Radar Altimeter Failure

T-45C TS & ADV BIFP-09

Instrument Failures

available. Be aware that in some AOA failure situations, the AOA approach lights will

also become either inoperative or signal incorrect readings to the ground observer/LSO.

Figure 2 shows one possible indication of a failed AOA indicator: an OFF flag. The

OFF flag does not have to be present for the indicator to give false readings because it

indicates only a lack of electrical power.

Figure 2: FAILED AOA INDICATOR

The procedure for dealing with a total AOA readout failure is:

1. Use the airspeed indicator.

2. Fly calculated approach speeds, using the airspeed indicator.

3. Inform Tower/Approach/LSO (as appropriate) in case the aircraft's AOA approach

lights have been affected.

RADAR ALTIMETER FAILURE 1.8.1.7.11.2

With a failed radar altimeter, you lose your height-above-ground reference. The only

cockpit radar altimeter readouts are in a digital format on the HUD and MFD displays. If

you are aware of your location and the local terrain, the danger is minimal. If you have

any doubt about your position or the topography of the surrounding area, you should

notify the controlling agency and immediately climb to a safe altitude. This is

particularly true at night and during IMC.

Once you are sure of the local surface elevation and have confirmed that the barometric

altimeter has the correct setting, you should be able to use it for all altitude references.

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