British Aerospace Plc BAe 146-100, VH-NJD

Investigation number

200205307

Occurrence date

11/01/2002

Location

Perth, Aero.

Report release date

20/08/2003

Report status

Final

Investigation type

Occurrence Investigation

Investigation status

Completed

Aviation occurrence type

Fumes

Occurrence category

Incident

Highest injury level

Minor

Safety Action Analysis Summary

Local safety action

The operator has undertaken to raise awareness among flight crew
about the risks of possible crew incapacitation from fumes and the
importance of not delaying the donning of oxygen masks during
emergency checklist actions. This notice should include reiteration
of the primacy of any immediate recall emergency checklist actions
over other operator documentation. This will be achieved by a
re-write of the procedures detailed in the operator OM-2 operations
manual.

The ATSB expressed concern to the operator about the lack of
advice provided to medical staff as to what medical tests should be
carried out on crew after possible exposure to fumes. The operator
undertook to introduce a procedure to communicate a list of
prescribed minimum tests, published by the airframe manufacturer in
SIL 21/45, to medical practitioners whenever crewmembers require
testing for fume exposure. This would ensure that the attending
doctor would have the latest testing information available at the
time of the test. It was agreed that the information should, as a
minimum, cover the appropriate medical tests for such exposure as
listed on Pages 10 and 11 of BAe SIL 21/45 Issue Number 1 dated
January 2001 (or as amended).

With regard to the concern about appropriate use of the diluter
type masks and portable oxygen bottles by cabin crew in heavy smoke
or fumes situations, the operator has undertaken to issue a flight
attendant safety memo (FASM). This FASM will raise awareness among
cabin crew of the limitations of the portable oxygen bottle and
diluter type masks when used in a fumes contaminated
environment.

The aircraft type has been the subject of recurring fume
incidents throughout its operating life as commented on by the PIC.
It has been subject to intense investigations by both operators and
the manufacturer. These investigations have resulted in the
promulgation of several service information letters, bulletins,
airworthiness directives and NOTOP troubleshooting
requirements.

Because of this history, the fume events may have become
`routine' in the thinking of some operating crew and awareness of
the possible risks may have diminished as a result. This
familiarity was a concern to the manufacturer as evidenced by the
wording in the AOM to the operator. Familiarity may have led the
PIC to delay the donning of his oxygen mask. The imperative to
ascertain the source of contamination as soon as practicable in
accordance with the operator's NOTOP directive may have also
influenced the PIC's decision making.

Although the PIC felt that there was no need for him to don his
oxygen mask, this action was contrary to the operator's emergency
procedures. The completion of the NOTOP diagnostic action should be
accomplished after any emergency checklist actions. By choosing to
remain exposed to potentially contaminated air, the PIC might have
risked degradation of his faculties, which then may have reduced
his ability to correctly determine if there was a flight hazard and
respond appropriately. This increased exposure may also have long
term or cumulative effects that are not yet understood.

If the emergency checklist had been performed first, both pilots
should have donned oxygen masks and the subsequent occasional
removal of an oxygen mask by one pilot for air sampling would have
likely had minimal safety consequences. This is further reinforced
by the fact that both pilots experienced some after-effects that
required stand down from flight duties even though one, the
copilot, had donned an oxygen mask early in the event.

The PIC's request to the FAs and their subsequent actions in
opening the flight deck door were contrary to procedures. The
smoke/fumes procedures in both cockpit and cabin are safety of
flight defences designed to minimise the potential for flight crew
incapacitation by isolating the flight deck from cabin hazards.
Again the possible perception that fume events are a `routine' part
of the environment in which the crews operate may have led both
flight and cabin crew to believe that the action was appropriate
under the circumstances.

The oxygen bottle used by the cabin crew was fitted with a
diluter or therapeutic type mask. This design does not provide
protection from smoke or fumes as most of the air mixture provided
is ambient air. Under certain circumstances involving heavy
contamination by fumes, the use of this type of mask might mislead
the user into a false sense of protection and lead to the
possibility of being overcome by the fumes. The limited protection
afforded by this type of mask should be brought to the attention of
cabin crew.

The crew carried out the takeoff in the British Aerospace Plc
BAe 146 (BAe 146) with number-4 engine air bleed selected on, and
engine numbers 1, 2 and 3 and the auxiliary power unit air bleeds
selected off in compliance with an item in the discrepancy log.
Shortly after take off, at approximately 700 ft above ground level,
the copilot switched on the remaining engine air bleeds and both
airconditioning packs. Shortly after selecting engine anti-ice on,
the pilot in command (PIC) asked the copilot if he could smell
fumes. The copilot agreed that he too had detected a smell. The
engine anti-ice system was then switched off.

