Maintenance and Certification

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Top 10 Tips for Turbines

by James Careless, Aircraft Maintenance Technology (AMT) contributor. This article was originally published in the July 2008 issue of AMT magazine, and is reprinted with permission.

Turbine engines are many aircraft technicians’ bread-and-butter. But even the most experienced technician can benefit from some sage advice on turbine repair and servicing, as provided by the experts at Dallas Airmotive and Standard Aero. Here is the cream of their collected wisdom, distilled into 10 Top Tips for Turbines!

1. Before you start, think
Tearing a turbine engine apart when you haven’t formulated a plan of attack first is a recipe for disaster. Not only could you miss the problem you are trying to fix, but you could even make matters worse, not better. This is why Standard Aero SVP of Technology Kim Olson stresses “getting your overall mindset together first. You need to go over the fault reports you’ve got, then pull out the manuals and look them over carefully,” he tells AMT. “Next, you have to use this information to put together a comprehensive plan of attack, making sure that you take the right tools for the job and follow the proper precautions as well. Do your homework before you start diving in and turning wrenches!”

 
Mechanic working on a turbine
Before you start working on a turbine, put together
a plan of attack with the right tools and manuals.
(Photo: Dallas Airmotive)

2. Talk to the flight crew
Troubleshooting an intermittent fault is a technician’s worst nightmare, especially when it can’t be recreated in the shop. This is why it is important to thoroughly debrief the flight crew to find out the conditions under which the fault occurred. “Does it only occur at 18 000 ft or when the anti-icing system is on? These are details that can help you pinpoint a problem,” says Larry Galarza, Dallas Airmotive’s 731 field service manager. “But you can only learn about these details if you talk to the flight crew and get comprehensive answers first. So get out there and ask questions; lots of questions.”

3. Let’s say it again—read the manual
When it comes to making mistakes in turbine repair, “the most common error is not to read the manual first,” says Olson. “I know we’re guys and that we like to assemble things before we ever look at a manual, but turbine engines are complicated. Read first, then act.”

4. Troubleshoot carefully
When you are troubleshooting a turbine, take your time and be careful not to jump to conclusions. “Every detail counts,” explains Olson. “Depending on the symptoms and evidence you find, troubleshooting will lead you to draw different conclusions. Rush through the process, and you could end up drawing the wrong conclusions; to the detriment of the engine and possibly yourself.”

5. Work methodically
Turbine engines are complex, so be sure to approach them in a logical manner. In particular, work in a methodical, step-by-step basis. You don’t want to find yourself at job’s end with a few unexplained spare parts!

6. Know your limitations
It is important to know what you are capable of doing on a turbine engine, and when you are out of your league. “Don’t be afraid to pick up the phone to ask someone for qualified advice,” says Terry Huecker, Dallas Airmotive’s Pratt & Whitney 300/500 field service manager. “Many companies such as Pratt & Whitney and Honeywell have excellent help desks. As well, it makes sense to build a community of technicians who you can consult and who can consult you. You can meet them at training courses, conventions, or even social events. Wherever you find them, get networking today to have people to call tomorrow.”

7. Get out your borescope
When in doubt, it makes sense to get a closer look at possible problem areas inside an engine using a borescope. “If you go in early enough, you can often catch a problem such as a cracked blade before it becomes serious,” says Olson. “Problems caught early are easier and less expensive to fix, and don’t result in additional problems such as having damaged blade fragment and damaging the entire engine.”

8. Take the turbine’s temperature
Tracking down an elusive problem? Try checking the turbine’s inlet temperature over time—using data downloaded from the aircraft’s monitoring system—“can guide you as to where you should start looking,” Olson says.

9. Don’t be rushed
When it comes to troubleshooting and then repairing a turbine engine, give yourself the time to do the job correctly. “A lot of times aircraft technicians get caught up in the hurry to get an aircraft back into service,” says Galarza. “Don’t let them put a flight schedule in front of you. Stick to your skills and your expertise, and do the job properly at the right pace.”

