Definition Of Terms

Address The unique code to which a Mode S transponder replies. This is not be confused with the "4096" code used for identifying ATCRBS transponders. The address of a Mode S transponder is not alterable by the pilot or crew.

Altitude the pressure of the aircraft as transmitted by a ATCRBS of Mode S transponder. This information is obtained is obtaine from an external sensor and transmitted to the transponder.

ATCRBS Air Trafic Control Radar Beacon Syatem. The original non-selective secondary radar beacon system usig the usual two-pulse interrogation and an auxiliary SLS pulse.

DPSK Differential phase shift keting. the method of modulation used for the selective Mode S uplink interrogation.

DF downlink format. the format included in a Mode S transponder reply to an interrogation or squitter message that indicates the type of message.

Mode S A secondary radar system where transponders can e individually interrogated or selected (the s in Mode S), so that the ammount of interference or garble can be reduced to a minimum.

Reply A transmittedresponse, from the airbone transponder, to an interrogation.

SLS Side Lobe Suppression. A pulse transmitted from an omni-directional antenna used as reference level to prevent replies to interrogations received from the secondary radar antenna sidelobes.

Squitter The self generated transmission made by a Mode S transponder, not in reply to an interrogation, for the use of collision avoidance systems.

Surveillance alt. An interrogation that causes only the addressed Mode S transponder to reply with its altitude.

Surveillance ID. An interrogation that causes only the addressed Mode S transponder to reply with its "4096" code.

"4096" code This refers to the octal number dialed into either a ATCRBS or Mode S transponder by the pilot or other crew member.

Air traffic control (ATC) adalah layanan pengatur yang dikontrol dari ground-based untuk mengatur lalu-lintas pesawat di darat dan di udara.
Fungsi ATC

• Mengatur lalu-lintas pesawat untuk mencegah terjadinya tabrakan
• Mengatur alur transportasi pesawat
• Menyediakan informasi dan pelayanan lainnya untuk pilot ketika dibutuhkan seperti cuaca dan informasi navigasi

Berdasarkan Standard yang dikeluarkan oleh International Civil Aviation Organization (ICAO), bahasa percakapan yang digunakan dapat menggunakan bahasa ingris dan bahasa yang dipakai di ground station setempat.

Untuk mengontrol keadaan lingkungan bandara dilakukan pengamatan secara visual atau langsung
Melalui airport traffic control tower (ATCT). ATCT secara struktur berdiri tinggi dan berjendela disekelilingnya untuk memudahkan pengamatan yang terletak di airport ground. ATCT bertanggung jawab untuk memisahkan dan mengefisenkan pergerakan dari pesawat dan kendaraan operational ketika melakukan taxing serta runways airport itu sendiri, dan pesawat yang berada di sekitar bandara, sekitar 5-10 nmi (3.7 – 9.2 km) tergantung pada prosedur airport.

be back

Sudah lama notesal tidak beredar di dunia maya,
ada beberapa alasan karena saat ini akses internet sangat sulit (pengenGratis.com).
Bandwidth dibatasi seminimal mungkin, bahkan email saja harus dihilangkan beberapa fiturnya.
Selain itu banyak kesibukan diluar sana (lebay.com), sorry bro jadi tidak ada tulisan yang bisa di share.

Padahal menulis bagian dari obat..lumayan hilangin stress. Banyak ide yang bisa dikembangkan
"ini lagi nulis apaan sih", gak nyambung ya....
nulis apa aja deh yang penting hari ini bisa share.

ok...gw jujur..blog ini punya email dan password,
sampai tadi pagi email dan password hilang entah kemana karena gw simpan di buku
catatan kecil gw, tadi pagi baru ketemu so..bisa ngeblog lagi.
Janji deh...gak bakal ilang lagi suerrrrrrrrrrrrrr.

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rest please...

Notes untuk kesekian kalinya membahas mengenai radio system,

mungkin ini waktunya sejenak untuk berpindah suasana, menulis tentang sesuatu yang lebih santai, tenang, damai tapi tetap not waste your time for nothing....heeeee

Pagi tadi tiba-tiba saja suasana menjadi ramai dan sedikit ceria karena semua orang tertawa..waaaa, untuk seuatu yang lucu so ..tentunya gak lucu donk kalau tertawa tanpa sebab.

Shinta dan Jojo...tiba-tiba terkenal dari keisengan mereka melalui tampang narsis yang di upload di you tube, narsis kayaknya nggak dech..soalnya lucu dan menghibur. Kreatif....tepatnya mungkin seperti itu. Lucu dan menghibur..lumayan buat hilangin stres untuk semua masalah di otak ini.

Thanks for shinta and jojo. Kami semua tertawa sampai lupa sama mahkluk bernama IJON. Cair...cair...cair. Ngerti gak, pasti tidak, biar aja cuma kita yang tahu...he.     

