EICAS
From Rise: The Vieneo Province
Engine Indication and Crew Alerting System
EICAS is an acronym for Engine Indication and Crew Alerting System.
One interlinked system that informs the crew about aircraft operation and warnings about abnormal settings or situations.
The Engine Indication shows normal operational information such as:
- Fuel available
- Thrust output
Additional information can be found depending on the model:
- Landing gear
- Pitch trim
- Flap settings
Legacy engine indications
On displays with the original single-ended thrust bars, including the T-19, the box above the engine shows an amber "REV" when reverse is selected. See the annotated legacy EICAS layout.
E-10, E-11 and A-4 split-flow indications
On the E-10, E-11 and A-4 split-flow displays, each engine bar grows outward from a central white datum. The upper half shows exhaust from the bow outlet; the lower half shows exhaust from the aft outlet. These are exhaust directions, not directions of aircraft motion: aft exhaust produces forward thrust, while bow exhaust produces reverse thrust.
The number beside each half is actual outlet output as a percentage of its own rating. Each half has an independent 0-100% scale. Both wing-engine halves can be filled during VTOL; two 100% readings do not mean 200% net axial thrust or 200% vertical lift. The bars report outlet output before its force is resolved into axial and vertical components. Moving chevrons stay inside the filled area and follow the exhaust direction. Remaining flow continues to be indicated during spool-down after the thrust request is released.
On the E-10 and E-11, the engine boxes identify ENG1 (left), ENG2 (tail) and ENG3 (right). On the A-4, ENG1 is the left engine and ENG2 is the right engine; both use the VTOL bars, arranged side by side without an aircraft background. These displays use the following mode labels:
- FWD / REV: aft-only or bow-only exhaust with the nozzles in their axial position. These are green normal-operation indications.
- MIX: both axial outlets have flow.
- TRANS: wing nozzles between the axial and VTOL positions; shown in amber.
- VTOL: wing nozzles in their VTOL position. Read the two percentages for actual flow; VTOL alone does not mean that thrust is being produced.
- IDLE / OFF: zero outlet flow with propulsion powered or unpowered, respectively.
- FAIL: the engine is failed; shown in red.
- DATA: valid propulsion data is unavailable; shown in amber with dashes in place of outlet percentages. Do not read this as zero thrust.
The E-10/E-11 tail engine remains axial during VTOL. Its bar shows actual tail thrust, including thrust allocated to balance axial force from the wing engines. The A-4 has two tilting engines and no tail engine. During atmospheric flight, ascent, suborbital coast, orbit and re-entry, the bars continue to show actual main-engine outlet flow; the presence of a bar does not mean VTOL is permitted in that flight regime. These bars do not display RCS activity. Landing-gear indications remain separate.
E-10 and E-11 RCS indications
The E-10 and E-11 show RCS activity on the aircraft outline, separately from the main-engine bars and landing gear. The four circular indicators represent vertical RCS groups at the front and rear hull shoulders. Lateral arrows appear beside the front and rear groups. The two forward arrows and the two aft arrows near the tail represent the shared fore/aft RCS indication; each pair repeats the same activity.
| Indication | Meaning |
|---|---|
| Cyan + inside a ring | RCS force toward the top of the aircraft (body up). |
| Cyan − inside a ring | RCS force toward the underside of the aircraft (body down). |
| Cyan arrow | RCS force in the arrow's direction: left, right, forward or aft. |
| Filled portion of the outer ring | Relative activity of that vertical RCS group; more fill means greater indicated output. |
| Gray outline, with no + or − | Output is at or below the 2% display threshold; small stabilizing corrections may still be present. |
| Amber RCS DATA | Valid RCS indication data is unavailable. Do not interpret this as zero thrust. |
Cyan arrows, circle signs and cyan ring fill appear only when the magnitude of that group's indicated output exceeds 2%. At or below 2%, the outlines remain gray and the circles have no + or −. Above the threshold, ring fill shows the original output percentage without rescaling. This display threshold does not change RCS thrust or automatic stabilization.
Directions are relative to the aircraft, not the horizon. RCS arrows indicate force direction, whereas the animated main-engine bars indicate exhaust flow. A pitch or roll correction can light opposite signs at different hull groups without translating the aircraft. The indications follow RCS activity under manual control, TVM and DOR, including atmospheric and orbital operation; they do not announce whether main-engine VTOL is available.
W-6 STOVL indications
On the W-6, ENG1 is the left engine and ENG2 is the right engine. Each engine has one shared 0-100% output scale for forward, reverse and downward thrust. The percentage beside the bar is their combined actual output. When more than one outlet is active, the smaller REV, LIFT and FWD numbers show its shares of that engine rating; the shares add to the total.
Forward thrust fills upward from the bottom of the bar, with animated flow toward the aft exhaust. Reverse thrust fills downward from the top, with flow toward the bow exhaust. Lift grows equally upward and downward from the engine center, with animation flowing outward left and right. Lift remains centered until an axial fill would overlap it, then moves only enough to make room. It returns toward the center as the axial fill recedes. The labels follow the same top-to-bottom order: REV, LIFT, FWD.
The engine box shows STOVL whenever actual downward output is present, including full vertical thrust and the remaining flow during spool-down after release. FWD, REV and MIX describe axial flow when downward output is zero. IDLE means powered with no outlet flow, including when the doors are open; OFF means unpowered with no flow. FAIL and DATA use the same red failure and amber unavailable-data conventions as the E-series indications.
Beneath each engine, DOOR CLSD and DOOR OPEN report the downward-nozzle door position; OPENING and CLOSING identify travel. The doors must open before downward thrust can flow and remain open through normal spool-down. DOOR --- means valid door/propulsion data is unavailable. Amber INHIB appears beneath the door status when powered propulsion is outside the permitted lift envelope or inhibited. It does not mean axial thrust is unavailable; read the engine mode and actual flow.
These indications follow the existing VTOL restrictions during ground operation, hover, atmospheric flight, ascent, suborbital coast, orbit and re-entry. Low speed alone does not establish that lift is available. In orbit, the doors remain closed and main-engine axial output remains available; RCS activity is separate and is not shown by these bars. Landing-gear symbols remain separate.
MFD page selection
Selecting Orbit or another MFD page does not acknowledge crew alerts or remove EICAS indications. A powered, serviceable EICAS continues showing the indications appropriate to the vehicle and its current state. Gear, engine, trim or CAS layers disappearing only while ORB1 is selected indicate a display-rendering fault; do not interpret that disappearance as a cleared alert.