10. Finally, a clean turbine is a happy turbine
Well, maybe not happy, but taking the time to do compressor washes on a regular basis can reduce blade corrosion. In turn, reduced blade corrosion means longer life and more efficient fuel usage; a critical concern given today’s sky-high fuel prices.

“I have seen a number of engines that were stored for future repair without having their compressors washed,” Olson says. “The resulting corrosion can be so bad that the engine may end up being irreparable by the time it gets pulled out of storage for servicing.” He adds that fuel nozzle cleaning “is also very important for a turbine engine’s health and longevity.” 

Double or Triple Release?

by Brad Taylor, Civil Aviation Safety Inspector, Operational Airworthiness, Standards Branch, Civil Aviation, Transport Canada

Maintaining a stores department for an air operator or distributor is not a simple task! Ensuring that high demand spares are always available requires a systematic approach for processing rotables and replenishing consumable materials. Success or failure in this discipline can mean the difference between profit and loss for an organization.

The personnel working in this capacity must be experienced in the handling and shipping of aviation components, ranging from lead acid or nickel cadmium batteries, static sensitive components, chemicals, and a wide variety of hazardous materials. Then, just to make the job just a bit more demanding, personnel are often called upon to be inspectors and are expected to be well versed on the regulatory requirements associated with the job, such as segregating serviceable and unserviceable products, purchase orders, eligibility and international agreements for maintenance acceptance.

The purpose of this article is to focus specifically on maintenance releases for rotable (repairable) parts that, on occasion, must be maintained by organizations located outside of Canada. This genre of spare parts represents a large investment for an organization and therefore demands the most attention by the stores personnel to ensure that it is managed as efficiently as possible.

Aeronautical products maintained under any regulatory system receive a maintenance release after the maintenance is complete, which states the pertinent data by which the work was completed and under which regulatory system the work is acceptable. The regulatory reference and the approval number of the organization that performed the work are also essential to the subsequent installer in order to determine whether the product has been maintained in accordance with the applicable standards of airworthiness for the aircraft or assembly on which the product is to be installed. This determination (eligibility) is the aircraft maintenance engineer’s (AME) responsibility and the basis for this decision is the country in which the aircraft or assembly is registered. Of course there are more factors involved in the decision, including parts numbers, mod status of the aircraft/component, etc., but the first step is determining the applicable regulatory system by which the aircraft or component must be maintained.

Approved maintenance organizations (AMO) and distributors find that having “maintained” aeronautical products in their inventory that have dual releases to be advantageous; these products are accepted for installation by two regulatory authorities, the European Aviation Safety Agency (EASA)/Transport Canada Civil Aviation (TCCA) or the U.S. Federal Aviation Administration (FAA)/EASA. A dual release adds value to the product in the resale market and provides flexibility to large operators when aircraft are registered in different countries. Applying the same logic, a part with a triple release would be of even more value, if it were possible.

Recently, we (Transport Canada [TC]) have been receiving some comments from EASA-based Part 145 AMOs, informing us that they were no longer allowed to issue a triple release. Some organizations hold EASA Part 145 approvals as well as FAA and Canadian approvals for repairing aeronautical products. They have often certified the work performed on an authorized release certificate with all three regulatory references so the customers could install the item on a wide variety of aircraft or distribute them to a broader customer base. It was a service that provided the customer with more flexibility with respect to their spares.

The issue with this practice isn’t that the organization doesn’t have the authority; it’s more of a technicality within the international agreements. The agreements are bilateral between parties such as Canada and EASA, or EASA and the FAA; they are not trilateral. Therefore, the agreements were never intended to be applied at the same time, which means the application of all three approvals on one authorized release certificate would not be appropriate or acceptable. This is also evident when examining the authorized release certificate forms or templates recognized by TC, the FAA or EASA. None of them allow for more than two regulatory references because the document is intended to be used with a maximum of two parties.

