Read More: The Pressure to Fix
May 20, 2019

Pressuring maintenance technicians to rush helps no one.

Feeling pressure to fly is a common topic of conversation in aviation safety circles. Flying an aircraft while maintaining the expected level of safety for all aboard is complex and should command our full attention.

There are many policies and industry best practices aimed at preventing external stressors from affecting pilots and crewmembers. These stresses are many and varied. They may include personal stressors from home or family; work stresses from co-workers, bosses, and customers; or flight conditions such as the current or forecast weather.

But what about the pressure on maintenance technicians? The number of aircraft in service today has outpaced the supply of maintenance technicians, resulting in fewer mechanics to service an ever-growing fleet. They perform both mandated maintenance and unexpected repairs, often in a rapidly changing environment. In many cases, the people they work for are concerned about the amount of time the aircraft will be out of service or the cost of the work to be performed. 

Human factors are a direct cause of or a contributing factor to most aviation accidents, and we should not forget that this applies to maintenance technicians too. One simple way to prevent an A&P from feeling pressure is to give them the time and space to do their job.

I was recently asked to repair the engine of a Beech Debonair that had developed an internal gear problem. I accepted the task and assembled a capable team to assist me. This not only enabled me to get the job done faster but also provided redundant quality assurance.

Read More: How Far Is Too Far?
February 26, 2019

Preventive maintenance is always better than reactive maintenance.

Earlier this year, I was having maintenance challenges with an aircraft. Sometimes everything was perfect and nothing amiss, but other times, something wasn’t right. The plane would be hard to start but then would run perfectly. Other times, it wouldn’t start at all.

I read maintenance manuals, troubleshooting charts, and online blogs. I spoke to tech support people. I checked p-leads, spark plugs, fuel delivery, and the electrical system. I changed the ignition switch and installed a new carburetor. But I didn’t get to the root of the problem until the last maneuver of a biennial flight review, when the engine quit and the proverbial light came on.

What I had been experiencing all along was an intermittent magneto problem—a dual magneto problem at that!

A dual magneto failure. What are the chances? I hadn’t thought it possible. Our machines are redundant in so many ways. The electrical system is designed to make a dual mag failure very unlikely.

Here are some clues as to how this happened: Both magnetos were installed new at the same time during an engine overhaul. Both had 950 hours on them. Although both magnetos should have had 500-hour inspections, that never happened. At each annual inspection, the timing was checked, along with all items spelled out in FAR Part 43, Appendix D. Ops normal.

For Part 91 operations, the FAA allows us to continue to fly our aircraft if they pass the Part 43 annual inspection. We do not have to abide by the criteria for manufacturers’ recommended inspection or recommended time before overhaul.

This usually works out because much has been done in the past five decades to improve the equipment we fly. The machining process is better. The lubricants we use are a lot better. Parts are precision machined and last longer than components of yesteryear.

Many owners and pilots continue to fly beyond the recommended time limits. Is that a problem? It could be. You must ask yourself: If I do not use the manufacturer’s limit, then what is the limit? How far beyond the inspection criteria is too far?

When you fly that component to failure, you will know exactly how far is too far. But when you reach that point, where will you be? On the ground at your local airport or helipad? Or in the air, perhaps far from a hospitable forced-landing site?

A few days ago, I was in a different aircraft, out of town on a short flight of about 35 minutes each way. On the way back, I experienced an alternator failure. Not as big of a deal as the dual magneto failure, but still I had to do some higher-level math to determine how soon I needed to get the electric landing gear down with available battery power. I was certainly grateful to have an engine monitor, an electrical system monitor, and a navigation system with time-to-go displayed.

With a little brain power, I calculated I could get back to base with no problem. I chose to slow down and lower the landing gear at 11.7 volts to allow some juice to spare for radios. It worked out nicely. The gear went down, and the radios, autopilot, and transponder continued to work with the battery power I had.

Upon landing, I went through the logbooks. The alternator had been in service for 20 years and one month, or 1,756 hours. Kudos to the company who assembled such a robust alternator, but it should have been replaced or overhauled well before that day.

