AT300 Frequently Asked Questions (FAQ)
What is your certification status?
What do you show besides terrain? Do you have Weather? How about Traffic?
How does the Vertical Speed Indicator work? Do I have to keep my existing VSI?
With which GPS systems are you compatible?
I fly a low-wing airplane. Will I be able to read the display in bright sunlight?
What are the specs for your display?
How complicated is the installation?
What is required to install the unit?
How do I update the database? How often? How much?
What are the power requirements?
Q: What is your certification status?
A: Aspen Avionics received FAA TSO authorization for the AT300 in November 2005. The AT300 is certified under TSO C8d (Vertical Speed Indicator) and TSO C113 (Multipurpose Display). The AT300 is eligible to be installed as the primary Vertical Speed Indicator in virtually all light piston engine aircraft. During the certification process, all functions performed by the AT300 were evaluated by the FAA for regulatory compliance.
Q: What do you show besides terrain? Do you have Weather? How about Traffic?
A: The AT300 shows aircraft vertical speed, it graphically depicts the current GPS leg and active waypoint on the moving map display, and it shows either side view terrain or textual GPS navigation information (current waypoint, distance, groundspeed, etc.). The unit also displays airport symbols for all hard-surfaced US airports and continuously displays current aircraft track and current aircraft height above ground (derived from the terrain database and barometric altitude). In the future, the AT300 can be expanded to support the display of other information, such as datalink weather, lightning, traffic, etc. As new features are added in future product releases, existing customers will be offered an upgrade path to add these functions as desired.
Q: How does the Vertical Speed Indicator work? Do I have to keep my existing VSI?
A: The AT300 includes a highly accurate pressure sensor, which is used to directly measure the aircraft vertical speed. To measure vertical speed and to render terrain data, the unit must be connected to the aircraft static system. We recommend replacing the existing VSI instrument with the AT300, allowing the AT300 to use the existing VSI static pressure connector. Aspen Avionics has received FAA TSO authorization for the AT300 under TSO C8d, making the unit eligible for installation as the primary Vertical Speed Indicator in virtually all light piston engine aircraft.
Q: What if I don’t want to replace my VSI? Do I still have to connect the AT300 to the aircraft static line?
A: The AT300 uses an internal pressure sensor to determine the aircraft MSL altitude. Terrain and obstacle color coding is based on the MSL elevation of terrain and obstacles with respect to the aircraft MSL altitude, as measured by the internal pressure sensor. To correctly color code terrain, the AT300 must be able to sense ambient atmospheric pressure and must therefore be connected to the aircraft static system.
Q: How much detail does the AT300 terrain display really show? I live and fly in Maine most of the time, so does the database have the resolution to be useful in the mountains here?
A: The core database resolution is 15 arc seconds and 100’ elevation. This covers about 1/4nm blocks in most areas. Our experience is that this is very satisfactory for typical usage—the normal en route zoom scale is between 20 and 40 miles, so mountain contours and valley profiles show up very well.
Q: With which GPS systems are you compatible?
A: The AT300 is compatible with virtually every panel-mounted aviation GPS receiver in use today, including most legacy panel-mount navigators (except Northstar). Contact us at if you would like to know if we are compatible with your GPS system.
Q: I fly a low-wing airplane. Will I be able to read the display in bright sunlight?
A: Yes. The high-intensity LED backlighting used in the AT300 provides excellent sunlight readability throughout the complete viewing envelope of the AT300’s high-resolution LCD display. The backlighting is automatically dimmed under low ambient lighting conditions to provide uniform, flicker-free illumination that will not overpower your other instruments.
Q: What are the specs for your display?
A: The AT300 uses a 2.5” 240 x 480 pixel high-resolution, color, Active Matrix Liquid Crystal Display (AMLCD) employing high-intensity LED backlighting. The LED backlighting is computer controlled for maximum efficiency and reliability.
Q: How complicated is the installation?
A: Installation is very simple. Electrically, only three wires are required—one each for power, ground, and GPS RS232 serial data. Mechanically, only three screws and a connection to the aircraft static line is required. A static-system leak check is also required following installation, which means that any pre-existing leaks in the static system should be repaired.
Q: What is required to install the unit?
A: The moving map functions of the AT300 require that the aircraft have a GPS system installed. The VSI function is independent of the GPS. The AT300 requires only electrical power and ground, a serial data input from the pre-existing GPS, and a connection to the aircraft static line. The unit installs directly into the existing VSI instrument panel cutout using the same mounting holes and screws.
Q: How do I update the database? How often? How much?
A: The terrain and obstacle database resides inside the unit on a removable compact flash card. To update the database, simply remove a foil label on the side of the unit, change out the data card, and replace the label with a new one that is provided in the database update kit. Fortunately, terrain data does not change very often. The obstacles data is updated more frequently, and we issue a new database approximately every six months. How often you choose to update your database is at your discretion; however, we recommend that it be updated during annual inspection or during your biennial static-system check, whichever is most convenient to you. The price of the database update kit is $50. The old data card is yours to keep.
Q: How big is the unit?
A: The AT300 fits in a standard 3 1/8 VSI or altimeter instrument cutout. The unit is 3.8 inches deep.
Q: What are the power requirements?
A: The AT300 will operate from 12V to 32V on a 2-amp breaker.
Q: What are your prices?
A: The AT300 has an MSRP of $3,995. Contact your local Aspen Avionics Authorized Dealer to obtain an installation quote.
Q: How do I order?
A: Contact an Aspen Avionics Authorized Dealer to place your order. See our Dealer Directory to find a dealer near you.
Q: What is your warranty?
A: Every AT300 features a full two-year warranty from date of retail sale or installation by an Aspen Avionics Authorized Dealer. Aspen Avionics will repair or replace any product, product component, or software that fails in normal use during the warranty period.