Aircraft Anti-Icing Systems

Negative Effects of Ice Buildup

1. Destroys smooth flow of air over wing, leading to severe decrease in lift and increase in drag forces
   
2. As angle of attack is increased to compensate for decreased lift, more accumulation can occur on lower wing surface
   
3. Causes damage to external equipment such as antennae and can clog inlets, and cause impact damage to fuselage and engines
   
4. Considered a cumulative hazard  because as ice builds up on the wing, it increasingly changes the flight characteristics
   
5. Can change pitching moment

Types of Ice

•

• Rime: “has a rough  milky white appearance and generally follows the surface closely”
  

•

• Clear/Glaze: “sometimes clear and smooth but usually contain some air pockets that result in a lumpy translucent appearance, denser, harder and more difficult to break than rime ice”
  
• Mixed

Ice Detection

• Electronic ice detection common, but can give false readings
  
• GM is developing a mass based ice detection system where ice builds up on external probe
  
• After mass of probe has increased due to additional ice, anti-icing systems are alerted and turned on
  
• This increases fuel efficiency and system life as de-icing systems are only turned on as required by conditions

•

Anti-Icing

–

• Preemptive, turned on before the flight enters icing conditions
• Includes: thermal heat, prop heat, pitot heat, fuel vent heat, windshield heat, and fluid surface de-icers

•

De-Icing

–

• Reactive, used after there has been significant ice build up
• Includes surface de-ice equipment such as boots, weeping wing systems, and heated wings 
  

Propeller Anti-Icers

•

• Ice usually appears on propeller before it forms on the wing
• Can be treated with chemicals from slinger rings on the prop hub
• Graphite electric resistance heaters on leading edges of blades can also be used 
  

Windshield Anti-Icers

•

• Usually uses resistance heat to clear windshield or chemical sprays while on the ground 
  
• Liquids used include: ethylene glycol, propylene glycol, Grade B Isopropyl alcohol, urea, sodium acetate, potassium acetate, sodium formate, and chloride salts
  
• Chemicals are often bad for the environment

Thermal Heat

•

Air Heated

–

• Bleed air from engine heats inlet cowls to keep ice from forming
• Bleed air can be ducted to wings to heat wing surface as well
• Ice can also build up within engine, so shutoff valves need to be incorporated in design
• Usually used to protect leading edge slat, and engine inlet cowls
  

•Resistance heater

–

• Used to prevent ice from forming on pitot tubes, stall vanes, temperature probes, and drain masts 
  

Boots

•

• Inflatable rubber strips that run along the leading edge of wing and tail surfaces
• When inflated, they expand knocking ice off of wing surface
• After ice has been removed, suction is applied to boots, returning them to the original shape for normal flight
• Usually used on smaller planes 
  

Weeping Wing

•

• Fluid is pumped through mesh screen on leading edge of wing and tail
• Chemical is distributed over wing surface, melting ice
• Can also be used on propeller blades and windshields
  

Electro-impulse Deicing

•

• Electromagnetic coil under the skin induces strong eddy currents on surface
• Delivers mechanical impulses to the surface on which ice has formed
• Strong opposing forces formed between coil and skin
• Resulting acceleration sheds ice from the surface
• Can shed ice as thin as 0.05”

Typical Anti-Icing

•C-130:

–

• Engine bleed air used for anti-icing wing and empennage leading edges, radome, and engine inlet air ducts.
• Electrical heat provides anti-icing for propellers, windshield, and pitot tubes.
  

•777:

–

• Engine bleed air used to heat engine cowl inlets. If leak is detected in Anti-Ice duct, affected engine Anti-Ice valves close.
• Wing Anti-Ice System provides bleed air to three leading edge slats on each wing. Wing Anti-Ice is only available in flight.  
  

References

•

• “Airplane Design, Pt 4.” Roskam
• http://www.aopa.org/asf/publications/sa11.pdf#search=%22anti-icing%20systems%20aircraft%22
• http://www.newpiper.com/promo/PIIPS/images/PIIPSPropSlingerRing.jpg
• http://www.fas.org/man/dod-101/sys/ac/c-130.htm
• http://www.airs-icing.org/AIRS_II/AIAAReno2006/AIAA-2006-206-739.pdf#search=%22transport%20ice%20%22in%20flight%22%22
• www.p2pays.org/ref/07/06047.pdf
• Ice Pictures
• http://www.idiny.com/eidi.html 
  

Pulse Repetition Frequency (PRF)

The Pulse Repetition Frequency (PRF) of the radar system is the number of pulses that are transmitted per second.

Figure 1: Radar pulse relationships

Radar systems radiate each pulse at the carrier frequency during transmit time (or Pulse Width PW), wait for returning echoes during listening or rest time, and then radiate the next pulse, as shown in the figure. The time between the beginning of one pulse and the start of the next pulse is called pulse-repetition time (prt) and is equal to the reciprocal of prf as follows:

PRT=1/PRF

The radar system pulse repetition frequency determines its ability to unambiguously measure target range and range rate in a single coherent processing interval as well as determining the inherent clutter rejection capabilities of the radar system. In order to obtain an unambiguous measurement of target range, the interval between radar pulses must be greater than the time required for a single pulse to propagate to a target at a given range and back. The maximum unambiguous range is then given by

Runamb = C0/2PRF

where c0 is the velocity of electromagnetic propagation.