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Old 3rd August 2017 | 14:52
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vilas
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Joined: Jun 2007
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From: Wanderlust
BKD
Airbus protections come from Flt Ctls, FMGS, ATHR. Unless one goes through these he cannot find correct answers.
1. While taking off with heavier weight S speed becomes close to VFE. Auto Retraction System retracts the flaps to increase the VFE to 230kts to help avoid VFE exceedance.
2. In OP CLB mode during TO/GA thrust even in TOGA with LVRCLB flashing FMGS will increase ROC to restrict speed at VFE. But if ALT* happens speed exceedance will happen unless thrust is brought to CLB detent.
3. With AP on the FMGS speed protection is available only with ATHR in Speed mode. Below FCOM:
When in SPEED/MACH mode, the A/THR does not allow speed excursions beyond the following limits, regardless of the target speed or Mach number: ‐ For a selected speed target, the limits are VLS and VMAX (VMO -MMO , VFE -VLE, whichever applies) ‐ For a managed speed target, the limits are maneuvering speed (Green Dot, S , F , whichever applies) and maximum speed (340/0.80-VFE -VLE, whichever applies).
4. With AP off only FD on in open mode and ATHR in THR if FDs not followed correctly and speed is allowed to increase then at VFE+4 FDs are removed ATHR will revert to speed and the original speed target will appear in selected and recover.
5. There is no flap load relief in A320.
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