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Off to a Good Start: Planning for your First Annual

Off to a Good Start: Planning for your First Annual

Evaluate and maintain a new-to-you aircraft using all of the tools available today.

So, it’s been a year since the pre-purchase/annual inspection was completed and you have been the owner of this new-to-you airplane. As the months passed, every flight revealed more details about the condition and usefulness of your new flying partner. 

You probably encountered a few issues that required immediate attention and many others that became line items on your to-do/wish list. (In last month’s Piper Flyer (November 2018), Dennis Wolter outlined best practices for preparing to tackle a renovation. —Ed.)

With this list and your maintenance technician’s familiarity with your new airplane, the arrival of annual inspection time presents the perfect opportunity to sit down with your mechanic and put together a schedule for the renovation of your airplane.

In the list that you put together when flying the airplane during previous months, it’s important to include maintenance and performance issues that need to be discussed before starting that all-important first annual. 

I definitely believe that you should read all applicable Airworthiness Directives and Service Bulletins and confirm that important issues are well-understood and properly completed. Just because an AD is signed off in the logbook doesn’t mean that it was done properly or even that it was done at all. A couple of times a year at Air Mod, we find evidence that a signed-off AD was, in fact, never taken care of. 

The point here is that between a thorough pre-purchase and the first annual, all issues are checked and verified, and your airplane should be off to a good start toward working its way to being a “good as new” machine.

From a safety standpoint, the condition of your airplane’s engine is of major importance. You should take advantage of every technical process available for evaluation and maintenance in this area. 

Back in the day, inspecting an oil filter for contaminates such as metal particles and performing a simple compression check were the two major engine evaluation processes that a technician used in determining the health of the piston engine.

Compared to my early days in this industry, we now have at our disposal far more inspection and diagnostic tools that make it possible to operate our engines longer with greater confidence. 

Determining engine health

A compression check is done to determine the health of the upper or power section of the engine where combustion takes place. Combustion exposes pistons, rings, cylinder walls, valves and valve guides to a lot of heat and combustion byproducts. 

The time-tested compression check involves a technician using compressed air and air pressure gauges to determine if the cylinder and all of its parts are doing the job of sealing in the combustion gases in such a way as to efficiently produce the desired pressure of pushing the piston down to turn the crankshaft and rotate the propeller. Any leaking of these high-temperature gases past the valves or the piston and ring assemblies will cause heat buildup, a decrease in engine performance and increased wear on these critical components. 

As good as the compression check was and is, it falls short of presenting all the information needed to fully evaluate the condition of the combustion components of a piston engine.

Beam-me-up-Scotty to 2018. Today, we have three diagnostic tools that bring engine condition tracking to a whole new level. 

Tool No. 1: Borescopes

The first implement I refer to here is the affordable, state-of-the art borescope. What’s that, you might ask? It is a 1/2-inch diameter, 18-inch-long fiber-optic tube that can be placed in an engine cylinder through a spark plug hole. It will present a high-resolution color-correct image on a bright screen that allows a technician to evaluate the condition of the cylinder walls, piston crown, valves, etc. 

Borescope being placed in an engine cylinder.

Often, an engine that has good compression will have stress marks on the cylinder walls or discoloration on valves that can only be seen with a borescope. These anomalies can indicate a potential for future problems. The borescope allows a technician to address an issue before it becomes a failure. Also, most borescopes have a built-in digital camera, making it easy to email a picture of a problem to the customer. So much for the good old days!

Here is a great example of the value of this technology. I called a good friend, Adrian Eichhorn, who has done quite a bit of research into the use of this technology, to help identify cylinder components that are in the early stages of failure. He sent me a photograph of an exhaust valve that presented an uneven color pattern, indicating that the valve was becoming too hot in one area and not sealing at that point on the edge of the valve. 

Uneven color pattern on an exhaust valve indicates a possible problem. 

If not corrected, the valve will eventually begin to deform and lead to serious and expensive valve failure. Eichhorn, in partnership with AOPA, came up with a chart showing various color patterns that indicate different types of potential valve failures. These charts have been distributed and used in the field with very positive results. Smart! (A link to the PDF is available under Resources at the end of this column. —Ed.)

These borescopes are miracle investigative tools that allow technicians to see into inaccessible areas in various parts of the engine and airframe. I have a customer who recently used one to find a badly-corroded elevator component that was close to failure.

Tool No. 2: Oil analysis

Another important area to be evaluated is the bottom end of the engine—the crankshaft, connecting rods, oil pump, camshaft, etc. Back in the good old days, about the only diagnostic tool a technician had to help establish the condition of these components and their bearings was to hold a magnet in the oil as it drained out of the engine and look for magnetic or ferrous metal particles sticking to it. A technician could also cut open the full-flow oil filter, if the engine was equipped with one, and look for metal fragments in the filter. 

