感谢同事的问题。
在 FCOM DSC-34-SURV-20-10 B DESCENT BELOW GLIDE SLOPE (MODE 5)中写到：
If the aircraft descends below the glide slope by more than 1.3 dots during precision approaches, the following alerts are triggered:
是否意味着 MODE 5 只用于 ILS 和 GLS（精密进近），而不适用于 FLS？
空客的回答简单来说就是只适用于 ILS, SLS, GLS，不适用于 FLS。
TR-81744461 原文
Q
In FCOM DSC-34-SURV-20-10 B DESCENT BELOW GLIDE SLOPE (MODE 5), it states:
If the aircraft descends below the glide slope by more than 1.3 dots during precision approaches, the following alerts are triggered:
Does this mean that MODE 5 is only applicable to ILS and GLS (precision approaches) and not to FLS?
A
We confirm that Mode 5 alerts cover only ILS/ SLS and GLS approaches.
Therefore GPWS MODE 5 warning will not occur in the case of a glide slope deviation during a FLS approach.
This behaviour is as per design. Here below is a detailed description of the GPWS Mode 5 alerting logic:
The Mode 5 provides alert when the aircraft flight path descends below the glideslope beam on front-course ILS (or GLS or SLS) approaches.
This mode is active during approach, if valid Radio Altitude is less than 1000 feet AGL and the landing gear is down.
The Mode 5 uses xLS data which can be ILS or GLS or SLS which depends on mode of MMR. ILS, GLS and SLS are precision approaches.
The Mode 5 is inhibited when valid MMR Mode data is received, and this data indicates that FLS or mix-FLS mode is selected (FLS is non precision approach).