So what can an organization receiving, selling or using maintained aeronautical products do? Firstly, in the short term, we recommend a discussion take place with your staff to ensure that everyone knows how to identify a discrepant authorized release certificate. Secondly, if an organization wishes to maintain this flexibility within its spares pool, it must be specified on the work order that the repair organization issued separate authorized release certificates in order to respect international agreements. This may add cost and paperwork to the process, but it will ensure that an organization has a spare part which is of maximum value to it.  

Distractions

by Gerry Binnema. Gerry is a renowned consultant and facilitator in all aviation safety management topics. For more information, visit www.gjbconsulting.com.

One of the greatest fears an aircraft maintenance technician has is making an error that leads to a fatal accident. Maintenance errors occur every day; fortunately these errors are usually caught well before anything terrible happens. The most common maintenance errors are errors of omission: the technician knows what to do, intends to do the right thing, but for some reason, a step is overlooked. A bolt doesn’t get properly torqued, a nut doesn’t get a cotter pin, or an assembly lacks an O-ring. A distraction at a critical moment is often a contributing factor to such errors.

Over the last couple of years, I have run several recurrent training sessions on human factors in maintenance. Through the use of a quick poll, I asked people which of the dirty dozen they find to be most significant in their workplaces. The results have been quite consistent, with distraction being the most significant issue that people are currently facing. This is certainly a sign of our times, as the prevalence of smart phones and the expectation of immediate responses to e-mails and phone calls has led to frequent disruptions in the workplace for all of us.

There is a fallacy that we are becoming better at multi-tasking and can therefore handle these disruptions. The truth is, multi-tasking is an illusion that our brain generates as we rapidly switch our attention between various tasks. We can only focus our conscious attention on one thing at a time, and while we focus on one thing, we lose our focus on whatever else we are supposed to be doing. This creates an opportunity for errors of omission.

Managing distractions is obviously a significant topic of discussion that we need to have in our workplace. During my last human factors course, I facilitated a discussion on managing distractions and promised to write an article based on that discussion. I am indebted to that class of experienced maintenance technicians for the following ideas on how to manage distractions.

Perhaps the first and most significant idea is to get rid of the belief that we are capable of multi-tasking. If you are conducting maintenance while also engaging in some other activity that requires your conscious attention, then you are setting yourself up for failure. Create rules in the workplace regarding common distractions such as phones, tablets, or other technology near a working technician. Even if a person says they will ignore incoming messages, a flashing light or soft beeping signalling a new message will distract the technician, affecting their focus on the work at hand. Keep this in mind driving around the ramp and for run-ups. If you are talking on a cell phone you are not focusing on the task at hand.

Another idea is creating an atmosphere and culture in the workplace that makes it okay to say “not right now.” Maintenance tasks often require an extra set of hands so we are often asked to help move an airplane, hold a propeller or provide other types of support. We all want to be good team members and we are always willing to help, but when those distractions come at critical moments, the possibility of an error of omission is introduced. We need to support the person who says “not right now” under those circumstances. Often we just need a couple of minutes to complete a step and then are able to help out, thereby eliminating the fear that something critical may be missed.

If you are distracted, or step away from the job even for a moment, review the last three steps of the job to make sure they were completed before you move on. Our minds are always thinking several steps ahead in the job we are doing and when we are distracted and then return to the job, it is often easy for us to believe that we were several steps further ahead than we actually are. Use the maintenance task card or checklist as they were intended to be used by signing off on each task as it is completed. This will help ensure that we don’t get too far ahead of ourselves.

Finally, plan ahead to avoid distractions. You may have many different responsibilities at your workplace and these may lead to conflicting priorities. If you are a crew chief or a manager, ensure that you set up your day so that you can deal with your managerial responsibilities during certain hours and then focus on your maintenance responsibilities when you are on the hangar floor.

None of these suggestions are especially difficult to execute, but they require a great deal of discipline to actually follow consistently. By taking the threat of distractions seriously, we can create a culture in our workplace that encourages good habits. I encourage you to bring up the threat of distraction at your next pre-shift briefing to discuss some of these ideas.

 

STOP! Inventory your tools after each job
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