolved, the Q400 incorporates a 6.8m (22.3ft) fuselage extension along with new engines, propellers and nacelles, flightdeck and avionics, and landing gear. Most systems have been revised (see Flight International, 9-16 September 1998 for a full technical description and cutaway).

The cabin, which accommodates 70 passengers in a standard 30in (78cm) pitch layout, is equipped with Ultra Electronics' noise and vibration suppression (NVS) system to reduce sound levels to 75-78dB. Bombardier hoped this improvement in cabin environment would help eliminate passenger aversion to turboprops.

Power is provided by two 3,420kW (4,580shp) Pratt & Whitney Canada (P&WC) PW150A turboprops driving Dowty six-bladed, all-composite propellers. The engines feature Hamilton Sundstrand dual-channel full authority digital engine control (FADEC). The Q400's flightdeck incorporates a new five-screen electronic flight instrument system (EFIS) with large liquid crystal displays and an integrated avionics system supplied by Thales.

Delayed certification

When the Q400 made its maiden flight in January 1998, certification was scheduled to be in place by the end of March 1999. But the programme was hit by a series of snags which delayed certification by nine months to December that year. The manufacturer also had to set up a post-production modification line to bring the first 24 Q400s up to current equipment standards. At the time Bombardier blamed the delays on "certification, and production spool-up. We have a large number of partners to work with," it said.

Q400 deliveries began in January last year to Copenhagen, Denmark-based Scandinavian (SAS) Commuter, and 47 aircraft are in service with seven operators worldwide. Three operators were interviewed for this report - Changan Airlines, SAS Commuter and Tyrolean Airways - which have all had the aircraft in service for over a year. Of these, only the latter was a Dash 8 operator prior to the introduction of the Q400. Alaska-based Horizon Air, the type's only North American operator, refused to take part in the survey.

Although it was not the first airline to order the Q400, SAS Commuter became launch customer for the 70-seater in 1997 after signing a $350 million order for 15 aircraft plus 18 options. SAS ordered the Q400 to fill a gap between the mainline SAS fleet, starting at the 100-seat Boeing 737-600,and the SAS Commuter fleet of 50-seaters. Its orders for the Q400 now stand at 28 aircraft, of which 23 have been delivered.

There were teething problems almost from day one, culminating in the airline's entire fleet being temporarily grounded in October last year. With hindsight, the regional arm of SASÊwould rather not have been given the task of introducing the type into service. "We have made it a policy now never to be launch customer for new aircraft," says Marku Eriksson, vice president technical operations at SAS Commuter.

The airline had planned to receive its first aircraft in August 1999, and the five-month delay to January caused problems because flightcrews had already begun type conversion, and had to be redeployed on its Fokker 50 fleet. SAS' first 72-seater eventually entered service in January 2000, initially on SAS domestic services and flights to Hamburg.

The late arrival of the first batch, and a series of ensuing technical problems forced the airline to revise phase-out plans forits Fokker 50s. From an early stage, SAS has been forced to operate with back-up aircraft, and of the 23 Q400s, two are permanently assigned to stand-by duty, while a third is going through post-delivery modifications at Stockholm. These take around a month per aircraft, and the programme is due to run until the end of 2002, says Eriksson.

SAS Commuter deputy chief engineer Lennart Persson says: "We have had to undertake a lot of modifications to the aircraft, but it has worked." Aircraft reliability is improving, though the use of back-up aircraft helps despatch performance, which is running at around 98%, says Eriksson.

Perrson says, however, that new problems continue to "pop up", making the airline reluctant to give a date for withdrawing the Bombardier-sponsored back-up aircraft. "We are using them every day," adds Perrson.

A "lack of reliability in the delivery schedule" has been a constant problem, says the airline, which has been frustrated by "late notification of delays which affected logistics and crew deployment". This has improved, but there are still problems with deliveries, though SAS' liaison officer at Bombardier "can now read the signals better", says Persson.


SAS admits it was partly to blame for the problems, as it was too ambitious with its Q400 scheduling, exacerbating the difficulties it has suffered.

By far the bulk of the problems afflicting SAS' Q400 introduction have been with cockpit nuisance-warnings, many of which have forced flights to be cancelled or aborted. SAS says there are many reasons for the false warnings, including problems with EFIS and FADEC software, as well as over-sensitive proximity switches on the cabin and undercarriage doors, and landing gear which gives "unsafe" warnings. The flap control unit has also played up, with surfaces stopping in the middle of travel or spurious asymmetry warnings being displayed.

To rectify the EFIS false warnings, Thales has implemented three generations of software upgrades to the flight management system, with the initial V520 being issued in spring of last year, followed by the V600 in September 2000 and the latest V700 instalment last April. SAS says there have also been upgrades from Hamilton Sundstrand for the FADEC software.

"The aircraft is very sensitive to the sequence of powering up or down, when switching between ground- or battery-power and the generator," says Persson. This could often result in different types of spurious powerplant messages being displayed at departure. There have also been problems with battery depletion.

