49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition
4 - 7 January 2011, Orlando, Florida
AIAA 2011-545
Design of an Air Ambulance Aircraft for the Australian
Environment
Allison L. Adorni-Braccesi1 and Cees Bil2
School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Melbourne, VIC 3001,
AUSTRALIA
Australia is a large country with the majority of its population living in capital cities on
the coast line. The inland part of the county, also referred to as the Outback, is sparsely
populated and not easily accessible. The Royal Flying Doctor Service (RFDS) is a national
organisation providing Australia an airborne medical transport and emergency paramedic
service. Currently the RFDS covers an area of 7,150,000 km2, flying on average 65,544 km a
day. Their fleet consists of about 60 aircraft, flying of 21 bases Australia wide. The
performance of the aircraft that the RFDS uses are critical to the quality of their services
they provide. To date, there has never been a custom build Air Ambulance, neither in
Australia, or the rest of the world, a surprising fact, when it is considered that there or over
100 Aero-Medical companies operating in the USA. The aircraft currently in use are
converted business or light regional aircraft that were not designed specifically for MediVac
operations. These conversions are both time consuming and costly, with the last purchase
and refit costing the RFDS over 8 million Australian dollars. This formed the basis of an
undergraduate student design project to design an aircraft specifically for MediVac
operations. The Request for Proposal was drawn up Air Ambulance Victoria whose staff
also provided valuable support to the students. This paper gives a summary of the findings
of that design project.
I. Introduction
T
HE Royal Flying Doctor Service (RFDS) is an emergency and primary health care service for those living in
rural, remote and regional areas of Australia. It provides health
care to people who are unable to access a hospital or general
practice due to the vast distances of the Outback. The service began
in 1928, originally as an experiment known as the Aerial Medical
Service (AMS) which was to run for a single year. This experiment
was based in Cloncurry, Queensland. It was formed by Rev. John
Flynn, the first Superintendent of the Australian Inland Mission
(AIM), a branch of the Presbyterian Church of Australia. The first
RFDS aircraft was a De Havilland DH.50 leased from the founders
of what was later to become Qantas Airways. Within the first year
of operations, the service flew approximately 20,000 miles in 50
flights, becoming the first comprehensive air ambulance service in
Figure 1. Patient loading through side
the world. The RFDS fleet numbers 60 aircraft:
door.
•
•
•
•
29 Beechcraft B200 King Air
5 Beechcraft B200C King Air
2 Cessna 208B Grand Caravan
24 Pilatus PC-12
1
Undergraduate Student, School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University,
PO Box 71, Bundoora, VIC 3083, Australia, AIAA Student Member.
2
Associate Professor, School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University,
PO Box 71, Bundoora, VIC 3083, Australia, AIAA Senior Member.
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Copyright © 2011 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
With the operation of our aircraft across and into many remote areas and places, airstrip maintenance staff and
facilities normally available at most population centres are often not available. As a result of this, to ensure the
safety of our crews and aircraft, the RFDS is reliant on people in remote and isolated areas to maintain a high
standard of maintenance to their airstrips. The general requirements are based on CAAP 92-1(1) Guidelines for
Aeroplane Landing Areas. The airstrip is maintained by the local population and must be kept operational at all
time. Before the arrival of an aircraft, the runway is checked with a motor vehicle and if necessary, prepared using a
grating device towed behind a motor vehicle. The RFDS services more than 80% of Australia (7,150,000 km2), an
area nearly the size of the United States of America. On average per day, it attends to 750 patients, performs 100
medical evacuations, flies 65,000 km with about 200 takeoffs and
landings.
The RFDS operates standard aircraft that have been modified for
MediVac operations. An interesting question is: what would an aircraft
look like if it was designed specifically for MediVac operations as
carried out by the RFDS. Would there be significant differences in
design features and aircraft performance. This question formed the
basis of an undergraduate student design project at RMIT University.
In collaboration with the Air Ambulance Victoria and Five Rings
Aerospace Pty Ltd a typical design specification was drawn up (see
appendix) and given to a design team of 12 students. This paper gives a
summary of the design proposal with discussions about their specific
Figure 2: Typical air ambulance
design choices.
interior.
II. Major Design Requirements
Using appropriate sizing estimations a matching chart was constructed and a suitable sizing was chosen for the
Air Ambulance (Figure 3). A number of constraints were considered in conjunction with the matching chart, these
include:
•
•
•
•
•
•
•
Stall requirements of maximum co-efficient of lift for different flap deployments.
