Barnard Microsystems Limited

Developing Unmanned Aircraft Systems to benefit Mankind

Environmental impact - Environment

InView near trees

Above: an InView landing in the countryside

Relative environmental impact of a manned aircraft and an Unmanned Air Vehicle

There is a rapidly growing awareness of the need for all of us to be more conscious of the environmental impact of our activities and to reduce our use of fossil fuels.

  • Raw materials usage on building and materials disposal on decommissioning:
  • a manned Cessna Skylane requires at least 860 Kg of raw materials to build
  • a UAV with a 10 Kg payload only requires 34 kg of raw materials to build

UAV environmental issues

From the “Metro”, 21 September, 2005

  • For every kilogram of AVGAS aviation fuel used, an aircraft engine produces:
  • 2.891 Kg of CO 2 +
  • 1.124 Kg of H 2 O +
  • 0.019 Kg of NO x
  • Fuel usage for every 100 Km flown:
  • a manned Cessna Skylane will use 15.20 Kg of AVGAS
  • a UAV with a 10 Kg payload will use 1.65 Kg of AVGAS
  • For a geophysical survey of a 100 Km by 100 Km region, at a line spacing of 100 m:
  • a manned Cessna Skylane will create 43,942 Kg of CO 2
  • a UAV with a 10 Kg payload will create 4,770 Kg of CO 2

NOISE LEVELS

manned Cessna 402 – REF 52

calculated for small UAV

cruising at 1,000 feet

72.2 dB

62.6 dB

climbing at 1,000 feet

76.5 dB

66.9 dB

Background noise level = 42 … 52 dB: primarily waves on the beach near the test area.

Anything above 85 dB is considered harmful. Noise power is doubled for each extra 3 dB.

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Fuel usage comparison

UAV environmental issues

Maynard Hill’s TAM5 UAV. From http://tam.plannet21.com/ “sm cutout TAM5.jpg.

UAV environmental issues

Cessna Skylane manned light plane. From www.cessna.com .

parameter

Small UAV

Typical specifications

$ 35,000

Manned aircraft

Cessna Skylane

$ 268,750

weight

Dry (no PL, in Kg)

~34

860

Max fuelled (Kg)

~81

1,406

Max payload (Kg)

10

91=load + 182=pilot

operational

Fuel type

methanol / Avgas100

Avgas 100 or 100LL

Fuel capacity Kg,L

40 Kg / 49 L

273 Kg / 333 L

Max range (Km)

2,400

1,793

Max flight time (Hr)

30 at 80 Kph

11.8 at 152 Kph

Fuel used: g / Km

16.5

152

CO 2 gen in L / Km

35

463

Max speed Kph

145

276

Stall speed Kph

50

91

Impact of accident:

KE = 0.5mv 2

KE = 0.5x91x50x50

= 114 KJ

KE= 0.5x1243x91x91

= 5,145 KJ

  1. Note that the UAV could fly on either methanol of ethanol. Ethanol can be produced from sugar cane. However, the main problem with both methanol and ethanol, is that the energy density of both is about 70% that of Avgas 100.
  2. The density of Avgas 100 LL, is taken to be that of petroleum = 0.82 Kg / litre.
  3. In the event of an impending crash, planes dump fuel to try to avoid a fire after the crash: the less fuel carried, the less the environmental impact of a fuel dump.

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