The document discusses different types of aircraft inlets. It describes subsonic and convergent inlets that can handle speeds up to Mach 1.2, as well as supersonic inlets that can handle speeds up to Mach 4. It also discusses inlet features like sand and ice separators. The document outlines common ice protection systems, including hot air, electrical, and hot oil systems, to prevent ice buildup that could disrupt airflow.

1. 15.3 INLET
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2. INLET PURPOSE
• To provide stream line air and to prevent air
speed going to compressor above Mach 1
(supersonic speed)
• To prevent from shock wave, compressor cant
work and damage might occurs.

3. SUBSONIC TYPE INLET
Aircraft speed can up to Mach 1.2
CONVERGEN TYPE INLET BELLMOUTH INLET (HELICOPTER)
Convergen duct
Mach 1 M< 1

4. SAND AND ICE SEPERATOR
TURBOPROP INLET
Sand stay at bottom due to inertia

5. SUPERSONIC TYPE INLET
Aircraft speed can up to Mach 4
VARIABLE THROAT AREA INLET MOVABLE PLUG TYPE

6. ICE PROTECTION
• Ice tend to make the airflow not smooth.
• Can cause engine un efficient due to turbulent
and compressor stall.
• Normally occur on intake lip and compressor
inlet ducting.

7. TYPE OF ICE PROTECTION
• Hot Air System
– Bleed from HP compressor and pass through pressure regulating valve
– Provide overheat sensor to prevent overheated
• Electrical System
– Normally on turboprobeller
– Electrical heating element bounded to outer surface of intake cowl
– Intake leading edge continously heated (anti-icing) and other strip
heted intermittent (de-icing)
• Hot Oil System
– Utilise hot scavenge oil to heat inlet casing
– Normally in conjuction with hot air anti-icing or electrical system