NOTE 27 - COSTS AND EXPENSES BY NATURE
| (a) | Costs and operating expenses |
The main operating costs and administrative expenses are detailed below:
| For the periods ended | ||||||||||||
| December 31, | ||||||||||||
| 2017 | 2016 | 2015 | ||||||||||
| ThUS$ | ThUS$ | ThUS$ | ||||||||||
| Aircraft fuel | 2,318,816 | 2,056,643 | 2,651,067 | |||||||||
| Other rentals and landing fees | 1,172,129 | 1,077,407 | 1,109,826 | |||||||||
| Aircraft rentals | 579,551 | 568,979 | 525,134 | |||||||||
| Aircraft maintenance | 430,825 | 366,153 | 437,235 | |||||||||
| Comissions | 252,474 | 269,296 | 302,774 | |||||||||
| Passenger services | 288,662 | 286,621 | 295,439 | |||||||||
| Other operating expenses | 1,381,546 | 1,424,595 | 1,293,320 | |||||||||
| Total | 6,424,003 | 6,049,694 | 6,614,795 | |||||||||
| (b) | Depreciation and amortization |
Depreciation and amortization are detailed below:
| For the period ended | ||||||||||||
| December 31, | ||||||||||||
| 2017 | 2016 | 2015 | ||||||||||
| ThUS$ | ThUS$ | ThUS$ | ||||||||||
| Depreciation (*) | 943,215 | 910,071 | 897,670 | |||||||||
| Amortization | 58,410 | 50,257 | 36,736 | |||||||||
| Total | 1,001,625 | 960,328 | 934,406 | |||||||||
(*) Include the depreciation of Property, plant and equipment and the maintenance cost of aircraft held under operating leases. The amount of maintenance cost included within the depreciation line item at December 31, 2017 is ThUS$ 359,940 and ThUS$ 345,651 for the same period of 2016.
| (c) | Personnel expenses |
The costs for personnel expenses are disclosed in Note 23 liability for employee benefits.
| (d) | Financial costs |
The detail of financial costs is as follows:
| For the period ended | ||||||||||||
| December 31, | ||||||||||||
| 2017 | 2016 | 2015 | ||||||||||
| ThUS$ | ThUS$ | ThUS$ | ||||||||||
| Bank loan interest | 347,551 | 352,405 | 331,511 | |||||||||
| Financial leases | 37,522 | 32,573 | 42,855 | |||||||||
| Other financial instruments | 8,213 | 31,358 | 38,991 | |||||||||
| Total | 393,286 | 416,336 | 413,357 | |||||||||
Costs and expenses by nature presented in this note plus the Employee expenses disclosed in Note 23, are equivalent to the sum of cost of sales, distribution costs, administrative expenses, other expenses and financing costs presented in the consolidated statement of income by function.