US Helicopter Safety Team (USHST)
Monthly Safety Report
November 2024
Fatal Accident Rate: 0.63 (+.08) above goal of 0.55 fatal accidents per 100K hrs by 2025
USHST Vision: A civil US registered helicopter community without fatal accidents
“Safety by the Numbers” (Monthly Metrics):
Days since last Fatal helicopter accident: 2 Days : 22 Hours : 37 Minutes : 56 Seconds
Fatal Accident Rate (5yr avg)(CY2020-24) 0.63 Fatal Accidents per 100K Flight Hours
Fatal Accident Rate (CY2024) 11 Fatal Accidents per 100K Flight Hours
Helicopter - Safety Enhancement (H-SE) Details
H-SE 2023-05, Training on effects of adverse wind situations.
The goal of this H-SE is to better illustrate the hazards posed by adverse winds on rotorcraft performance, especially when operating at low airspeeds. As an example, similar, but unrelated efforts, have been undertaken in the fixed wing world around loss of control events and the use of Angle-of-Attack (AOA) indicators. Vertical flight operations at low airspeed are predictable when the air-circulation through the rotor system is able to maintain a steady-state. It can be visualized as a bubble of air circulating around the rotor system. If this bubble is disrupted, or “popped”, a corresponding loss of lift can result. This creates a performance scenario that is not indicated by any instruments and is not able to be planned through a chart, but rather is managed by the pilot through a combination of forethought, experience, knowledge of wind directions and intensity around the aircraft, distance from obstacles and power reserves available. Given that it is not currently possible to provide rotorcraft pilots with an indicator that shows an impending loss of lift, this H-SE seeks to promote effective training solutions for pilot decision making and more effective risk assessment during operations.
For any questions regarding the information within this notice please contact Clarke Pleasants, Assistant Professor of Aerospace, MTSU, at 615-898-2054 or email at clarke.pleasants@mtsu.edu
