ETSO-C2d#4 – Airspeed Instruments
Deviate from SAE AS8019A § 3.2.1 and allow 10 knot graduations with speed labelling every 20 knots and no minor graduations. In addition, a digital display is provided. This proposal is in line with the recommended symbol 18 of SAE/ARP4102-7 App. A.
ETSO-C2d#5 – Airspeed Instruments
The SAE AS 8019A 3.2.6 requirement for range marking on the nameplate shall not apply for EFIS displays.
ETSO-C6d#3 – Direction Instrument, Magnetic (Gyroscopically Stabilized)
Deviate from ETSO-C6d to modify the requirement 3.6 in SAE AS 8013A and to provide an integral health monitoring with an associated health message. The detailed requirements are not adequate to AHRS not using the synchro or rotating gyro technology.
ETSO-C6d#4 – Direction Instrument, Magnetic (Gyroscopically Stabilized)
Deviate from ETSO-C6d to modify the requirement 3.13 in SAE AS 8013A and use a sensor combination with a mathematical process to provide heading in line with magnetic heading. When no alignment is needed the indication of the alignment and/or failure of alignment status is not necessary. Remark: It is EASA interpretation that a mathematical process bringing the heading in line with magnetic heading is an automatic function as described in the requirement and no deviation request is needed for such a function.
ETSO-C10b#5 – Aircraft Altimeter, Pressure Actuated, Sensitive Type
SAE AS392C § 4.2.1 states, “4.2.1 Increments: Markings shall be provided at intervals not exceeding 20 feet of altitude with major increment markings at 100 foot intervals.” Instead, a combination of a tape and a digital readout for indicating altitude shall be used. Following current PFD conventions, the proposed tape shall have graduations every 100 feet with markings every 500 feet. The proposed altitude display comports with recommended symbols 39 and 40 of SAE/ARP4102-7 App. A.
ETSO-C10b#6 – Aircraft Altimeter, Pressure Actuated, Sensitive Type
ETSO-C10b §4.1 No maximum operating altitude shall be marked on the integrated instrument.
ETSO-C146#7 – Stand-Alone Airborne Navigation Equipment using the Global Positioning System (GPS) Augmented by the Wide Area Augmentation System (WAAS)
Deviate from RTCA DO-229C § 2.2.1.2.3 and stop operation if a data base error has been determined. The consequences of data base failures are not transparent and for safety reasons the system operation is stopped.
ETSO-C146#8 – Stand-Alone Airborne Navigation Equipment using the Global Positioning System (GPS) Augmented by the Wide Area Augmentation System (WAAS)
RTCA DO-229C § 2.2.1.4.4 requires displaying the bearing in true or magnetic bearing as selected. Only magnetic bearing is provided.
ETSO-C146#9 – Stand-Alone Airborne Navigation Equipment using the Global Positioning System (GPS) Augmented by the Wide Area Augmentation System (WAAS)
RTCA DO-229C § 2.2.1.4.5.3 requires the track angle error to be displayed with 1° resolution. No numerical display will be provided. Instead, the aircraft track is displayed on the primary flight display with a track marker (green diamond) and by the position of the flight path marker. Desired track is shown on the primary flight display with a waypoint bearing marker (magenta waypoint star) and a perspective, highway-in-the-sky path depiction. Aircraft track is displayed on the navigation display with a track marker (green diamond) and lubber line (segmented green line). Desired track is shown on the navigation display with a waypoint bearing marker (magenta waypoint star) and a depiction of the flight plan route with active leg shown in magenta and other legs shown in white. The displays provide a superior method for the pilot to understand the relationship between aircraft track and desired track and offer an equivalent level of safety to a numerical display of track angle error.
ETSO-C146#10 – Stand-Alone Airborne Navigation Equipment using the Global Positioning System (GPS) Augmented by the Wide Area Augmentation System (WAAS)
DO-229C § 2.2.2.4.3 requires in oceanic/remote, en route, or terminal mode to provide either a display or electrical output of cross-track deviation with a range of at least ± 20 nm (left and right). DO-229C § 2.2.3.4.3 requires in non-precision approach mode to provide either a display or electrical output of cross-track deviation with a range of at least ± 9.99 nm (left and right). No numeric cross-track deviation display shall be provided. Instead, the aircraft relationship to the desired track is graphically shown on the navigation display.
