Memorandum submitted by the Institution
of Mechanical Engineers (SAGE 15)
1. The Institution of Mechanical Engineers
is the fastest growing engineering institution in the UK, with
a membership of over 90,000 professional engineers in the UK and
overseas. As a Learned Society the Institution is committed to
providing impartial engineering perspectives on a wide range of
topics, from transport systems, an engineering response to climate
change, education and critical skills, to energy production and
The answers to the questions below refer
specifically to the Icelandic volcanic ash eruptions in spring
What are the potential hazards and risks and how
were they identified?
2. The hazards of aircraft flying into volcanic
ash are, at the extreme, potential damage to critical airframe
surfaces and systems and potential loss of engine power leading
to crashing of the plane. At medium ash densities, there can still
be damage to engines and airframe causing economic loss but at
very low ash densities, there is no hazard or risk. These hazards
have been identified from past flying experience where 126 incidents
have been reported over the 55 years of jet engine travel. Unfortunately
no quantitative demarcations have been established between the
high, medium and low levels of ash density that allow us to be
certain of the safety risks in each actual volcanic eruption.
How prepared is/was the Government for the emergency?
3. The Government was very well prepared
in the sense in that it had a clearly defined regulatory body
(the Civil Aviation Authority) and a clearly agreed international
safety procedure (of zero tolerance to exposure to atmospheric
ash) that controlled the UK response to the risk.
4. The circumstances leading to the closure
of European airspace were therefore predictable but unprecedented.
The new and unique conditions that prevailed consisted of a very
large and energetic volcanic eruption which caused ash to be ejected
to high altitudes in the atmosphere coupled with sustained wind
directions which carried it over Ireland, the UK and Western Europe.
5. It is arguable that the consequences
of the closure of airspace should have been considered prior to
the event through scenario planning and thereby contingencies
being better organised. For example, an important consequence
of the closure of airspace was the stranding of UK citizens abroad.
The solution chosen appeared to be ad hoc, uncoordinated and largely
dependent on the differing reactions of the individual airlines
concerned. As the closures stayed in place for longer then the
consequences on the UK economy became multiplied. The situation
confirmed the role important of international air transport as
a facilitator of the economy and greater consideration should
now be given to future possible disruptions.
What are the obstacles to obtaining reliable,
timely scientific advice and evidence to inform policy decisions
in emergencies? Has the Government sufficient powers and resources
to overcome the obstacles?
6. The time needed to collect new data is
much greater than that available as the economic and social consequences
of an airspace closure develop. The advice and evidence therefore
need to be those available prior to the event. The Government
has powers to ensure the quality of that prior data through the
regulator (the Civil Aviation Authority).
7. The difficulty is with the infrequency
of the risk in UK controlled airspace. The best data is obtained
from real life field measurements which by definition are rarely
possible. The opportunities until now have always been in overseas
jurisdictions. In common with many other low probability, high
consequence, risks International sharing of experience is essential
to maximise the understanding of these rare events.
8. The sufficiency of the powers therefore
relates to the ability of the UK Government to influence others
overseas to collect data as the opportunities arise. These opportunities
generally have not been taken to date as another, easier, cheaper,
option has been to avoid flying through the ash clouds at all.
How effective is the strategic coordination between
Government departments, public bodies, private bodies, sources
of scientific advice and the research base in preparing for and
reacting to emergencies?
9. The Government has a role in bringing
together the various parties which are responsible for informing
this decision and it appears that this role was discharged during
the volcanic ash event. It appears that this coordination (between
the regulator, the operators and the manufacturers) was extensive
and effective notwithstanding the International limitations expressed
above. However, there was a lack of background data and hence
understanding of three key issues:
(a) The amount and type of ash actually present
in the controlled air space.
(b) The sensitivity of different aircraft and
engine types and flight paths to the ash cloud.
(c) The process necessary to balance the unknown
safety risks with the social and economic costs of a flight ban.
10. As the element of risk could not be
quantitatively assessed, a high degree of caution was properly
exercised. However, we consider there should have been more open
engagement on the risks by various public agencies during the
crisis, both with the learned institutions and especially with
communication with the public at large. Arguably, inadequate quantitative
demarcation of the hazards, together with insufficiently accurate
and timely scientific measurement and forecasting of the density,
composition and position of the ash clouds, were significant obstacles
to more effective policy decisions.
How important is international coordination and
how could it be strengthened?
11. In 1991 the aviation industry decided
to set up Volcanic Ash Advisory Centres (VAACs), one for each
of nine regions of the world, acting as liaisons between meteorologists,
volcanologists, and the aviation industry. The UK and Western
Europe is covered by a VAAC embedded in the Meteorological Office.
There is therefore in existence extremely good framework for international
collaboration for the interaction between volcanic ash and air
operations, possibly because air transport is an international
activity. An alternative safety solution however (zero tolerance)
has been applied because it was effective in the overseas territories.
There was no motivation amongst our partners to solve a problem
of flying through ash clouds when it has not been necessary to
do so until now. This latest episode gives impetus to using the
current framework to create and share data on exposure.
Professor Roderick A Smith,
Deputy President Institution of Mechanical Engineers
13 September 2010