DISCLAIMER Although this software has been used by myself and other people for several kinds of aircrafts, no warranty, expressed or implied, is made by the author (Allan Emrén) as to the accuracy or functioning of the software and related software materials nor shall the fact of distribution constitute any such warranty, and no responsibility is assumed by the author in connection therewith. Also, changes needed for customization purposes are made at the users responsibility. --------------------- Licence conditions ------------------ This software may be downloaded and used by anyone without any charge. If you find it usable, I appreciate if you send 20 SEK or 2 Euro or 3 USD to Allan Emrén Runnshultsv. 3 SE-44896 Tollered By sending this amount, you will contribute to the development of other software that is usefult for general aviation. My E-mail address is allan@nuchem.se Anyone may distribute the software under the following conditions: * No charge of any kind is allowed, not even for distribution media (diskettes, CD-ROM etc) * The software and the readme file both have to be included. If you want to have the software customized for your own aircraft, I will do this at a flat rate of 10 USD or corresponding amount of money in other currencies. You will be requested to send figures and diagrams needed for the calculations. I hope, however, that you will be able to customize it yourself using the instructions below. User instructions ----------------- The software is customized for specific individuals of PA28-140, PA28-161, PA28-181, Cessna 172, and Robin 100/210 and should be used without modifications only for evaluation purposes. To use the software, you need Microsoft Excel or any software which is able to use Excel files. Data should be entered only in fields coloured blue. Sheet 1: Balance Enter actual weights of people and baggage as well as the quantity of fuel at take off. In the diagram you will see weight and balance during the flight. You will also get a warning if the aircraft is overloaded. If you have to burn a certain quantity of fuel before landing, this quantity is calculated. Sheet 2: Start In this sheet, distance for take off (to 50 ft) is calculated for actual weight, wind, altitude, surface conditions and air temperature. Sheet 3: Trip Distance, general track direction, wind ws altitude, cost of fuel, oil and other costs of your aircraft. The flight time and cost of the flight is calculated for different power settings and cruise altitudes. To get the fastest flight possible, you should use full power (no leaning) during climb and 75 percent during cruise. In all other cases, the best economy arises from using cruise power during the climb, and leaning as soon as possible after take off. The climb will be slower, but the fuel consumption is reduced considerably. A descent rate of 300 ft/min is supposed, as well as cruise power during the descent. As a result, you will regain some of the time lost during climb. The leaning state of the engine has to be checked at least every 3000 ft to avoid too lean mixture at low altitudes. You also have to be careful to avoid speeds in the yellow region of the speed-meter. Even if you are descending through smooth air, you might suddenly enter a turbulent layer. The time and distance needed to climb are adjusted for reduced speed and propeller efficiency. Time and distance for descent are corrected for the increase in speed during descent. Should the remaining distance after climb to a certain altitude not be enough, this is corrected for by an increase in the total distance as a result from overshoot. This in turn results in an increased total flight time and cost for the flight. Sheet 4: Fuel planning The purpose of this sheet is to plan how to draw the available fuel out of the tanks. Such planning is important to avoid imbalances due to too much fuel at one side, but also to avoid arriving at the destination with the legal reserve of 45 minutes but distributed with 20 minutes in one tank and 25 in another. Sheet 5: Turbulence If you encounter severe turbulence, there is a risk for structural damage of the aircraft or that it goes out of control. The optimal speed from a safety point of view varies during the flight, as the aircraft looses weight. The sheet calculates the IAS for optimal safety at different times after take off. Sheet 6 - 9: Power setting diagrams One sheet for each power setting, e.g. 55, 65, and 75 percent power. Sheets give curves for RPM vs pressure altitude and temperature. Customizing the sheets for your own aircraft -------------------------------------------- Let's start with a few important notes: Properties specific for a certain kind of aircraft or a certain individual have to be changed suitably. All fields which have to be customized are marked with yellow colour. NEVER change the content of a cell that is not coloured, unless you know exactly what you are doing and why. Any such changes may interfere with the functioning of the software, which may cause dangerous errors in the calculations. Note also that fields to be changed may be situated in parts of a sheet, which are not visible without scrolling. Sheet 1: Balance ---------------- Simply enter the correct figures into the yellow fields. Make sure to use figures according to the aircraft documents to get correct empty weight etc. To get the envelope of the balance diagram, fill the yellow fields under headline 'Limits'. If the number of corners differ for your aircraft, a line is simply added or removed in the diagram. Similarly, the sheet is easily modified to handle more than two tanks or rows of seats. Sheet 2: Start -------------- This is the most tricky part to customize. If possible use measured values for your aircraft. Usually, such figures are not available, and then figures from the handbook have to be used. You should bear in mind that handbook figures are valid for a new aircraft in perfect condition, and thus in most cases over optimistic. Begin with cell C57. There, put the side wind component above which reduced or no flaps should be used for take off. If no figure is given in the handbook, use about 75 percent of max side wind component. Next insert figures in cell D68, D69 and D70. There should be three weights for which the take off distances (to 50 ft) at sea level and std temperature are known. Put the corresponing distances in cell E68, E69 and E70. To find the constants e and f in the model for weight dependence use the Goal Seek tool. Start with cell C69. Make it equal to E69 by changes in cell B64. Then match C70 to E70 by changing B65. Iterate this procedure until the calculated distances C69 and C70 both are within one meter from the correct value. Next find the temperature dependence similarly by entering three temperatures and corresponding distances in cells A79 - A81 and I79 - I81 respectively. Iterate goal seek again on H80 and H81 to find values for cell B75 and B76. The final step in getting constants for the equation is to take care of the altitude dependence. Enter in A93 an altitude (feet) for which you know the take off distance at the weight weight given if cell C93. In B93 the corresponing temperature should be entered and in K93 the distance. Use Goal Seek to modify B88 so that J93 matches K93. Finally insert a proper range of weights in A102 - A109. The range should include all legal weights of the aircraft. WARNING! Although the software is able to calculate take off distances for weights higher than the max weight of the aircraft, the distances calculated are underestimated as there is an extrapolation beyond the range of definition for the function. Furthermore, the increase in stall speed is only partially taken into account. One should also mention the risks for tyre explosions and poor climb performance with an overloaded aircraft. Sheet 3: Trip ------------- In the first ten rows modify all yellow fields. The currency used in I3 - I6 will determine the the currency in which the costs will be expressed further down. Make sure to use the correct units in R5 - R10. Tampering with the units will lead to errors unless conversions are carried out at all appropriate places in non-coloured cells. Enter TAS at level flight in column B for the altidudes and power settings. Preferrably, measured values should be used rather than values from the pilot handbook. The reason is that the figures in the handbook are valid for a new aircraft handled in an optimal way and without antennas and other things increasing the drag. This could lead to dangerous overestimates of the range. If no measured values are available, I suggest a reduction of the handbook figures by five percent. Sheet 4: Fuel planning No customisation is needed unless you have more than two tanks. Sheet 5 - 8: Power setting diagrams The diagrams for PA28 can be customised to any aircraft with a fixed pitch propeller. For aircrafts with constant speed propeller cusomize the Robin 100/210 workbook. With a fixed pitch propeller, simply insert the correct figures in C38 - C53. Use interpolation and extrapolation if figures for some altitudes are missing. Similarly, adjust yellow fileds if you have a constant speed propeller. Good flight! Allan Emrén