Distribution and Risk Factors of Water-Related Accidents for General Aviation Aircraft

Table 1

Univariable logistic regression for a fatal flight.

						95% confidence intervals
Issue	Parameter		Comparison	value	Odds ratio	Lower	Upper
Pilot issue	Pilot certificate (types)	547	3+
			2	0.869	0.897	0.246	3.265
			1	0.676	0.771	0.228	2.605
			None	0.352	0.575	0.18	1.841
	Occupational pilot	510	Yes
			No	0.476	1.153	0.779	1.708
	Pilot age	527	70+
			60-69	0.819	0.929	0.494	1.746
			50-59	0.336	1.31	0.755	2.272
			40-49	0.395	1.269	0.733	2.199
			17-39	0.418	1.296	0.692	2.429
	Pilot sex	568	Male
			Female	0.224	0.385	0.082	1.797
	Second pilot present	574	Yes
			No	0.056	0.626	0.387	1.012
	Pilot total flight time (hours)	527	0-500
			500-999	0.339	0.755	0.424	1.343
			1000-1999	0.283	1.441	0.74	2.805
			2000-4999	0.919	0.968	0.515	1.817
			5000-9999	0.952	1.019	0.554	1.874
			10000+	0.493	1.274	0.638	2.543
	Pilot flight time make/model (hours)	425	0-99
			100-299	0.115	0.56	0.272	1.152
			300-499	0.290	0.661	0.307	1.424
			500-999	0.637	1.25	0.494	3.162
			1000+	0.469	1.437	0.539	3.837
	Instructor rating (types)	529	3+
			2	0.598	1.167	0.657	2.075
			1	0.281	1.518	0.711	3.238
			0	0.864	1.058	0.555	2.015
Aircraft issue	Airplane rating (types)	530	4+
			3	0.194	0.506	0.181	1.416
			2	0.501	1.318	0.59	2.946
			1	0.288	0.684	0.34	1.378
			0	0.021^a	0.436	0.216	0.88
	Certified max gross weight (lbs)	443	0-1999
			2000-2999	0.051	1.947	0.998	3.8
			3000-4999	0.022^a	2.2	1.12	4.323
			5000+	0.300	1.451	0.718	2.932
	Rated power (hp)	513	0-99
			100-199	0.014^a	3.238	1.273	8.239
			200-299	0.001^a	3.696	1.649	8.283
			300-499	<0.001^a	5.097	2.145	12.109
			500+	0.001^a	4.2	1.751	10.073
	Number of engines	568	1
			2	0.002^a	2.737	1.462	5.126
	Engine type	582	Turbo
			Reciprocating	0.025^a	0.513	0.286	0.918
	Airworthiness certificate	515	Normal
			Experimental	0.842	0.934	0.476	1.833
			Other	0.435	0.745	0.356	1.558
	Time since last inspection (hours)	175	0-19
			20-49	0.927	1.05	0.371	2.972
			50-99	0.782	1.167	0.392	3.471
			100+	0.277	0.544	0.182	1.629
	Airframe total time (hours)	444	0-499
			500-999	0.333	1.343	0.739	2.442
			1000-4999	0.403	0.745	0.373	1.486
			5000+	0.916	1.027	0.626	1.684
	Seats	508	1 or 2
			3 or 4	0.894	0.967	0.594	1.575
			5+	0.481	0.835	0.506	1.379
	Aircraft category	588	Airplane
			Other	0.902	0.968	0.574	1.631
	Amateur built	591	Yes
			No	0.631	0.897	0.577	1.396
Weather issue	Weather condition	586	VMC
			IMC	<0.001^a	14.6	5.633	37.838
	Conditions at accident site	584	Visual conditions
			Instrument conditions	<0.001^a	13.049	5	34.054
	Condition of light	588	Day
			Night/dark/dusk/dawn	<0.001^a	3.783	2.231	6.414
	Visibility	573	0-9
			10+	<0.001^a	0.277	0.163	0.473
	Wind speed/gusts (knots)	580	Calm
			2-4	0.284	1.362	0.774	2.396
			5-9	0.872	0.958	0.566	1.62
			10+	0.129	0.724	0.476	1.099
	Precipitation and obscuration	488	No precipitation; no obscuration;
			Rain or snow or thunderstorm	0.134	2.513	0.754	8.377
			Rain and fog	0.331	0.5	0.124	2.022
			Fog	0.816	1.2	0.257	5.593
Flight issue	Broad phase of flight	468	Takeoff
			Maneuvering	0.097	1.857	0.893	3.86
			Landing	0.679	0.859	0.418	1.765
			Cruise	<0.001^a	8.369	3.541	19.78
			Approach	0.731	0.848	0.332	2.169
			Other	0.928	1.04	0.439	2.465
	Distance (nautical miles)	588	0-0.9
			1-9.9	0.100	2.921	0.813	10.49
			10-49.9	0.742	1.258	0.32	4.943
			50+	0.606	1.5	0.322	6.991
	Purpose of flight	590	Personal
			Instructional	0.102	0.667	0.41	1.084
			Other	0.062	0.488	0.229	1.037

^aStatistically significant factors .