Please refer to tender documents for Amendment #1 to the Request for Proposal 24-58361
________________________________________________________________________________________________________________________________________________________________________
PART 1 - GENERAL INFORMATION
1.1 Security Requirements
There is no security requirement for this Request For Proposal (RFP).
1.2 Statement of Work
The National Research Council of Canada (NRC) seeks a Boeing 737 Max 8 (or 9) Wet Lease. The aircraft shall be a Boeing 737 Max 8 (ICAO code B38M), or a Boeing 737 Max 9 (ICAO code B39M) configured for Canadian Aviation Regulations (CAR) 705 (Airline Operations) or FAA Part 121 (Regularly Scheduled Air Carriers)), for the purposes of cabin airflow and human tidal volume measurements on ground and during flight in accordance with the detailed Statement of Work attached at Annex A.
ANNEX A - STATEMENT OF WORK
Boeing 737 Max 8 (or 9) Wet Lease – Flight Testing: Ventilation & Human Tidal Volume
OBJECTIVE:
The National Research Council Canada (NRC) requires a Boeing 737 Max 8 (or 9) Wet Lease (Boeing 737 Max 8 (ICAO code B38M), or a Boeing 737 Max 9 (ICAO code B39M) configured for Canadian Aviation Regulations (CAR) 705 (Airline Operations) or FAA Part 121 (Regularly Scheduled Air Carriers)), for the purposes of Cabin Airflow and Human Tidal Volume Measurements on Ground and During Flight. The proposed scope of work includes measuring the aircraft cabin air flow rates with a Boeing 737 Max aircraft on the ground and in the air using two measurement techniques. The two non-contact techniques include directing cabin airflow through an airflow measurement device, and a tracer gas technique.
1.0 Overview
The purpose of the flights is to collect ventilation and human factors data in support of the Federal Aviation Administration (FAA) sponsored project to develop a preparedness plan for communicable disease in air travel [1]. The FAA’s mission is to provide the safest, most efficient aerospace system with the use of a Safety Management System (SMS) to integrate the management of safety risk into decision making [2].
The FAA and its partners, are developing computational models that will be made available to the public and the aviation industry to determine the infectious disease transmission risks during the next disease outbreak, and to demonstrate what controls, if any, can reduce the risks to an acceptable level by the public health officials having jurisdiction. These risk assessment models require data to
(1) ensure that ventilation boundary conditions and passenger respiratory parameters are correct and (2) validate the design and implementation of the models.
NRC staff will be present onboard to conduct ventilation and human factors experiments.
The NRC ventilation team will measure the cabin air exchange rate down the length of the cabin for each phase of flight, which includes ground operations (gate and taxiing) and flight operations (take-off, climb, cruise, descent, and landing). This will be accomplished with no changes to the aircraft or to how aircraft is operated. It will require careful consideration with the aircraft operator as to when and how the measurement equipment can be used, especially during times when crew and passengers are required to be seated.
The NRC human factors team will recruit eight participants who will serve as passengers during each flight. The participants will wear physiological measurement equipment to measure how the human respiratory and cardiac systems respond to each of phase of flight. These participants will be seated in the over-wing exit rows and monitored by two NRC human factors researchers while the NRC ventilation team conducts their measurements forward and aft of the over-wing exit rows of the aircraft.
2.0 Equipment
The aircraft operator shall provide the aircraft to carry out the work described under section 5. Preference will be given to airlines that can also provide the support equipment, which includes a Pre-Conditioned Air (PCA) unit, passenger boarding bridge (or portable air stairs), and/or Ground Power Unit (GPU) equipment. If an airline cannot provide the support equipment, NRC will procure the services of this equipment with the fixed-base operator at the airport where the flight will originate.
2.1 Aircraft
The aircraft operator shall supply an aircraft that is a Boeing 737 Max 8 (ICAO code B38M) or Boeing 737 Max 9 (ICAO code B39M) configured for Canadian Aviation Regulations (CAR) 705 (Airline Operations) or FAA Part 121 (Regularly Scheduled Air Carriers). The aircraft may have a multiple cabin class configuration but it must have an economy class section with a minimum of seventeen (17) rows installed at a pitch of 30 to 32 inches. The aircraft must have been used for revenue generating service within the past thirty (30) days prior to the work defined in this document.
