Ibu2 dan Bapak2 ysh,
Mohon petunjuk sekali lagi.
Untuk menentukan rute suatu pesawat penumpang sipil dari kota A ke kota B, pertimbangannya apa saja? Landasan teorinya bagaimana?
Terima kasih banyak. Merdeka!!!
mac
Rute penerbangan ditentukan sama seperti hal lain dalam aviation:
1. Safety. Yang jelas tidak boleh ada terrain yang terlalu tinggi melampaui kemampuan terbang pesawat. Pesawat dengan 2 engine juga tidak boleh terbang lebih jauh dari 1 jam penerbangan dengan kondisi OEI (one engine inoperative) dari suitable alternate airport. Endurance pesawat juga menentukan panjang sektor yang bisa diterbangi atau technical stop untuk refuelling.
2. Ekonomis. Semakin lurus, mengikuti great circle, semakin hemat bahan bakar dan semakin cepat sampai. Untuk great circle silahkan lihat di wikipedia atau encarta di Navigation.
3. Traffic flow. Pada rute tertentu yang sangat padat seperti jakarta - surabaya pesawat diharuskan terbang pada rute yang berbeda. Yah semacam jalan searah. Ini urusannya department perhubungan. Department perhubungan mengeluarkan enroute chart yang harus diikuti oleh semua penerbangan sipil dan militer (di masa damai). Airways dilengkapi dengan Navigation Aids seperti VOR, DME dan NDB. Dephub juga mengeluarkan minimum enroute altitude (MEA) untuk setiap airway. khusus seperti Training Area, Air Defense Identification Zone, Danger Area dan Restricted area juga harus diperhitungkan
Regards
Leo Yudianto Nugroho
ATP/B737, MD80/90
Bung mac,
Jawabannya tergantung pada apa sebenarnya yang ditanyakan. Misalnya saja anda seorang milyarder baru, bisa menyewa beberapa pesawat yang tidak terlalu mahal dan tidak terlalu tua. Lalu anda ingin tahu, sebaiknya jenis pesawat apa (berapa penumpang, jarak tempuh etc) yang perlu disewa dan digunakan untuk melayani rute2 mana saja. Katakan karena anda orang Surabaya maka kantor pusat anda ada di Surabaya dan pesawat2 anda akan melayani kebutuhan transportasi udara dari Surabaya ke semua penjuru Indonesia. Bagaimana caranya menentukan sebaiknya kota2 mana saja yg anda layani dengan pesawat2 anda, dan bagaimana penjadwalannya, sehari 3 kali atau seminggu 2 kali saja etc etc.
Masalah seperti ini memang adalah masalah nyata. Misalnya saja Tiger Airways milik Singapura punya 6 pesawat yg dioperasikan di Australia, yaitu pesawat2 Boeing 737-800 kalau tak salah. Tentu mereka harus membuat analisis yang cermat tentang kota2 mana saja di Australia yg akan dilayani, dan kota mana yg dijadikan pusat operasi. Lion Air yang berkongsi dengan perusahaan Australia (lupa namanya) kalau tak salah juga akan menggunakan 9 (?) pesawat 737-900 barunya utk melayani rute2 di Australia.
Masalah ini jelas tidak mudah dan melibatkan ilmu ekonomi disamping ilmu teknik dan mungkin juga ilmu matematika (operation research), psychology dan entah apa lagi. Jadi jawaban dari pertanyaan anda hanya dapat diperoleh dengan kuliah di MIT atau universitas2 lain yang memberikan kuliah dibidang itu. Untuk sekedar mempelajarinya sendiri, silahkan baca diktat kuliah di MIT-OCW yg gratis. Dibawah ini disampaikan alamat situs web MIT-OCW untuk jurusan Aeronautics dan Astronautics. Mungkin bahan kuliah yang anda inginkan ada dimata kuliah Airline management atau Airline Schedule planning ataupun Logistical and Tranportation Planning Method, atau cari sendirilah didaftar yg ada dibawah ini.
