August 2005-
Last month I spoke about my hunt for a navigation system to go into my new sport airplane and, after investigating the possibilities, I settled on a portable GPS system from True Flight (aviationsafety.com; 866-443-3342).
The unit I purchased—a Flight Cheetah FL250—had a large and bright display screen, a remote-mounted computer box and a plug-and-play interface with the WxWorx Data Link to provide satellite weather reception.
I’ve operated the unit for the last few months and I’m basically pleased with its performance. But first, let me list the disclaimers—which I’ll begin with by quoting myself from last month’s article: “True flight is a small company and, as such, there are some minor gaps in the things they are doing.
“For example, the User Guide that comes with the product is quite good with helping you get the unit installed and operating (lots of clear photographs of exactly what to plug into where), but somewhat incomplete in its operational instructions. Going through the book carefully when the unit first arrived, I found that some of the User Guide sections generated more questions for me than answers.”
Compounding the User Guide problem is that True Flight is continually evolving their software and user interface and, as such, various features inside the unit are subject to change. Most of these changes are for the better. But sometimes when engineers and technicians fiddle with all those zeros and ones that are wandering around inside the computer case, a change for the better in one area yields an unintended consequence on some other screen.
None of these small anomalies have created anything more than just a few annoying moments at times, so it’s not really a giant pitfall for the product—it’s more like a speed bump on life’s technology highway. The major difference between the True Flight GPS and the high-end panel-mounted avionics that I had operated in my light twin is that this portable unit is Windows-based—which means that it comes with all the strengths and weaknesses that any Windows-based computer is heir to.
The bottom line is that any operator of the True Flight GPS (or any other Windows-based system) will occasionally find himself in need of the familiar owner’s trick known as “reboot.”
In my own experience, the number one anomaly has been the unit’s inability to shut itself down as it is supposed to. Just like your Windows-based laptop or desktop, it is strongly recommended that you go through the normal software shutdown procedure before removing power from the unit. In the True Flight, that means scrolling to the System menu, then Shutdown entry. Unfortunately, on occasion the unit will just lock up at that point and display the dreaded frozen screen.
Since our installation includes an aircraft panel switch that shuts off the electrical power to the portable outlet that the True Flight computer is plugged into, we can always make the frozen screen image melt into blackness.
On every instance so far, the unit has always powered up the next time we flipped the aircraft’s switch back up—but the True Flight folks tell us that this is not really good for the software, which prefers to shut down in the sequence the engineers had ordained for it. Hopefully, some revision to the software will keep the software shutdown pattern consistently on track in the near future.
Speaking of power, one option with the unit is the ability to have it power up automatically whenever it first senses electrical power being applied. This is a particularly convenient when the computer box is remotely mounted (our unit sits beneath the aircraft’s rear seat) where it’s not convenient to push the on/off button on the computer itself.
Once the power is applied, the screen is up and running in a couple of minutes with current position being displayed on whichever map (a combination of range, features and style of chart) that had been selected last.
On our unit, the instructions that you see surrounding the screen are my own entries, done with an office supply store labeling machine. The notations remind me and my partner that the Enter key is used to toggle between the various weather layers that you’ve set up, and the up/down arrows are the access method of getting through the various map features that you’ve customized into individual layers.
When a map screen is selected, the left and right arrows bring the range scale up and down. The notations that I added above the display screen are reminders as to what color the weather symbols on the map will turn in what types of ceiling/visibility weather conditions.
The unit’s keys are a pleasure to deal with, and one of the major reasons why the True Flight unit is far more user-friendly than some other portables that require fiddling with a stylus or smallish keys and knobs.
The plus and minus buttons on the screen control the display brightness and, even in our very sunwashed cockpit, the display screen is always clearly and easily visible. The GPS functions are straightforward and what you’d expect, excepting that their flight plan category is sort of clunky and not particularly useable in its current format (the True Flight folks assure me that this area will become much more user friendly very soon). In the meanwhile, I’ve found that it’s easier to have a list of flight plan waypoints in my hand and simply go “direct” to each successive waypoint as I pass the last one.
True Flight has done a good job with terrain and tower alerts. Since I usually fly my airplane low and slow, I keep the terrain alerts off but do rely on the tower alerts—which are the best that I’ve seen, since even when selected they will change color and eventually disappear from the screen when your height above or distance from them exceeds certain parameters.
Towers change from red to yellow when the aircraft’s (GPS) altitude is more than 500 feet but less than 1,000 feet above its charted height, turn to green from 1,000 to 1,500 feet, and disappear completely when the tower is more than 1,500 feet below. A very useable format.