The flights are to be conducted on four different aircraft, two aircraft which have not had a major overhaul of the aircraft cabin or the ventilation control system (i.e., no heavy maintenance checks). The other two aircraft would have had a heavy maintenance check where the aircraft cabin was disassembled and re-assembled. All four aircraft shall have the Boeing Sky Interior cabin installed. The airworthy aircraft are to be flown by the aircraft operator’s flight deck and cabin crews. The cabin crew is not required if the aircraft operator flight deck crew provides a safety briefing as what to do in the event of an emergency. The aircraft must have all ventilation control systems operative throughout the flight, including the recirculating air fans. The aircraft will be fueled as required to carry out each flight described in this document. The Auxiliary Power Unit (APU) shall be serviceable. No aircraft will be modified to carry out the work described under sections 4 and 5. The airline will need to have a Designated Airworthiness Representative (DAR) sign off on the measurement plan as defined under section 5.
2.2 Pre-Conditioned Air (PCA) Unit
On the ground, the pre-conditioned air (PCA) system shall be provided and used to provide conditioned outside air to the aircraft low pressure manifold. The PCA system shall be capable of delivering conditioned air at a flow rate of 123 kg per minute (270 lb per minute) at a pressure of at least 7 kPa (28” w.c.). The PCA does not need to have cooling capacity as we expect the work to be carried out during Fall 2025. The cooling capacity should be similar to what is required for airline operations at the airport. The PCA shall have sufficient heating capacity to maintain cabin temperature at 20°C which parked at the airport. The PCA may be bridge-mounted or portable provided it is equipped with at least 100 feet of flexible 14” ducting connected to a 8” coupling used to connect to the aircraft low pressure manifold.
2.3 Personnel Access
The aircraft shall be accessed by the airport passenger boarding bridge or with portable air stairs connected to the forward, left-hand door of the aircraft that is normally used during normal airline operations.
2.4 Ground Power Unit (GPU)
The aircraft may be powered by a ground power unit (GPU) or the APU while parked at the airport gate. The GPU should provide sufficient power to run both recirculating fans, cabin lighting, and any other systems that the aircraft operator requires to be operational for any test condition.
3.0 Personnel and Security
3.1 Personnel to carry out the flights
The aircraft operator shall provide the crew required to carry out the work as described under sections 4 and 5; and to meet the local aviation regulations where applicable. In lieu of cabin crew, the aircraft operator may opt to provide a safety briefing to the research team (as defined under section 5.1) on how to operate the doors and exit during an emergency evacuation ordered by the pilot-in-command. However, NRC requests that one flight attendant is provided to oversee the safety of the eight human participants onboard each flight. These eight human participants will be seated in the two exit rows and will be willing to operate the over-wing exits as directed by the flight attendant.
3.2 Security
The aircraft operator should provide a security escort to the research team and participants at the airport where the flights will depart and land.
4.0 Trip Plan
Each flight will depart and arrive at the same airport. The flights can be conducted at any time during the day or night that is allowed by the airport authority. The flight will depart from an airport gate equipped with a pre-conditioned air (PCA) unit. The total block hours will not exceed ten (10) hours per trip. The flight starts with the aircraft parked at the airport gate for a minimum of three (3) hours with ground electrical power connected and energized and without the need for any on-board powerplants. The aircraft will be moving for a minimum of three (3) hours, which includes push-back, taxi, climb, cruise, descent, and taxi. The remaining four (4) hours will serve as a buffer to allow for unforeseen or unplanned circumstances (e.g., air traffic control, de-icing, turbulence, availability of ground staff, problems with data acquisition, etc.). Upon return, the airline has the option to return the aircraft to the airport gate or elsewhere on airport grounds provided that the research team and participants are provided the means to depart the aircraft (i.e., jet-bridge or air stairs). The aircraft cabin lights will be turned on to full capacity to allow the research team to carry out their work.
4.1 Ground Profile
The aircraft will be parked at the airport gate, or a designated parking spot on the tarmac with the air stairs attached to one of the aircraft doors. The PCA and ducting will be positioned near the aircraft and available for use. The PCA will be connected to NRC’s Remote Air Terminal (RAT) mobile device designed to measure the mass air flow rate, temperature, and pressure of the air (as shown in Figure 4). The RAT mobile is equipped with a set of 14” flexible ducting and 8” coupling device use to connect to the aircraft’s low-pressure manifold. The RAT mobile will be shipped inside NRC’s locked 20 foot long high-cube shipping container and dropped off airside under the direction of the aircraft operator (see Figure 3). It will be shipped to and stored at the aircraft operator’s facility one week prior to the start of the work and removed within one week after completion of the work. For all test conditions, the out-flow valve will be kept open to allow the air to exhaust normally. The temperature for the duration will be set to facilitate a comfortable working environment inside the aircraft cabin unless cooling is not available. The operator may opt to use trained personnel to oversee the ground operations in lieu of flight crew and cabin crew. Section 5.3.1 details the research plan, which includes details of how the PCA and APU will or will not be used. The general layout of the ground test plan is shown in Figure 1.
