Frank Taylor_paper_Ustica_illustrated.pdf

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A case history involving
wreckage analysis
The following paper was presented by
invitation to a conference in Rome during
October 1998 but now includes pictures
from the presentation and a few
additional explanatory notes. The
conference and paper had two main
objectives, to clarify issues relating to the
Ustica DC9 accident and to reiterate the
point that Italy should have an
independent air accident investigation
authority as called for by ICAO & the EU
(which it now has).
Sea off the coast of Italy and near to the
island of Ustica at approximately 1900 hrs
GMT while flying from Bologna to Palermo.
Most of the wreckage sank to a depth of
some 3500 metres and all 81 on board died.
Floating debris and 38 bodies were recovered
during the following few days from an area of
several hundred square kilometres. Very
soon there were suggestions that the DC-9
had been shot down by a missile and this
view has been expressed strongly by many
people ever since.
Newspaper reports in the USA and the UK as
well as in Italy have regularly implicated the
Italian Air Force, the US Navy, the Libyans,
the Israelis, the Russians, in fact practically
everybody. There have been several TV
programmes, at least one film and several
books, most it is believed ‘proving’ a missile
theory but not necessarily the same one!
Lessons from the Ustica
investigations
A. Frank Taylor
Cranfield University
– now Visiting Fellow
1 Introduction
This is an account by an outsider who for
many years knew of the accident but not of
the controversy surrounding it. The
background information picked up after
becoming involved, as presented below, is no
doubt incomplete and may in some cases be
incorrect but is included to give an idea of
what an open minded investigator has felt to
be of interest. However it is not the
background that is really important, it is the
lessons to be learned from the wreckage.
Since even a ‘domestic’ accident has
international implications this account has
been written with a wider audience in mind,
which should explain the lengthy
introduction, unnecessary in Italy!
There has been much misinformation
circulated and many accusations of ‘cover-
up’. In Italy ‘Ustica’ is still a cause célèbre.
At the end of 1997 one of Italy’s more
important newspapers stated that 30 fighters
were in the vicinity at the time, all with their
transponders intentionally shut off to avoid
being identified; so far as is known there is
absolutely no evidence to support the claim
but this appears to be typical of the long
series of such claims made over the years
since 1980.
Over recent years internet web sites have
appeared, some on general air safety matters
but at least one devoted purely to the Ustica
accident, the latter and almost all the others
have supported the various missile theories,
thus the disinterested observer may well
wonder why the ‘mystery’ has still not been
resolved. This paper seeks to shed some
light on the mystery, to demonstrate that the
key to the investigation lay in the wreckage
which, at the time all speculation started, was
1
An Itavia DC9 showing logo and colour scheme
On 27 June 1980 the DC-9 aircraft I-TIGI
owned by Itavia crashed into The Tyrrhenian
still some 3500 metres beneath the surface of
the sea and to point out a few lessons learned
from the Ustica investigations.
2 The investigations
The evidence available during the first few
years after the accident was confined to
floating bodies, seat cushions containing a
considerable number of fragments, radar
recordings and a variety of pieces of
circumstantial evidence. As none of this was
conclusive various Commissions failed to
agree except that the aircraft probably did
break up in flight and the cause of this was
either a missile or an internal explosion.
In 1990, despite the recovery o f a f a i r
amount of wreckage from the sea bed during
1987-1988, found in three distinct areas and
thus providing still more evidence of an in-
flight break-up, the ‘Blasi Commission’,
named after the Judge who was in charge of
the enquiry, split and was also unable to
decide whether the 'cause' was a missile or an
internal explosion.
As a result a further Technical Commission,
this one under the Tribunale di Roma was
established in September 1990. This, the fifth
Commission over all, was the first to be
‘international’, having two from the UK
(including the author), two from Sweden and
one from Germany joining five from Italy and
serving under another Judge, Dr Rosario
Priore. A second German, with specialist
knowledge of missiles, was added to the team
in 1993.
At the very beginning of the Priore
investigation, in the autumn of 1990, it was
stated that: ‘The experts will examine all
judicial records, documents, exhibits already
found and to be found and will make every
necessary investigation in order to ascertain
the causes of the air crash and the means to
effect it’. The unusual aspect for the non-
Italians was that our report would form part
of a Public Prosecution case against various
named and unnamed people, principally
Italian Air Force officers, for causing the
accident and/or withholding evidence.
As is usual with Italian investigations the
majority of the members had relatively little
prior experience of accidents investigation
although all were respected and experienced
‘experts’ in their own fields. Before very
long this situation will change since Italy,
along with many other European countries,
will follow a European Directive and have its
own new Accidents Investigation Agency,
independent of the judiciary and of all other
aviation agencies.
2.1 The situation prior to 1990
The most widespread theory was, as has
already been suggested, that the DC-9 was
hit by a missile fired by some unknown
fighter aircraft. Although there have been
several different variations upon this theme
perhaps the most coherent was presented in
1982 on a BBC Panorama programme. As
the wreckage recovered by the Blasi
Commission during 1987/88 provided no
hard evidence to effect this view the
Panorama programme continued to provide
an apparently logical argument for a
deliberate missile attack on the DC-9. The
argument may be summarised something like
this:
The bodies recovered showed no
extreme injuries so the impact with
the sea was at low velocity.
The radar records showed another
aircraft flying towards the starboard
side of the DC-9 from the west, out
of the sun.
2
At least two metal fragments found in
seat cushions showed evidence of an
explosion.
