wilycoyote4
Charter Member
I think this is the DLC, or direct lift control system. Basically, the spoilerons are used to augment the elevators for more responsive glideslope control. when the DLC system is active, it lifts the spoilers up about 1/3 of the way for the entire approach. If the pilot pushes forward on the stick, the elevator goes down as well as the spoilers lift up higher, dumping more lift. When the pilot pulls back on the stick, the elevator goes up and the spoilers retract. This enhances the sensitivity of the controls for the Tomcat.
The AOA indexer comes in many derivations, but its used for approach and landing, not turning flight. The indexer is different from the AOA indicator - it has the three lights, two chevrons and a circle - is basically set for an optimum approach AOA. When you're 'on speed,' (the amber center circle is lit up) this means the indicated airspeed will yield the optimum approach AOA, which is largely based on current aircraft weight. Higher the weight, obviously, the higher the required airspeed to reach this proper AOA and vise versa. IF the upper chevron (usually a green light) is lit up, this indicates indicates a slow airspeed (too high an AOA). If the lower chevron is lit (usually a red light) this means you're flying too high an airspeed (relating to too low an AOA).
Thank You, well said by my opinion. I think I understand better.
However, once you slow below about 110 or so (at that weight), stall horn should go off (the only thing that causes a stall is exceeding the critical AOA - at any speed) and decent rate should increase dramatically till around 90-100 kias when the plane departs controlled flight. But, it wouldnt indicate much stall 'break'. The loss of controllablility at slow speeds is what accounted for Vmc issues. IF an engine flamed out (which they did due to compressor stalls in the "A" model frequently) during the approach at this slow speed, the asymmetric thrust from the other engine would exceed the rudder authority (actually, the original design for the F-14 was with only one vertical stab, not two! The Grumman engineers determined in wind tunnel tests that it needed two