4.2 Airborne Profile
The aircraft will taxi to the runway and climb to and cruise at an altitude of at least 35,000 ft and descend back to the same airport. The cruising altitude should correspond to a cabin pressure of 7000 ft for consistency with previous research on human physiological responses during commercial air travel [3]. This will also ensure that the cabin conditions are similar for all four flights. The research team desires a climb and descent rates similar to normal airline operations (see Figure 2). The aircraft shall carry more fuel than required to load the aircraft to simulate normal engine operations with 90% load factor (e.g. 90% of the seats occupied by passengers). The research team expects 10 minutes for taxi-out, 20 minutes for the climb out, 120 minutes for the cruise, 20 minutes for the descent, and 10 minutes for taxi-in. Flight data for the aircraft type suggests an average of 1,400 to 1,600 feet per minute (fpm) of climb. After cruise, the aircraft will descend at a rate similar to normal airline operations. Past flight data suggests a descent rate around 2,200 to 2,400 fpm down to 10,000 ft of altitude; with the descent rate slowing down to 700 to 1,000 fpm. The final flight profiles and ground time are at the discretion of the pilots, air traffic control, and weather conditions. Prior to the flight, the NRC staff will work with the aircraft operator to develop and approve a flight plan that meets the desired flight profile. Section 5.3.2 details the research plan, which involves in-flight measurements of the cabin air flow conditions.
5.0 Research Plan
5.1 Research Team
The research team consists of eight (8) individuals: six (6) from the NRC, one (1) from Boeing Commercial Airplanes (BCA), and one (1) from the U.S. Federal Aviation Administration. There will also be eight (8) participants onboard who will serve as passengers only and wear physiological monitoring equipment. The nationalities will be Canadian and/or American and will have their passports available on them at all times while at the airport.
The six (6) NRC staff members will carry their Canada Restricted Area Identity Card (RAIC) which provides them with access to restricted areas with approval by the Canadian airport authority where the flights depart and land. However, the BCA and FAA individuals and human factors research participants do not carry such RAIC cards and will require escort, which can be provided by NRC if the flights depart and arrive at the Ottawa International Airport (YOW).
5.2 Measurement Equipment & Techniques
All of the equipment used for all flights will be packaged in a single 20 foot long high-cube storage container as shown in Figure 3.
5.2.1 Pre-Conditioned Air (PCA)
The conditions of the air delivered to the aircraft during the ground profile of the work will be recorded by NRC staff. It involves measuring the mass flow rate, temperature, and humidity of the air supplied to the aircraft with the Remote Air Terminal (RAT) mobile device (see Figure 4). The RAT is mounted on a baggage cart that can be towed with any tow tugs or tractors operated by an FBO (Fixed-Based Operator). The RAT will not change how the ground crew connects and operates the PCA system to supply conditioned air to the aircraft while the aircraft is stationary. The PCA will connect to the RAT with the usual 14” flexible ducting and 8” coupling device designed to be connected to the Boeing 737 low-pressure air manifold.
5.2.2 Cabin Air Flow Measurement Device
The balometer measurement technique has been used as a safe technique for measuring airflow in exhaust and supply diffusers in buildings, including heritage buildings [3]. A modified version has been used by Boeing Commercial Airplanes staff as an investigative tool for identifying problems with the air supply system into the cabin. A similar technique will be used for these flights.
Four (4) hand-held balometers weighing approximately six (6) pounds (lbs) each will be used by NRC researchers inside the aircraft cabin during the ground and airborne parts of the flight. Figure 5 show one (1) of the four (4) foot wide balometers that have been used to measure the cabin air flows without any modifications or damage to the aircraft cabin. They are held up by the seated NRC researcher to the sidewall supply diffuser to measure the amount of air delivered into the cabin.
Figure 5: One (1) of four (4) custom balometers used to measure the air flow from an individual sidewall cabin air supply diffuser.