The power-up problems were partly to do with the electrical configuration that SAS requested for its aircraft. The Q400 was configured as a direct current (DC) aircraft despite the fact that SAS specified 115v alternating current (AC) capability to provide compatibility with power supplies at its stations, says Persson. "We now treat the Q400 as a DC aircraft, and it treats us better," he says. Problems have also been reduced as flightcrews and groundcrews have gained experience with the aircraft.

The Q400 is equipped with a DC starter-generator on each engine, and on the auxiliary power unit. The generators' control units initially had too narrow a window, which caused them to trip out during start-up due to system-wide voltage loss, but this has been fixed by new software.

Early on, a problem was identified with an oil line on the PW150 engines, which cracked owing to vibration, and resulted in fumes entering the cabin through the air conditioning system. This also had the effect of setting off the lavatory smoke detectors. The engines had to be removed and sent to Canada for modification.

Last year, over-sensitive smoke detectors in the luggage hold resulted in several emergency landings. These, combined with an emergency landing when a Q400 flightcrew lost some primary cockpit instrumentation due to a blocked pitot tube, led to the grounding of the fleet in October last year. At the time SAS Commuter president Ole Pedersen said: "There have been too many problems. We want the aircraft's performance to be brought up to a level where we can have a normal working day."

"Our main concern was that the continuing faults were damaging the pilots' confidence in the aircraft's systems," says Kent Sauerberg-Hansen, vice president flight operations at the airline. The carrier was also worried that the high-profile problems were threatening to damage its image in the marketplace. "Aircraft were not returned to service until various modifications had been implemented to rectify the problems," adds Sauerberg-Hansen.

While the pitot tube blockage was identified as a one-off manufacturing flaw in the drilling of a water drain-hole, the smoke-detector problem could only be resolved by replacing them with a different model of sensor. "We tested them and discovered they were sensitive to radiation being emitted from mobile phones which passengers had left switched on in their luggage," says Persson.

Quick response

Overall, SAS says that Bombardier has been extremely responsive to the airline's needs, and reacted "fairly quickly to problems". The manufacturer has been working with SAS to sort out problems, but the supply of modification kits and spares needs to be quicker, says the airline. "Product support across all suppliers has been good," it adds.

Although flightcrews coming from the Fokker 50 appreciate the Q400's jet-like performance, "they have mixed feelings about the aircraft due to its history of technical snags," says Sauerberg-Hansen.

The Q400 is replacing SAS McDonnell Douglas DC-9s on certain sectors, and Sauerberg-Hansen says passengers see the aircraft as "an adequate alternative to a jet". He adds the aircraft can be turned around easily within 30min on domestic flights, using forward and aft doors.

The NVS cabin noise reduction system has also given SAS a few headaches, with three software upgrades, and modified active tuned vibration attenuators (ATVAs) installed. "The original ATVAs were going crazy and creating noise rather than suppressing it," says Persson.

SAS' deal with Bombardier included an option to switch some orders to the smaller -300 model. Instead, the airline is taking its last five Q400s on order in a 58-seat configuration for a reduction in price. These can be reconfigured to 72-seats later for a fee to Bombardier for the paperwork.

Changan Airlines introduced its first two Q400s into revenue service in November last year, and the third aircraft arrived in late September this year. The first aircraft had been due to arrive in August 2000, but a combination of production delays at Bombardier and financing issues held up delivery, says Changan assistant president Jimmy Guo.

To prevent a further slip in the delivery schedule, an aircraft earmarked for UNI Air was reassigned as Changan's second aircraft after the Taiwanese regional deferred, and eventually cancelled, its order for Q400s.

Guo says it was Changan's requirement for funds to purchase the Q400s that led to the airline's eventual acquisition by, and consolidation into, Hainan Airlines Group. "It was a difficult time to get financing," he says. "They came to Hainan and we found the terms were right for an agreement."

Guo makes no bones about the fact that the Q400's introduction into service with Changan was far from smooth, though he accepts the 70-seater is extremely economical to operate. "A month after operations began we had a difficult time," he says. "One aircraft had an engine problem, and the engine had to be removed from the aircraft but there was no spare engine at that time. We waited for a month. It was really a headache for us."

P&WC did not have a replacement engine immediately available, and then problems in gaining customs clearance created a further hold-up. Guo says the technical problems were mainly focused on the engines, avionics and NVS system, which needed a software upgrade to work properly. "Reliability is not as good as we expected," says Guo.

Spares inventory

Changan established a limited Q400 spares inventory at its Xi'an base, where a Bombardier technical representative has been permanently stationed to help support the three aircraft. At some points during the past year, as many as three of the manufacturer's engineers have been on site to address operational difficulties, says Guo.

Guo says the Q400 operation has been improving after the initial period. "The aircraft itself is very rugged and the basic design is good," he says.

According to Bombardier, the airline's Q400 fleet is achieving a schedule completion rate of 99.13%, and 28-day average despatch reliability of 97.98%.

