For example, in level flight over the ocean at 90 KIAS and with 200 feet indicated on the RADALT, the BARALT will indicate a mere 150 feet if calibrated to the local altimeter setting.
If the BARALT consistently indicated higher than the RADALT, then pilots using the BARALT as their primary altitude instrument would think they had more clearance from the terrain below than they actually do.
By this time my pilot had brought us beneath the overcast layer to VMC conditions, but I continued to focus on the RADALT. My pilot advised me that I could reset my green ring and take off my mask.
This could have prevented confusion and delays as I attempted to control the aircraft's communications, RADALT, and navigation systems.
As we were once again conned into position via the crew chief's calls, the swimmer again swung underneath the aircraft and into the beam of the radalt
, again causing it to fail.
I glanced at the radalt
and saw it rapidly pass through 50 feet, as I established control.
When the pilot caught the deviation, our VSI was about 2,000 fpm down, and our radalt
annunciator was flashing in the pilot and copilot primary flight display (PFD) (the current software does not have an associated tone).
I'd then immediately engage radalt
hold to let the aircraft's automatic-flight-control system (AFCS) input power as we approached the preset 150-foot altitude in the radalt-hold pot.
When do you reset your radalt
between the bombing and strafing pattern?
An initial scan showed we had lost all of our fuel indications, radar altimeter (radalt
), radar, and the reduced-authority-thrust system (RATS).
No one knew what happened, but the learning points are clear: compartmentalization, radalt
discipline, adherence to the minute-to-live rule, and basic air work.
I set the radalt
for landing, and we turned off all unnecessary avionics and displays, except the HUD.