ETSO-C146#11 – Stand-Alone Airborne Navigation Equipment using the Global Positioning System (GPS) Augmented by the Wide Area Augmentation System (WAAS)
DO-229C § 2.2.3.4.3 requires in non-precision approach mode either a display or electrical output of cross-track deviation with a range of at least ± 9.99 nm (left and right). Instead a "skyway” and other perspective symbols in lieu of a vertical deviation indicator are used.
ETSO-C146#12 – Stand-Alone Airborne Navigation Equipment using the Global Positioning System (GPS) Augmented by the Wide Area Augmentation System (WAAS)
DO-229C § 2.2.3.3.4(c), 2.2.4.4.4 non-numeric vertical deviation display: Instead of a vertical deviation indicator a "skyway” and other perspective symbols are used.
ETSO-C146#13 – Stand-Alone Airborne Navigation Equipment using the Global Positioning System (GPS) Augmented by the Wide Area Augmentation System (WAAS)
DO-229C § 2.2.3.4.4, 2.2.3.4.5 Instead displaying the distance to the Missed Approach Waypoint (MAWP) and the bearing to the MAWP, the aircraft relationship to the MAWP is graphically shown on the navigation display. For the use of a moving map, no deviation request is necessary.
ETSO-C151a#1 – Terrain Awareness and Warning System (TAWS)
ETSO-C151a App. 1 § 3.3.e states, “If a two tone sweep is used to comply with RTCA Document No. DO-161A, paragraph 2.3, the complete cycle of two tone sweeps plus annunciations may be extended from “1.4” to “2” seconds. No “Whoop-Whoop” tone is provided. The provision of a “Whoop-Whoop” tone is not required by Appendix 1 of ETSO-C151a, per the “if…used to comply” statement. In addition, the voice alerts specified in DO-161A conflict with those specified in ETSO-C151a. Applicant proposes the aural and visual alerts in the following table to comply with the requirements of the ETSO. These alerts are based upon the alerts in the ETSO and offer an equivalent level of safety to the alerts specified in DO-161A.
| Alert Type | Caution Visual |
WARNING AURAL |
VISUAL “PULL UP” |
AURAL “TERRAIN, TERRAIN; PULL UP, PULL UP” |
|---|---|---|---|---|
| FLTA | “TERRAIN” | “Caution, Terrain; Caution, Terrain” | ||
| PDA | “TOO LOW” | “Too Low Terrain” | “PULL UP” | “Pull Up, Pull Up” |
| GPWS Mode 1 | “SINK RATE” | “Sink Rate” | “PULL UP” | “Terrain, Terrain; Pull Up, Pull Up” |
| GPWS Mode 2 | “TERRAIN” | “Caution, Terrain; Caution, Terrain” | ||
| GPWS Mode 3 | “TOO LOW” | “Too Low Terrain” | ||
| GPWS Mode 4 | “TOO LOW” | “Too Low Terrain,” “Too Low Gear,” or “Too Low Flaps” depending upon aircraft speed and configuration | “GLIDE SLOPE” | “Glide Slope” |
| GPWS Mode 5 | “GLIDE SLOPE” | “Glide Slope” | ||
| 500 Foot Wake-Up | “Five Hundred” |
ETSO-C151a#2 – Terrain Awareness and Warning System (TAWS)
ETSO-C151a App. 1 § 4.7, § 4.9 Instead of providing multiple, selectable messages for certain alert conditions, a fixed set of alert messages is provided.
ETSO-C151a#3 – Terrain Awareness and Warning System (TAWS)
ETSO-C151a App. 1 § 10.2 and § 10.3 In the conditions for defining the Terminal or Approach Phase the decreasing range to nearest runway threshold is not used.