Technical problems aside, Guo says pilots like flying the Q400 because of its superior speed and performance compared with the Xian Y-7 it replaced.

Profitable operation

Although Changan's Q400 operation is profitable, Guo says the aircraft lacks passenger appeal as the Chinese market favours jet aircraft. He admits he would like to see the Q400s leave the fleet "as soon as possible" and be replaced with a large regional-jet type.

Guo believes the Bombardier turboprop does not provide enough of an advantage over even the Chinese-built Xian Y-7 to dissuade passengers from choosing to fly on jets operated by Changan's rivals.

"We were advertising a Western fleet, but the passengers thought it was still the old Y-7 airplane," says Guo. "The customers, when they have the option, prefer to select a jet airplane. When the previous management made the decision [to order Q400s] they were looking at the economics not customer preference," he adds.

This about-face on turboprops by Changan follows its take-over by Hainan, which was already pursuing a regional-jet strategy. "Changan wants to phase out the Q400 because Hainan Airlines plans to have an all-jet fleet, which already includes 19 Fairchild Dornier 328JETs," says Guo.

Guo says that if Changan's parent Hainan Airlines Group goes ahead with plans to acquire 50- and 70-seat regional jets, these would replace the Q400s. The chosen manufacturer would also be required to take back the Q400s as a trade-in, he says.

When it received its first Q400s in May last year, Tyrolean Airways was alreadya well-established Dash 8 operator withits first -100s having entered service in 1985. The Innsbruck, Austria-based airline's Dash 8 fleet now totals 19 aircraft, including five Q400s, which are all flown by a single pilot pool.

The airline placed its initial order in January 1997 for four 72-seat Q400s plus four options which it has since firmed up. Tyrolean's Q400s are deployed on domestic and international services from Vienna and on weekend charters around Europe and to North Africa. On shorter routes of less than an hour, the Q400 has replaced Fokker 70 jets, where the turboprop operates "almost the same block times. On Vienna-Innsbruck the Q400 burns the same fuel-load in pounds as the Fokker does in kilogrammes," says Manfred Helldoppler, Tyrolean's manager of flight operations support. Passengers like the aircraft and there has been no negative reaction to the switch from a jet.

The aircraft has "met or bettered" its performance guarantees in almost every area, says Helldoppler, although there are some penalties in certain icing conditions: "We are in discussion with Bombardier and I think this will be resolved," he adds.

Helldoppler believes it was Tyrolean's experience of Bombardier, rather than the Dash 8 itself, which helped the airline through the troubled introduction of the Q400: "It is called a Dash 8, and looks like a Dash 8, but is in fact a completely new aircraft. There is very little commonality with the earlier models," he says. "However we know how to operate aDash 8 and we understand Bombardier's philosophy," he adds.

According to Tyrolean's technical director Hermann Winter, every Q400 delivery to Tyrolean so far has been behind schedule. "The first arrived six months late in May 2000, and Bombardier has provided a BAe 146 to maintain our capacity," he says.

The manufacturer also covers the difference in operating costs between the two aircraft. Although the delays have been improving, things are expected to deteriorate following lay-offs at the Bombardier production plant in Toronto, says Winter.

Like SAS, the airline has suffered the nuisance warnings and spurious power plant messages, but it has always stayed top of the Q400's reliability rankings, says Winter: "It started at 97% and is now around 98.5% - but it is still not good enough. We want 99%."

Problems have been exacerbated because "the reaction time of Bombardier has been too slow. The programme partners are responsible for problems in their parts of the aircraft and the liaison between them hasn't worked and still doesn't," he says.

Winter is a member of the Q400's fleet- wide steering committee, which has been given the task of addressing outstanding reliability, performance or airworthiness issues. "We have drawn up a list of the top 25 and top 50 issues which Bombardier must address," he says.

Areas of difficulty

On a positive note, Winter says that "the engines have behaved very well and P&WC have been very proactive."

Beyond the nuisance warning problems, which are improving, other specific areas of difficulty for Tyrolean include starter-generators; doors (the seals, proximity switches and mechanical issues); and maintenance manuals and part numbers.

The starter generators have proved too fragile, says Winter, with their life having to be reduced from an original 1,600h to 700 cycles. "They are now surviving, but somebody is having to pick up the cost," he says.

Door seals have had to be replaced due to pressurisation problems, while the door manufacturer Mitsubishi Heavy Industries has developed a series of modifications for the handles and lugs/stops.

In addition to all the reliability issues, trouble-shooting has been hampered by incomplete maintenance manuals, says Winter, while there are also discrepancies between some component part numbers and serial numbers. "This is still a bit of a mess but is slowly being cleared up," he says.

This last comment could be applied to the entire Q400 programme. Bombardier has seemingly undermined the impressive earning potential that the high performance turboprop can offer over jets in difficult yield environments by taking too long to address the Q400's poor reliability upon introduction, thereby allowing its image to be tarnished.

Source: Flight International