BOM (Broadcasting Outer Module) Company Standards
Effective Date
12/6/17
Page
10
of
12
Document No.
42
Revision
1
Code Number
D-0005
changes, your navigation software of choice will allow you to input the altimeter setting at
your current location.
Both the differential and absolute pressure sensors are calibrated using a previously calibrated
and tested pressure sensor as a reference. The altitude is calibrated from sea level to 18,000 ft.
and the deviation after calibration cannot be more than ±40 ft. The Air Speed is calibrated from
0 to 320 kt. and the deviation after calibration cannot be more than ±3 kt.
9.2
Vibration Sensor
The sensor is designed to aid the BOM determine when to wake up. The BOM is designed to
turn ON with power input from the turbine, but since this process requires a minimum speed
of 60Kts, the BOM will not start until after takeoff. For this reason, the Vibration sensor is
mean to recognize an “Engine ON” versus “Engine OFF” state based on vibrations caused by
propeller’s RPM. When “Engine ON”, the BOM will initialize all its systems using power
from an internal battery. If an “Engine OFF” state is measured, and there is no power provided
by the turbine, the BOM will shut off after 15 seconds. If the battery is not charged, the
vibration sensor will not work, thus The Vibration sensor is not a guaranteed method for power
ON and is meant only for enhancing the BOM, and NOT as a primary switch ON feature.
9.3
Angle of Attack
The AOA is based on differential pressure sensor, and indicated airspeed. The angle of attack
requires user calibration to set the “near stall” point and the “max L/D” point of the aircraft.
The AOA data will be disabled until these two values are calibrated. This calibration is
performed using Levil’s dedicated AHRS Utility App on a tablet. To measure near stall point,
the pilot must fly at a minimum controllable airspeed and “SET NEAR STALL” using the App
interface. To measure the “max L/D” point, the pilot must fly at the Speed that will allow for
the best rate of climb (Vy), and “SET MAX L/D” using the App interface. Once the two
calibration points have been determined, the AOA gauge will be enabled.
9.4
Micro SD Memory Card
There is an internal memory designed to record telemetry data during flight, thus the BOM can
be used as a “Black Box”. The internal memory is not meant to be removable. The stored data
is instead broadcasted via Wi-Fi upon commands. The user can request a list of stored files
and/or the contents of a specific file. The Filename must contain the unique serial number, date
and time for the flight. Data can be stored at a rate of 1Hz or 5Hz (user selectable). Data inside
the file includes but is not limited to Identification (Call sign), GPS telemetry (track, speed
altitude etc.) AHRS telemetry, pressure data, error messages, etc.