Take-off requirements for FAR 23.
Landing requirements for FAR23.
Climb rate and climb gradient requirements specified by FAR23.65.
Climb rate requirements specified by FAR23.67.
Climb gradient requirements specified by FAR23.77.
Cruise requirements at a speed of 245 kts and an altitude of 25000 ft.
The design point P was chosen to
minimise the necessary power required
and the surface area required. Using an
estimated takeoff weight of 5693 kg, the
following sizes for the Air Ambulance
were found:
Wing loading
Power loading
Wing surface area
Power available
1,266 N/m2
35.2 N/kW
44.11 m2
1,584 kW
A. Cargo Door
Possibly the most important and
necessary element of a custom built Air
Ambulance is the cargo door, used to
Figure 3. Matching chart with chosen design point P.
load the patients, and the patient loading
system itself. While the current Air Ambulance aircraft have these elements fitted to their aircraft in the best way
possible, designing an Air Ambulance around what is most comfortable, safest and least disruptive for the patient is
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paramount to the success of the aircraft. If the patient does not have to be inclined on steep angles during loading,
and does not have to change from a road stretcher to an aircraft stretcher, it will be easier for paramedics to attend to
them, and in the case of spinal injuries, the less movement the better.
It is from this requirement in the RFP that the basis of the aircraft is formed. Having little to no inclination of the
patients’ means that it is best for the aircraft to be low to the ground, thus a high-wing configuration has been
decided upon. This decision is supported by the fact that the RFP states that the aircraft must have Short Take-off
and Landing (STOL) capabilities, as most of the rural airstrips that are used by the RFDS are not of normal length.
The rear patient door for the Air Ambulance aircraft is an inward opening plug-type stressed door. The door is
located in a highly loaded area of the fuselage due to the forces from the empennage, and represents a large cut-out
in the fuselage so the door will be a stressed type in order to transfer the stresses to the fuselage structure. The door
is an inward opening plug type for various reasons, including in-flight safety, pressurisation and structural
considerations. It is hinged from the top as required and the hinges are attached to the rear bulkhead for structural
reasons. Using the rear bulkhead to attach the empennage and the rear door means that it must be flat rather than the
optimal cylindrical design for pressurisation leading to increased weight, but it is believed that this configuration
will be lighter than the alternatives of providing a separate structure for these attachments. The dimensions of the
rear door and empennage can be seen in Figure 4.
B. Cabin Configurations
The RFP also states that there are
to be 4 specific cabin configurations
for the Air Ambulance (Table 1).
This is due to the fact that in the
converted Air Ambulance aircraft,
there is a limited amount of room to
move, and therefore some aspects
that the RFDS require are not able to
be implemented. Therefore, it has
been decided that the length and the
size of the custom designed and built
Air Ambulance will be a direct result
of the internal configurations. The
Figure 4. Patient Rear Loading Door.
largest of these configurations
consists of 2 stretchers, 4 passenger
seats and 2 medical personnel seats and therefore the aircraft cabin must be able to adhere to this requirement. These
different pieces of equipment must not only fit into the cabin, but the medical personnel seats must be able to access
both patients, and the medical cabinets, in which the necessary supplies are stored. For this reason, it has been
decided that these seats will operate on a rail system, ensuring that there is adequate access for the medical
personnel, and that they are able to remain belted in for the duration of the flight, which ensures both their safety and
the safety of the patients.
Table 1. Four cabin configurations for Air Ambulance aircraft.
Configuration 1
Configuration 3
2
1
3
2
1
Stretchers
Medical Seat
Passenger Seats
Medical Cabinets
Carry on Life Raft
1
2
4
2
1
Stretcher
Medical Seats
Passenger Seats
Medical Cabinets
Carry on Life Raft
Configuration 2
1
2
1
1
2
1
Stretcher
Medical Seats
Passenger Seat
Neonatal Unit
Medical Cabinets
Carry on Life Raft
1
2
2
2
1
Bariatric Stretcher
Medical Seats
Passenger Seats
Medical Cabinets
Carry on Life Raft
Configuration 4
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These four configurations are shown in Figure 5:
(1)
(2)
(3)
(4)
Figure 5. Reconfigurable cabin layouts based on mission.
