Multiple reporters have approached the ATSB with safety concerns in relation to excessive aircraft cabin temperatures during ground operations.
One reporter provided the following example of a recent flight where the cabin air-conditioning was unserviceable while the aircraft was on the ground. This subsequently resulted in uncomfortable conditions for passengers and cabin crew throughout boarding and disembarkation.
The reporter states, on [date] they operated [flight] [Location 1]-[Location 2]. Prior to boarding, the cabin crew noticed the cabin was already hot and became very hot once all [xxx] passengers were on board. Some guests commented about it and asked why. One guest seated in [seat] called a crew member to advise they were feeling dizzy and sweating a lot. They were provided water to help make them comfortable. During cruise, another guest in [seat] started vomiting and their [parent] informed the crew that this was most likely the result of the heat on the ground from boarding until the air-conditioning started working once airborne. This guest was very pale as well when the crew assisted [them] in-flight. The reporter further states, all cabin crew were feeling very hot at the time.
The reporter advised, the flight crew were asked if it was possible to have any form of air-conditioning on the ground for the next sector ([Location 2]-[Location 3]), as it would be very hot in [Location 2] and they had a passenger load of [xxx]. The flight crew advised that unfortunately even if they were given a gate with air-conditioning facilities supplied to the aircraft, the company's directive does not allow it. The flight crew mentioned this policy had been in place for the past [xx] months. The reporter advised, the [manual relating to cabin crew], under section [x.x.x.] (Cabin Temperature), states 'prior to boarding/post flight duties, every effort should be made to make the cabin temperature as comfortable as possible prior to boarding and post flight'. It also states, 'boarding should not commence until acceptable measures to cool the environment are implemented'. The reporter further advised, this is in contradiction to what the flight crew explained with regard to crew not being able to source air-conditioning supply on the ground. The reporter states not having an air-conditioned cabin during this time of the year can create health and general wellbeing concerns for our crew and our guests. The particular event caused guests to sweat, become dizzy and even vomit.
A reporter states, if an aircraft has no air-conditioning supplied while on the ground during boarding and disembarking, they should not be put in this situation. The reporter firmly believes this should be a top priority for the company, to ensure their crew and guests are in a safe environment.
Another reporter operating on the following flight from [Location 2] to [Location 3], states that upon boarding they were informed by the flight crew that the auxiliary power unit (APU) was not operational and subsequently there would be no air-conditioning available. At this point the cabin was warm although not unbearable. Once the doors had closed and the aerobridge withdrawn, the cabin temperature became unbearable to the point of becoming a critical safety issue with the potential to cause harm to the passengers and crew. The flight crew advised the cabin crew that during pushback and engine start, the cabin would begin to cool down and a decision was made to continue. This was not the case and the reporter advised they became unwell with symptoms including severe dehydration, excessive sweating and nausea. The reporter further states that passengers were becoming irate and experiencing similar symptoms to that of the reporter. Once the aircraft was airborne, the crew maintained a regular supply of water for the passengers to prevent dehydration and thermal stress. The reporter advised the following flight was due to depart [Location 3] and conducted a ground return citing 'extreme thermal stress'.
The reporters collectively state that aircraft operating without operational air-conditioning pose a serious health risk to both crew and passengers particularly during the summer months. The reporters are further concerned that this aircraft in particular has been operating for some time without an operational APU and acknowledge that the issue may not be sufficiently reported by other crew members.
In response to the REPCON please see the below summary. We would like to thank you for providing the information to [Operator] as we see this an opportunity to learn and develop our systems and processes under the Safety Management System.
Upon reviewing the REPCON we have taken the below immediate steps which include:
- Raising the REPCON as a confidential report in the Safety Management System to ensure the report and concerns are captured and appropriate actions can be taken by the necessary stakeholders.
- Thermal hazards in the cabin will be raised at the safety committees in [Month] and next steps will be discussed and briefed at the [safety forum].
- A risk review will be undertaken across the broader divisions to establish any further controls that can be implemented.
- [Operator] has conducted a review of the available information related to the flights in question and based on the report it appears there are multiple concerns raised which include:
- Not addressing defects on the aircraft which have the potential to cause a thermal hazard in the cabin.
- Provision of a safe environment for crew and guests to be in and the responsibility of [Operator] to do so and the availability and supporting policies for the provision of air-conditioning on the ground when temperatures become uncomfortable.
Aircraft Auxiliary Power Unit (APU) defect management
The aircraft that operated this series of flights had a Minimum Equipment List (MEL) for an APU Bleed Inoperative applied on [date]. The aircraft operated [x] sectors under the MEL which rendered the APU unserviceable. After the [x] sector and on the [following day], the defect was rectified, the MEL was removed and the APU was serviceable.
It should be noted that [Operator] take APU defects very seriously and look to rectify the issues as quickly as possible to avoid any safety outcome. Upon reviewing data from the engineering teams and to address some of the concerns from the reporter, we would like to provide the following:
- In the last 12 months, the average number of days to clear an APU Bleed Inoperative MEL is 2.2 days.
- In the last 12 months, the overall serviceability of the APU and having APU Bleed available is 99.1 per cent across a fleet of [xx] aircraft.
Provision of safe environment in the cabin
[Operator] has clearly documented policy and procedures in the [operations manuals] which provide guidance and clarity to the actions required to be taken in relation to thermal temperatures in the cabin.
The policies detail that it is the responsibility of the flight crew to determine whether the operating environment at the time of departure poses a health risk to crew and guests based on the temperature. Flight crew, in the absence of APU Bleed Air have the option to utilise Pre-Conditioned Air (PCA) which is arranged by the [team], and this is documented in the policies and procedures. [Operator] has [x] mobile PCA units which are located at the major ports as well as static units housed on aerobridge gates. While it is noted that the PCA units may not be as effective as the bleed air from the APU, they still provide a more comfortable cabin when available. In addition, as documented in the policy and procedures for cabin crew, prior to boarding they are required to make every effort to keep the cabin cool which includes but is not limited to closing window blinds, opening air vents and keep cabin doors open when ground service equipment (GSE) is in place to maximise air flow.
In this event reported through the REPCON, unfortunately, there was no available PCA unit to support the flights and the flight crew, in accordance with the policy and procedures documented, made the determination to continue to operate as they determined the condition to be suitable to continue to operate.
Next Steps
The safety of our crew and passengers comes first and is at the heart of everything we do as an airline. As such, following discussions at the relevant safety committees in [Month], [Operator] will review the current policies and procedures to ensure they are robust, specifically in relation to the deployment of an aircraft without APU Bleed Air or the provision of a PCA unit when temperatures are at a certain level. Discussions will also include any relevant communication to crew in relation to current guidance on managing thermal hazards in the cabin.
Finally, the [team] have also commenced a review of the PCA unit availability and serviceability to ensure there are sufficient available across the network. [Team] will also commence training additional resources to operate PCA units.
We would like to thank the reporters again for sending this through.
CASA has reviewed the REPCON and the operator’s response. CASA considers the matters contained within the REPCON to be a valid concern that may impact safety and acknowledge the Operator’s immediate actions. CASA will include the information provided within the REPCON in its oversight approach for the identified operator.