Magnetic fragments mean a steel component is experiencing high wear; nonmagnetic fragments mean a nonmagnetic component such as a bushing is wearing, or something is rubbing the aluminum crankcase. Fragments don’t always provide enough information to accurately diagnose a potential problem. Big pieces of metal indicate serious pre-failure issues.

The second engine diagnostic tool I’m going to discuss is oil analysis. It can vastly improve a mechanic’s ability to assess an engine’s health. 

Here’s how it works: as the technician is draining old oil out of the engine, a small cup is filled with an oil sample that is sent to a laboratory for analysis. After testing, the lab returns a report to the technician that indicates the percentage of metal residue found in the oil, measured in parts per million and listed by type of metal. Iron can indicate wear on the oil pump gears; silver can indicate wear on a plain bearing such as connecting rod or crankshaft main bearings; bronze can indicate wear on valve guides, and so on. 

As the engine builds hours and additional oil samples are analyzed, a technician can track data and determine wear trends of the various internal engine components. If a high reading of a specific metal is noticed, the technician can use this information to identify a possible point of failure and initiate the appropriate maintenance action.

Tool No. 3: Engine monitors

The third 21st-century device that has revolutionized the monitoring of piston engine operation and maintenance is the digital engine monitor with data download capability. The complexity of these systems can range from basic exhaust gas and cylinder head temperature monitors to systems that replace existing round engine instruments with a full screen that has multiple additional read outs for voltage, percentage of horsepower, fuel remaining and even outside air temperature.

Digital engine monitor with data download capability.

These systems allow valuable information to be downloaded and analyzed by an owner, a technician or an online company, to track engine condition trends. Science fiction has become reality. We should take advantage of these contemporary tools to ensure the safe and efficient operation of an engine all the way to TBO. (See Resources for a list of PFA supporters. —Ed.)

Other items to evaluate

Hoses

An annual inspection item that I believe is sometimes not carefully looked at is the age and condition of the fuel, oil and vacuum flex hoses. Many rubber flex hoses in service today have a service life of five years. Failure of an oil or fuel hose can definitely contribute to a bad day! 

I highly recommend replacement of timed-out hoses with hoses fabricated with cost-effective, safety-enhancing orange fire-resistant sleeves, which protect the hose and its often-flammable contents in the event of an electrical or engine fire. The photo shows a typical black hose with a service life of five years as well as a stainless steel fitting, fire-sleeved silicon rubber, extended service life, top-of-the-line hose.

Extended service life hose on top, typical black hose below. 

Engine accessories

Moving beyond the engine itself, it’s important to monitor the service life and condition of the engine accessories. A good pre-buy inspection should have clarified the times in service and inspection status of all the stuff that keeps the engine running. 

An owner needs to be aware of the status of these components in order to prevent as many surprises as possible.

Magnetos

Let’s focus now on a big item: magnetos. Most brands of magnetos require a 500-hour half-life inspection and a 1,000-hour overhaul or replacement. Experience has shown that scheduled maintenance and monitoring is very effective in increasing the reliability of these critical components. 

Vacuum pumps, propeller governors

We know that dry vacuum pumps driving traditional gyros have a higher failure rate after 500 hours of operation. Propeller governors are best overhauled at engine change. The failure of a prop governor can send engine-damaging metal through the engine’s lubrication system—that means big bucks to fix! The point here is to have a meeting with your maintenance tech and totally vet the status of all firewall-forward systems. 

Engine overhauls

OK, I’m walking on thin ice here. No discussion about piston airplane engines would be complete without talking about the often-debated subject of time between overhauls (TBO). It seems like experts are all over the map as to when a seemingly great-running engine should be overhauled. Opinions range from “TBO is cast in stone” to “TBO is an arbitrary, money-making number set by the engine manufacturer.” (See “Further Reading” in Resources for more on this topic and other topics discussed in this article. —Ed.)

Here’s an 18-year-long anecdotal study I was unintentionally exposed to during the time Air Mod was located next to one of the more active field overhaulers in the country. Located by their hangar were two dumpsters. One contained rejected ferrous metal engine parts (crankshafts, connecting rods, gears, cams, etc.). The other contained rejected nonferrous aluminum parts (crankcases, cylinder heads, etc.). Most of the engines going through their facility were overhauled at or near TBO. 

Based on the quantity of rejected parts that got hauled off to the recycling facility, I tend to think that the manufacturers base TBO numbers on experiences they’ve had tracking these engines for almost a century. Just remember, you can’t write the check on the way down!

If it’s time for you to schedule that engine overhaul, tune in next time as we look at the options and process involved overhauling your trusted engine. Until then, fly safe.

