| Level Bust Statistics
Last Updated:
20 December 2008
Updates to the causal factors here The Scale of the Problem:
Level Busts & Losses of Separation by Year
NATS figures for 2004 to end of October 2008
Click to enlarge
Source: NATS Division of Safety
Level Busts by Safety Significant Event and Year
NATS figures for 2004 to end of March 2008
Click here for an
explanation of the SSE Scheme
Click to enlarge
Source: NATS Division of Safety
SSEs1-2 (a + b) remain consistently high at 7
in 2007 even though the overall number of SSEs1-4 has fallen.
Level Busts reported
by NATS October 2004 to September 2007
| Category |
Level
Busts |
Percent of
UK Flights |
Percent of
UK Levelbusts |
| Air
Transport |
1071 |
93.19% |
78.69% |
|
Private |
235 |
5.83% |
17.27% |
| Military |
55 |
0.98% (GAT) |
4.04% |
| Total |
1361 |
|
|
Biz jets continue to represent a
disproportionately high percentage of Level Bust reports and were
responsible for 5 out of the last 6 level bust SSE1-3s (Jan 08 to
date - Apr 08), or 10 out of 19 such events since Jan 07 to date.
Source of the data above is the UK Flight Database (UKFDB)
which contains flight planned data from a flight plan processing
system and actual flight details from a radar data processing system.
Aircraft which do not file a flight plan are not counted in the data.
Level Busts reported
by NATS January to December 2006 by Operator Type
| Category |
Level
Busts |
Percent of
UK Flights |
Percent of
UK Levelbusts |
| Air
Transport |
434 |
93.1% |
78.2% |
|
Private (Non AOC) |
96 |
5.9% |
17.3% |
| Military |
25 |
1.0% (GAT) |
4.5% |
| Total |
551 |
|
|
Level Busts January 2004 to December 2006 by Region of Operator
| Region |
Level
Busts |
% of Flights |
% of Level busts |
| Asia |
31 |
1.76% |
4.55% |
|
Europe |
207 |
19.49% |
30.35% |
| Ireland |
81 |
14.23% |
11.88% |
| North
America |
73 |
6.02% |
10.70% |
| UK |
290 |
58.51% |
42.52% |
| Total |
682 |
|
|
Level Busts January to December 2006 by
Region of Operator
| Region |
Level
Busts |
% of Flights |
% of Level busts |
| Asia |
13 |
1.84% |
4.41% |
|
Europe |
96 |
19.76% |
32.54% |
| Ireland |
43 |
14.30% |
14.58% |
| North
America |
29 |
5.76% |
9.83% |
| South
America |
1 |
0.03% |
0.34% |
| UK |
113 |
58.31% |
38.31% |
| Total |
295 |
|
|
Figures above are taken from the NATS level
bust league table, only events involving the airlines included in
the league table are included above therefore the total figure is
not equal to the total number of events in the year
12 Month Rolling Total to
October 2008
(click
to enlarge)
Source: NATS Division of Safety
The graph above shows that since Jan 08 level bust reports have
remained more or less steady at about 450 – 460 reports in the 12
month rolling total. Although this has been against a background of
traffic growth (until the recent downturn), the persistence of this error type confirms the need
for our continued focus on level busts.
This data has been taken directly from the
eIRS and has only been validated from 2004 onwards, however
from previous level bust data we can be confident that the
data presents a fair representation of the historical trend.
A detailed review of the reported level busts in 2004 and
2005 was undertaken in March 2006 following the highest number of
reported events in a single month in February. The summary of the work is that
we believe that in 2004 level busts increased (and so did the reporting of
them); however in 2005 the increase appears to be due to improved reporting by
controllers and pilots. However, even if the increase is due to better reporting
there are still too many level busts in the UK.
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