Each balometer uses a custom 3D printed hood connected to a Dwyer FLST-C6 air flow station that measures the air velocity pressure, which is measured with a TSI barometer attached to the hood as shown in Figure 5. It works on the same principle as a TSI Alnor Balometer designed for the built environment [4]. Each balometer is powered by four (4) AA sized, single use, non-rechargeable alkaline batteries.
Upon boarding the aircraft, the NRC researchers will use non-marring, gaff tape to identify the location of all diffusers throughout the cabin. We’ve successfully used this concept without any damage to aircraft cabins (as seen in Figure 6).
Figure 6. Coloured gaff tape used to identify the location of the sidewall air supply diffusers located above the window panels.
5.2.3 Tracer Gas Measurement Method
Tracer-gas techniques have been used in residential and commercial buildings for the purposes of measuring the ventilation rates [5]. The technique has been used before in commercial transport category aircraft for the same purposes during revenue flight operations [6]. In this project, the use will be expanded safely without passengers other than those identified in section 5.1. It will (sulphur hexafluoride) SF6 gas injected into the cabin for short periods of time with the corresponding decay rate measured to estimate the cabin air exchange rate.
5.2.3.1 Design Philosophy
NRC design philosophy of the entire tracer gas injection and sampling method uses the assumption that the probability of failure is 100%. The design starts with the “chair” to secure the equipment used onboard the aircraft. The chair is designed to withstand 16G impact forces with all of the equipment mounted to it. Figure 7 shows the orange painted chair buckled into a Boeing 737 economy class seat. If required by the aircraft operator’s DAR, NRC will conduct electromagnetic interference (EMI) tests to ensure that no aircraft equipment is affected by the installation and operation of the tracer gas electronics.
Figure 7. 16G rated device buckled into a Boeing 737 aircraft seat.
There will be two (2) types of chairs:
a) Gas Injection Chair (GIC); and,
b) Gas Measurement Chair (GMC).
There will be three (3) identical sets for each type.
The GIC will secure a compressed gas bottle, gas regulator and flow shutoff valve, gas orifice plate, and tube manifold. The concept is shown as Figure 8 with the GMC. Everything is secured with brackets to prevent anything from coming loose up to 16G impact forces. Two 6.4mm (0.25”) fire-retardant tubes will run from the tube manifold and brought to the two cabin sidewall diffusers at the same row where the gas injection chair is secured. Given the lightweight of the tubes, they will be secured with non-marring tape along the floor and up the cabin sidewalls. Each gas injection chair is expected to weight around 50 lbs.
Figure 8. Concept of the tracer gas delivery and sampling system buckled into an aircraft seat.
The GMC measurement chair will secure four gas sensors, four miniature pumps, microprocessor, LCD display, and 12V lead acid batteries. The chair will be powered without the need for external power while onboard the aircraft. Each gas sensor will have 6.4mm (0.25”) fire-retardant tubing that will be secured to the cabin sidewall as done for the gas injection tubing. Four air sampling locations will be used:
1) Cabin slot diffuser on one side;
2) Cabin return register located in the same row as the chairs;
3) Cabin return register located two rows ahead of the chairs; and,
4) Cabin return register located two rows behind the chairs.
The layout of the GIC, GMC, four air sampling locations, and two gas injection locations is illustrated in Figure 9.
Figure 9. Layout of one of three measurement locations consisting of a gas injection chair (GIC), gas measurement chair (GMC), and where the tubes will inject or draw gas.
5.2.3.2 Tracer Gas
Sulfur hexafluoride (SF6) will be used as the tracer gas for this study. The inert gas is transported as Class 2.2 (Non-flammable and non-toxic gases) and will be transported by the research team on the tarmac side with access provided by the aircraft operator [7]. The 8-hour TWA (time-weighted allowable) concentration limit is 1,000 ppm [8]. The gas was selected as alternative tracer gases are either flammable (e.g., isopropyl alcohol or C5F10O), toxic (C4F7N), or would require a large amount of gas that would exceed regulatory restrictions (e.g., carbon dioxide). SF6 gas is the only tracer gas suitable to safely collect cabin air flow measurements during flight operations. The total release will not exceed 10 kgs (or 1.5 cubic meter) per flight nor exceed 25 ppm.