Special use airspace and TFRs (downloaded via the WxWorx connection) are selectable, although at this moment it is difficult to determine what their vertical limits are. There is a major change to this format that is due to be released by the time you read this, so from what I’ve been promised, the True Flight unit will easily yield whatever information about an upcoming piece of Special Use Airspace that a pilot would like to know.
The weather displays have been nothing short of great. NEXRAD images are downloaded every few minutes and they show up quite nicely on the display screen. METARs and TAFs are sent into the box periodically and—as is the case with the type of broadcast system that WxWorx utilizes—once you’ve been on the air for several minutes, the entire nation’s weather should be sitting inside your computer box just waiting for you to tap into it.
There are some areas in the True Flight unit that could use some improvement, and the company has told me that nearly every one of the shortfalls that I observed is already on the drawing boards for improvement. By the time you read this, they promise me that most of my nitpicking will have been resolved.
Updating the software is simply a matter of popping a CD into the computer’s tray and hitting Enter.
On the last flight that I took, the True Flight GPS with its WxWorx interface gave me everything that I could ask for as I headed back toward my home field. It was a windy day, so I called up a major airport nearby to check the heft and direction of the breeze—only to have the display screen simply freeze up (this was possibly caused by me hitting the keys too quickly or too many times in the bumpy air, or, perhaps, by evil spirits inside the box or evil spirits attached to my personal karma on that particular afternoon).
This was the first time that the True Flight unit had ever locked up in flight, and for a moment the failure took me by surprise. With the unit’s keys now dead to the world, I reverted to my laptop years and simply shut down the power switch. A few moments later I powered back up again. Less than two minutes after that, the True Flight screen was alive and well and quite happy to provide me with whatever data I asked for—which is really quite a lot of good navigation and weather stuff.
I expect that as this product continues to evolve, there will be fewer problems of this sort occurring less often and lots of interesting improvements being added. The True Flight GPS is basically a good unit right now, and promises to get even better in the future. Stayed tuned—I’ll be giving ongoing updates.
Editor-at-large Thomas Block has flown nearly 30,000 hours since his first hour of dual in 1959. In addition to his 36-year career as a US Airways pilot, he has been an aviation magazine writer since 1969, a best-selling novelist. He owns an L-19 Birddog, which he contends is a straight cross between a Piper Super Cub and a high-wing Cessna taildragger.
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• Battery compartments and vents
• Wheels wells and landing gears
• External skin areas
• Window seals
• Cavity drains
• Piano hinges
• Control surface recesses
• Bilges
• Control cables
• Welded areas
• Electronic equipment
Check all areas which do not require removal of fasteners, panels, etc. Preventive maintenance or early detection and treatment reduce cost, out of service time, and possibility of flight related incidents. For further, and more in depth information, I highly recommend reading AC 43-4A. Happy Corrosion Hunting.
Norm Ellis has is an instrument-rated private pilot, flown 24 different aircraft, has been a Mechanical Design Engineer Consultant for the last 16 years. Ellis holds three Multi-STCs certified on 118 aircraft. Send comments or questions to editor@www.piperflyer.com.
For More information about protecting your plane from corrosion:
Corrosion Technologies
800-638-7361
he �ig� �e of, do not remove them from the oil cooler when sending it out for overhaul. The best advice is to leave fittings undisturbed unless absolutely necessary to do otherwise.
WHEN BACKUP IS CALLED FOR
One other extremely common—and entirely avoidable—form of oil cooler injury is caused by not using a backup wrench when dealing with fittings and oil line connections. Each oil cooler manufacturer has its own uniquely-shaped boss for the threaded holes that the fittings screw into. Most of them are hex or square in shape so that it is possible to place a wrench on them. Except for Harrison oil coolers, which have a round boss that requires the use of pliers or a pipe wrench.
In every case, failing to steady the boss on the oil cooler when attempting to connect or disconnect the oil lines or the fittings from the cooler will allow the cooler’s threaded boss to bend from side to side and cause the oil cooler to crack and leak.
AND FINALLY
As with most other things, when it comes to aircraft oil coolers the commonly made mistakes are also the easiest ones to avoid—if you know what to look for and what to look out for. Remember, a fluid ounce of prevention is always better than 11 quarts of cure.
Wayne Thomas is a longtime member of the aircraft maintenance industry and has written a number of articles about issues and procedures concerning aircraft engine maintenance which have appeared in publications such as TBO Advisor and AirMaintenance Update. He soloed in 1973 at age 15 after receiving just 12 hours of dual instruction at El Monte Community Airport’s flight school. Wayne joined Pacific Oil Cooler Service, Inc. of South El Monte, Calif. in 2000.
