The case of temporary overspeed aural warning during slats / flaps retraction after a heavy-weight take-off
In the particular case of a heavyweight take-off, the risk of a temporary overspeed aural warning is increased. Indeed, in this configuration, S speed is quite close to VFE CONF 1+F because the aircraft weight is higher and the lift needed to climb is higher too. Therefore the slats need to remain extended for longer. As a result, the crew will order flaps retraction at a speed that might be higher than the Flaps Auto-retraction speed.
In that case, should the acceleration of the airplane be rapid, a VFE aural warning may momentarily trigger.
This logic is as per design and structural limits are not encountered.
For example, an A320 at a Take-Off Weight (TOW) of 76T, S speed of 205 kts, the pilot will order flaps retraction most probably at or slightly above
210 kts, which is precisely the Flaps Auto-retraction speed. Once the slats / flaps control lever is in the retracted position, the VFEred and black strip is no longer displayed on the PFD speed scale. If the airplane accelerates rapidly, then the airspeed may catch up the actual instantaneous VFE momentarily, which will trigger the VFE aural warning.
Again, this logic is as per design and structural limits are not encountered.
Source:
Airbus Safety First Magazine 20. Page 12