Spitoon,
Would you agree that the 'unavailable portion' as you've described it, is part of the Manuevering Area? If it isn't, why not? If it is, why would this area not be held to he standards of the rest of the manuevering area, such as surface integrity, clearance to position, etc?
If you need clearance to taxi on the taxiway, why would you not need clearance to move through the displaced portion? If potholes on the apron are notamed, or marked, why would they not be on the pre threshold portion? If there were some obstacle on the displaced part, wouldn't they then have to re-displace the displaced threshold temporarily to avoid the obstacle?
The quote I\'m most familiar with regarding this (from local regulations) is as follows.
MATTERS OF OPERATIONAL SIGNIFICANCE AFFECTING AIRCRAFT PERFORMANCE
The condition of the movement area and the operational status of related facilities shall be monitored and reports on metters of operational significance of affecting aircraft performance given, particularly in respect of the following.
a) construction or maintenance work;
b) rough or broken surfaces on a runway, a taxiway or an apron;
c) snow, slush, or ice on a runway, a taxiway or an apron;
d) water on a runway, a taxiway or an apron;
e) snow banks or drifts adjacent to a runway, a taxiway or an apron
f) anti-icing or de-icing liquid chemicals on a runway, a taxiway or an apron;
g) other temporary hazards, including parked aircraft;
h) failure or irregular operation of part or all of the aerodrome visual aids; and
i) failure of the normal or secondary power supply.
Spitoon, what is it that you are speculating could be taking place on this displaced portion that the pilot wouldn\'t know about?