E-Jets Verdict: High reliability rate & Thrust increase & Maintenance cycles

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High reliability rate

Flybe’s E-195 TDR is running in “the region of 98.5%, which I believe for an introduction is unique”, says Kontorravdis. “This is better than the global E-170/190 fleet.”

Kontorravdis says that Flybe has suffered just two cancellations since introduction of the E-195 due to technical problems, and has “less than 20 ‘WATOG’ events” [defined as a technical delay]. “But of course we would like the aircraft to perform at 99% and above consistently.”

During the first month in service, the first aircraft’s reliability was “remarkable” says Chance. “We only had two technical delays, one of which we think was our fault,” he says, adding that the airline has been “amazed at how few components we’ve had to change”.

But he acknowledges that the airline has benefited from the experience Embraer has accumulated in the three years since the first E-Jet deliveries began. “Although we were the lead for the E-195, there had been so many E-170/175s and E-190s delivered to other operators,” he says.

Horton says that from the pilot’s perspective, the E-195 is a “fantastic machine” and Flybe’s flightcrew, who have come from the Bombardier Q400 and the BAe 146 fleets, “love it”. The airline’s E-195s are equipped with the Rockwell Collins head-up display, which is due to be certificated in September, and will eventually be approved for Category 3A operations. “The jury’s out whether we really want to go for that [minima], given the training that would be required,” says Horton.

He praises the functionality of the flightdeck in an emergency situation. “The system tells you: ‘You have a problem, this is what I’ve done about it and this is what you’ve got left’.” He adds that the clarity and design of the instrument displays are among the best he has ever used. “The information is presented in such a clever way that your situational awareness is superb,” he says.

Despite its impressive design, Horton cautions that the Honeywell avionics suite is still not mature, and software upgrades are arriving “thick and fast”, while Kontorravdis adds: “We’ve had one significant avionics upgrade from Honeywell.”

According to Horton, “the problem with every upgrade is it will address a certain amount of problems, but introduce a few new ones”.

One issue that was still to be addressed earlier this year on the E-195 was the inability of the flight management system to recognise fuel flow data. “Pilots are required to key them in manually, which has certain MEL [minimum equipment list] restrictions,” says Horton.

Although it is a fly-by-wire aircraft, the E-195’s hand-flying qualities are “great”, says Horton. “The E-190/195 has some very good automatic trim compensations when you make configuration changes, for example when the gear or flap is deployed it is automatically trimmed out”. Horton says although the aircraft does have a degree of envelope protection, for example VMO, flap over-speed and pitch limits, there is no automatic bank limit.

Flybe has found that the E-195’s performance is about 3% better than predicted “in terms of fuel consumption and lift capability out of certain airfields where we might have been limited”, says Horton. “We’ve been pleasantly surprised.”

© Luis Rosa
Paramount Airways says early glitches with the Honeywell avionics affected its ability to perform quick turnarounds, compromissing its daily utilisation

Thrust increase

After introduction, Flybe’s CF34-10E engines have been upgraded from the E5 to the E7 specification through a chip change, which provides a 1,500lb thrust increase in contingency rating (from 18,500lb to 20,000lb) in the event of an engine failure to improve field performance. “It helps us, particularly in Southampton on hot days,” says Chance.

Horton says that the E-195 cruises at Mach 0.76 to 0.78, typically at an altitude of 36,000ft (FL360). The aircraft’s maximum altitude is 41,000ft, although this height tends to only be explored during air tests, he adds.

The only complaint that the pilots have about the aircraft is the uncomfortable seat, says Horton. “The seat cushion isn’t thick enough, but Embraer has developed an improved, recontoured cushion that is about to be delivered.”

Flybe’s E-195s are configured in a single-class 118-seat layout four-abreast, which means the cabin has 29 rows of seats. “It does make a very long cabin,” says Chance, but he adds that this is not an issue during turnarounds. “Normally we use the forward airstairs, but if we are trying to do a particularly short turnaround then we can put a set of airport stairs at the rear door and use both exits,” he adds.

Horton says that for an aircraft of this size, the centre of gravity envelope “is surprisingly big”.

Chance says that the one disappointing aspect of the E-195 introduction was the engineer training provided by Embraer’s European partner SAT in Zurich.
“There were many issues, but our main complaints were that they were just not ready to begin training for the E-190/195.

Their instructors were inexperienced and had a heavy predominance on the E-170, with little or no knowledge of the E-190/195. But Embraer put pressure on SAT to redo the courses.”

Mauro Kern, Embraer executive vice-president, airline market, says that there was “one isolated case” of an inexperienced SAT instructor teaching an avionics course as part of Flybe’s E-190/195 programme. SAT is now “going deeper into the details” for the course, says Kern, adding that “feedback from other courses was very positive”.

Flybe has also expressed its displeasure to Embraer about the E-190/195’s maintenance programme, which has intervals that are much shorter than promised.

“The assumption was that they’d take the E-170 programme and read it across to the E-190, but the authorities in Brazil wouldn’t allow that. As a consequence the intervals are much shorter than on the E-170,” says Chance.

© Embraer
LOT says that the build quality of its E-Jets has been steadily improving

Maintenance cycles

For example, the threshold for the structural tasks is between 8,000 and 16,000 flights, compared with 20,000 cycles on the E-170. The landing-gear overhaul interval is 20,000 on the E-190 compared with 30,000 on the E-170. “We have a promise from Embraer that they will resolve this, but it is still an open issue,” says Kontorravdis.

Embraer’s Kern says the airframer is working to “harmonise” the maintenance intervals: “We expect to have the TBO extended from 20,000 cycles to 30,000 cycles before we reach that [maintenance event],” he says.

Flybe says the length of the E-195's 118-seat cabin has not been an issue during turn-arounds