Semoga bermanfaat dan anda berhasil mendapatkan informasi yg dibutuhkan
salam
HW
Notify me of course updates
Updated within the past 180 days | MIT Course # | Course Title | Term |
| 16.00 | Introduction to Aerospace Engineering and Design | Spring 2003 |
| 16.01 | Unified Engineering I, II, III, & IV | Fall 2005 |
| 16.02 | Unified Engineering I, II, III, & IV | Fall 2005 |
| 16.03 | Unified Engineering I, II, III, & IV | Fall 2005 |
| 16.04 | Unified Engineering I, II, III, & IV | Fall 2005 |
| 16.050 | Thermal Energy | Fall 2002 |
| 16.06 | Principles of Automatic Control | Fall 2003 |
| 16.07 | Dynamics | Fall 2004 |
| 16.100 | Aerodynamics | Fall 2005 |
| 16.120 | Compressible Flow | Spring 2003 |
| 16.13 | Aerodynamics of Viscous Fluids | Fall 2003 |
| 16.20 | Structural Mechanics | Fall 2002 |
| 16.21 | Techniques for Structural Analysis and Design | Spring 2005 |
| 16.225 | Computational Mechanics of Materials | Fall 2003 |
| 16.230J | Plates and Shells | Spring 2007 |
| 16.30 | Estimation and Control of Aerospace Systems | Spring 2004 |
| 16.31 | Feedback Control Systems | Fall 2007 |
| 16.322 | Stochastic Estimation and Control | Fall 2004 |
| 16.323 | Principles of Optimal Control | Spring 2006 |
| 16.333 | Aircraft Stability and Control | Fall 2004 |
| 16.337J | Dynamics of Nonlinear Systems | Fall 2003 |
| 16.355J | Software Engineering Concepts | Fall 2005 |
| 16.358J | System Safety | Spring 2005 |
| 16.36 | Communication Systems Engineering | Spring 2003 |
| 16.37J | Data Communication Networks | Fall 2002 |
| 16.394J | Infinite Random Matrix Theory | Fall 2004 |
| 16.399 | Random Matrix Theory and Its Applications | Spring 2004 |
| 16.410 | Principles of Autonomy and Decision Making | Fall 2005 |
| 16.412J | Cognitive Robotics | Spring 2005 |
| 16.413 | Principles of Autonomy and Decision Making | Fall 2005 |
| 16.422 | Human Supervisory Control of Automated Systems | Spring 2004 |
| 16.423J | Aerospace Biomedical and Life Support Engineering | Spring 2006 |
| 16.512 | Rocket Propulsion | Fall 2005 |
| 16.522 | Space Propulsion | Spring 2004 |
| 16.540 | Internal Flows in Turbomachines | Spring 2006 |
| 16.61 | Aerospace Dynamics | Spring 2003 |
| 16.621 | Experimental Projects I | Spring 2003 |
| 16.622 | Experimental Projects II | Fall 2003 |
| 16.652 | Inventions and Patents | Fall 2005 |
| 16.653 | Management in Engineering | Fall 2004 |
| 16.682 | Prototyping Avionics | Spring 2006 |
| 16.72 | Air Traffic Control | Fall 2006 |
| 16.75J | Airline Management | Spring 2006 |
| 16.76J | Logistical and Transportation Planning Methods | Fall 2004 |
| 16.76J | Logistical and Transportation Planning Methods | Fall 2006 |
| 16.77J | Airline Schedule Planning | Spring 2003 |
| 16.810 | Engineering Design and Rapid Prototyping | January (IAP) 2005 |
| 16.810 | Engineering Design and Rapid Prototyping | January (IAP) 2007 |
| 16.812 | The Aerospace Industry | Spring 2004 |
| 16.83X | Space Systems Engineering | Spring 2002 |
| 16.851 | Satellite Engineering | Fall 2003 |
| 16.852J | Integrating the Lean Enterprise | Fall 2005 |
| 16.862 | Engineering Risk-Benefit Analysis | Spring 2007 |
| 16.863J | System Safety | Spring 2005 |
| 16.881 | Robust System Design | Summer 1998 |
| 16.885J | Aircraft Systems Engineering | Fall 2004 |
| 16.885J | Aircraft Systems Engineering | Fall 2005 |
| 16.886 | Air Transportation Systems Architecting | Spring 2004 |
| 16.888 | Multidisciplinary System Design Optimization | Spring 2004 |
| 16.891J | Space Policy Seminar | Spring 2003 |
| 16.892J | Space System Architecture and Design | Fall 2004 |
| 16.895J | Engineering Apollo: The Moon Project as a Complex System | Spring 2007 |
| 16.89J | Space Systems Engineering | Spring 2007 |
| 16.901 | Computational Methods in Aerospace Engineering | Spring 2005 |
| 16.910J | Introduction to Numerical Simulation (SMA 5211) | Fall 2003 |
| 16.920J | Numerical Methods for Partial Differential Equations (SMA 5212) | Spring 2003 |
| 16.940J | Computational Geometry | Spring 2003 |
| 16.985J | Proseminar in Manufacturing | Fall 2005 |
Bung mac,
Dibawah ini disampaikan judul2 mata kuliah bidang Airline management dari MIT-OCW yg dapat anda download gratisan. Anda juga diperbolehkan menerjemahkannya dalam bahasa Indonesia dan menggunakannya sebagai bahan kuliah. MIT hanya minta supaya anda menulis dibagian depannya bahwa bahan kuliah itu adalah terjemahan dalam bahasa Indonesia dari mata kuliah yg diberikan gratis di MIT-OCW.
