Abrupt Wing Stall

During envelope expansion flights of the F/A-18E/F in the Engineering and Manufacturing Development phase, the aircraft encountered uncommanded lateral activity, which was labeled “wing drop”. An extensive resolution process was undertaken by the Navy and its contractors to resolve this issue. A production solution was developed, which concluded revising the flight control laws and the incorporation of a porous wing fold fairing to eliminate the wing drop tendencies of the pre-production F/A-18E/F. The wing drop events were traced to an abrupt wing stall (AWS) on either the left or right wing panel, causing a sudden and severe roll-off in the direction of the stalled wing.

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Ship/Airwake Analysis

Perhaps the most demanding of all aviation environments, the operation of aircraft from ship platforms involves turbulent airwake produced by a ship’s superstructure. This phenomenon is a major contribution to the workload required for such operations. Past airwake modeling efforts were, at best rudimentary, offering only representative levels of turbulence for a particular ship class. The current study involves the prediction of time variance for ship dynamics variables.

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Optimizing Extraction Parachute Operational Parameters

C-130 with drogue chute.

C-130 with Drogue Chute.

A current area of interest in the US Army operational and test community is the application of aerial delivery at high speed and at relatively low altitudes. The High-Speed Container Delivery System (HSCDS) is such a program intended to address this type of operational need. In conjunction with this program, a series of simulations have been conducted that attempted to cover a parameter space of operational variables such as aircraft type, aircraft flight speed, extraction line length, and drogue parachute design and size. The objective here is that with validated and verified modeling and simulation results anchored to actual flight test data, future exploratory test and development work may be performed with increased reliance on information derived from modeling and simulation with potential savings in the use of airdrop assets.Continue reading