5.2.3.3 Gas Injection Technique
The gas will be injected for a short period of time at the port- and starboard-side wall diffusers at three rows located at the front, middle-rear, and rear of the aircraft cabin. Figure 9 shows the relative layout 12 of the gas injection locations. The gas will mix with the cabin supply air and leave the cabin via the sidewall registers located below the windows. For each row, the gas will be released from a 9.1 kg (20lb) bottle which contains compressed SF6 gas. The pressure of the gas will be regulated down to around 34.5 kPa (5 psi) with a two-stage regulator equipped with a shut-off valve. The gas will pass through a flow control orifice to ensure a consistent flow of gas supplied to 6.4mm (0.25”) fire retardant tubes that route the gas to the side wall diffusers. The gas will be manually turned on and off by the NRC researcher seated next to the gas injection chair.
5.2.3.4 Gas Measurement Technique
Three sets of four standalone gas sensors packages will be used throughout the aircraft cabin to monitor and record the gas concentrations.
Each set of sensor packages are powered with lead acid 12V batteries and connects to a microprocessor and display. Each sensor package consists a Witec INFRA.sens AK250G gas sensor, vacuum pump, wiring, and 6.4mm (0.25”) fire-retardant tubing to each location where the cabin air will be sampled. The vacuum pump draws 1 liter per minute (lpm) of cabin air through the gas sensor and exhausted back into the cabin. The sensor is connected to a microprocessor board to record and display the gas concentrations. The four locations where the gas will be sampled and analyzed are:
1) Cabin sidewall diffuser (ahead of the gas injection)
2) Sidewall register at row where sensors are installed
3) Sidewall register at row ahead of sensors
4) Sidewall register at row behind sensors
Each set will consist of an UPAS sensor that will record environmental conditions, like cabin pressure, temperature, humidity, particle concentrations (PM2.5 and PM10), and carbon dioxide (CO2) concentrations. All electronics within the package uses 20W of power from a pre-charged lead acid that complies with Canadian [9] and USA [10] regulations.
5.2.4 Human Factors Measurements
Recruited participants will be instrumented with Hexoskin ProShirts (see Figure 10), which have embedded sensors for measuring cardiac and respiratory activity and a triaxial accelerometer that detects body movement. Data will be stored on the Hexoskin Smart Device (see Figure 11), which connects directly to the shirt and is located in a small pocket on the side of the participant’s torso. The Hexoskin Smart Device has a rechargeable Lithium-Ion battery and Bluetooth LE 4.1 wireless technology.
The fitted ProShirts will donned by each participant on the ground before boarding the aircraft and worn underneath their normal clothing. The Smart Devices will be synchronized to a research computer on the ground before boarding the aircraft. The human factors research team will have smart phones and laptops onboard the flight to monitor Hexoskin data quality via Bluetooth and document passenger activities. Respiratory signals measured by the ProShirt will be calibrated for each participant against a spirometer on the ground before or after the flight.
As described under section 5.2.3.1 (tracer gas design philosophy), NRC can conduct EMI testing of this equipment as directed by the aircraft operator DAR.
Figure 10: Hexoskin ProShirts for female (left) and male (right) participants. Source: https://hexoskin.com/
Technical Specifications:
• 36+ hours of battery life, rechargeable
• 30 days of raw data store-and-forward capacity
• Heart rate (HR), Heart rate variability (HRV), and Heart rate recovery (HRR)
• Bluetooth LE™ 4.1 wireless tec hnology transmits data to in-range mobile devices
• Free Hexoskin User Dashboard for detailed raw and processed data visualizations. Grant access to family members, friends, and administrators. Export data in CSV, EDF, and Binary formats.
• Hexoskin OneSync Data Sync Software (requires OSX 10.5+ & Windows 10 or later)
• Compatible with 3rd party apps
The Hexoskin Smart Device Measures:
• QRS events and RR Intervals with a 1-Lead electrocardiogram
• Breathing rate, Tidal volume, Inspiration & expiration events
Figure 11: Hexoskin Smart Device for data recording. Source: https://hexaskin.com/
5.3 Ventilation Measurement Plan
5.3.1 Ground
The research objective on the ground is to record the cabin air flow rates down the length of the aircraft cabin with air delivered by the gate PCA system. The PCA system will be operated by the operator’s ground crew. All gaspers inside the aircraft will be turned off except for those provided to the flight and cabin crew (if applicable). Six (6) test conditions are to be conducted as described in Table 1 with all doors closed except as noted.
Table 1. Test conditions for ground profile measurements.
Test # PCA APU Door LH1 Recirculating Fans
1.1 Connected with max flow Off Open Off
1.2 Connected with 50% of max flow Off Open Off
1.3 Disconnected and off Off Open Both on
1.4 Disconnected and off On Open Off
1.5 Disconnected and off On Open Both on
1.6 Disconnected and off On Closed Both on
The sidewall air flow rates will be continually measured by a NRC research team member holding the balometers at two seats. One located near the front and one located near the back. After the tracer gas run is complete, the NRC research team will measure the air flow rates down the length of the cabin with the balometer.
