Smoke Fumes in Aircraft Air and Crew

Source: Aviation Contaminated Air Reference Manual

British Aerospace - All Operator Message Ref 00/030V © 10th April 2008
by Susan Michaelis

FODCOM 17/2000 was followed in early 2001 by a British Aerospace, All Operator Message (AOM) Ref 00/030V. AOMs contain safety related information and the one issued by British Aerospace on 5 January 2001 was entitled: Smoke and Fumes (Smells). The relevant extracts of the AOM are shown below:

All Operator Message Ref 00/030V
SUBJECT: Smoke and Fumes (Smells)
Aircraft Type: BAe 146 and Avro 146-RJ
Distribution: Flight Operations, All Flight Crew and All Cabin / Operations Staff
Date: 5 January 2001


Introduction

During the last year there have been several reports of the appearance of smoke or fumes originating from the air-conditioning system. Investigation has identified most of the root causes of these incidents:

  • Technical (the majority), rectification of which prevented further occurrences.

  • Self-inflicted, such as ingestion of de-icing fluid through the APU intake and into the cabin air supply.

  • Perceived, due to condensation in the air supply. This may occur if an inappropriate cabin temperature is selected, causing the air conditioning system to overcool the cabin air.

Incident reports from other aircraft manufacturers continue to identify flight crews' sensitivity to the issue of smoke and fumes. This is understandable, given the recent aviation industry's history of tragic accidents that resulted from fire within the aircraft structure. The following information is given for guidance and in particular to avoid any possibility of crew incapacitation from any air related cause, however rare an event that may be.

General

  • If smoke or fumes (smells) do appear from the air conditioning system, follow the appropriate abnormal crew procedure - Smoke from Air Conditioning System - and don the oxygen masks.

  • If at any time the crew is unsure as to the air quality they should don oxygen masks.

  • If at any time a crew member appears to be unwell and uses oxygen all crew members should use oxygen as a precaution against any unidentified contaminant. Cabin crew should be encouraged to remind the flight crew of this requirement - follow crew resource management (CRM) principles.

There are many technical reasons why aircraft have smells or minor appearances of smoke from air conditioning systems including, for example, inappropriate temperature settings relative to ambient conditions or inadvertent ingestion of hydraulic fluid or de-icing fluids. Recently, the main focus of attention has been on the possibility of oil from either the main power plant or APU contaminating the cabin air via these systems. The air supply is protected from contamination by seals, which achieve maximum efficiency during steady state operation. However, they may be less efficient during transients (engine acceleration or deceleration) or whilst the engine is still achieving an optimum operating temperature. Improvements in seal design continue to increase efficiency, and when available, modifications are provided for the engines and APU.

Summary

  • If smoke or fumes appear from the air conditioning system, follow the abnormal crew procedure - smoke from Air Conditioning System - don the oxygen masks.

  • If at any time the crew is unsure as to the air quality they should - don oxygen masks.

  • If at any time one crew member appears to be unwell and uses oxygen, it is recommended that all crew members use oxygen as a precaution against any unidentified contaminant. Cabin crew should be encouraged to remind the flight crew of this requirement - follow crew resource management (CRM) principles.

Flight crew should always report occurrences of smoke or smells as a technical defect; give the maintenance engineers a clear description of the incident such as the air supply in use, system selections and recent switching.

Any occurrences of crew incapacitation should be immediately reported to BAE SYSTEMS on Tel. +33 (0)5 3460 7444 (24-hour). All other reports of smoke or fumes should be sent to BAE SYSTEMS for the attention of the Continued Airworthiness office.


British Aerospace - All Operator Message Ref 01/004V

After All Operator Message (AOM) Ref 00/030V British Aerospace issued another AOM, AOM Ref 01/004V 30 days later on 14 February 2001. AOM Ref 01/004V was entitled: Revision of BAe 146 and Avro RJ MOM Vol. 3 – Abnormal and Emergency Checklist – Smoke and Fumes. The relevant extracts are given below. By referring to the earlier checklist [29] it can be seen that the guidance previously had referred to only smoke and fire, whereas the amended checklists now added the term ‘FUMES.’

All Operator Message Ref 01/004V
SUBJECT: Revision of BAe 146 and Avro RJ MOM Vol. 3 - Abnormal and Emergency Checklist - Smoke and Fumes

Aircraft Type: BAe 146 and Avro 146-RJ
Distribution: Flight Operations and All Flight Crew
Date: 14 February 2001

Reason

To alert operators to the revision of all BAe 146 and Avro RJ aircraft Abnormal and Emergency Checklists MOM Vo1.3 part 2.


Background

A serious incident occurred on a BAe 146 aircraft where multiple crew incapacitation was suspected. A National Authority is investigating, as yet no conclusive reason for the incapacitation has been determined. However, operators are reminded that the use of oxygen in these types of incident is an essential safeguard against either a deterioration of the crew members performance or a multiple crew effect if there is a common source to the incapacitation. Whilst the cause of the suspected incapacitation in the incident referred to above is unknown, the presence of smoke or unusual smells indicating the presence of fumes should trigger the immediate use of an abnormal or emergency drill.


Description

All BAe 146 and Avro RJ aircraft Abnormal and Emergency Checklists MOM Vol. 3 part 2 will be amended to require the crew to use oxygen at any time that unusual smells indicating the presence of fumes are detected, as there is a possibility that these may be associated with incidents of suspected crew incapacitation. The amendment will be issued by temporary revision to all BAe 146 checklists and by change of card for Avro RJ aircraft. The amendment will consist of the addition of the word FUMES to all titles for the relevant smoke drills as shown by the examples below. Operators should amend their drills immediately on receipt of the BAE SYSTEMS documents…

MOM Vol. 3 Abnormal and Emergency Checklist - Replacement Titles

New Titles:

SMOKE, FUMES OR FIRE ON FLIGHT DECK OR IN CABIN ANY SOURCE
SMOKE OR FUMES FROM AIR CONDITIONING SYSTEM


Flight Safety Aspects of Contaminated Air


References

29. BAe (1990) BAe 146 Manufacturer’s Operations Manual: Emergency and Abnormal Procedures Check List/Smoke or Fire Protection. British Aerospace Systems, Hatfield.


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