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B. Aircraft Range and Altitude
In order for the aircraft to service the greater parts of Australia, it must have an adequate range to reach the
patients and return to their designated care facility. Although the range is specified in the RFP as 250 NM, however,
after discussions with the RFDS and Air Ambulance Victoria, it was decided that a range of this size would only just
service Victoria, and therefore did not have a hope
of being able to reach the rural and remote areas.
Due to this fact, it was decided that the Air
Ambulance would be designed to a range of 1000
NM. This design requirement will ensure that all
areas of Australia will be able to be reached, and the
Air Ambulance will also have the possibility of
becoming not only an Australian ambulance, but an
ambulance that can be sold and used world-wide.
The design critical mission profile is shown in
Figure 6.
The Air Ambulance is required to be capable of
cruise at FL250, which, for the purpose of this
design, will be simplified to an approximate altitude
Figure 6. Critical mission profile.
of 25,000ft (7620m). In addition to this cruise
altitude, a second related requirement is that the Air
Ambulance is to be pressurised to that of seal level up to 14,000ft (4,267m). This requirement must be met by the
design team, as it ensures the safety and comfort of those travelling onboard.
C. Short Take-Off and Landing
It is clearly stated in the RFP that this Air Ambulance must be of Short Take-Off and Landing (STOL)
capabilities. Therefore, the chosen wing configuration is a “high-wing” design, as the structural and aerodynamic
advantages outweigh the opposing wing configurations. One of the major draws to a high-wing placement is its
historical success in STOL aircraft, as well as the area advantage for high-lift devices.
The fuselage is able to be placed closer to the ground with a high-wing configuration which is beneficial for the
loading and unloading of cargo. This is obvious is the C-17, C-5 and C-141 designs - primarily military aircraft –
which all utilise a high-wing design as the loading and unloading of cargo is smoother without the need for special
ground-handling gear, which can be linked to the loading and unloading of patients for the Air Ambulance Aircraft.
When designing the tail of the Air Ambulance, the STOL requirements were considered, as well as the benefits
of utilizing rear cargo doors without having too much of a structural disadvantage/interrupting the tail plane, a TTail arrangement has been chosen for this aircraft. It is believed that this configuration has the benefit of a larger
ground clearance, which is imperative, given that the aircraft will be required to land on rough runways. In addition,
reasons for this configuration include that it will aid the desired RFP requirement of having a rear cargo door, as
well as being clear of the downwash from the wing, which is advantageous for STOL conditions.
D. Aircraft Stability
The design of the Undercarriage not only aids in the STOL characteristics of the aircraft, but also contributes to
the aircraft’s stability. As this aircraft will be transporting serious ill and injured patients, stability is of paramount
concern to the design team. It is also a requirement of the RFP that the undercarriage must be able to operate from
unsealed and wet / soft airstrips, and the cabin floor must remain level while on the ground, allowing for ease of
loading and unloading of passengers and patients, as well as allowing the medics to easily move within the cabin to
attend to the patients.
Using these considerations, it was determined that a nose-wheel layout is the most suitable for this aircraft. In
order to keep the aircraft close to the ground, the undercarriage is mounted to the fuselage in a blister configuration.
The main advantage with this configuration being that the landing gear is shorter and therefore lighter than that
required if it were mounted under the wing or engine nacelle.
E. Material and Structures Considerations
As this aircraft will be a fairly low performance aircraft, many of the expensive materials such as composites and
titanium that are used for their high strength and low weight will be unnecessary. Therefore, the majority of this
aircraft will be made from aluminium as it has a high strength, low weight, is cheap to purchase and has a low
manufacturing cost.
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Figure 7. V-n diagram for structural sizing.
As there are several aluminium alloys
available with very similar properties, careful
evaluation of each alloy was employed to
determine which would be the most
appropriate. It was determined by the design
team that the Air Ambulance will use 2024T3 Aluminium as the main material for the
aircraft. This material is best resistant to
object damage and relatively easy to repair.
Steel is also used in some components of the
aircraft due to its high specific strength.
Components which are strength critical
structures such as the undercarriage, control
surface tracks, fasteners (bolts), wing and tail
to fuselage attachments will be machined
from this material.
F. Final Aircraft Design
The final Air Ambulance Aircraft design can be seen in the following CAD drawings.
