A flight of four C-17's training for an Operational Readiness Inspection flew a mission following an incorrect track altitude profile which caused them to fly through TRACON airspace at a low altitude.
Synopsis
A flight of four C-17's training for an Operational Readiness Inspection flew a mission following an incorrect track altitude profile which caused them to fly through TRACON airspace at a low altitude.
Narrative
Flight of 4 C-17's were flying preplanned low level Instrument Route (IR). We were cleared routes and altitudes and continued to fly at the top of the block due to weather on the route and the fact that we were a 4 ship formation. At point E on the route we were able to descend to 500 AGL. Passing point K we were to contact Approach. We climbed to 1;500 FT as we passed point K and attempted to contact Approach. We were unsuccessful and talked to Center on frequency. Center informed us that we were supposed to be at 5;000 FT passing point K and gave us an alternate frequency for Approach. We talked to Approach Control; nothing more was said and we proceeded to North Field to complete our training. Upon return to our home base we were told that Approach Control had contacted our home station to report the incident and would be filing a Pilot Deviation Report. As we researched the event to see how we missed the altitude restriction we found that the in-flight guide we had been using for the low level had a discrepancy on the altitude at point K as well as some ambiguity with the AP/1B. In addition; limited time to review the products for the low level and the training mission due to this sortie being a part of an Operational Readiness Exercise at our home base in preparation for the Operational Readiness Inspection contributed to the oversight. Possible preventive measures should include an update to the in-flight guide to mirror the AP/1B as well as more definitive terms used in the AP/1B. In addition; the crews should have more time to complete a thorough route study before flying an unfamiliar low level. The Mission Planning Cell could also provide a better route study for the pilots and include on the charts the altitude restrictions at each point to combat any confusion while flying the low level.
NASA callback
The Reporter stated that a Mission Brief was conducted by Wing Briefing Personnel shortly after midnight and prior to the flight. The main discussion items related to military intelligence; chemical/ biological concerns; low level airspace and noise sensitive areas but the Class D airspace was not specifically discussed. The Reporter believes the Briefer did not discuss the Class D constraint because the AP/1B includes the airspace restrictions so the flight crew should have picked it up from that document. In reality not enough time is allocated from the crew to research much beyond the briefing packet. The key point the crew missed was that after Point K the aircraft were supposed to climb to 5;000 FT and maintain that altitude until exiting the IR. If they had followed that profile the airspace violation would not have occurred. The Reporter stated that future briefings with include the Class D airspace constraint so that crews know to climb prior to it.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.