Radar altimeter
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Hi All,
When I fly the F-16A upside down, does the radar altimeter still receive the signal reflected from the ground?
When all instruments are normal, why is there no altitude warning when the F-16A is about to hit the ground?
Sorry, the question I asked is about the real F-16A.
thanks!
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I think that the radar altimeter is positioned on the underside of the plane.
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When the plane flips, is the height of the HUD wrong?
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suggest a good read of the BMS dash-1
Hud chapter, paragraph 1.5.8
The CARA has limitations depending on altitude and pitch roll (bank angle).
Pitch or roll angle limits are 10° at 50000 feet, 15° at 25000 ft, 25° at 10000 ft, 30° at 5000 ft and 30° in pitch and 60° in roll at 3000 ft.
A combination of pitch and roll angles further reduces CARA altitude capability.
When outside the specification of the CARA altitude the HUD CARA display is blanked.
CARA is therefore most useful at low altitudes below 3000 feet. -
When all instruments are normal, why is there no altitude warning when the F-16A is about to hit the ground?
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Because the warning depends solely on the radar altimeter. If the radar beam is pointed at the sky, it’s not going to be of much help in determining altitude.
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The A model RDR ALT warning is based on the ALOW figure or DWAT logic compared to sensor reading. DWAT does use both baro and radar so I think it should still function without radar sensor data. In absence of radar data there should be no warning outside of the 3 minute DWAT window.
I don’t know if the A model has a “MSL floor” like the C.
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Sorry, what is DWAT? I have no idea.
thank you!
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Descent warning after takeoff
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Sorry, what is DWAT? I have no idea.
thank you!Bms Dash-1 again:
4.2 Descent Warning Advisory
Descent Warning After Takeoff (DWAT) provides an audio warning of an unintended dive or descent during the departure phase of flight. The Voice Message Unit (VMU) descent warning advisory “Altitude, Altitude”, will occur when all the following conditions are met:
• The landing gear handle is up.
• The time from takeoff is less than 3 minutes (from WOW).
• The aircraft has climbed at least 300 feet above the runway elevation referenced to Mean Sea Level (MSL), but not yet gained 10,000 feet above runway elevation.
• There is a descent rate present such that the aircraft will descend to the runway MSL elevation within the next 30 seconds.
• The DWAT message has not previously occurred since takeoff.
If for whatever reason you want to start the 3 minute timer before takeoff selecting ENABLE on the GND JETT switch starts the DWAT timer as well.Predictive Ground Collision Avoidance System (PGCAS)
In addition, the CARA ALOW code was rewritten in 4.32 so that it behaves more like the real one. Specifically, the ‘AL <alt>’ label will flash when you are below the selected <alt>value as measured by height AGL. If you descend through the ALOW limit, you get the VMS warning once unless and until there is a CARA reset.
Resets happen if you go back above the limit altitude, or if the RALT reading is lost (like when you roll inverted and the radar can’t see the ground). A reset also occurs if your rate of climb as measured by the radar altitude exceeds 1200 feet per min. Note this last one means that you can hear the VMS message even when flying along in level flight or even climbing if the terrain below you has sudden significant slope. Normally though you should only hear one VMS altitude warning per trip below the limit value.</alt></alt>
Do yourself a favor, open the books
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Dear All,
Since an F-16A of the our Air Force took off at night two minutes later, after leaving the tower radio, disappeared from the radar at an altitude of 7000 feet, there is no abnormal radio communication , at present, it is should have fallen into the sea, also found the signal from the transmitter.
I don`t have much time to read the books, I just want to confirm when the pilot enters the Spatial Disorientation, will there be a “pull up” warning when approaching the sea?I didn`t really want to say it before I investigated it, thanks guys!