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Table 2. Principal Aircraft and Performance Characteristics
Pilatus
PC-12
Mitsubishi
MU-2
Beech King
Air 200
RFP
New
Design
280
30,000
1,100
295
15,000
1,259
308
35,000
329
245
25,000
1000
245
25,000
1,200
82
808
558
969
902
786
867
900
900
297
832
585
820
747
1
2
1
2
2
2+
2
Turbine Engine
Single pilot flight
Ramp Weight (kg)
Takeoff Weight (kg)
Landing Weight (kg)
Zero Fuel Weight
(kg)
Usable Fuel Capacity
(kg)
Typically-Equipped
Empty Weight (kg)
Useful Load (kg)
Full-Fuel
Payload
(kg)
Max Payload (kg)
Yes
Yes
3,985
3,969
3,856
N/A
Yes
Yes
6,849
6,804
6,804
5,670
Yes
Yes
4,760
4,740
4,500
4,100
Yes
Yes
5,273
5,250
5,001
4,513
Yes
Yes
5,711
5,670
5,670
4,990
Yes
Yes
5,720
5,692
5,692
Yes
Yes
5,693
5,693
5,693
1,009
1,638
1,226
1,225
1,653
1,243
2,355
2,761
3,490
3,300
3,338
1 860
753
1,728
458
796/1
204
1,141
Exterior Height (m)
Exterior Length (m)
Wingspan (m)
Cabin height (m)
Cabin width (m)
Cabin length (m)
Baggage
Capacity
(m3)
Standard
Seating
Capacity
Cruise speed (ktas)
Certified Ceiling (ft)
Range Max payload
(nm)
Takeoff
Distance
MTOW (m)
Landing
Distance
MLW (m)
Rate of Climb at sea
level (mpm)
Number of Engines
Cessna
Grand
Caravan
184
25,000
150
738
547
Beech
King
Air 350
313
25,000
947
1,006
2,291
900
1,694
685
2,313
1,564
1,134
1,209
953
1007
4.72
12.68
15.88
1.37
1.62
6.49
0.9
4.37
14.22
17.65
1.45
1.37
5.94
2.0
4.26
14.4
16.62
1.47
1.52
5.16
1.13
4.17
12.01
11.94
N/A
1.50
6.55
N/A
4.52
13.36
16.61
1.45
1.37
5.08
1.6
10
9
standard
11 max
9
11
8 standard
10 max
900
800
5.0
14.5
18.5
1.6
1.5
7.47
Conclusion
In this paper, a custom built Air Ambulance aircraft design has been discussed. The aircraft has 2 turboprop
engines (PTA-65B), mounted on the underside of the wing. There is access to the aircraft through a front pilot and
passenger door, and patient access through a rear cargo door. This door is a stressed, plug type door, opening into
the aircraft, and attached to the fuselage by a hinge at the top of the door. There are 4 main cabin configurations that
will be used in this aircraft. The cabin can be converted in 30 minutes, and at its maximum configuration, it will be
able to carry 2 paramedics, 2 neo-natal units, 2 passengers and the pilot.
It is true that the RFDS can continue to work and save lives all over the country without a custom built aircraft.
However, with the help of this new aircraft, and the changes that have been implemented within this design, the
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RFDS will become more efficient, and will be able to provide the quality of care that is both wanted and needed all
over the country. The cost of the aircraft will depend on the demand for the airframe as a utility aircraft.
Appendix
RFP: Design of a Dedicated Aero-Medical Fixed Wing Aircraft
1. Background
1.1 Fixed wing aero-medical aircraft provide emergency and non-urgent medical services across the country for the
purposes of transferring sick and injured patients.
1.2 Fixed wing medical services include the transfer to/from hospitals of patients with a critical illness or injury.
Sometimes these patients require stabilization prior to transport and/or clinical management during transport.
Usually, flights consist of a pilot and a flight paramedic. On other occasions, additional doctors and paramedics
will also accompany the flight paramedic.
1.3 Fixed wing aero-medical aircraft are also for the transport of specialized medical/rescue crews to assist local
Ambulance and medical resources during a major incident.
1.4 The continuation of the patient’s medical and nursing care during transport between the referring and receiving
hospitals is essential. The aircraft becomes an extension of the hospital.
1.5 Aircraft used for fixed wing aero-medical operations are generally passenger transport aircraft that have been
extensively modified to accommodate a medical interior and provisions for patient loading and unloading. In
Australia, the two most common aircraft utilised as fixed wing aero-medical aircraft are the Pilatus PC-12 and
Beechcraft Super King Air B200. For example, Ambulance Service New South Wales operate B200 aircraft
with an interior that has been modified to accommodate two stretcher patients and three passenger seats. Each
aircraft is fully furbished with a comprehensive range of up-to-date medical and nursing equipment.
