Perencanaan Landas Pacu Bandara Perintis

Sebagian perencanaan Runway (landas pacu) sudah diuraikan pada post sebelumnya. Didalam post ini kami ingin mengraikan perencanaan runway untuk bandara perintis atau untuk pesawat kecil. Di Indonesia cukup banyak bandara-bandara kecil yang merupakan bandara perintis yang difungsikan untuk pengoperasian pesawat-pesawat  kecil seperti pesawat CN-235 dengan maksimum 35 penumpang, Fokker 50 dengan penumpang 50 orang, pesawat Merpati yang baru yaitu MA-60 dengan maksimum penumpang 60 orang maupun pesawat ATR 72-500 yang dioperasikan oleh Wing air.

Didalam ICAO Annex 14 -Aerodromes Section 3.1.9 Width of runway (lebar landas pacu), yang mana didalam perencanaan lebar runway supaya mengacu kepada Tabel tersebut yaitu :

Code                                         Code Letters
Number           A               B            C            D            E               F
   1               18m            18m         23m
   2               23m            23m         30m
   3               30m            30m         30m        45m
   4                                                  45m        45m        45m          60m

Code number dan letter diatas mengacu kepada Tabel 1.1 Aerodrome Reference Code.

Sebagai contoh kalau kita akan mendesign bandara perintis yang melayani pesawat paling besar sejenis MA-60 dengan wingspan  29.20m termasuk kedalam Code Letter C (range span 24 s/d tidak termasuk 36m) , yang mana kalau masuk kedalam Code Number 3 yang memerlukan runway dengan panjang antara 1200m s/d  tapi tidak termasuk 1800m. Dibutuhkan lebar runway 30m.

Slope (kemiringan) longitudinal/memanjang runway sesuai ICAO Section 3.1.12 untuk Code Number 3 dan 4 diperlukan slope 1 %, kalau Code number 1 dan 2 bisa slopenya 2.0 %. Sedangkan transverse slopenya adalah 1.5 % untuk Code Letter C,D,E dan F.

Keperluan dimensi Runway End Safety Area (RESA);

Dimensi daripada Runway Safety area paling pendek adalah 90m, diukur dari runway strip. Dengan lebar minimal dua kali lebar runway. Kalau mengacu kepada ICAO section 3.4.3. panjang RESA yaitu :
     240 m untuk Code Number 3 dan 4 ;  120m untuk Code Number 1 dan 2
Jadi RESA tersebut dianjurkan didalam ICAO supaya diperpanjang sampai batas obstacle seperti ILS (lampu-lampu ILS).

Clearway dan Stopway

Didalam Appendix A ICAO diuraika mengenai Declared Distance, yang mana kalau kita naik pesawat mau take-off ada sign board didekat Runway yaitu : TORA (Take-off run available), LDA(Landing distance available), TODA (take-off distance available) dan ASDA (accelerate stop distance available).

Kalau diujung runway dilengkapi dengan Stopway, maka panjang ASDA termasuk panjang Stopway. Sedangkan kalau runway dilengkapi dengan clearway maka panjang ASDA termasuk panjang Clearway.

Panjang Clearway mencakup panjang stopway. Panjang stopway sebenarnya tergantung dari performance pesawat yang menggunakan runway. Karena fungsi stopway adalah sebagai panjang tambahan kalau pesawat tidak jadi take-off karena mesinnya fail, sehingga cukup untuk berhenti sampai di stopway.


    

Airport View

View beberapa Bandara kecil di Indonesia, seperti Bandara Binaka di Pulau Nias - SUmatera Utara seperti dalam image dibawah diphoto pada April 2006- dari pesawat Merpati airline CN-235, runway bandara Binaka hanya bisa dioperasikan dari satu arah saja (dari R/W 27 sebelah timur), karena diarah satunya terdapat obstacle bukit yang cukup tinggi.  Dengan panjang R/W 1.650m pada tahun 2007, sudah bisa didarati pesawat dengan jenis Fokker-50, DASH-7, ATR-72 dan C-130 dengan beban terbatas.  

