dynamic rollover


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dynamic rollover

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If a helicopter lands on a sloped ground, there is a likelihood of its rolling over. In such a situation, a moment is produced by the horizontal component of total rotor thrust about the point of ground contact of the skid. This moment is opposed by weight of the helicopter. If the angle of bank of the helicopter, i.e., slope of the ground, is beyond a certain figure the restoring moment is too small to stop the helicopter from rolling over.
A tendency of helicopters to begin rolling when they exceed the critical angle. Dynamic rollover is possible when a skid is caught by a projection on the surface or when landing on a slope. A helicopter is normally permitted to land on a 15° slope, but if the cyclic goes to full travel before all skids touch the surface, it should not be landed. Rollover occurs quickly because of the rapid decrease in the restoring moment. This same phenomenon occurs with floatplanes executing high-speed step turns in which the angular rotation becomes too high.
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However, the FMVSS 216 test procedure has been criticized for being a quasi-static test that does not accurately represent vehicle structural responses to real-world dynamic rollover [3,4,5].
This research aims to build a nonlinear dynamic model that considers articulated steering movement, swing bridge movement, and ground environmental parameters to obtain the instability mechanism and dynamic rollover stability index for the ASVs.
The potential for drift close to the ground increases with time, and with it the risk of dynamic rollover also increases.
14) The pending bill requires NHTSA to develop and implement a dynamic rollover test program for the vans--one that tests real-world performance--and include the vehicles in the NCAP program.
She was in the right side passenger seat on a training flight when, her citation reads, "her Bell TH-57 Sea Ranger helicopter entered a dynamic rollover situation and would not recover despite control inputs by the flight instructor.
The agency also is considering how best to disseminate the results of NHTSA's evaluation of driving maneuver tests for the dynamic rollover consumer information program that Congress mandated beginning in the 2003 model year.
This amount includes funding to support implementation of the Transportation Recall Enhancement, Accountability and Documentation (TREAD) Act, which will enable NHTSA to aggressively pursue new rulemakings for dynamic rollover tests,
But with the attention that vehicle rollover accidents have received in the last year, and the subsequent passage of the TREAD Act by Congress, which requires NHTSA to develop a dynamic rollover test, TRW is now looking to SUVs, for the lion's share of the system's sales Speaking of Vs Cunningham says, "We see this system as part of the solution to help the driver maintain control of the vehicle.
Dynamic rollover failure: Failure to dynamically recognize that rollover has occurred in real-time mode and make the proper adjustments.
The only dynamic rollover test conducted on the F-150 four-door SuperCab the dolly rollover test--was for defense purposes in Alaniz.
As part of the Tread Act signed into law last November, Congress has ordered NHTSA to develop a dynamic rollover test program to rate the susceptibility of particular vehicles to rollover.
NHTSA's new dynamic rollover tests will give consumers a valuable new tool for comparing vehicle safety and ultimately save lives," said CU Senior Vice President for Technical Policy, Dr.
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