2. Aircraft General Specifications
2.1 The Aircraft must meet the airworthiness standards of CASR Part 23 Normal or Commuter Category (FAR Part
23.
2.2 The Aircraft must be certified, equipped and maintained for single pilot flight under the IFR by both day and
night.
2.3 The Aircraft will be multi-engined and be capable of performing at ISA + 10C at loadings per the primary cabin
configuration requirements specified, with sufficient IFR fuel for 250 nautical miles plus reserves, into an out of
the SLAs listed in Annex 1.
2.4 The Aircraft will be turbine powered.
2.5 The Aircraft will be equipped with an engine fire detection and extinguishing system as well as approved
portable fire extinguishers mounted in the cockpit and cabin.
2.6 The Aircraft will have Short Take-Off and Landing (STOL) capability.
2.7 The Aircraft will be capable at FL250 of a normal cruise speed of at least 245 knots True Air Speed at normal
cruise power settings.
2.8 The Aircraft is to have a pressurised cabin, capable of maintaining sea-level pressure to at least 14,000 feet
altitude, and is to be fitted with a Cabin Pressure Controller capable of varying the cabin altitude in level flight.
Back lighting of the rear altimeter is to be provided.
2.8 The Aircraft will be equipped with anti-icing and/or de-icing facilities to the standard required to meet the
Aircraft Flight Manual requirements for flight into known icing conditions.
2.9 The Aircraft is to be fitted with suitable foul weather channelling around doors (and wing lockers, if applicable)
to limit water entry onto stowed medical equipment during transit stops in adverse weather conditions.
2.10 The Aircraft will have high floatation type landing gear or equivalent, enabling operations to and from unsealed
and wet / soft airstrips.
3. Primary Cabin Configurations
3.1 The Aeromedical Fitout will cater for four (4) primary cabin configurations as detailed in this section.
3.2 For Cabin Configuration 1 the cabin will be configured with:
3.2.1 two (2) stretchers;
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3.2.2 one (1) medical seat;
3.2.3 three (3) passenger seats; and
3.2.4 two (2) medical cabinets.
3.3 For Cabin Configuration 2 the cabin will be configured with:
3.3.1 one (1) stretcher;
3.3.2 two (2) medical seats;
3.3.3 four (4) passenger seats; and
3.3.4 two (2) medical cabinets.
3.4 For Cabin Configuration 3 the cabin will be configured with:
3.4.1 one (1) stretcher;
3.4.2 two (2) medical seats;
3.4.3 one (1) provision for neonatal unit;
3.4.4 one (1) passenger seat; and
3.4.5 two (2) medical cabinets.
3.5 For Cabin Configuration 4 the cabin will be configured for one Bariatric patient with:
3.5.1 one (1) bariatric patient stretcher;
3.5.2 two (2) medical seats;
3.5.3 two (2) passenger seats; and
3.5.4 two (2) medical cabinets.
3.6 Cabin Configuration 4 assumes a patient in the weight range of 160kg - 240kg and specialised stretcher. The
stretcher will be positioned within the cabin to allow an oversized patient to be secured. Note Cabin
Configurations 1, 2 and 3 will not be required to carry a patient in excess of 160kg.
3.7 For all four cabin configurations a position will be allocated for the carry-on life-raft.
4. Secondary Roles
4.1 The Aeromedical Fitout will cater for the Secondary Roles as detailed in this section.
4.2 Secondary Roles will include Victoria Police operations involving Special Operations Group (SOG), Search and
Rescue (SAR) and Major Collision Unit (MCU).
4.3 For Secondary Roles the cabin will be configured with between four (4) and eight (8) passenger seats.
4.4 For Secondary Roles the remaining cabin volume will be used for carry-on-equipment in transit cases as detailed
in Annex 4.
4.5 Carry-on-equipment will be secured by cargo nets and appropriate tie-downs.
4.6 The Contractor will provide cargo nets and appropriate tie-downs for Secondary Roles.
5. Additional Configuration Related Requirements
5.1 The Aircraft will be able to be re-configured between any of the configurations in 30 minutes. This includes both
primary items and support equipment such as rafts, life jackets.
