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时间:2011-09-26 01:07来源:蓝天飞行翻译 作者:航空
曝光台 注意防骗 网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者

Over the period from 1992 to 1994 our non-pref approval rate went from 47% to 89% and our annual calculated fuel savings from 4.9 to 19.6 million pounds.
Late in 1994 the FAA announced its intention to expand the “NRP” in January 1995. The new plan was to allow UPTs without coordination with ATCSCC, provided the fights initial cruise altitude was above a prescribed value and the first and last 200nm were operated on approved published routes. The prescribed altitudes were planned to be lowered incrementally throughout 1995 until FL290 was reached. During this time the users were allowed to qualify under either old NRP rules (AC 90-91) or “expanded” NRP rules, whichever produced the greatest benefit. In many cases flights operating on short routes at low altitudes were much better off under AC 90-91 rules than “expanded” NRP rules.
Until the NRP “expansion”, a flight might qualify for NRP status in two ways (rule based or coordinated), but in each case the flight was to be filed with “NRP” in the remarks section of the flight plan. This alerted controllers that while this flight was not on the FAA pref, all required coordination had been accomplished. Now a new airborne element was introduced, where a pilot or controller might initiate a non-pref route change, for a flight above a certain altitude, and no downline coordination was required. Additionally, in some cases, pilots and/or controllers were inadvertently de-optimizing flight plans by attempting “direct” routings that were not fuel/time efficient.
Also, the “expanded” NRP created some unexpected problems for pre-flight planning. Since qualification for NRP status now depended on the altitude reached, the dispatcher was faced with the possibility that a change in payload might lower altitude capability and put the flight back on a pref routing, thus increasing fuel burn. It was also unclear where the 200nm limitation began or ended since many Standard Instrument Departures (SIDs) and Standard Terminal Arrival Routes (STARs) were not 200nm long. Also, in other ARTCCs the flows for some high density areas (NYC) sometimes began at points greater than 200nm from the destination.
These are not insurmountable problems, as we learned under the old coordinated NRP. However, under the “expanded” NRP, the feed-back loop was cut off. Now, if the flight plan met the new rules, no message was sent to ATCSCC for coordination and so information on flow problems was not routinely available.
Due to these problems and other controller concerns the altitude lowering of the “expanded” NRP was halted in July. It is expected to resume in November 1995.
It is interesting to note that many view the NRP as beginning in January 1995 and seem to ignore the data and experience collected in the previous 3 years. Among the many issue raised by the NRP in its many forms are the following:
1) Sometimes trying to simplify a complex, multifaceted problem may not make matters better but worse.
 
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