Evolution Owner's Newsletter

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Information for the Evolution Owner and Builder Redmond OR; October 28, 2013 Correcting Fuel Gauge Mismatch As you know, the fuel level indications on your MFD come from two different sources. The conventional pictorial gauges are driven by capacitance sensors in the tank and are calibrated prior to the Airworthiness inspec- tion process. Once set, these do not change. The other indication of fuel state is the digital data on the ENGINE – FUEL selection on MFD. These numbers are based on the fuel flow signal sent to the G900 from the flowmeter on the engine. The flowmeter has a small turbine wheel in it that spins as the fuel passes through it and an electronic sensor that counts the rpm. The RPM of this flow sensor is then converted to a gallons per unit of time number through a mathematical algorithm called the “K Factor”. You may have noticed that the gallons used when re- filling the tanks do not match the gallons used (and re- maining) in the digital data on the MFD. Generally this mis-match overstates the amount used (and therefore understates the amount remaining). That’s not danger- ous, but we all would feel better if we knew it was correct. Having this number correct affects the instantaneous Fuel Flow, the Reserve and Maximum Range Rings on the maps and all the digital fuel related information on the MFD. This mismatch is correctable by changing the “K Factor” in the MFD setup, but first you need to know what your mismatch is. Start collecting data on your fuel fills and compare the actual amount put into the tanks with the “amount used” shown in your MFD. Longer flights are better, and give a more accurate indication of the error, but use a mix of flights to establish the percentage of error, i.e., your MFD shows you used X gallons but it took X+Y to re-fill. Using this method determine your percentage of error either + or -. If you are overstating the use of fuel you must reduce the K Factor. If you are understating the use of fuel you must increase the K Factor. Once you know this number, adjust the MFD by following this procedure: 1. Before powering up aircraft, pull MFD and PFD breakers. 2. Power up aircraft. 3. Press and hold MFD ENTER key and while hold- ing, reset MFD breaker, continuing to hold (about 10 sec.) until screen shows Initializing System. Figure 1: 4. Repeat process with PFD (Both screens should now be open in the System Status mode as shown in fig.1., but you will not be doing anything on the MFD). newsletter evolution owner’s October 2013 5. On the PFD, rotate the right hand “Large FMS Knob” to select the “CAL” page at the far lower right hand corner of the screen as in fig. 2. (This selection will disappear after a few seconds but the page will remain in the correct mode). Figure 2:: 6. Starting with the far right hand soft key, press once each of the four soft keys moving right to left. (There are twelve keys with “#1” on the left, so this would be keys 12,11,10,9). This unlocks the calibration function and the screen should look like fig. 3. Figure 3: Correcting Fuel Guage Mismatch, cont’d 7. Look at the upper left hand corner and you will see the fuel “FUEL FLOW ” as shown in fig. 3. 8. Do not be bothered by ENG 1 and ENG 2, we only have “1 ENG”…. But the 1.0000 shown in ENG2 provides a clear example of no correction. The .93000 shown in ENG 1 is the default correction number set dur- ing the setup of your system and reflects a 7% reduction in the standard no-correction signal to the counter. If this was re-set to.90000, it would show reflect a 4% decrease in the fuel flow from the .93000 in the correction line. This would change the fuel consumed to reflect a value 4% less than the default setting and your digital readout should show 4% more fuel “Remaining” on the MFD. You change that number in the “config “ screen in the normal Garmin fashion, i.e., push the Small FMS Knob to turn on the cursor, then rotate the large knob to highlight the ENG 1 field with the cursor, then select the digit with the Big Knob. Rotate the Small Knob to change the value. When re-set, de-select the cursor by a push of the Small Knob. Fig.3a illustrates the actual change in N424SM which required a value of .92800 or a 1% change. 9. Shut off the PFD and MFD’s by pulling the break- ers. 10. Re-start the PFD and MFD normally by pushing in the breakers. 11. Run further flight tests to validate. Figure 3a newsletter evolution owner’s October 2013 MMEL There has been a lot of conversation over the last few months about the Master Minimum Equip- ment List (MMEL) and you’ve probably noticed that latest update to the Evolution POH (July 2014) contains a recommended MMEL for the Evo. The purpose of an MMEL is to list equipment that is required to be pres- ent and operational during various phases of flight (Day, Night, IFR,VFR). The presence of this list is required by the FAR’s in a part 23 certified turboprop aircraft and it becomes part of the aircraft’s required documenta- tion by way of an STC (Supplemental Type Certificate) added to the Type Certification of the airplane. The area of controversy on this topic centered around the apparent disconnect in the FAR’s between the statement that “All Turbine and Turboprop powered aircraft are required to carry an MMEL” (FAR part 91.213), and the resultant opposing supposition that Experimental Category aircraft are exempt from this requirement because they are not “Certified” aircraft. The EAA, LOBO, Lancair, and some other interested parties asked the FAA for clarification on this issue, i.e. is the MMEL required or not required in an Experimental Category Turboprop? The first reaction was that yes, it was, because the “Turboprop” trumped the “Certified”. However, upon further examination and discussion this has been set aside by the fact that the MMEL is an STC to a particular Certified aircraft. Since the Evolution is not Certified, there is no STC process by which to attach the MMEL to the Experimental Category