5.2 The general design of the Aeromedical Fitout should aim to reduce weight wherever possible. It is an aim to be
able to carry four passengers and two Neonatal cots with full fuel.
6. Stretcher Requirements
6.1 Aircraft cabin will accommodate two complete (stretcher top and base) FW 50E road ambulance stretchers
arranged head to tail within the cabin with sufficient room to allow access to both stretchers from the Medical
seat. Stretchers can be arranged with both stretchers on one side of the cabin or on alternate sides. The only
unacceptable configuration is for the forward most stretcher to be on the same side as the medical cabinet.
6.2 The stretcher restraint mechanism will support the aircraft certification basis cabin seating loads assuming a 160
kg patient. Note: The FW 50E is designed to meet the requirements of AS4535:1999.
6.3 The stretcher restraint mechanism will be released via foot action.
6.4 In Cabin Configuration 4 the restraint will be sufficient to secure a 240 kg patient. Note the restraints for Cabin
Configuration 4 are not required to be in place all the time and Cabin Configuration 4 can be retrofitted (refer
reconfiguration time requirements).
6.5 Each stretcher will be capable of being off loaded or loaded into the cabin with the other stretcher remaining in
place and loaded with a patient.
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6.6 It is desirable for aircraft seats to remain in position while stretchers are loaded and unloaded.
6.7 Bariatric Patient Stretcher
6.7.1 Two stretchers capable of carrying a patient weighing up to 240kg (refer Cabin Configuration 4) will be
provided by the Contractor, of appropriate dimensions to suit this patient type, and with appropriate
restraints.
6.7.2 Note this requirement exists even if road ambulance stretchers are to be used for all other configurations.
6.7.3 For these stretchers all of the requirements specified, excluding dimensions and weights, in the previous
stretcher descriptions remain.
7. Neonatal Units
7.1 The Aircraft will be capable of carrying a neonatal unit at either stretcher position.
7.2 It is desirable that the Aircraft will be capable of carrying two (2) neonatal units at the one time.
7.3 The existing neonatal units have a mounting interface for the FW 50 stretcher top.
8. Medical Seat Requirements
8.1 Medical seats will be designed to slide along the seat rails.
8.2 There will be one medical attendant seat (the primary seat), mounted in rails adjacent to the stretcher positions,
that can be slid for and aft to allow the attendant to align with both stretcher position and slide forward to access
the forward medical cabinet.
8.3 This primary medical seat will be able to rotate to face forward, aft or 90 degrees to face the stretcher. (The
ability to lock anywhere in the 180 rotation arc is preferred but locking in one of three (3) positions is
acceptable). Locking and unlocking will be a one (1) handed operation.
8.4 If a ‘side facing’ position is available then there must be sufficient space between the seat and the stretcher for
the attendant.
8.5 This primary medical seat will have a four-point harness with lockable shoulder inertial restraint. Shoulder
restraint unlock movement will be sufficient to allow the occupant to reach the far side of a patient on the
stretcher.
8.6 The primary medical seat will have armrests that can be folded upward to align with the seat back.
8.7 There will be a secondary medical seat that can be mounted in the medical seat rails.
8.8 The secondary medical seat will be the same as the primary seat with the exception that it can be non-rotating
but able to be mounted either forward or aft facing.
8.9 When not in use the secondary medical seat will be able to be removed and stowed in the baggage area or wing
locker.
8.10 The fitment or removal of the removable seats within the aircraft will be able to be undertaken in no more than
5 minutes, without special tooling, by the Flight Crew.
9. Passenger Seat Requirements
9.1 The passenger seats will be required to be able to be mounted facing either forward or aft.
9.2 The passenger seats will have a four-point harness with lockable shoulder inertial restraint.
9.3 The passenger seats will have an aisle side folding armrest.
9.4 One passenger seat will be mounted aft facing opposite the forward medical cupboard.
9.5 The fitment or removal of the passenger seats within the aircraft will be able to be undertaken in no more than 5
minutes, without special tooling, by the Flight Crew.
10. Medical Cabinet Requirements
10.1 The aircraft will be fitted with two medical cabinets. One cabinet will be mounted directly behind the forward
bulkhead on the port side. The second cabinet will be mounted in the aft cabin.
10.2 The forward medical equipment cabinet will face into the aisle with a rear profile to match the contour of the
cabin lining.
