Dornier dangerously low EGCC

[euroman]

Not a good day today for Euromanx, a report on the BBC about a safety report on an incident at Manchester but if you look on the AAIB site they have 2 report out this month.

http://news.bbc.co.uk/1/hi/england/manchester/6042360.stm


http://www.aaib.dft.gov.uk/publications/bulletins/october_2006/dornier_328_110__d_cprw.cfm

http://www.aaib.dft.gov.uk/publications/bulletins/october_2006/dornier_328_110__d_cprw__06_.cfm

[fragul]

:confused:
As I understand it from p36 of the report:

During the descent, the autopilot pitch
mode initially changed to FLC CAS , followed about
20 seconds later by a change to the V/S mode; the rate
of descent increased to about 1,500 fpm. As the aircraft
descended the crew said that the “nav is armed ” . As
the aircraft approached 3,200 ft QNH, the autopilot pitch
mode changed to Altitude Selected. Capture followed,
14 seconds later, by a change to Altitude Hold. The
aircraft levelled off at 3,000 ft QNH, by which time
it had completed its right turn and was on a magnetic
heading of 209º. About that time, ATC advised the crew
to maintain 160 kt to 4 DME.
When approximately 10 DME from the runway
(Figure 1 , Point A), ATC cleared the aircraft to descend
to 2,000 ft for the ILS, which the PNF acknowledged.
The autopilot Pitch mode then changed to V/S, the
aircraft started to descend at about 1,500 fpm and, a
short time later, the Altitude Alert ‘chime’ sounded as
the aircraft descended through 2,700 ft QNH. There
was no apparent response from the operating crew.

The descent from 3000ft in response to the ATC clearance to 2000ft was initiated purely by the selection of V/S pitch mode, but without actually changing the PSA to 2000ft.

Is this normal for all aircraft or unique to the type?

I am a little worried that inadvertent selection of V/S pitch mode could allow such a scenario.

Also is it normal to only receive an alt alert when 300ft below PSA indicated level, and no further alerts despite continuing to deviate from PSA?

[atprider]

I do remember the Dornier 328's having a couple of high ROD level busts going into IOM around the same time - Unrelated or perhaps due to the same SOP issues?