Eagle Tree Systems Seagull Glide manual Altitude Measurement

Page 3

Page 3

NOTE: Additional Pitot Tube kits are available for purchase on our website.

Method A: If the airplane’s fuselage is relatively sealed, with no large “ram” air openings in the nose of the plane, you can likely obtain good readings by just leaving the static airspeed connections unconnected.

Method B: A true static pickup can be created with a piece of brass tube (not included). The diameter of this tube is not critical. See Figure 1 for details of this method. To create the static pickup, you will need to drill 4 small holes into the side of the tube, spaced equally around the circumference of the tube. If it is difficult to drill all four holes around the tube in a circle, two of the holes can be drilled farther forward than the other two. Also, a larger diameter tube can be used to make this easier, if the extra weight can be accommodated.

These holes should be drilled 1.5” or more from the front of the tube, but should not be too close to the tube mount. The holes should be approximately 1/32” in diameter, and should be deburred if there are burrs from drilling. Once the holes are drilled, the front opening of the tube should be plugged with epoxy or other. The static tube is mounted parallel to the direction of travel, near the pitot tube, as shown in the below figure.

Method C: A static source can be obtained from the side of the fuselage, with the rubber tube (or a short piece cut from the pitot tube) mounted absolutely flush with the side of the fuselage, so that the mouth of the tube is pointing perpendicular to the direction of plane travel. The location of the static tube should be chosen so that the least disturbance of air possible occurs.

Altitude Measurement

The Seagull Glide system measures altitude via a sensor inside the unit. Altimeters measure slight pressure differences to determine elevation. Since these pressure differences are relatively small, it’s important that the airplane’s internal pressure doesn’t vary much due to propwash or moving through the air. Such variation can occur if the front portion of the plane has an opening that causes air to compress inside of the plane when air is forced into this opening.

If you get lots of altitude variation at level flight, check to see if there are openings in the front of your plane that allow air to enter and increase pressure inside the fuselage. If your plane is not airtight or at least sealed well up front, you may have altitude jumpiness, since the altimeter measures changes in air pressure. If you have this problem and/or want very accurate altitude measurements, a static source can be obtained as follows:

Copyright © 2003-2005 Eagle Tree Systems, LLC

Image 3
Contents Steps to Follow Please read this manual before using your new systemIntended Uses Packing ListInstall your Data Acquisition Module Recorder Connecting the Airspeed Pitot TubeImportant Warnings Altitude Measurement Using the Seagull Wireless Dashboard Powering the Glide RecorderInstalling the Seagull Transmitter in your Model Connecting the Seagull Transmitter to your Data RecorderPage Ready for Action Adjusting the VariometerInstalling the RPM Sensor Installing Temperature SensorsPage Removing the Recorder from your Plane Setting up the Recorder with the ApplicationTelling the Recorder what to Log Setting the Joystick Configuration ModeSeagull Configuration Wizard Setting Metric or English UnitsSeagull Dashboard Data Setup Utility Instructions Page Using your Seagull in Laptop Live Mode Configuring Variometer AlarmsServo Display on the Dashboard Recorder’s LED Using the Recorder/Data LoggerAfter You’ve Flown Recorder’s PushbuttonGraphing/Spreadsheet Compatibility Saving Flight FilesTroubleshooting Recorder FCC Information FCC InformationTransmitters SpecificationsETSI, CE Limited WarrantyProduct Warranty Registration