Read More: Ensure Fuel Purity with Soak Testing
November 16, 2020

The performance and safety of your aircraft depend on this procedure.

At my firm, Aviation Marketing Services, we’re often asked about soak testing, which is used to verify the purity of aviation fuel.

If you’re responsible for—or depend on—fuel in your work, you likely know how important it is to perform a soak test after completing new construction or major repairs to tanks or piping. This applies to both fuel storage systems and servicing vehicles. Afterward, a laboratory evaluation of the fuel samples used in the soak test can detect any potential contaminants—from solvents used in coatings and linings, welding flux, preservative oils (corrosion inhibitors), valve grease, and other debris—that could compromise the performance and safety of the fuel.

Because soak testing is such an important step in purchasing fuel, any acquisition or modification contracts for new fuel systems or servicing vehicles should include a clause that requires the manufacturer or contractor to provide evidence that a proper soak test has been performed. The clause should also require that the test results verify the fuel meets the appropriate ASTM International specifications.

Let’s review how to conduct a soak test and the various lab tests involved.

Fuel Systems, Storage Tanks, and Related Equipment

A soak test consists of filling a fuel system (stainless steel, aluminum, epoxy lined, or rubber bladder) with an adequate volume of the appropriate-grade fuel and, after following the recommended recirculation procedures, allowing it to soak for a period of time recommended by ASTM or the specific fuel supplier. Before putting the fuel in the system, be sure to retain a sample to serve as a control batch should testing reveal ­off-specification product.

By following the stringent requirements of Energy Institute (EI) Standard 1541, Requirements for Internal Protective Coating Systems Used in Aviation Fuel Handling Systems, you’ll dramatically reduce the risk of fuel contamination. Adherence to this industry standard ensures that the proper coating materials were correctly applied and allowed to fully cure as recommended by the manufacturer, and that storage tanks (including piping, pumps, valves, meters, filter vessels, and so on) are filled to the normal level and the fuel recirculated completely at least once and allowed to soak for a minimum of four days and a maximum of seven.

At the end of the designated soak period, obtain a 1 gallon sample from the new or repaired system and send it off for laboratory evaluation. The best location from which to obtain a sample is the low-point drain. Remember to displace an adequate volume in the sampling piping to ensure a truly representative sample of the tank bottom.

Fuel-Servicing Vehicles and Hoses

All fuel-servicing vehicles with tanks and piping made of aluminum or stainless steel should have the appropriate fuel circulated throughout the system. Fueling vehicles (whether new, repaired, or those that have undergone an extended period out of service) should be filled to the normal level and the fuel recirculated completely at least once and allowed to soak for at least an hour. You may obtain 1 gallon representative samples of fuel from any combination of multiple low-point drains and combine them into a single sample.

For proper soak testing, every fueler loading hose and every aircraft fueling hose must meet industry standard EI 1529/IOS (International Organization for Standardization) 1825 for hoses and assemblies. The hose must initially be filled completely with the appropriate fuel and allowed to soak for at least eight hours. The fuel in the hose must then be disposed of properly and the hose refilled.

To verify the absence of any manufacturing residue, you must perform an appearance check of the fuel for discoloration. The fuel should then be recirculated in an amount equaling at least twice the volume of the hose, back into storage, upstream of filtration. Follow up with a hose-end nozzle strainer inspection to confirm the absence of any particulate contamination.

Lab Testing of Avgas and Jet Fuels

In the case of avgas 100LL (aviation gasoline 100 low lead), the critical aspects of contamination are interfacial tension (how well water separates out from the fuel) and gum contamination, which leads to engine anomalies. The tests that should be performed on avgas 100LL are:

  • ASTM D4176, appearance
  • ASTM D381, gum content
  • ASTM D1094, water reaction
  • ASTM D2887, simulated distillation (this test is more sensitive to residue and chemical contamination than the standard test for distillation, ASTM D86).
    The tests for aviation turbine fuels (also known as jet fuels) are the same as those for avgas 100LL, with the addition of the following:
  • ASTM D156, Saybolt color test
  • ASTM D3948, MSEP (microseparometer analysis, for water separation)
  • ASTM D2624, electrical conductivity
  • ASTM D3241, jet fuel thermal oxidation test (JFTOT)
  • ASTM D56, flash point.