Semoga informasi ini membantu anda memperoleh jawaban dari pertanyaan 2 anda. MIT-OCW juga memberikan seluruh mata kuliahnya secara gratis online. kalau tak salah ada juga beberapa universitas terkenal lainnya yg melakukan hal yg sama , tetapi MIT adalah yg pertama dan menjadi motor penggeraknya. Ada sekumpulan universitas ternama yg bergabung dalam usaha memberikan bahan kuliah terbaik yg ada didunia supaya bisa digunakan secara gratis oleh universitas2 lain didunia. Universitas2 ternama itu, kalau taka salah adalah beberapa universitas terkemuka di Amrik, Cina dan Jepang. mungkin juga ada universitas di Inggris yg melakukan hal yg sama. Cranfield kalau tak salah memberikan sebagian dari bahan kuliahnya gratis online. Kalau tak salah bahkan Oxford dan Cambridge juga melakukan hal yg sama. begitu juga Bristol seingat saya. Jadi tidak ada penghambat untuk bisa memberikan bahan kuliah yg sama baik di STTA ataupun di MIT! Terserah pada dosennya, bersedia memeras otak dan menghabiskan tenaga dan waktu utk menyerap informasi yg ada, menterjemahkannya dalam bhs Indonesia dan mengilahnya supaya bisa disampaikan kepada para mahasiswa dalam bentuk yang menarik minat mahasiswa untuk mempelajarinya secara serius. Tak ada alasan utk mengatakan bahwa mutu kuliah jelek karena buku2nya sangat mahal, jadi tidak bisa mengakses informasi terbaru dan terbaik didunia. Informasi itu ada dan dapat diperoleh secara gratis lewat internet.
salam
HW
SES # | Topics | LECTURE NOTES |
1 | Course Introduction - Review of Syllabus and Subject Requirements - Introduction to Airline Planning Processes and Systems | Introduction to the Airline Planning Process (PDF) |
2 | Airline Economics Review - Demand and Market Share Models - Differential Pricing and Revenues | Airline Economics Review (PDF) |
3 | Operating Costs and Productivity - Components of Airline Operating Costs - Measures of Aircraft and Labor Productivity | Operating Costs and Productivity (PDF) |
4 | Load and Spill Analysis - Demand Stochasticity and Flight Leg "Spill Models" - Estimation of Unconstrained Demand | Load Factor Analysis (PDF)# (Courtesy of Boeing. Used with permission.) Airline Demand Analysis and Spill Modeling (PDF) |
5 | Airline Schedule Development - Network Supply Definitions and Concepts - Timetable Development Issues and Constraints | Airline Schedule Development (PDF) |
6 | Passenger Choice Models - Decision Window Market Share Model - Consumer Choice of Path/Fare Options | Introduction to PODS Passenger Choice Models (PDF) Decision Window Model (PDF)# (Courtesy of Boeing. Used with permission.) |
7 | Introduction to ePODS Airline Management Game - Baseline Networks and Schedules - Overview of Inputs and Outputs | ePODS Airline Management Educational Game (PDF) |
8 | ePODS Work Session - Present and Discuss Baseline ePODS Results - Software Installation and Instructions | |
9 | Fleet Assignment Optimization (Prof. Barnhart) - Incorporation of Spill and Recapture Rates - Leg Independent vs. Itinerary-based Approaches | Airline Fleet Assignment (PDF) (Courtesy of Cynthia Barnhart. Used with permission.) |
10 | ePODS Work Session - Presentation of Round 1 Input Strategies - Results: Initial Fleet Assignment | |
11 | Route Planning and Network Strategies - Route Evaluation in Hub Networks - Route Profitability Estimation Issues | Route Planning and Evaluation (PDF) |
