A comparison of general aviation accidents involving airline pilots and instrument-rated private pilots

Introduction: The extremely low accident rate for U.S air carriers relative to that of general aviation (∼1 and ∼60/million flight hours respectively) partly reflects advanced airman certification, more demanding recurrency training and stringent operational regulations. However, whether such skillset/training/regulations translate into improved safety for airline pilots operating in the general aviation environment is unknown and the aim of this study. Methods: Accidents (1998–2017) involving airline pilots and instrument-rated private pilots (PPL-IFR) operating non-revenue light aircraft were identified from the NTSB accident database. An online survey informed general aviation flight exposure for both pilot cohorts. Statistics used proportion testing and Mann-Whitney U tests. Results: In degraded visibility, 0 and 40% (χ² p = 0.043) of fatal accidents involving airline and PPL-IFR airmen were due to in-flight loss-of-control, respectively. For landing accidents, airline pilots were under-represented for mishaps related to airspeed mismanagement (p = 0.036) relative to PPL-IFR but showed a dis-proportionate count (2X) of ground loss-of-directional control accidents (p = 0.009) the latter likely reflecting a preference for tail-wheel aircraft. The proportion of FAA rule violation-related mishaps by airline pilots was >2X (7 vs. 3%) that for PPL-IFR airmen. Moreover, airline pilots showed a disproportionate (χ² p = 0.021) count of flights below legal minimum altitudes. Not performing an official preflight weather briefing or intentionally operating in instrument conditions without an IFR flight plan represented 43% of airline pilot accidents involving FAA rule infractions. Conclusions: These findings inform safety deficiencies for: (a) airline pilots, landing/ground operations in tail-wheel aircraft and lack of 14CFR 91 familiarization regulations regarding minimum operating altitudes and (b) PPL-IFR airmen in-flight loss-of-control and poor landing speed management. Practical Applications: For PPL-IFR airmen, training/recurrency should focus on unusual attitude recovery and managing approach speeds. Airline pilots should seek additional instructional time regarding landing tail-wheel aircraft and become familiar with 14CFR 91 rules covering minimum altitudes.     

煤系固体废物与污泥混合用于矿区复垦的试验研究

矿区复垦作为生态恢复的重要手段,在国内外应用中有很多种方法,在此分析了粉煤灰、煤矸石及污泥各自的特点、应用特征,指出单一废物用于复垦存在的缺陷;通过对3种废弃物及其按不同质量比混合后各土样的pH值、电导率、氮（N）、磷（P）、钾（K）等理化指标的测定分析,研究了粉煤灰、煤矸石等煤系固体废物与污水处理厂排放污泥混合用于矿区复垦的可行性。结果表明：不同比例基质pH值、电导率、各配比样的营养标准均可满足植物生长的需要。说明该方法用于矿区生态修复的优势所在。     

Information seeking in documents by pilots: Assessment of the reliability problems caused by the transition from paper to electronic

Information seeking is completely ignored in research on aviation psychology and more generally in issues of air transport safety. But information seeking occupies a central place in the pilots’ work. And this activity is undergoing an important development: the transition from paper to electronic documents. A contribution to the assessment of this transition is presented here. The assessment is focused on deterioration of information access, understanding and exploitation, and their possible negative consequences in terms of reliability. The exploitation of the documentation by pilots, and particularly the information seeking activity, are described and linked to their contexts (i.e. the main tasks of flying that require information seeking). Then an users test is presented where some information-seeking tasks are evaluated in terms of cost and errors, by comparing electronic and paper documents. The results show that electronic documents provide new functions that seem useful but also that too many new functions generate difficulties. Then it seems that pilots need some time to learn how to use these new documents. Reducing attention needed to perform a task such as calculation is risky. Some aspects of information seeking by the pilots should be better analysed and evaluated.     

成都市扬尘对大气环境影响初探

本文论述了成都市扬尘污染现状并统计了成都市扬尘排放量，说明成都市扬尘污染相当严重，已成为影响大气质量的主要因素之一。加强扬尘管理和治理应成为大气环境管理和治理的一项重要内容。