Published Report (DOT/FAA/CT-94-36)

involving a ground crew member during the push back from the
jetway is reported. For this reason, only accidents caused by
system failures or pilot errors are used in the determination of
the phase rates. From data supplied by the FAA, the number of
air carrier operations or departures is estimated to be about
33.3 million. The phase rate is determined by dividing the number
of fatal accidents by the number of departures.
Phase of Flight Reported Fatal Fatal Accident Rate
Accidents
(per Approach)
Start and Taxi 1
Take-of f 6
Climb 0
Cruise 3
Descent 1
Approach 2
Landing 1
2.9998 x
1.7999 X
-
8.9995 x
2.9998 x lo-*
5.9997 x 10-8
2.9998 x
Total 14 4.1998 X
Table 1.
3.3 ESTIMATING FINAL APPROACH RISK
Since the NTSB reported two fatal accidents during the approach
phase, the estimated rate for the final approach segment is 6 x
fatal accidents per departure. Since most approaches are
flown in visual flight conditions using visual flight rules (VFR)
it is necessary to adjust the rate to reflect the number of
approaches under instrument meteorological conditions using
instrument flight rules (IFR). The number of instrument
approaches is no longer recorded by the FAA; however, using data
available in the FAA Statist ical Handbook of Av iat ion. 1970, the
percentage of precision approaches is estimated to be about 15%,
the percentage of non-precision approaches is estimated to be
about 2%, and the number of visual approaches is estimated to be
about 85%. Since average weather conditions are assumed to be
constant through the years, these percentages are assumed to
still be accurate.
I .
Since about 33.3 million operations were recorded for the years
1983 - 1988, the number of precision approaches is about 15% of
33.3 million or 5 million precision approaches. The two fatal
accidents reported in the time period both occurred during
precision approaches. This leads to an estimated fatal accident
rate for precision approaches during the same period of time of
4 x or about 1 fatal accident per 2.5 million approaches.
L-5