12 | ePODS Work Session - Presentation of Round 2 Input Strategies - Results: Hub Schedule Shifts and Fleet Assignment | |
13 | Scheduling and Operational Constraints - Aircraft Rotations and Irregular Operations - Demand Driven Dispatch - Flexible Fleet Assignment | Demand Driven Dispatch (PDF)# |
14 | ePODS Work Session - Presentation of Round 3 Input Strategies - Results: Route Selection and Evaluation | |
15 | Mid-Term Exam (In Class) | |
16 | Airline Fleet Planning Issues - Commercial Aircraft Categories and Characteristics - Technical and Performance Characteristics - Implications for Fleet Changes in ePODS | Airline Fleet Planning Models (PDF) |
17 | AMG Work Session - Presentation of Round 4 Input Strategies - Results: Impacts of Fleet Changes | |
18 | Revenue Management Concept and Models - Introduction to Seat Inventory Control Process - EMSR Flight Leg Optimization | Introduction to Revenue Management: Flight Leg Revenue Optimization (PDF) |
19 | Overbooking Methods - Overview of Theory and Current Practice - Evolution of Probabilistic/Cost-Based Models | Flight Overbooking: Models and Practice (PDF) |
20 | O-D/Network Seat Inventory Control - Network Optimization Models - O-D Control Development in Practice | Network Revenue Management: Origin-Destination Control (PDF) |
21 | ePODS Work Session - Presentation of Round 5 Input Strategies - Results: Full-up Scheduling and Route Selection | |
22 | Open Session - Guest Lecture on Pricing/RM | |
23 | Airline Pricing Structures and Strategies - Differential Pricing and Fare Restrictions - Implications for Price Changes in ePODS | Pricing Challenges: ePODS and Reality (PDF) |
24 | Airline Revenue Management Systems - Evolution of Capabilities and Current Status - Relationships to CRS and Distribution | Origin-Destination Control: What Have We Learned? (PDF) |
25 | ePODS Work Session - Presentation of Round 6 Input Strategies - Results: Limited Fare Modifications | |
26 | Summary: Airline Management Challenges - Discussion of ePODS Lessons - Relationship to Current Airline Industry Issues | |
Dibawah ini disampaikan judul2 mata kuliah dari MIT-OCW bidang Airline Schedul Planning
salam
HW
Lecture Notes
Microsoft® Powerpoint® software is recommended for viewing the .ppt files in this section. Free Microsoft® Powerpoint® viewer software can also be used to view the .ppt files.
Many of the lecture notes in this section are in Powerpoint® format in order to retain elements of animation.
LEC # | TOPICS | 1 | Course Introduction and Overview Airline Schedule Planning (PPT) | 2-6 | Optimizing Flows on Networks Multi-commodity Flows (PPT) Multi-commodity Network Flows: A Keypath Formulation (PPT) Multi-commodity Flows, Linear and Integer (PPT) | 7 | The Passenger Mix Problem (PPT) | 8-11 | The Fleet Assignment Problem (PPT) | 14-17 | Crew Scheduling, the Aircraft Routing Problem, and the Integrated Crew Pairing-Aircraft Routing Problem The Crew Scheduling Problem (PPT) Aircraft Maintenance Routing (PPT) The Extended Crew Pairing Problem with Aircraft Maintenance Routing (PPT) | 18 | Integrated Fleeting Models | 19 | The Schedule Design Problem (PPT) | 20-22 | Operations Recovery Airline Operations - Lecture #1 (PDF) Airline Operations - Lecture #2 (PDF) Airline Operations - Lecture #3 (PDF) | 23-24 | Robust Scheduling New Approaches to Add Robustness into Airline Schedules (PPT) | |
Dibawah ini disampaikan judul2 mata kuliah bidang Metoda2 Logistik dan perencanaan untuk transportasi.