 

Cut Nyak Dhien Airport - Meulaboh - West Aceh- Indonesia

View of Cut Nyak Dhien Runway from the Helicopter during approach for Landing. This airport was renovated after the Tsunami desaster at December 2004. As shown on the picture, the runway is so closed to the beach line about 400m. Through the program of BRR NAD-Nias (Government Agency for rehabilitation and reconstruction) all infrastructure in Aceh that damage or destroyed by tsunami. The runway has been extended become length 1800m in 2007. Runway designation 15 - 33, elevation is 3 m above sea level, runway width is 30 m, pave by asphalt concrete.

 

Lasikin Airport - Simelue Island - Aceh - Indonesia

The Lasikin Runway as shown on the above picture (Jan-2007) has one obstacle at the end of R/W 25 is the existing hill. Runway dimension is 1400 m x 30 m, can operate the aircraft type Fokker-50 and ATR -42. So this runway shoukd operate for landing and take-off from one direction only, except the hill has been cut up to under the approach slope.

Perhitungan Panjang Runway (Landasan Pacu)

Oleh : I Made Utarka

I. Perhitungan Kebutuhan Panjang Landas Pacu (Runway)

Kebutuhan panjang landas pacu (runway) dipengaruhi oleh beberapa factor antara lain :

1. Karakteristik pesawat kritis (critical aircraft) yang akan beroperasi baik untuk keperluan lepas landas (take-off) maupun mendarat (landing).

2. Kondisi Cuaca, baik angin maupun temperatur

3. Kondisi landas pacu (runway) seperti kekasaran permukaan runway maupun kemiringan (slope) permukaan.

4. Lokasi Bandar udara yaitu ketinggian atau elevasi dari permukaan laut yang akan berpengaruh terhadap tekanan udara.



Kriteria perhitungan panjang runway yang digunakan adalah sebagai berikut :

1. Operating Empty Weight (OEW) pesawat kritis yang akan beroperasi

2. Pay Load untuk penerbangan dengan jarak terjauh.

3. Landing Weight pada Bandar Udara tujuan tidak boleh melebihi maximum structural landing weight yang diijinkan pesawat tersebut.

4. Kebutuhan bahan bakar selama perjalanan untuk keperluan climb, cruise dan descent.

5. Take-off weight pesawat dihitung dengan menjumlahkan berat bahan bakar yang diperlukan dengan OEW, atau menggunakan grafik Payload/Range dari Boeing. Berat take-off tidak boleh melebihi Maksimum Take-off Weight (MTOW) yang diijinkan untuk pesawat tersebut.


Contoh Data-data Critical Aircraft untuk Bandara Internasional yang akan mengoperasikan pesawat berbadan lebar (wide body aircraft) sejenis Boeing B-747-400 adalah sebagai berikut :

1. Critical Aircraft adalah : Boeing B747-400

2. Aircraft Dimension/characteristic (sumber Boeing) adalah sebagai berikut :

• Wing Span : 64,92 m

• Length : 70,67 m

• Tail Height : 19,51 m

• Typical Seating capacity : Upper Deck ; 42 buisness class

Lower deck : 24 first; 32 Buisness and 302 economy

Total : 402 seats

• MTOW : 396.894 Kg.

• Max. Design Landing Weight : 285.764 kg

• Spec Operating Empty Weight (OEW) : 178.756 kg.

• Max. Structural Pay Load : 67.319 kg.

• Usable Fuel capacity : 215.991 ltr.= 173.426 kg

• OEW + Max. Payload : 246.075 kg



I.1 Perhitungan Kebutuhan Panjang Lepas Landas (Take-off.)


Kebutuhan panjang landas pacu untuk keperluan take-off, dengan beban 336,00 ton (contoh untuk jarak tempuh sekitar 3.410 NM= 6.310 km), dengan menggunakan Grafik yang dikeluarkan oleh Boeing (zero wind), maka diperoleh panjang landas pacu (runway), untuk sea level adalah 2.250 m.

Koreksi karena elevasi

Panjang runway bertambah sebesar 7 % setiap kenaikan 1000 feet (304,8 m) diatas Mean Sea Level (MSL).

Fc = 1 + (0,07 x El/304,8.) dimana : Fc Faktor koreksi karena elevasi

El. = elevasi Bandar udara (m)



Fc = 1 + (0,07 x 19,161/304.8) = 1,0044



Koreksi akibat temperatur :

Panjang runway bertambah 1 % setiap kenaikan 1˚C dari Airport Reference Temperature (ART). Setiap kenaikan 1000m dari elevasi muka air laut (MSL), maka temperature turun 6.5 ˚C.