10.3 The aft medical equipment cabinet will cover the port side of the rear pressure bulkhead only and have a roof
and upper wall profile matching the profile of the cabin roof.
10.4 The rear cabinet will be open storage of 650 mm from the floor to the underside of the cabinet to provide
clearance at the foot end of the aft stretcher (if required) and space for bulk cargo or luggage. This cavity is to
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be enclosed with cargo netting attached to the front lower edge of the cabinet with attachment points across the
floor. The remaining cabinet volume will be divided into six (3) equal size compartments with doors.
10.5 The medical cabinets will have stain-resistant, wipe clean surfaces.
10.6 Total payload of the forward cabinet will be 100kg, the cabinet will be certified to the base aircraft design
loads.
10.7 Total payload of the aft cabinet will be 40kg.
10.8 All drawers and doors on the medical cabinets will have an automatic and positive catch-lock system, manually
released to open drawers and doors. The drawers for drug storage will be lockable and keyed alike.
11. Aero-Medical Oxygen
11.1 The Aircraft will be fitted with a medical oxygen system capable of storing and supplying at least three
thousand (3,000) litres of medical oxygen to be distributed to standard outlets mounted in the Aircraft cabin
walls.
11.2 The design, installation and testing of the medical oxygen system shall conform to AS 2896-1998 or higher
airworthiness standards as applicable.
11.3 The pressure reduction system for the oxygen will be fitted at the bulk supply.
11.4 The medical oxygen system will provide three (3) oxygen twin-outlets for medical oxygen supply as well as
two venturi suction outlets in the cabin.
11.5 Oxygen with twin outlets will be located in close proximity to each stretcher head and between passenger seats.
11.6 The oxygen fittings will be recessed where possible and positioned to preclude head-strike.
11.7 The oxygen fittings will be recessed where possible and sealed against the trim in such a manner as to ensure
no gaps that preclude adequate cleaning exist.
11.8 The Aeromedical oxygen system is independent of and in addition to the Aircraft emergency oxygen system.
11.9 The medical oxygen distribution and oxygen control plumbing system will conform to US MIL-T-6845 or
higher airworthiness standard as applicable.
11.10 A low pressure electric solenoid on/off valve, or manual on/off valve, will be connected to the oxygen
pressure regulator and is to be controlled from both the Aeromedical Attendant’s position in the cabin and the
Pilot and Co-pilot positions in the cockpit.
11.11 Each of the outlets will be capable of delivering a flow rate of sixty (60) litres per minute at a pressure of
400Kpa.
11.12 An oxygen contents gauge and low-pressure oxygen alarm will be installed within the Aircraft cabin at a
location easily visible to the medical seating positions.
11.13 A medical oxygen transfer rig is to be provided by the Contractor for the purpose of transporting medical
oxygen from the bulk supply to the Aircraft. The maintenance of the rig and its components will be the
responsibility of the Contractor.
11.14 In addition to the main Aeromedical oxygen supply, a minimum emergency supply of at least six hundred
(600) litres of medical oxygen will be located within the cabin.
12. Suction Systems
12.1 The Aircraft will be fitted with adjustable high-level suction, provided by two (2) complementary systems for
airborne and ground operation.
12.2 The Aircraft is to be fitted with a primary, under-floor-mounted, electro-mechanical suction system, and
recovering fluid collection to sealed environmental and occupationally safe canisters with a minimum capacity
of 350 mls.
12.3 The Primary suction system will be powered from the Aeromedical electrical system and be capable of being
operated without the main generators for a duration of 10 minutes.
12.4 The design, installation and testing of the primary suction system will conform to AS 2120.1 as well as the
CASA certification requirement.
12.5 Primary suction outlets will be located in close proximity to each stretcher head.
13. Cabin Environmental Systems
13.1 The Aircraft will be equipped with an air-conditioning system that covers both the cockpit and cabin areas, and
is capable, during normal engine operations, of maintaining 20C.
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American Institute of Aeronautics and Astronautics
13.2 The Aircraft cabin windows will be fitted with multi position slide blinds that are non-intrusive in the cabin
area.
13.3 The ventilation system, used when the engines are not operating, will be capable of providing at least 20 air
changes per hour.
14. Cabin Floor and Surfaces and Trim
14.1 The cabin sidewalls and headliner will be covered with a smooth, non-moisture absorbing, and washable
surface.
