J.P. Instruments EDM-800
If development of engine-monitoring equipment is a drag race, then J.P. Instruments has just put its foot down hard on the accelerator. In its latest iteration, JPI's popular EDM-700 engine monitor has been bumped up a hundred to be called the EDM-800. With this upgrade come standard fuel-flow features — they were an option on the 700 — and a clever percent-of-power computer. In order to make the horsepower computer work properly, all 800s will come with all-channel exhaust-gas temperature (EGT) and cylinder-head temperature (CHT) probes, a fuel-flow transducer, an outside-air temperature (OAT) probe, a manifold-pressure (MP) sensor, and an engine-speed pickup. Options include temperature probes for engine oil, induction air, and up to two turbine inlet temperature (TIT) channels for turbocharged applications.
Computation of power is done automatically and is shown in a new dedicated window at the top center of the display. The EDM-800 measures manifold pressure, engine speed, fuel flow, and outside-air temperature and calculates a percent of power. Standard, the 800 comes set up with a middle-of-the-road skew factor that you can adjust for your installation. During calibration flights, you can set up a matrix of cruise-power configurations and correct back to the charted power levels from your airplane's handbook.
For example, say your handbook predicts that at 24 inches and 2,300 rpm your engine is making 70-percent power at 6,000 feet on a 50-degree day. If you reproduce those conditions and settings — the 800 makes it easy with a manifold-pressure readout accurate to one-tenth of an inch and an engine-speed display to 10 rpm — you can with confidence skew the EDM-800's horsepower readout to 70 percent by adjusting the calculation variable. For best results, you should perform this calibration at several combinations of manifold pressure, rpm, and altitude. (In fact, the 800 does not directly measure altitude, but alters the computation by the outside-air temperature.)
It took several flights in the Beech P35 Bonanza test aircraft to nail down the variable. At that point, the accuracy of the horsepower readout was within 2 to 3 percent in the normal cruise-power range, but less accurate than that at the extremes of the scale. Understand, also, that the EDM-800 does not take into account mixture settings on the rich side of peak EGT before the lean-find mode has been used. As a result, moving the mixture control has no effect on displayed horsepower although it actually has a profound influence.
With the EDM-800, JPI has designed in new lean-find features as well. Before, when you used the lean-find mode, the instrument would give you the maximum temperature of the first cylinder to reach peak EGT; from that number, you had to subtract to get to your desired leaned setting. Now the 800 does the math for you, showing a direct numeric relationship to the peak temperature. Leaning is now as easy as pushing the lean-find button, moving the red knob until one of the columns begins to flash, and then reading the number on the display. Usually, the lean-find mode will put you slightly on the lean side of peak before a column flashes, so you can merely enrich until the number indicates your desired margin from peak. This simple feature greatly speeds the mixture-setting process.
For operators who run their engines on the lean side of peak EGT, JPI has another clever trick. Selected in advance in the program mode, the lean-of-peak lean-find programming shows each cylinder as it reaches peak and creates an "icicle" display, with each cylinder's EGT value descending from the top row. This display has much greater resolution than the standard leaning mode and is tremendously useful in determining the variations in mixture strength among the cylinders. The reference-to-peak calculation in this mode is taken from the last cylinder to reach peak.
All of the recent EDM-700 upgrades remain in the 800, including simultaneous display of all cylinder EGT and CHT as well as oil temp or TIT in bar-graph and numerical form. There' s also full-time data logging, easily calibrated (and therefore accurate) fuel computer, and user-defined limits and alarms. JPI expects to upgrade the data-logger's chip to handle 50 hours of data; that's impressive considering how much new data is in the 800's brain.
Despite the improvements, the EDM-800 is not significantly more dear than the 700. The standard price includes everything for a four-cylinder engine at $3,600; for a six, $3,800. JPI has an upgrade program that allows EDM-700 owners to convert to the 800 for just the cost of the additional sensors. For example, if you have a 700 with fuel flow, you need to purchase and install only the manifold-pressure and rpm sensors ($650) and return the unit to the factory for the upgrade. About the only add-ons are the oil-temp probe ($150) and TIT probes (also $150 each).
JPI deserves a round of applause for cramming 20 pounds of features into a 10-pound instrument, all the while skirting the perilous waters of overcomplexity. The EDM-800 is a sophisticated piece of avionics that's also easy to use and, now with a calculated-horsepower display, even more useful.
Contact J.P. Instruments, Post Office Box 7033, Huntington Beach, California 92646; telephone 800/345-4JPI; or visit the Web site ( www.jpinstruments.com). — Marc E. Cook
King Private Pilot Knowledge Test Course
The private pilot knowledge exam is a hurdle that must be crossed, and most of us have mixed feelings about it. Acquiring the knowledge is a goal that we readily accept, but we would like it to be as painless as possible. And, of course, we want to pass — the first time.