Industrial designer and aviation enthusiast Dennis Wolter is well-known for giving countless seminars and contributing his expertise about all phases of aircraft renovation in various publications. Wolter founded Air Mod in 1973 in order to offer private aircraft owners the same professional, high-quality work then only offered to corporate jet operators. Send questions or comments to .

RESOURCES >>>>>

ENGINE MONITORS – PFA SUPPORTERS

Electronics International
Insight Instrument Corp.
J.P. Instruments Inc.

AOPA FOUNDATION’S VALVE FAILURE CHART

“Anatomy of a Valve Failure”
PiperFlyer.org/forum under “Magazine Extras”

FURTHER READING

“My engine is 50 hours from TBO….” by Bill Ross
Piper Flyer, September 2018
“A Step-by-Step Guide to Overhauls” by Jacqueline Shipe
Piper Flyer, February 2018
“Is Your Engine Worn Out?” by Steve Ells
Piper Flyer, October 2017
“Dissecting a Dry Air Pump” by Jacqueline Shipe 
Piper Flyer, June 2017
“I Found This in my Oil” by Jacqueline Shipe 
Piper Flyer, May 2017
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Papa’s Got a Brand New… Fuel

Papa’s Got a Brand New… Fuel

Swift Fuels’ 94 Octane Unleaded Avgas

Earlier this month I burned 25 gallons of Swift Fuels’ 94UL unleaded Avgas in the 180 hp Lycoming O-360 in my 1960 Piper Comanche, Papa. 

Swift Fuels of Lafayette, Ind. has submitted its 102 octane unleaded (102UL) Avgas to the FAA for testing in the Piston Aircraft Fuels Initiative (PAFI) program, but it also announced in mid-2015 that it was producing a 94 octane unleaded (94UL) Avgas. 

In the last year and a half, 94UL hasn’t gained much traction even though it’s approved for operation in a wide range of GA engine and airframes. 

94UL is produced to ASTM Standard D7547, the specification for hydrocarbon unleaded aviation gasoline. This lead-free Avgas was developed at the request of the military in 1994 for use in its drone fleet. 94UL is a stable fuel with a “tank life” of two years. 

I am looking forward to the day when Avgas will be free of tetraethyl lead (TEL), and when I saw that Swift offered a lead-free Avgas that I could legally use, I wanted to try it. What I found was very interesting.

By the end of my flight testing I hadn’t seen one iota of discernible difference in any engine parameter—EGT, CHT, manifold pressure, rpm or oil temperature—between the 94UL and 100LL Avgas. 

 

Data collection

The data I’ve captured is by no means an exhaustive test. I haven’t done an extreme heat or extreme cold temperature starting test. I haven’t done a high altitude (18,000 feet MSL) operational test. I haven’t done an in-flight restarting test. Nor have I done a fuel system compatibility test. 

But thanks to the data collection feature of my Electronics International CGR-30P and 30C engine monitor, I could collect and plot the engine data gathered during the three test flights using EGView from EG Trends. 

I also asked Joe Godrey and Savvy Analysis to check my plots. He verified my findings.

 

Preparing for the tests 

There is one 30-gallon bladder-style fuel tank in each wing of my airplane. The fuel selector valve has three positions: left to the engine, right to the engine, and off. There’s no both position. 

After flying the right tank empty and sumping the remaining unusable fuel out through the system low point drain, I paid Rabbit Aviation Services at the San Carlos Airport (KSQL) $118.37 to pump 26.6 gallons of 94UL into the right-wing tank. 

I also topped off the left tank with 8.4 gallons of 100LL ($38.22). That crunches down to 100LL at $4.55 a gallon and 94UL at $4.45. (Vendors set the pump prices; when buying from Rabbit there’s minimal direct cost savings.) The fuelers at Rabbit asked if my airplane was approved for auto gas or 94UL Avgas before dispatching the 94UL truck. 

Initial observations

94UL smells different than Avgas and is clear. I checked the two fuels for weight. The 94UL is lighter at 5.79 pounds/gallon than the 100LL at 5.94 pounds. 

I flew three one-plus hour flights, switching back and forth between the left and right tanks. 

I switched during a full power climb; I switched with the mixture leaned to peak EGT on the first cylinder to peak; and I switched during my normal cruise power and mixture settings while level at 5,500 feet MSL. I also switched on descent and while idling before flight and after landing. 

In addition to collecting the engine parameters digitally, I also watched for any EGT difference in the seconds following the switches. I never saw the numbers change.

 

Users’ reports

John Poppy at the Portage Municipal Airport (C47) in Portage, Wis., a popular fueling stop near AirVenture, said he’s heard “zero negative feedback” about 94UL. 