Ft = 1 + (0.01 x (T- (15-0.0065E)

Dimana : Ft = factor koreksi akibat temperature

T = Airport Reference Teperature (˚C.)=30 ˚C (Data PT. AP-II)

E = Elevasi runway = 19,161 m (contoh)

Jadi :

Ft = 1+ (0,01x (30- (15-0,0065x19,161)

= 1,151



Koreksi terhadap kemiringan (slope) centerline runway :

Panjang runway akan dikoreksi sebesar 10 % untuk setiap 1 % perbedaan slope runway.

Fg = 1 + (0,1 x G)

Dimana : Fg = factor koreksi akibat kemiringan runway (m)

G = slope rata-rata (%) = 0,9 % (data dari PT. AP-II)

Fg = 1 + (0,1 x 0,9) = 1,09


Dengan demikian panjang runway untuk keperluan take-off adalah :

L = 2250 x 1.151 x 1.0044x1.09 = 2. 835 m. dibulatkan menjadi 2850 m


Perhitungan kebutuhan panjang take-off diatas menggunakan grafik dengan asumsi tidak ada angin (zero wind), jadi kalau ada head wind akan mengurangi kebutuhan panjang take-off.



I.2 Perhitungan Kebutuhan Panjang Pendaratan (landing)


Dengan menggunakan Grafik dari Boeing untuk FAR Landing Runway Length Requirements – FLAPS 30 terlampir, dengan menggunakan data MDLW = 260.362 kg diperoleh panjang runway untuk landing adalah 2000 m.

Grafik tersebut adalah pada kondisi dry condition (permukaan kering), sehingga perlu dikoreksi kalau runway dalam kondisi basah (slippery) sebesar 15 %, sehingga panjang runway untuk landing menjadi : L = 2000 + (0,15 x 2000) = 2300 m.

Runway extension from length 2500 m to
3000 m, for future operation of wide body aircraft Boeing B-747-400. as shown on the picture
runway extension is under construction,
using flexible pavement with cement treated base
and asphalt concrete. This extension of the existing runway, afected to relocation of many utilities like
Approach Lighting System Category I,
Threshold light, and also Navigation system
PAPI, Midle Marker and Glide Path + DME

Wide Body Aircraft Characteristic

General dimension and Characteristic of Wide Body Aircraft
with 4 (four) engine.


Item       Description                        Units                                                  Aircraft


No.                                                              B-747-200         B-747-400        A-340-300        A-340-400


1. ICAO Airport Ref. Code                               E                         E                         E                         E


2 MTOW (Max. Take-off weight)  ton             340.10               394.63                  257.00


3 MLW (Max. Design Landing weight) ton       255.80              285.76                  186.00


4 Length (A) m                                                  70.40                 70.67                    63.69


5 Wing span (B) m                                             59.64                 64.94                    60.30


6 Wing-tip vertical clearance -min (Y) m              5.36                    5.11                      7.53


7 Tail height -max. (Z) m                                   19.58                  19.58                     17.03


8 Fuselage width (R) m                                       6.50                    6.50                       5.64        


9 Fuel capacity lt                                             198,400.00        215,900.00           138,600.00    


10 Cargo Volume m3                                      173.00                173.00                  162.80         


11 Main gear width (G) m                                 11.00                  11.00                    10.70


12 Nose to nose gear (D) m                               7.75                    7.75                       6.67


13 Nose to main forward gear (E) m                 33.37                  33.37                     32.04


14 Nose to door (L1) m                                     9.50                    9.50                       5.85


15 Engine (inboard) from acft. cl (L) m               12.12                 11.64                       9.37


16 Engine (outboard) from acft. cl (M) m            21.29                20.83                       19.6


17 Engine clearance above ground


Inboard -min (W) m                                             1.14                   1.14                         1.22


Outboard - min (X) m                                          1.82                    1.82                         2.34


18 Aircraft Service Point


Pressure refueling from nose (Q) m                     32.31                    32.31                       30


Pressure refueling from CL (Q`) m                     14.02                     14.02                        12.6

Runway Design (Perencanaan Landasan Pacu)

The most important facility in the airport is a Runway (in Indonesian call landasan or landas pacu). We can not operate the airport without any runway, otherwise we can operate the airport without the taxiway or Apron, particularly for small airport. Length and width of the runway is depend on the type of the aircraft (biggest or critical aircraft) to be operate in a airport, and also some other factor affect the length of the runway are elevation, local temperatur and runway slope.