King Schools' new interactive CD-ROM knowledge test course meets all those goals. It explains the information without taking any shortcuts, yet makes the experience entertaining.
What you'll get for your $279 is a notebook containing 15 CD-ROM disks. The last one is a bonus — your own searchable copy of the Federal Aviation Regulations and the Aeronautical Information Manual. Also included is a thick book of all the questions on the FAA exam.
The opening screen shows a path with learning blocks along the way, sort of a yellow brick road with the private pilot knowledge exam waiting for you at the end. Using the chart, it is easy to see what you have accomplished and how much more there is to learn. Just to make it easier, there also is a humorous depiction of a cross-country flight: An airplane icon moves from California to the East Coast as you progress through the course.
As always, John and Martha King offer their well-practiced classroom instruction in video clips with sound and motion right on your computer screen. Each lesson is designed to provide enough to keep your interest, but only that amount of knowledge that can be easily absorbed. The lesson is followed by a quiz. If you have a problem, the video can be watched again, or a quick text explanation can be brought up on the screen.
The software is simple to use, and the course is self-paced. The software will keep track of lessons that you have completed. At the end are proven tips on how to take the test, and, finally, practice exams make sure you are ready to ace the actual knowledge test.
System requirements include a Windows-based computer of 133 MHz speed or faster; a video card capable of high-color, 16-bit display; an 8X CD-ROM drive; 16 MB of RAM (32 MB recommended); and 50 MB of available hard-drive space. You will also need a sound card with speakers. Customers ordering before November 15 will also receive a free video, Surviving Your Most Feared Emergencies.
To order, call 800/854-1001 or 858/541-2200; fax 858/541-2201; or e-mail [email protected]. Or write to King Schools Inc., 3840 Calle Fortunada, San Diego, California 92123. — Alton K. Marsh
Briefly Noted
A-Enterprises has introduced its Stay-Put wheel chocks that are designed to keep the chocks from sliding on hard-surface or turf parking spots. A nonskid rubber pad on the bottom holds the chocks in place on hard surfaces while stainless-steel stakes anchor the chocks into soft surfaces. Nonskid grip tape is installed on the side of the chock facing the tire while the outer surface can be personalized with the airplane's registration number. One chock can be slid inside of the other for compact storage. Price of the chocks is $45. For more information, contact A-Enterprises in Pewaukee, Wisconsin, at 414/691-4358. — Peter A. Bedell
Survival Products Inc. of Hollywood, Florida, has introduced a new line of FAA-approved life rafts that are claimed to be the world's most compact, lightweight, and affordable rafts for commercial or private use. The four-person raft with a canopy measures 4 by 13 by 16 inches when stored and weighs 16.2 pounds. It has an overload capacity of six people. Both four-person and eight-person rafts are available with various options, such as canopies and survival equipment to meet the requirements of parts 91, 121, or 135 of the Federal Aviation Regulations. Prices for the four-person raft start at $1,425 while the eight-person raft starts at $1,945. For more information, call 954/966-7329, or visit the Web site ( www.survivalproductsinc.com). — PAB
LightSpeed has introduced its new 25XL active noise-canceling headset. The 25XL features an auto shut-off that senses when the headset is off of the user's head and shuts the ANR circuitry off so that you are not faced with dead batteries on your next flight. A small inline control box houses twin volume controls, a mono/stereo switch, and an LED battery-life gauge to alert the user when to replace the headset's two AA batteries. LightSpeed claims 25 to 28 decibels of active cancellation and 22dB of passive cancellation. The weight is 15 ounces. The minimum advertised price of the 25XL is $585. For more information, call 800/732-8999, or visit the Web site ( www.lightspeed-tek.com). — PAB
AvTracker is a new software program developed for aircraft owners and operators to make management of aircraft a simpler affair. The program allows for precise tracking of fixed and variable aircraft expenses, maintenance events, fuel and oil consumption, and pilot medical and BFR status by using downloadable software from the Internet. The program walks you through the setup process and allows the user to customize warning schedules for the various events affecting the airplane or its pilots. The $129 program makes data entry simple, and the resulting log reports are easy to read and understand. A free 30-day trial period is available. The software requires an IBM-compatible computer with 32 MB of RAM and a 166 MHz or better processor. For more information, see the Web site ( www.avtracker.com) or call 888/444-2299 or 514/769-2299. — PAB
Unless otherwise stated, products listed herein have not been evaluated by AOPA Pilot editors. AOPA assumes no responsibility for products or services listed or for claims or actions by manufacturers or vendors. However, members unable to get satisfaction regarding products listed should advise AOPA. To submit products for evaluation, contact: New Products Editor, AOPA Pilot, 421 Aviation Way, Frederick, Maryland 21701; telephone 301/695-2350. Links to all Web sites referenced in this issue can be found on AOPA Online ( www.aopa.org/pilot/links/links9911.shtml).
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