We have the right and authority to fly our machines beyond manufacturers’ recommended limits if we do not fly for compensation or hire. But we need to be smart about it and not put ourselves in a position where we fly them to failure. If you fly a component beyond the manufacturers’ recommendations, fine. But then whose recommendations will you follow?

Fugere tutum! 


Read More: The Win-Win of a CASS Program
November 13, 2018

Evaluating your maintenance performance leads to safer, more efficient operations.

As stated in 14 CFR 135.431, Part 135 operators who operate aircraft with at least 10 passenger seats are required to set up and maintain Continuing Analysis and Surveillance (CASS) programs. The CASS program ensures the overall effectiveness of an operator’s inspection and maintenance activities by collecting data on their performance and analyzing and correcting deficiencies. It will also help operators to identify hazards and to structure control measures to minimize risks, thereby increasing the safety of their operations.

Your CASS program should contain the following elements to ensure that your maintenance activities are carried out effectively and in full regulatory compliance:

  • Gather the data necessary to evaluate the performance of your maintenance activities
  • Identify deficiencies and positive or negative trends
  • Facilitate in making appropriate revisions and modifications when necessary.

Inputs into a CASS program generally come from two sources: performance information from aircraft and engines, and the results of a systematic audit of maintenance activities.

Performance Analysis

Data sources for this part may include inspection forms, minimum equipment list items, pilot reports, scheduled and unscheduled component removals, service difficulty reports, engine performance data, and reports from flight-data monitoring or health and usage monitoring systems.

Problems that affect or could affect airworthiness or the safety of passengers and crew must be given top priority and the root cause determined and corrected ASAP. Put a system in place so that urgent issues are reported to the appropriate levels of management in a timely manner, and make sure everyone understands when it is appropriate to use the emergency response channel for their reports.

Nonemergency items that affect safety can be sorted into those that require short-term or long-term monitoring. They will also need to be prioritized according to their severity and likelihood, and analyzed for subsequent corrective action. Problems not related to safety can be prioritized according to scope, financial impact, convenience, or accepted as part of the cost of operation with no corrective action required.

Audit Function

The audit function needs to include at least the following areas: removed component condition/evaluation and follow-up, review of the administrative and supervisory aspects of the maintenance program (both internal and vendor), and ensuring regulatory and policy compliance.

It has been estimated that in 65 to 70 percent of all maintenance-related incidents and accidents, failure to follow approved policies and procedures was a major contributing factor. In addition to the potential for a serious accident to occur, failure to comply with appropriate documentation frequently places the operator and maintenance personnel in a position of regulatory noncompliance and all of the associated problems that come with it.

A good audit program is one that is structured to provide a continuous audit of the maintenance system to ensure that everyone, at all levels, who is connected with the system are in compliance with:

  • All applicable government regulations
  • OEM policies, procedures, and maintenance instructions
  • Your customers’ required or recommended policies and procedures
  • Your own company’s policies and procedures
  • Industry standards.

As the Part 135 operator, you are responsible for ensuring that all external suppliers and vendors also are in compliance with all applicable government regulations. This means that your outside suppliers and vendors must be included in your audit program, as you need to gather the relevant information that substantiates their compliance.

The audit program should ensure that:

  • All technical data are current and readily available to the user
  • All maintenance is performed in accordance with the methods, standards, and techniques specified in the appropriate technical data
  • All maintenance documentation, such as inspection forms, work orders, and so on, are regularly reviewed for completeness, accuracy, and proper entries
  • All airworthiness releases are properly executed by the appropriate individuals
  • All carry-over/deferred maintenance items are properly handled
  • The receiving department identifies and inspects parts and materials in accordance with regulations and best practices
  • All shelf-life items are properly controlled
  • Procedures for the calibration and control of tools and equipment are in place and being followed
  • Housekeeping requirements are being met to ensure a safe working place.

While you may not be required to run a CASS program, there can be significant benefit for operators who use 14 CFR Part 135, Subpart J, Mainte­nance, Preventive Maintenance, and Alterations, as a template for developing their own maintenance quality assurance program.