Sustaining High Gs at High Airspeeds
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- Joined: 02 Dec 2014, 17:12
Is the reason why the F-16 and other jet fighters can sustain high Gs at high airspeeds, but cannot sustain those same high Gs at lower airspeeds because:
1) AOA is lower at higher airspeeds
2) A jet fighter produces higher thrust at high airspeeds and lower thrust at low airspeeds
Is it because of both?
Thanks,
Delta
1) AOA is lower at higher airspeeds
2) A jet fighter produces higher thrust at high airspeeds and lower thrust at low airspeeds
Is it because of both?
Thanks,
Delta
Surfaces areas and deflection is small but enough for optimum ALTITUDE AND AIR DENSITY . So at high alt you need more speed to get max. performance BUT MAYBE NOT 9 G JUST LOWER ONES . With FBW systems and negative stability of the aircraft the deflection of the stab. for 9 G IS NOT THE SAME FOR THE ENTIRE SPECTRUM OF SPEEDS AND ALTITUDES . 9G is sometimes obtained at 15 AOA and 450 KNOTS , but over 1. 4 Mach the 9 G is at 6 AOA.and lower alt. were air density is bigger .But there is more , CONTROL SURFACES DON'T STOP IN PLACE AFTER GETTING 15 AOA AND an max.9 G BECAUSE aircraft will overshoot 9 G , SO THEY MUST DUMP THE INITIAL DEFLECTION IN A SECOND TO A LOWER ANGLE OF DEFLECTION AND THEN COME BACK maybe with more deflection IF NEEDED BECAUSE OF LOST OF THE SPEED AT HIGHER G NUMBER .THESE WAY YOU MAINTAIN A LOWER INDUCED DRAG and keeping allowed G MORE TIME THEN NO FLY BY WIRE AIRPLANES .At slow speed F16 STABILATOR go down until mechanical stop (25 DEGREES),FOR 25 AOA then go up TO THE NEGATIVE 3 DEGREES DEFLECTION to not overshoot 23 OR 25 AOA and only 1 G.THESE WAY FBW WORKS ,in my understanding .Hope this is easy to understand for you .
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