The JFTOT is notable because it reveals any change in volatility along with oxidation characteristics and evaluates insoluble and soluble materials that form deposits in the engine.

Correct Sampling

Fuel sample preparation, handling, and ­follow-through are all key to successfully testing aviation fuel. If a jet fuel sample is drawn through sample points that incorporate metals such as cadmium, brass, or copper, the JFTOT results may fail. Similarly, using galvanized piping (zinc) in avgas 100LL could alter the lab results.

Finally, make sure the sampling point is clean and flushed before taking a sample. Accumulated solid particulate matter or any free water should be removed, and final fuel samples should be clear and bright. Use a 1 gallon, approved epoxy-lined sampling container, and flush and triple-rinse it with the fuel to be sampled and tested. 

Read More: PPE in These Unprecedented Times
June 07, 2020

During a global pandemic, personal protective equipment is hard to find—and still critical.

What a difference a month makes. Not long ago, many of us in my neck of the woods were counting the days until spring break, ready to cast away winter in favor of the great outdoors and warming temperatures. But then, on March 11, COVID-19 was declared a pandemic by the World Health Organization, signaling a global health crisis and putting a clamp on both the present and the immediate future.

With so many people remaining at home, the crisis has had some obvious effects on the aviation industry, including reduced operations. But there’s another, perhaps less-recognized concern.

Read More: If You See Something, Say Something
January 17, 2020

Modern safety management empowers every employee to speak up.

We’ve come a long way managing aviation safety since the early years.

I read that when aviation pioneer Jimmy Doolittle was on loan from the US Army in 1926 to perform flight demonstrations in his P-1 Hawk biplane in South America, he broke his ankles in a barroom stunt. With both ankles in casts, Dolittle had his mechanic bolt them to the rudder pedals. The flight demonstrations went well, and Doolittle returned to the States to spend time at Walter Reed Army Medical Center to mend from his antics. That’s one version of the story, at least, and one worthy of campfire folklore.

In decades past, safety was a bottom-up approach: if the pilot or mechanic/engineer thought it reasonable, then managers didn’t balk. There was often an attempt to power through the situation. When all was good, such as in Doolittle’s stunt, the mechanic/engineer or pilot was hailed as a hero. If the attempt at safety failed, they were said to have made a poor decision. This haphazard approach to safety management was bad for everyone involved: companies, owners, shareholders, employees, pilots, and passengers alike.

Fast-forward to 2020. The buzz term in aviation safety today is “safety management system,” or SMS. It’s centered around decision-making, process improvement, and a positive safety culture, and it employs a top-down AND bottom-­up approach to managing safety.

Top-down is important because for SMS to be effective, an organization must have a positive safety culture, something that can’t be done without the buy-in of senior leadership. Everyone from the CEO down must endorse the company’s commitment to safety and a just culture. When the going gets rough—when the pilot turns down a flight because of weather or a mechanic/engineer grounds an aircraft—it’s crucial that management back their decisions. Ensuring flight safety must be prioritized over the company’s bottom line.

The bottom-up part of SMS comes in because it recognizes that safety isn’t just the responsibility of the pilot, the safety director, or any one person: it’s everyone’s job. SMS requires open communication about detecting hazards and managing risk, granting authority at all levels to point out safety concerns.

Often the mechanics/engineers in a flight department, especially if the company is small, are left to manage safety themselves, thinking issues through without any help from management. They often work alone without supervision and many times late at night to support the daytime flight schedule. 

If you’re a manager, empower all your employees to feel free to speak up if they see something out of place or that doesn’t seem right. That puddle under the aircraft the flight nurse pointed out is probably water from the air-conditioning condenser, but what if it’s fuel? Your pilot thinks he might have exceeded a time limit for torque, so he writes it up and notifies the mechanic/engineer. A quick look at the exceedance page verifies he didn’t exceed a limit, but without the benefit of having a positive safety culture and SMS in place, that pilot may not have been comfortable speaking up.