Poppy has a 1,000 gallon tank and says he pays two cents a gallon for shipping for the five-hour drive from the Swift production plant in Lafayette, Ind. Poppy sells 94UL for $3.35 a gallon—59 cents per gallon less than his 100LL. 

Poppy told me that one customer who flies a Cessna 182 has been using it for over a year while commuting to another state. According to Poppy, the customer’s mechanic asked if he had taken his engine apart and cleaned it after pulling the cylinders for a top overhaul. 

Rich Volker of RV Airshows burns it in the 600 hp Pratt and Whitney R-1340 that powers the Harvard Mk IV he flies in his airshow routine. Volker told me he flies his routines at full power and in his opinion, his engine can’t tell the difference. 

Dennis Wyman runs the engine shop at G&N Aircraft in Griffin, Ind. Wyman told me that his experience is that running 94UL results in less deposits on pistons and valves. In his experience, the switch between the two fuels is transparent. 

The only change Wyman has seen is that the combustion chamber of an engine that uses 94UL looks slightly darker than a 100LL chamber. Can you use 94UL?

You can use 94UL is your airplane fits into one of the following options:

• Airframe/engine combinations that have an Auto Fuel STC (e.g., an STC from Petersen Aviation);

• Airframe/engine combinations OEM-approved for auto fuel (e.g., ultralights, LSAs and experimental aircraft);

• Airframe/engine combinations Type Certificated to operate on Grade 80 (listed as Grade 80/87 in ASTM D910) or Grade UL91 (ASTM D7547) Avgas; (Note: If the fuel data plate on the engine lists 80/87 as the fuel, you can legally use 94UL without an STC. This includes Piper singles such as PA-18, -20, -22 and 150 hp PA-28s.) 

• Airframe/engine combinations Type Certificated to operate on minimum 80 octane or lower (e.g., 73 or 65 octane) Avgas; or

• Airframe/engine combinations with an Avgas STC purchased from Swift Fuels.

The engine data plate on my Lycoming O-360-A1A specifies 91/96 octane fuel, yet my Piper PA-24 Comanche had never been approved for an auto fuel STC. My only avenue to use 94UL was buying an Avgas STC from Swift. 

Where can you get 94UL?

Per the user map on the Swift Fuels website, there’s only one public source for 94UL west of the Mississippi River, and it’s in California. 

There are also 14 that are cited as “private users.” The 18 other public outlets for 94UL include three in Florida, one in South Carolina, one in Ohio, one in Missouri, four in Indiana and eight in Wisconsin. (Note: If you would like find out more about setting up a 94UL station, contact the folks at Swift. They have a team that will tell you how to get started.)

One of the potential roadblocks between availability and pumping 94UL at your airport is tankage. Most airports now have two tanks—one for jet fuel and one for 100LL. One option for adding a third is installing a box station from U-Fuel in Elk Mound, Wis. 

U-Fuel offers a split tank—94UL on one side and 100LL on the other. It appears that split models have the same footprint as existing single-fuel models. 

 

94UL is here now; PAFI fuel is a few years away

Since most privately owned and operated airplanes in the GA fleet can safely burn 94UL, and since Swift sells it for less than today’s 100LL, Swift’s 94UL seems like a winner. 

No one knows when the new unleaded 100 octane Avgas will be produced—it’s still being tested in the Piston Aviation Fuels Initiative (PAFI) program. 

The PAFI program is scheduled to complete the fuels testing in 2018, but there could well be a time lapse between the approval date and the production and delivery to your local airport. 

Based on my testing and my belief that TEL creates a wide range of problems in our air-cooled engines, I would be burning unleaded aviation fuel today if there was a pump with a Swift 94UL placard close by. 

Steve Ells has been an A&P/IA for 44 years and is a commercial pilot with instrument and multi-engine ratings. Ells also loves utility and bush-style airplanes and operations. He’s a former tech rep and editor for Cessna Pilots Association and served as associate editor for AOPA Pilot until 2008. Ells is the owner of Ells Aviation (EllsAviation.com) and the proud owner of a 1960 Piper Comanche. He lives in Templeton, Calif. with his wife Audrey. Send questions and comments to

RESOURCES >>>>>

Engine monitors and cluster gauge replacements
Electronics International – PFA supporter

 

EGView software – data analysis tool
EG Trends Inc.

 

Engine rebuilding, engine overhaul and engine sales
G&N Aircraft, Inc.

 

Auto fuel STCs
Petersen Aviation, Inc.

 

94UL fuel service (West Coast)
Rabbit Aviation Services, Inc.

 

Savvy Analysis – engine monitor data organizer
Savvy Aircraft Maintenance Management, Inc.

 

94 octane unleaded Avgas, Avgas STC
Swift Fuels

 

Aviation fuel stations
U-Fuel 

  

Further reading
FAA PAFI program
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