Dear Capt Kay,
I am leery (apprehensive?) of flying the British Airways B777
from Detroit to London. ( I have always flown Northwest DC10 or B747).
On a web
site "amigoingdown.com" it calculates odds using various variables. While
both the airlines are deemed quite safe, the calculated odds are better for
the
B777. This surprises me. Could a 2 engine plane actually be safer
when
both are from reputable airlines?
N. Strause
Hi Strause,
The statistics given by "amigoingdown.com" are based on
the information
published by the various aviation authorities. They take the
overall
mortality risk figures for airline fatalities, and adjust that
figure
depending on where you are flying to, the safety record of the
particular
Airline and other relevant safety factors. According to "amigoingdown.com,"
the probabilities of the statistics are worked out using mean
variances of
the different parameters and weighted accordingly, so as to
produce an
approximate probability.
The statistical information is updated as and when it comes in.
When
incidents or accidents occur, all the relevant details are entered
onto
their database. These contribute to their future statistics. The
data spans
over several years, so you may get a below average result from an
airline
whose recent safety record is excellent, but who had a bad year in
1996.
The safety of commercial flight can be described as thus; if you
were to
take a flight every day, you would have to travel for about 1,000
years on
average before being involved in a fatal accident. In essence, the
probabilities produced by "amigoingdown.com" highlight
how safe it is to
travel by air .
The above information are from the "amigoingdown.com"
Site and they came together with a disclaimer that the statistics may have errors.
Although the information may at times be inaccurate, in my
opinion, for comparison purposes, the statistics give a good
indication as to how safe a
particular Airline or aircraft can be. For instance, the latest
air crashes caused by the kamikaze hijackers on the Boeing 757 and 767 on the 11th of September in New York and Washington DC
will invariably affect the statistics of the Airline and
aircraft. Without any statistics, one cannot quantify a
particular event.
Back to your question as to whether a 2 engine airplane can be
safer than a
3 or 4 engine airplane, the calculated odds you extracted from the
Site,
took into account the age of the aircraft, their accident rates,
the safety
record of the Operator, the history of past accidents involving
the 3 or 4
engine airplanes and also other safety factors.
In the past years or so,
DC-10's and B 747's have suffered some fatal accidents and these
certainly contributed to their statistics being less favorable to
that of the 2 engine B 777's. So far, the B 777's seems to
be having quite a good record in terms of safety and what more,
they are also the newer airplanes with the latest safety features.
(See my article on safety of
modern airplanes)
Regards,
Capt Kay
