The State of Play

(SETA Report RA/2005/03. Issue 8.  6 July 2007)

Single-Engine Commercial Operations

Synopsis

The report summarises the ‘State of Play’ as regards single-engine turboprop commercial operations at night and/or in IMC (SE-IMC) with particular regard to the proposed European JAA/EASA requirements.  The updated key accident rates’ comparisons are summarised and the major issues explained and the proposed rules justified.  The relevant supporting reports are referenced.  The conclusions are:

1) SE-IMC commercial operations have been shown to be notably (2 to 3 times) safer than those for comparable light twins.

2) The risk of a fatal accident following engine failure is much lower on a single turboprop than on comparable UK light twins.

3) Single-engine turboprops have suffered one fatal accident following loss of power, resulting in 2 killed and 2 injuries, in 6.053 million hours of commercial operations, compared to 4 accidents to UK light twins in public transport operations, resulting in 10 killed and 4 injuries in only 1.1 million hours.

4) Two years ago ICAO made the decision to amend its Standards and Recommended Practices to permit SE-IMC, specifically not requiring Landing Sites to be available within gliding distance en-route over land.

5) The JAA proposals are considerably more conservative than ICAO, or any other national regulations permitting SE-IMC.

6) The JAA Committee decided that it could not resolve the conflicting positions of its constituent national authorities so that, by default, the rulemaking process has now passed to EASA.  QinetiQ has been commissioned to carry out an independent study of all the evidence and to complete their report by the end of September. This should help the decision process.  EASA is requested to give SE-IMC the priority that is needed to promulgate a new rule that will reflect the ICAO Standards effective since November 2005 at the earliest opportunity.  This reflects the potential for reducing the fatal accident rate for aeroplanes with a Maximum Take-Off Weight of < 5,700 kg.