In that case it can come from the horse's mouth.....what are the reasons for which they allow the dispensations, and why didn't Wednesday night qualify?
From what was said above, it sounds like they gave them yesterday, but that would not seem to be materially different to the previous day when they were denied.
Pretty clear reasons, for instance here is an A380 approval from last year, (QF cancelled that 10.55 service BTW last night, so I am not sure if any were given):
DETAILS OF DISPENSATION
Date: Friday, 25 March 2010
Aircraft: A380-800
Registration: VH-OQB
Operator: Qantas
Operation: Departure after 11pm
CIRCUMSTANCES LEADING TO REQUEST
Qantas flight QF31 (Sydney to Singapore) encountered a landing gear fault on pushback.
Engineers were able to rectify the problem. Qantas requested a dispensation to depart
Sydney no later than 11:20pm. There were 349 passengers and 26 crew members onboard.
Approved: Yes
REASONS FOR APPROVAL
The delegate was satisfied that the circumstances met the three mandatory criteria required for the issue of a curfew dispensation. The Delegate approved the application as it was determined that the fault that occurred was immediate and not able to have been foreseen. Qantas was unable to make alternative arrangements. Dispensation granted for take off no later than 11:20pm.
So you can see it was exceptional circumstances that applied hence the dispensation:
http://www.infrastructure.gov.au/av...ews/SydneyAirport/DispensationGuidelines.aspx
What Constitutes Exceptional Circumstances
General criteria
- To be considered exceptional the circumstances must generally be:
- of immediate origin;
- of such a character that they could not reasonably have been foreseen;
and
- not reasonably able to be met by alternative arrangements.
Note: Paragraph 6 sets out the criteria for determining whether or not a circumstance will generally be considered an exceptional circumstance. These criteria must be satisfied before a dispensation will be considered.
- Where all of the above criteria are satisfied, the following matters may be taken into account to determine whether or not a dispensation should be granted:
- by what margin the predicted time of movement falls into the curfew period ie, is it shortly after 11.00 pm or shortly before 6.00 am;
- whether the take-off or landing is over water;
- whether the cause of delay is within the control of the operator;
- the noise level of the aircraft;
- the number of passengers involved; and
- the severity of the likely hardship.
Note. Paragraph 7 sets out additional matters which may be considered once the criteria specified in paragraph 6 have been satisfied.
Example:
- An indicative example of a situation that may qualify for a dispensation would be where a large passenger aircraft was delayed by the need to off-load baggage for security reasons because a booked passenger had not boarded, where:
- the aircraft could not depart before the curfew, but
- could do so very shortly after its commencement.
Unavailability of main north-south runway
- Major maintenance of runways at Sydney Airport is carried out on a schedule which requires the partial closure of the main runway for an extended period every eight to ten years. There may also be, from time to time, a need to close the runway to carry out urgent repairs or to accommodate other works at the Airport. Under the Act, a dispensation is required if permitted curfew traffic is to use runways other than those specified in the Act.
- Notwithstanding paragraphs 6 and 7, an exceptional circumstance will exist in circumstances where the main north-south runway (that is, runway 16R and runway 34L as defined in section 4 of the Act) is not available because of maintenance of the runway or associated equipment necessary for the safe operation of the Airport.
Note: These situations constitute exceptional circumstances. It is envisaged that the public will be given notice of impending works which could result in changes to the normal patterns of curfew operations.
A dispensation under this provision will be limited to approving operations by normal curfew traffic only over Botany Bay.
I might add that the curfew is not something ATC in general really like given the extra pressure it puts on operations, and they are there all night anyway to handle the freight movements!
