November 11, 2009
June 1 Panel Power, In Action
Just in time for AOPA's annual Fly-In on Saturday, June 3, Muncie Aviation Company put the finishing touches on our/your Win a Six's brand-new panel. I arrived in Muncie to take delivery and soon was winging my way east to AOPA's home base at the Frederick (Maryland) Municipal Airport. It was a flight that took just under three hours, and my experience with the panel was a memorable one. But first, a quick review of those final touches.
Test flights I went on three test flights before leaving on my trip. I accompanied test pilot (and avionics technician) Ken Talhelm, and we mainly set about wringing out the S-Tec System Fifty-Five X autopilot, the Sandel SN-3500 electronic horizontal situation indicator, and the JP Instruments EDM-930 engine gauge cluster.
The Fifty-Five X on this airplane includes S-Tec's flight director and altitude preselector. But Talhelm's first concern was making slight adjustments to the autopilot's gain in altitude hold mode. The S-Tec performed nearly flawlessly out of the box, but in altitude hold the airplane would do a slight porpoise ranging from 20 to 40 feet up and down from the selected altitude. Talhelm adjusted the gain so that the airplane stayed dead-on at a selected altitude.
Next came a test of the Sandel SN-3500 EHSI. It performed well, also. We shot a couple of ILS approaches, and the EHSI and autopilot intercepted and flew the approaches with a minimum of fuss.
The great thing about the Sandel is its depiction of multiple sources of navigation information at the same time. In this, it can act as a conventional RMI (radio magnetic indicator.) You can have one needle depict the course arrow for an ILS approach, with localizer and glideslope indications. Simultaneously, you can configure a second needle to act as a bearing pointer to a VOR or other navigation source.
The Sandel also depicts traffic on its screen, and you can also add airports, navaids, and airspace on customized screens. You also have the option of an arc display, or a conventional, circular HSI presentation. And of course, there's a heading bug.
The Fifty-Five X also has roll steering, so as you fly your flight plan the course needle(s) automatically slew to the next leg's course line. All of these functions performed flawlessly.
The EDM-930 had one main issue that delayed the final logbook signoff: Its tachometer was reading double the propeller's actual speed. This, I was told, was caused by the Unison Lasar ignition system's dual electrical pulses during the course of the magnetos' single rotations. JP Instruments shipped a custom-programmed chip to adjust for this, and on the final test flight we were looking at 2,400-rpm cruise propeller indications - not the 4,800-rpm indications we first saw.
Hot cylinders I'd been noticing that cylinder head temperatures (CHTs) on cylinders number three and four would routinely rise to 400- to 420-degree Fahrenheit levels under climb and high-speed cruise situations. Redline is 500 degrees, but even so, temperatures above 400 degrees are not desirable. LoPresti Speed Merchants is looking into a cowl modification that will improve cooling.
However, during a test flight, Talhelm pulled the Lasar system's circuit breaker to see if cutting the Lasar out of the loop would make any difference on CHTs. The magnetos will still function, of course, but without the Lasar the engine won't develop as much power, and magneto timing returns to conventional specifications. There was a slight drop in rpm - and corresponding drops of some 20 to 30 degrees in CHTs. Lasar says adjustments can be made to its ignition system to help lower CHTs, and in the near future we'll be exploring them.
Chafed magneto wiring Muncie Aviation Company did some fine troubleshooting when the airplane once wouldn't start. It was quickly learned that the magneto wires - both of them - were shorting out where they passed through the firewall. The wiring bundle showed signs of kinks - and worse. The friction of magneto wires rubbing against the firewall had stripped them of their insulation.
This was a potentially disastrous condition. If the bare wires touched the firewall, both magnetos would cease functioning, and a dead-stick landing could follow. Instead - this time, anyway - the shorted wires prevented the engine from starting.
Muncie technicians fixed the problem by enlarging the hole in the firewall, installing a larger, better-fitting rubber grommet, and insulating the wires so that they ran in the center of the hole and were protected against ever touching the firewall. Good catch on their part, and another testimony to the thoroughness of Muncie technicians. I'd recommend them to anyone wanting quality work.
First flight... ...with the new panel, that is. And what a pleasure it was. For the first time I had a wonderful autopilot to help share the flying workload and a ton of other gear to help with situational awareness, deal with weather, and advise me of traffic.
I can't say enough in favor of the Avidyne EX500 multifunction display. It depicted datalinked Nexrad radar returns from the XM Satellite Weather receiver (from Heads Up Technologies) on the "Map" page of the EX500's display. You can also dial up METARs and traffic. The traffic information plays on both the EX500 as well as the GNS 530 and the Sandel SN-3500. Avidyne's TAS600 Active Surveillance Traffic System detects nearby aircraft with altitude-reporting transponders, then plots them as targets according to the protocols set up for the much more expensive traffic alert and collision avoidance (TCAS) systems used in high-end business jets and airliners. Nearby targets are color-coded according to their threat level (open white diamonds become yellow dots, then become red squares as conflicting aircraft fly closer to your position.) Moreover, the TAS600 tells you how high or low the targets are, relative to your altitude. The numerals above a target reading "+05," for example, mean the traffic is 500 feet above your altitude.
Nexrad weather The XM Satellite Weather sure came in handy on the return trip. Although I always advise pilots to plan their trips for very early in the day when convection isn't likely, the day of my departure I violated that rule. I left at noon.
By the time I reached Columbus, Ohio, a line of thunderstorms had cropped up along my route. But by using the EX500 and the datalinked Nexrad imagery, I could steer clear of the returns. And avoid the box delineating the convective sigmet for those storms. Sigmet and airmet boxes are also plotted on the Avidyne display.
Another line of storms suddenly popped up as I crossed the northern portion of West Virginia. For the second time, datalinked Nexrad came to my rescue. I threaded my way around the cells I couldn't see out the window (the haze and clouds prevented a clear view) and had an uneventful flight along a cloud-, but not haze-free, ride through to Frederick.
I didn't get a chance to sample the in-flight entertainment system provided by the PS Engineering PAV80 on this trip, but the PMA8000B audio panel installed easily and then performed flawlessly.
Undoubtedly, my next trip in the Win a Six - to the National Cherokee Fly-In at Osage Beach, Missouri - will give me more chances to explore the entertainment system and the other features of this wonderfully capable airplane. The Fly-In is from June 16 to 18. I hope to see you there.
And, as always, stay tuned to this Web site for more updates.
Dr. Jonathan Sackier talks about allergies.
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