A short time after commencing the cabin service, a flight
attendant (FA) called the flight deck and informed the PIC of fumes
in the cabin and that they were particularly bad near the rear of
the cabin where another FA had donned an oxygen mask. This mask was
of the diluter type that supplies a mixture of the incoming oxygen
with the ambient air that is then delivered to the user. The
copilot then indicated to the PIC that `he felt he should go onto
oxygen' and donned an oxygen mask, but the PIC did not feel he
needed to perform the same action at that time.

The PIC later stated that he did not don his oxygen mask at this
time, as he was considering if the fumes were oil related in
accordance with a notice to pilots (NOTOP) from the operator. This
NOTOP required the PIC to make a diagnosis as to the source of
contamination `wherever it is safe and practicable to do so'. The
PIC's findings were required by the operator to determine the level
of response required to later rectify the problem and return the
aircraft to service.

The PIC stated that the aircraft type had a history of fumes
related problems and not donning his oxygen mask was a normal
practice for himself and, he believed other aircrew employed by the
operator. He said `most smells and odours were considered the
normal environment of the day to day operation of the BAe 146' and
he would have discontinued his NOTOP diagnostic action if he
perceived a flight hazard issue and would have reverted to the
emergency checklist action. He also stated that the copilot, being
on oxygen, could confirm a successful isolation procedure by
occasionally removing his mask and comparing pure air with the
ambient air of the flight deck.

This was at variance with the emergency checklist for
SMOKE/FUMES/FIRE IN COCKPIT/CABIN. This list takes priority over
any other action. The first item on the checklist is `Oxgen masks
and goggles...Flight crew don, check 100%'. The imperative in
relation to fumes events was also highlighted in an all operator
message (AOM) from the manufacturer, which states in part `pending
the definition of any necessary corrective actions, oil leaks and
cabin/flight deck smells must be regarded as a potential threat to
flight safety and not just a nuisance'.

The copilot completed fault isolation checks that appeared to
improve the air quality on the flight deck. The PIC then asked the
FAs if they could come to the flight deck so that he could better
assess the situation in the cabin. The FAs came forward in turn,
opened the flight deck door and entered. This action was at
variance with the operations manual actions for flight attendants
in the event of smoke/fumes in the cabin. The manual stated that,
in the event of smoke/fumes, the FAs were to inform the PIC via the
intercom and were not to open the flight deck door.

In his original report, the PIC stated that `each time when they
opened the flight deck door, we noticed that the odour
intensified'. The FAs' cabin crew reports to the operator also
stated that the odour and fumes were still evident in the passenger
cabin during the remainder of the flight. The PIC described the
odour to be unlike any odour previously encountered and then
decided the safest option was to return to the departure
airport.

The incident operating crew underwent medical examinations that
evening as directed by the operator after the event. The PIC stated
that the medical practitioner they visited told him she knew very
little about the effects of odours on crew and was unaware of any
specific blood testing requirements for such an event. Medical
testing information printed by the aircraft manufacturer in Service
Information Letter (SIL) 21/45 Issue Number 1, dated January 2001,
details specific test requirements. The PIC stated that it was
sometimes difficult to find a medical practitioner at short notice
(especially late at night) who was familiar with the required
testing procedures.

After advising the medical practitioner that he was unsure if he
would be able to work the following day, the PIC was given a
medical certificate excusing him from flight duties for the
following 24 hours. Even though he donned his oxygen mask, the
copilot was similarly affected and was also excused from flight
duties for the same period as the PIC. The operator reported that
the remaining crew did not exhibit any residual effects from the
incident.

A maintenance investigation by the operator included compliance
with the latest airworthiness directive and service bulletins. All
engines and the auxiliary power unit were checked. The
airconditioning regenerative ducting and the delivery ducting to
the rear cabin were also dismantled and inspected. That
investigation determined that the number-3 engine was the likely
source of the fumes and the engine was changed. The aircraft was
returned to service with subsequent operating crews reporting no
further fumes problems.

Aircraft Details

Manufacturer

British Aerospace PLC

Model

BAe 146

Registration

VH-NJD

Serial number

E1160

Operation type

Air Transport High Capacity

Departure point

Perth, WA

Destination

Paraburdoo, WA

Damage

Nil