Splinters of window plastic and rivets
from the fuselage skin also found in
the cushions showed that the
explosion was outside the aircraft and
not inside.
The DC-9 had therefore been hit by a
missile and had subsequently spiralled
slowly down into the sea.
Other fragments identified as being
from the front of the cabin were
found embedded in parts from further
back.
The missile therefore exploded near
the front of the cabin on the starboard
side, driving these fragments back
down the cabin.
6 As the missile went towards the front
of the aircraft and not to the rear,
where the engines are located, it was
not a heat seeking missile but a radar
controlled one.
The pilot of an aircraft approaching as
shown by the radar returns and having
released a missile that would lock
onto the DC-9 would have had time
to recognise that an error had been
made and could have switched off the
missile guidance system.
As this was not done then the missile
attack was deliberate and not
accidental.
The programme might well have added that:
As the material of the metal fragments
showing evidence of an explosion did
not appear to match any of those used
in the DC-9 then they must have
come from elsewhere, this could only
have been from a missile.
3
Fragment showing hot gas wash & rolled edges –
typical of damage by an explosion
As this paper unfolds information, comment
particularly relevant to the above hypotheses
and more general lessons to note, will appear
in bold italic type.
2.2 Early stages of the Priore Commission
One of this Commission’s first decisions was
that it could not proceed far while having
only the wreckage already available, it
therefore immediately called for the recovery
of more wreckage but of course this took
some time to organise.
Wreckage recovered by the Blasi Commission
2.2.1 The wreckage
In the meantime some progress became
possible as the wreckage already available
was laid out and studied. From many areas
of interest certain points stood out:
The relative positions of the engines, of
the fuselage pieces and wings, and of the
tailcone and tailplanes, in recovery Zones
B, C and A respectively, not only fitted
the expected locus of debris expected
from an in-flight beak-up but also gave the
approximate position of the break-up.
Port engine intake
The three recovery Zones
There were red paint marks on and slight
damage to the tailplane, also consistent
with this being hit by pieces from the
fuselage side.
2.2.2 The bodies
Photographs of the 38 bodies found floating
on the sea surface shortly after the accident
showed few with major injuries and most
with no external injuries at all. Most were
recovered with their clothes either stripped
off or forced to the extremities of their arms
and legs. These points suggested that they
had not been within the cabin when it hit the
sea but had fallen out following the opening
of the fuselage, supporting the conclusion
already suggested, from the wide spread of
floating debris, that there had been an in-
flight break-up. Autopsies and X-rays of the
bodies had shown no external signs of an
explosion nor any buried particles from an
explosion and had thus given no valid reason
for the break-up.
The statement made in the Panorama
programme that the aircraft had spiralled
slowly down into the sea was thus not the
only valid possibility. Indeed the wide
spread of floating debris, which included
the cushions, made this interpretation
rather unlikely but from this evidence alone
we could not rule it out completely.
This position was sufficiently far to the
east of the break-up point shown by radar
as to suggest that there was first a partial
break-up, followed by an ‘S’ shaped flight
path and a second, main break-up with
much of the wreckage falling into the
three sites already found.
The fuselage frames at the centre section
were virtually undamaged; the few pieces
from the nose were badly damaged; the
leading edge of the starboard wing was
badly buckled but the rest was only
slightly damaged; the port wing was
hardly damaged at all but appeared to
have been torn up and over the fuselage.
Undamaged frames
2.2.3 The recovery of further wreckage
There were red and white paint marks on
the port engine intake (the red already
confirmed as being the same paint as on
the fuselage side along the window belt),
but nothing similar on the starboard
intake.
4
Using a trajectory analysis program
developed at Cranfield
1
and used during the
Lockerbie B747 investigation
2
, knowing the
approximate position, height and velocity of
the aircraft and of the wind at the time, it was
possible to predict the likely spread and
extent of the wreckage trail. As the DC-9
was flying almost due south at about 24,000
feet and there was a strong westerly wind at
high altitude veering to a north-westerly at
sea level the downwind trail would be long
and distinct.
diminished further back and, consistent with
the lack of damage to the centre section
frames already noted, non-existent at the
centre section. At that stage nothing had
been recovered of the rear fuselage above
floor level.
Starboard front fuselage
Proposed new recovery area
The buckling of the front fuselage, cockpit
windows and the starboard wing clearly
showed that these parts had entered the
water at high speed, almost straight down,
with the wing leading edge parallel with the
sea surface and the fuselage just over the
vertical.
This information was presented t o
Commission members at one of the first
meetings but was initially ignored in favour of
raising more wreckage from the areas already
located by the Blasi Commission. Since it is
practically axiomatic that the first pieces to
break away from an aircraft are also those
most likely to indicate why they broke away
the non-Italian members continued to press
for the search and recovery to move to where
these first pieces were likely to be found.
The delay in recovering direct evidence
concerning the break-up seriously hampered
the investigation although at least the
recovery or wreckage from the original site
and its reconstruction (by attaching pieces to
a tube and mesh framework roughly the
shape of the DC-9 fuselage) established how
the various parts had entered the sea.
The majority of the additional wreckage
recovered was soon identified as being from
the forward fuselage with more debris from
the engine nacelles and from the tail area,
each from their respective recovery zones.
The buckling of the fu selage skin was
extremely severe at the front and gradually
5
Probable attitude on hitting water
Such an attitude was also consistent with the
quite different damage to the port wing. At

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