Just noticed in one of my engineering training books that it says:
"The PVD is enabled by:
*Airplane on ground
*Not Rollout Mode engaged
*LOC Data valid
*Course error less than 45 degrees
*Ground speed more than 40kts"
The last item seems to conflict with the Singapore Airlines 006 incident report which says the PVD unshutters at lineup.
http://www.airdisaster.com/reports/n...CAAR-02-01.pdf
The second last item seems to conflict with another manual which says that the displays provide guidance ...
"when the airplane initially turns to within 2.0 degrees of the runway centerline. The guidance stops when the airplane deviation exceeds 3.2 degrees."
Is this a reference to track, rather than heading? Or something else?
Trying to make sense of the information.
All comments welcome