salam
HW
Home > Courses > Civil and Environmental Engineering > Logistical and Transportation Planning Methods
Lecture Notes
A Jogger's Problem (PDF)
Functions of Random Variables 1 (PDF)
Functions of Random Variables 2 (PDF)
Functions of Random Variables 3 (PDF)
Queueing Systems 1 (PDF)
Queueing Systems 2 (PDF)
Queueing Systems 3 (PDF)
Queueing Systems 4 (PDF)
Queueing Systems 5 (PDF)
Queueing Systems 6 (PDF)
Congestion Pricing (PDF)
Spatial Queues 1 (PDF - 1.6 MB)
Spatial Queues 2 (PDF)
Networks 1 (PDF)
Networks 2 (PDF)
TSP Heuristics (PDF)
Hi Mas Ardi Apa Khabar , Gimana masih di Jogja
Sedikit menambah, sesuai moderator kurang spesifik, mudah2an kalau saya nggak salah arah nya tentu dari segi teknis.
Untuk rute, sudah di jawab oleh Mas Leo. cuma mau menambah urutan / metoda nya:
Di UAE kalau kita memberi approval route baru seperti misalnya Emirates,
pertama mereka harus submit dulu airport (destinations approval) termasuk audit yang mereka laksanakan dan di verifikasi oleh Civil Authority, misalnya mau ke Patagonia Airpot, biasanya kita pelajari audit airportmya, dari mulai landasan, safety equipment, fire category, approach (VOR.ILS/GPS dll), termasuk fasilitas komunikasi di flight operations dan dokumen & record mereka dst dst ,biasanya operator menambah chek diluar safety, seperti passenger handling, ruang tunggu, transport dari ke airport, akomodasi crew (semua di audit & sebagian besar di verifikasi oleh civil aviation authority)
Setelah kita beri approval, maka Operations Specification yang merupakan bagian dari AOC (Air Operating Certificate) holder kita revisi untuk memasukan list of new airport setelah disetujui airport tsb laik dan legal utk dipakai.
Selanjutnya mereka akan propose Proving flight, umumnya utnuk airport yang category A (ref JAROPS/ CAROPS) sudah bisa langsung terbang, sedang category crew nya harus yang paling qulified & test di Simulator dulu supaya skill & knowledge nya siap.
Sedang untuk flight planning, database dari performance pesawat di upload ke program flight planning yang ada terrain dan bluechart (data maritm) ini untuk ETOPS (nanti ada cerita lagi utnuk ETOPS), dari sini dapat dihitung yang diceritakan Mas Leo, kalau satu mesin mati apa masih bisa jaga ketinggian dengan terrain, kita sebut yang namanya escape route, lalu airport alternate juga dihitung.
Sekira nya cukup menambah data anda untuk ngajar eh kalau masih lo?
salam
Azzy
Boeing 777 disertifikasikan utk boleh terbang 3 jam (180 menit) dengan 1 mesin tak berfungsi. Informasi lebih lanjut dapat dibaca dibawah ini
salam
HW
ETOPS
Extended Range Twin Engine Operations
http://www.avsim.com/geoffschool/airlinecourse/etops.htm
It has now become part of everyday normal operations, for twin engine aircraft, to cross the Atlantic and Pacific Oceans and the deserts. I will in this article give some idea on how ETOPS works.
Most twin engine airliners are certified so that have to be able to fly normally within a hour of an airfield in the event of an emergency. That is not a problem normally in Europe, but over the Oceans and at night in Africa where airfields often close, this could present a problem. A set of rules were developed by the Civil Aviation Authorities of the world, to allow long distance flights with twin engine aircraft. Aircraft have to be built and designed with proven engines. Hours are fed back and monitored by Authorities and manufacturers. Before these operations commence the airline has to be certified and assessed as well.
The Atlantic Ocean for example could not be crossed with the normal hour restriction. It could be crossed with a two hour restriction, however vast areas would not be able to be crossed as they are outside of the range of some of the airports. For an airline to be able to cross the Atlantic on all daily routes would require at least 138 minutes certification . For flights from America to Hawaii would normally require 3 hours certification as Hawaii from the West Coast of the USA is 6 hours flying. Airlines not certified for more than 2 hours would have to route further North crossing nearer Iceland and Greenland.
How does this affect the Pilots ?
