The SAFIRE ATR42 offers a big scientific payload

The ATR42 is very suited for medium troposphere studies: chemistry, microphysics, remote-sensing, turbulence. It is registred as F-HMTO and available for research experiment since the beginning of 2006. It is an original ATR 42-320 specially modified to scientific use.

Aircraft modifications

Nose section:

•  A radome differential-pressure system
•  4 instrument-mounting pads (N1 supports) just aft of the radome for sensor mounting

Fuselage section:

•  4 different probes (like PMS canisters) are installed on the pods carrying crown at the same aircraft station.
•  7 instrument-mounting pads (N1 supports) distributed along the forward part of fuselage.
•  1 under fuselage pod to carry radiometers sensors
•  1 upper fuselage pod to carry radiometers sensors
•  Up to 4 windows can be equipped with probes or air lets (4 pads for each windshields)

 Apertures:

•  2 large & rectangular under fuselage apertures, one forward and one at aircraft aft. The dimensions are 700 x 450 mm for the aft one and 650 x 450 for the forward one. It can be equipped with BK7 glass to permit lidar and radar shoots.
•  4 circular upper fuselage apertures of different diameter (400, 200 & 150 mm) along the fuselage to be equipped by glass or radiometer for example.
•  3 circular under fuselage apertures of diameter (250, 200 & 150 mm) along the fuselage to be equipped by glass or radiometer for example.

Under wing:

•  up to 3 PMS canisters could be installed under each aircraft wing, see picture below.

Flying performances

Aircraft performance critically depend on its mass. The quantity of fuel, the number of crew mambers and the scientific payload are as many parameters on which the following parameters are depending :

• Usual cruising speed : 100 m/s (min 70m/s max 134 m/s)
• Typical endurance in operations: 3h30, max 6 h (depending on payload)
• Max range at typical altitude 4000m : 1500 km, max.3000 km
• Typical ceiling in operations: 5000 m, max. 7500 m (25000 ft)

Dimensions

•  Length: 22.67m
• Height: 7.59m
• Wing span: 24.57m

Weight:

•  empty: 11 300 kg
• Max Take-off Weight: 16 900 kg

Payload:

• Max. payload: 4600 kg
• Scientific payload (normal operation): 2500 kg

Electrical power

A scientific power supply rack is delivering electricity to all the scientific equipments, see picture below.

The aircraft generators and alternators are providing 28V DC & 115V AC to this rack. It is connected to 5 different distribution units (D.U.) in cabin and to a scientific junction unit (B.J.S.) to supply external probes.

D.U. can deliver 28 V DC, saved 28V DC, 220 AC/50Hz, 115V AC/400Hz & 26V AC/400Hz.

The electrical power available is then:

• 18 kVA at ground with external power
• 20 kVA in flight
• 14 kVA in hotel mode (only generators are functioning, useful at ground if any external power is available)