The most important factors in an airline's selection of an airframe maintenance firm typically are quality, turnaround time (TAT) and price, in that order. Airlines usually rank TAT ahead of price because it can cost $10,000 a day to lease a narrowbody for each day of planned TAT, and several times that for a widebody, according to maintenance consultants at Oliver Wyman. Unplanned TAT delays cost even more in revenue losses.

Special circumstances can shift customer priorities. If an airline temporarily has more jets than needed to fly its schedule, as was true for some carriers in 2009, or if an aircraft is transitioning from one airline to another, TAT becomes less important. But for a fleet sized right for its network, as most fleets soon will be, short TAT is key to minimizing total maintenance costs.

Several major MRO firms have used the slack maintenance market to cut TAT dramatically, by nearly one-third in some cases. This progress should prove to be a strong competitive advantage when the market tightens again.

Moreover, rivals may not catch up quickly. "Reducing TAT by Lean and Six Sigma are not for the faint-hearted. They take several years," stresses Chris Doan, president of TeamSAI. "There can be differences in TAT of 30%-40%. We think it will be a key differentiator in the next couple of years."

To differentiate itself, SR Technics has blazed a fast pace. It began applying Lean, Six Sigma and kaizen to airframes a year-and-a-half ago, aiming for 30% shorter TATs, especially for six-year Intermediate Layover (IL) checks on Airbus jets. "We reviewed all our processes, eliminating redundancies," says Helmut Himmelreich, senior EVP, aircraft maintenance.

SRT's C checks on A320s now take three to four-and-a-half days for full-support customers and four to five days for drop-in customers. IL checks take 17 days, and 12-year heavy maintenance visits (HMVs) on A320s require 21 days.

C checks on A330s and A340s require from 54 hours up to four days, depending on whether the check is an even or uneven C, and whether the customer is on a full-support contract. These checks are shorter than equivalent checks on A320s because SRT can put more mechanics on widebodies. IL checks on widebodies are 21 to 24 days, depending on painting requirements. The 12-year HMV comes in at 24 to 26 days, again depending on painting. SRT aims to cut that further to 21 days.

"As far as I know, nobody is quicker," Himmelreich says. "Given the current situation, short TAT is not so important for some airlines now but will become so in the future."

For narrowbodies, SRT offers equalized checks, used for six years by one large low-cost fleet. Equalized maintenance distributes the work of A and C checks into 36 packages done in overnight checks at 600 flight hours, 500 cycles or 66 days, whichever comes first. A320s get Es from 10 p.m. to 6 a.m. "The big advantage is much better availability," says Emil Frehner, head of heavy maintenance. Replacing Cs that take 4 to 6 days every 18 months, E checks have saved 17 days of downtime in six years, while customer easyJet enjoyed 99.4% dispatch reliability on very high utilization.

At six years, equalized-checked A320s still require IL checks. SRT has cut TAT on these ILs from 21 days to 14 days, including painting of the vertical fin and fuselage, but not wings. If the operator continues with the E program, then a total of 28 days of downtime will be saved over 12 years, at which time a full heavy check will be needed. SRT aims to save more time by reducing E program ILs to 12 days.