As stated in my previous article on flying the Atlantic , pilots will monitor where they are all the times. They will nominate three airfields where at a given time, the weather is above limits at the time they fly through the area . For example Shannon in Ireland, Keflavik in Iceland and St Johns in Canada . As stated Atlantic tracks change each day on route. The pilots get a copy of the tracks and use a plotting chart before the flight to plot the tracks .The pilots then draw arcs for the 3 airports which show the arcs where the ETOPS maximum range.
Note
ETOPs ranges circles are based on a "declared" True Airspeed and are not adjusted for wind. However, actual "on the day" diversion times/fuels use actual winds - which may result in a diversion being longer than the operators approved time (120, 180, 207, minutes) but always within the maximum range circle distance.
The pilots then can work out which airport is closer to divert in an emergency. They then plot the mid track equal distance point in each sector ensuring it is within the ETOPS certified range.
See the diagram below please read it from bottom to top
Point A and B are Equal Distance Points
Each circle represents the permitted ETOPS range allowing for wind.
The pilots must ensure the aircraft is always within the ETOPS Range. Therefore an aircraft travelling from Europe at the bottom of the diagram would use Shannon as a diversion airfield until reaching point A. From point A until reaching point B Keflavik would be the diversion airfield and then on reaching point B ST Johns would be the diversion airfield. If the Oceanic Control Centre offered tracks not in the ETOPS range the Pilot should refuse.
For Flight Simulator we do not have plotting charts, but we can work out the midway point by using the GPS doing the following :-
Warning do not push the enter button or you will lose your flight plan . Or get an aircraft with a FMC then you can program these equal distance points in.
Push the direct to key on the GPS type in the airport ID it should give a heading and distance to the airport . Note the miles and time then repeat the process with the second airfield and note the distance. Obviously which ever is closer is your diversion airfield. Repeat this on a regular basis.
You therefore need to know the 4 letter ID of the three airports for the flights. It is suggested you use these three airports as standard. It gives you something to do whilst flying the Atlantic. To get yourself onto the Atlantic you can purchase charts from Aerad or Jeppesen. The links are on other parts of the flight school. There is also a North Atlantic Chart for you to purchase at Aerad.
One final note ETOPS often applies in Africa as some airfields close at night and the desert becomes the same as an ocean. Pacific and many other areas of the world require ETOPS considerations it is not only the Atlantic Ocean. Pilots apply this for a diversion airfield plan even when flying short haul using a similar method.
Before an aircraft goes on an ETOPS flight the aircraft has to be certified for the flight. The certificate lasts for one journey only it could allow an intermediate stop. Once the aircraft arrives at the final destination. Another inspection is made before the aircraft is re-certified for the return long distance leg. So an Aircraft could get its certificate issued at Luton for a Journey to Orlando allowing a stop at Newcastle Outbound.
The Boeing 777 is the first airliner to be built certified for 3 hour ETOPS on delivery date.
Dari sejarah perkembangan pesawat diawali dengan menggunakan mesin piston. Mesin piston ini ternyata rawan terhadap failure dikarenakan vibration. FAA sebagai aviation authority membatasi pesawat hanya 60 menit dari alternate airfield.
Setelah memasuki era mesin jet terbukti mesin turbine lebih sedikit vibrasi sehingga lebih reliable, sehingga FAA & ICAO membolehkan pesawat untuk terbang matanya lebih dari 60 menit dalam kondisi One Engine Inoperative.
Dalam ETOPS pesawat harus mendapatkan sertifikasi, engine- airframe pairing juga harus mempunyai failure rate yang rendah. Untuk ETOPS 180 failure harus kurang dari 1/100,000 jam operasi.
Selain itu airline harus mendapatkan sertifikasi juga dari aviation authority. Selain pilot & FOO, maintenance personel juga harus mendapatkan training untuk menghindari kesalahan yang sama terjadi pada dua engine.
Perlu juga diketahui bila suatu airline/pesawat mengalami engine failure rating ETOPSnya bisa diturunkan.
Lebih lengkapnya bisa baca di wikipedia :
http://en.wikipedia.org/wiki/ETOPS
Regards,
Leo Yudianto Nugroho
ATP 737/MD80-90
http://en.wikipedia.org/wiki/Air_navigation
http://groups.yahoo.com/group/AerospaceIndonesia/msearch?ST=Rute+Pesawat&SM=contains&pos=0&cnt=10