14.2 The floor covering will be of a smooth, non-skid, anti-static, washable vinyl or heavy-duty rubber material,
sealed against the aircraft sidewalls to window level or minimum height of 100 mm.
14.3 All cabin surface materials will be suitable to be wiped clean using VIRCON or equivalent cleaners.
14.4 For night flights, opaque washable / dry cleanable curtains or dividers will be fitted between the cockpit and
cabin.
14.5 Roof-mounted Douglas Track, or equivalent, will be fitted from above the stretcher locations along the entire
length of the stretcher.
14.6 Roof tracks will have purpose designed carriers and quick disconnect fittings to provide single hand operation
mounting points, to a capacity of 5 kilograms, for equipment such as IV drips, patient support equipment and
spot lights.
14.7 Four (4) recessed pockets will be located within the interior side panels of the medical cabin in close proximity
to the medical attendant seats and both stretchers, with the capacity to hold 0.5kg.
15. Door and Stretcher Loading System
15.1 The Stretcher Loading Device (SLD) will be designed to provide occupationally safe and efficient loading and
unloading of stretcher patients on AV Aircraft.
15.2 The SLD will require no more than one (1) person to deploy and assemble the device, without excessive
manoeuvring and with a maximum weight of fifteen (15) kilograms to be borne by the individual.
15.3 The SLD will be designed to be stowed inside the cabin, in an unobtrusive position when not in use.
15.4 The SLD will be powered from the independent, 28 volts, Aeromedical electrical subsystem. Operation of the
SLD will be taken into account when establishing the 30 minute operational capacity of the Aeromedical
supply system.
15.5 The SLD will have a minimum safe working load capable of handling the Bariatric Patient, stretcher and
loaded bridge.
15.6 Stretcher loading or unloading will require not more than two (2) persons, with a maximum weight of fifteen
(15) kilograms to be borne by each person
15.7 Loading and unloading of stretcher patients will be achieved without excessive manoeuvring, or rotating the
patient more than ten (10) degrees in roll, or eight (8) degrees in pitch, relative to the floor of the Aircraft.
15.8 The stretcher loading device will be designed to ensure that clinical treatment of the patient can continue during
loading or unloading.
15.9 The Aircraft is to be fitted with a large rear access door (cargo door) hinged at the top, measuring a minimum
of 1.24m in width x 1.32m in height.
15.10 The cargo door will be mechanically operated/assisted to avoid manual handling of the door.
15.11 The Aircraft will be fitted with a cabin/air stair door with a second door support cable, which may be
incorporated into the rear cargo door, hinged at the bottom, and incorporate integral step and handrail
assemblies which automatically extends and retracts as the door is opened and closed.
15.12 If the cabin air stair door is fitted to the cargo door the air stair door may be operated manually.
15.13 A means of boarding and exiting the Aircraft with the cargo door open will be provided.
15.14 The SLD will be able to be operated manually in the event of its power system failing.
15.15 The cargo door will be able to operated manually in the event of its power system failing.
16. Additional Stowage
16.1 Provision will be made for dedicated watertight baggage and cargo storage outside of the cabin area and be of a
design and dimensions that ensure no interference with patient and the SLD.
16.2 The aircraft will include a visual warning system for unlocked wing lockers to be located in the aircraft cockpit.
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American Institute of Aeronautics and Astronautics
16.3 Provision will be made for the carriage and stowage of passenger / patient cabin baggage to a limit of five (5)
kilograms of soft-bag luggage per passenger.
16.4 The approved and required cargo restraining nets for the Aircraft, are to be carried on all flights and suitably
stowed when not in use.
Acknowledgments
The authors would like to acknowledge the contributions of the team members to this design project. Also, the
input of several people, who have been key to the considerations and decision making process throughout the year,
are acknowledged. Thanks to the academic staff at the School of Aerospace, Mechanical and Manufacturing
Engineering at RMIT University. Sincere thanks must also be extended to Air Ambulance Victoria, and in particular
Mr. Shane Foster, to Mr. Michael Rogers, to Mr. Paul Harrison and Mr. Szymon Koronczewski from the Royal
Flying Doctor Service, to Mr. Davis Jedynak and Ms. Caz Kemister from the National Transport Service, and to Mr.
Glenn Secomb, Chief Engineer at Jet City Engineering, for their endless patience and for sharing their wealth of
knowledge with us. A special thanks also to Mr Greg Hanlon of Five Ring Aerospace Pty Ltd who proposed the
project initially.
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