If you’re a pilot, mechanic/engineer, or crew member, communicate with your managers to promote open channels of conversation and keep them informed of any challenges you may encounter doing your job. Your comments may help them to connect the dots and detect a safety hazard.

In aviation, we’re surrounded by people with type A personalities. We like to do it all ourselves. But collaboration can offer great solutions if you let it. Another term for this in our industry is “crew resource management”—using all available resources to achieve a desired result. 

If you still doubt the importance of enforcing an SMS from top to bottom no matter the size of your business, I’ll leave you with this thought: if you think safety is expensive, try having an accident. Better yet, don’t.

Fugere tutum!

Read More: Launching a Successful Human Factors Program for Maintenance
December 10, 2019

What could possibly go wrong?

Most safety professionals will tell you that “selling” human factors to maintenance technicians can be a daunting task. It’s no wonder they, having endured a multitude of failed safety improvement programs over the years, regard human factors as more of the same. “Flavor of the month” is a term often heard. Others compare it to a bad case of indigestion with the wistful words, “This too shall pass.”

By the end of a typical human factors course, that skepticism has turned to enthusiasm. Negativism is replaced by comments like, “Superb course,” “I recommend this to all technicians,” and, “We should have started this a long time ago.”

That’s a great start for your human factors program, but it’s just the beginning. Technician support is essential to the success of any human factors program aimed at reducing maintenance errors and improving workplace safety. Garnering this support involves more than just providing the training, however. Certain conditions must be embraced by the entire workplace, including technicians, management, and leadership, to create the conditions that will allow your human factors program to flourish.

Get management buy-in. At the conclusion of human factors training, the most frequently heard question is, “This sounds great, but will our management support and follow through with it?” The vision of management and technicians working together to identify and eliminate factors that lead to errors seems improbable to some maintenance personnel.

A strong initial statement of support, delivered personally by a ranking company manager, and accompanied by consistent follow-through is necessary to overcome this skepticism and encourage continued technician support and participation. If management support is lukewarm or inconsistent—if the “flavor of the month” charge turns out to be true—your organization’s human factors program will fail.

Adopt a clear, fair, and consistently applied discipline policy. When the Boeing Maintenance Error Decision Aid (MEDA) tool was first introduced in the airline industry, it wasn’t immediately accepted. The process relies on maintenance personnel to provide crucial data about the factors that caused the error. If those personnel are unsure how the collected data is to be used, it’s not surprising that some would be less than forthcoming.

For this reason, it’s vital that human factors error-reduction programs include a policy aimed at instituting or strengthening an organization’s just culture. An unintentional error must be treated as a process or training issue, rather than a disciplinary one. The focus is on improving safety, not punishment. Management should provide maintenance personnel with clear guidance on how both unintentional and intentional errors will be handled—and stick to it every time.

Use real-world examples to define benefits. As previously mentioned, maintenance personnel are naturally skeptical of soft-skill training. I’ve found the wisest approach isn’t to ignore this skepticism but rather to address it via a well-reasoned introduction. To this end, you may want to pose to them two questions: What are human factors? And why should I care?

Even under the best conditions, defining the term “human factors” can be difficult. Clear, practical definitions of terms such as “human error” and “maintenance error,” accompanied by real-life examples, can begin to build the case that this is a topic worthy of technician and management attention.

Achieving a high level of buy-in, however, requires a convincing answer to the second question. Strong evidence from aviation safety and economics is needed. Use both positive examples (how a human factors issue was spotted and corrected to provide a measurable safety improvement) and negative ones (there are a multitude of examples of this, unfortunately). Properly presented, this evidence leaves no doubt in the mind of the maintenance professional that this is a topic that requires and is worthy of technician support.

Employ a practical, team-based approach to reducing human error. Overcoming technicians’ stereotypes of soft-skill programs like human factors requires the program to have a practical utility that any technician can readily understand and in which he or she can actively participate. Implementation of an ­error-reduction process, such as the MEDA process, can provide such practical utility.

With this process, when an incident occurs, technicians are involved in identifying the human factors that contributed to the incident and recommending strategies to reduce further occurrences. Participating in the process allows technicians to come face-to-face with the practical reality of human factors, how these factors contribute to errors, and the role they can play in preventing future incidents. 

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.