Once the above is complete, the PCA airflow rate is changed and the above is repeated. Upon completion of the four ground test conditions, the tracer gas injection equipment is removed but the sensor packages and balometers will remain onboard to monitor the cabin ventilation conditions. The tracer gas bottles and injection equipment will be removed from the site. The aircraft can be prepared for flight with the NRC research team on board.
5.3.2 Airborne
It is anticipated that the NRC research team will have to remain seated and buckled during the push-back, engine start-up, taxi, take-off, and climb-out to cruise altitude. During this time, the tracer gas will be injected into the supply diffuser and monitored to achieve a concentration of 50 ppm delivered into the aircraft cabin. The tracer gas will be shut off and the PCA or APU still running to flush out the tracer gas out of the aircraft cabin. The resulting tracer gas decay will be measured by the twelve (12) sensor packages located throughout the aircraft cabin.
During cruise conditions, the NRC team will be allowed to stand up and start collecting cabin air flow measurements down the length of the aircraft cabin throughout the duration of the cruise phase of the flight. The tracer gas system will not be used during this time.
During descent, the NRC team will be reseated and continue to collect cabin measurements with the tracer gas system in the same manner as the climb-out.
5.4 Human Factors Measurement Plan
The eight participants instrumented with Hexoskin ProShirts will serve as passengers onboard the aircraft and will not carry out any specific research tasks. They will board the aircraft, accompanied by the NRC human factors team, with carry-on bags containing items they need for the flight (e.g., personal items, electronics, books/magazines, snacks). They will take their seat and follow the safety instructions of the on-board flight attendant. They will be asked to stay in their seat throughout the flight, unless they need to use the washroom, to minimize disruption to the ventilation measurement procedures. The human factors research team will sit beside or behind the recruited participants to observe and document individual differences and changes in behaviour (e.g., talking, sleeping, reading, etc.). Following the flight, the eight participants will remain in the seat until they are cleared to exit, while accompanied by the NRC human factors team.
References
[1] "Communicable disease preparedness: M&S framework for analyzing cabin health hazards," 30 11 2022. [Online]. Available: https://rip.trb.org/View/2072042.
[2] U.S. Department of Transportation, "Safety Risk Management Policy, Order 8040.4C," U.S. Department of Transportation, 2023.
[3] E. McNeely, J. Spengler and J. Watson, "Health effects of aircraft cabin pressure in older and vulnerable passengers," Federal Aviation Administration, Washington, DC, 2011.
[4] B. Tejedor, E. Lucchi, D. Bienvenido-Huertas and I. Nardi, "Non-destructive techniques (NDT) for the diagnosis of heritage buildings: Traditional procedures and futures perspectives," Energy and Buildings, vol. 263, no. 15, p. 112029, 2022.
[5] TSI, "Alnor Balometer Capture Hood EBT731," [Online]. Available: https://tsi.com/products/ventilation-test-instruments/alnor/alnor-capture-hoods/alnor balometer-capture-hood-ebt731/. [Accessed 07 04 2024].
[6] M. Sherman, "Tracer-gas techniques for measuring ventilation in a single zone," Building and Environment, vol. 25, no. 4, pp. 365-374, 1990.
[7] J. P. Rydock, "Tracer Study of Proximity and Recirculation Effects on Exposure Risk in an Airliner Cabin," Aviation, Space, and Environmental Medicine, vol. 75, no. 2, pp. 161-171, February 2004.
[8] "Transportation of Dangerous Goods Regulations," 25 10 2023. [Online]. Available: https://laws lois.justice.gc.ca/PDF/SOR-2001-286.pdf. [Accessed 07 04 2024].
[9] Airgas, "Safety Data Sheet: Sulfur Hexafluoride," 22 2 2021. [Online]. Available: https://www.airgas.com/msds/001048.pdf. [Accessed 07 04 2024].
[10] Canadian Air Transport Security Authority, "Guidelines for Batteries," [Online]. Available: https://www.catsa-acsta.gc.ca/en/what-can-bring/guidelines-batteries. [Accessed 07 04 2024].
[11] Transportation Security Administration, "What Can I Bring?," [Online]. Available: https://www.tsa.gov/travel/security-screening/whatcanibring/all. [Accessed 07 04 2024]