Refer to ICAO Annex 14, Table 1.1 Aerodrome Reference Code, devided the aerodrome become Code Number 1 to 4, Number 4 for runway length 1800 and over, Also the aircraft classified become Code Letter A to F depend on the wing span, for Boeing 747-400 have wing span 65m called Code Letter E.

Runway length and width;
The length of the runway shall be calculated base on the critical aircraft specification or performance graph and added the converstion of elevation above mean sea level, temperature and longitudinal slope. For example runway lnegth 3000m can operate critical aircraft B747-400, as at Ngurah Rai International Airport -Bali also at Sultan Iskandarmuda Airport - Aceh -Indonesia

The width of the runway for operate the aircraft with Code Letter E and Code Number 4 shall be 45 m (refer same Annex section 3.1.9). The shoulder of the runway for same Code letter and number shall be 7.5 m at both side, so total width of the runway become 60.0 m ( as shown on the picture)

Runway Strip
The runway strip at both side of the runway shall be slope to the drain system 2.5 % and shall be planted grass. No any fix structure shall be allowed on the runway strip more than 30 cm high except for the navigation or meteorology equipments. The width of runway strip shall be 150 m from the center line of the runway to both side of the runway, for instrument and precision runway Code letter 3 or 4. .

Airport Facilities (Fasilitas Bandara)

Before I will provide the detail the main facilities of the airport, important to know what kind of facilities that have to be provided or constructed in the international airport. The facilities of the big and international airport shall be as follows :
Airport area devided in 2 (two) sides called airside and landside. Airside area for the aircraft operation, it's restricted area. Landside area is for public area like car parking, access road for passanger departure and arrival, supporting facilities/building.

Airside area :
1. Runway ; paved runway for take-off and landing purpose of the aircraft
2. Runway strip ; un-paved area at both side of the paved runway, shall be grassing as a safety area of the runway
3. Runway Thereshold and safety area at both edge of the runway
4.Taxiway ; paved access for the aircraft taxiing to and exit the runway. There are parallel and exit taxiway or also rapid exit taxiway.
5. Apron ; this facility usually pave by concrete slab for parking of the aircraft, push back and also apron taxilane
6. Apron access road ; for operation of the ground equipment, airport bus and others
7. ALS (airfield lighting system) and Approach Lighting System
8. DVOR ; Dopler Very High frequency Omni Radio range
9. AWOS (Automatic Weather Observation System) ;
10. Control Tower building that complete with air traffic service equipment or radio communication.
11. Terminal Building ; check-in counter area, waiting lounge area
12. Fire fighting trucks and other supporting facilities

Landside Area;

Landside facilities are :
1. Carpark, buspark, motorcycle
2. Access road
3. Terminal Building Domestic and International for Departure and Arrival
4. Security building
5. Clinic
6. others

Airport Engineering

Airport Engineering (Teknik Bandara)
Airport engineering is complex engineering or sciense, if you want to build a new international airport or carry out expansion, you will need so many engineer (integrated) that will involve the engineers as follows : civil, structure, architecture/building, mechanical, electrical, fuel, electronic, navigation, meteorological and also economic. For design and construction of new international airport you will have to provide some study like : feasibility Study, Basic Design, Master Planning, Detail engineering etc.

ICAO (international Civil Aviation Organization) and FAA (Federal Aviation Administration) provide many standards and references that you have to provide before carry out design and construction of the new airport. ICAO issued reference standard from Annex 1 to Annex 18 and also for design reference. These ICAO standard can not download from the internet, you have to registered or buy. For FAA reference you can download free from the website of FAA, http://www.faa.gov/.

In the next article I will upload some design and construction procedure/practice of the airport infrastructures like runway, taxiway apron and other facilities, especially for the students or colleges to improve their knowledge regarding the airport engineering, construction and operation.