mercoledì 25 marzo 2015

Avionics Bending: GPWS Computer (GPWC)

For various flight conditions, the ground proximity warning system (GPWS) provides aural and visual warnings of airplane closeness to the terrain. The potentially dangerous flight modes are:
(1) Mode 1 - Large Descent Rate
(2) Mode 2 - Large Terrain Closure Rate
(3) Mode 3 - Too Much Altitude Loss During Climbout (at Takeoff or in Go-Around) When Not In Landing Configuration
(4) Mode 4 - Not Enough Terrain Clearance
(5) Mode 5 - Too Much Deviation Below The Glide Slope Centerline
(6) Mode 6 - Aural Callouts When Descending Through Selected Radio Altitudes
(7) Mode 7 - Windshear Detection

The system consists of:
(1) 1 - Ground Proximity Warning Computer (GPWC) or Enhanced GPWC
(2) 1 - GND PROX Light - G/S INHB Switch/Light
(3) 1 - WINDSHEAR Light
(4) 1 - PULL UP Light
(5) 1 - Ground Proximity Test Switch
(6) 1 - Gear Override Switch
(7) 1 - Flap Override Switch

The ground proximity warning computer (GPWC), or Enhanced GPWC, is located on the E1-5 rack in the main equipment center. The GPWC (or EGPWC) LRU is the main element of the Ground Proximity Warning System (GPWS).
The GPWC LRU front panel contains a toggle switch and an 8-character LED BITE display.
Present status or flight history data shows on the BITE display when the toggle switch is selected.
The computer receives and processes input signals to determine the alert and warning mode conditions. It also generates the aural and visual alert and warning messages.
The computer continuously monitors the validity of input signals and internal functions. System failures detected are stored in a non-volatile memory.

mercoledì 4 febbraio 2015

New static inverter

To replace my old and small generator, I bought a static inverter able to output pure sine wave 115VAC 400Hz 3 Ph with a rating of 3000VA and an efficiency of 80%; the Input is 28VDC up to 140A.
It should be enough to power all cockpit gauges and computers.
The unit features 3 inverter units which are controlled to have a phase shift of 120° and has an active cooling system provided by internal fan.

Here you can see a video during unit startup and shutdown.

lunedì 26 gennaio 2015

Avionics bending: Flaps Position Indicator

The trailing edge flap position indicating system provides flap position and flap system failure information to the flight deck.
Flap position is indicated by a dial indicator with needles for indicating right and left wing flap and slat position.
The flap position indicator needles are normally driven by the outboard synchro position transmitters in each wing.
The primary source of flap and slat position information is the flap/slat position indicator located on the P3 panel.
The position indicator uses two needles, "L" and "R" to indicate flap and slat position between the 1-unit and the 30-unit positions.
The position indicator shows operation of the slats between the UP and the takeoff position.
When any slat leaves the retracted position the position indicator needles move halfway to the 1-unit mark.
When the slats reach the takeoff position the needles move to the 1-unit position.
Here is SSM reference: