Just say 'no' to your mechanic

Useless maintenance can do more harm than good

October 11, 2013

When it comes to maintaining aircraft, owners bite the bullet, open the wallet, and pay whatever it takes to the keep the aircraft in airworthy, tip-top condition. But, Mike Busch, an A&P with inspector authorization who owns Savvy Aircraft Maintenance Management, cautioned that owners should be careful not to fall prey to “overkill maintenance” that could hurt the aircraft and break the bank.

During an Oct. 10 seminar, “Avoid useless maintenance,” Busch likened aircraft maintenance to surgery. More isn’t better. The more invasive it is, the higher the likelihood that the procedure itself will cause damage. He pointed out, however, that mechanics and owners seem spring loaded to overhaul an item—think open heart surgery on an engine—when a simpler repair would suffice.

“Most owners have a hard time saying ‘No’ to their mechanics,” said Busch, but doing so on certain squawk items could save owners thousands of dollars a year. Busch shared dos and don’ts that he’s practiced for the past 25 years that he said can cut maintenance costs almost in half.

The key, he said, is to perform only the work needed to keep the aircraft safe and reliable, and to comply with any regulations.

If owners tell their mechanic not to address a certain discrepancy, they should do so in writing in order to absolve the mechanic of any liability. Busch recommends writing, “I decline,” and then fill in the blank with a specific list of items not to address.

Say ‘no’

Time-based preventive maintenance. Busch said that preventive maintenance items recommended at fixed time intervals, such as engine, propeller, and other TBOs, be changed to a condition-based evaluation. If an engine is still performing well and showing no indications of problems, it’s safe to run it past its time between overhaul. Or a main battery that is recommended be replaced every two years—why not when its capacity remaining reaches a certain level? Condition-based maintenance allows the mechanic to decide whether an item needs to be repaired or replaced instead of having to perform time-based maintenance on items that don’t need it.

Maintenance intended to prevent acceptable failures. “If a component won’t hurt someone or leave you stranded, then run that component to failure,” Busch said. For example, Busch said his Cessna 310 has two engine-driven fuel pumps. The manufacturer recommends replacing them every 500 hours. The failure of one of the pumps isn’t critical, so he runs it until failure. As he joked with the audience, “I don’t euthanize vacuum pumps.” However, he admitted to carrying a spare and some tools in his aircraft in case one fails at an in opportune time, like a long trip away from home.

Overkill. “Never overhaul if a repair will suffice,” Busch said, using magnetos as an example. Often, magnetos should be repaired, not overhauled. The difference, Busch explained is that in an overhaul all bearings must be replaced regardless of condition, whereas a repair would allow the mechanic to only replace those bearings that needed it. He also suggested using rebuilt parts instead of new ones.

Say ‘yes’

Maintenance required by regulation. Manufacturers’ maintenance recommendations are not mandatory, but airworthiness directives, airworthiness limitations in aircraft certified under Part 23 (verses CAR 3, which doesn’t have airworthiness limitations), required inspections, biennial certifications, and emergency locator transmitter (ELT) battery replacement must all be complied with, no questions asked.

Airworthiness items. While owners should be cautious that some IAs might call almost everything an airworthiness item that needs to be addressed, most of the time the list of discrepancies truly needs to be dealt with. An airworthiness item, Busch said, is one that an “IA judges to be serious enough that he can’t sign off the annual as airworthy unless it is fixed.”

Above all, Busch recommend that owners research a maintenance shop before using it for major work like an annual inspection. He suggested testing the company with smaller repair items to see how they perform before entrusting a large project to them.

“Consistent application of [these] principles routinely cuts maintenance cost in half without reduction in safety or reliability,” he said.