RAYTHEON COMPANY 333 Notes to Consolidated Financial Statements (Continued) 33333333333333333333333333333333333333333333 Inventories at Raytheon Aircraft, Raytheon Airline Aviation Services, and Flight Options totaled $1,603 million at December 31, 2003 (consisting of $647 million of finished goods, $717 million of work in process, and $239 million of materials and parts) and $1,612 million at December 31, 2002 (consisting of $557 million of finished goods, $761 million of work in process, and $294 million of materials and parts). Included in inventories was $103 million and $76 million at December 31, 2003 and 2002, respectively, related to the Horizon aircraft. The Company anticipates certification of the Horizon aircraft in the third quarter of 2004 and first delivery by year end 2004. Property, plant, and equipment consisted of the following at December 31: The Company provides long-term financing to its aircraft cus- tomers. The underlying aircraft serve as collateral for general avia- tion and commuter aircraft receivables. The Company maintains reserves for estimated uncollectible aircraft-related long-term receivables. The balance of these reserves was $60 million and $69 million at December 31, 2003 and 2002, respectively. The reserves for estimated uncollectible aircraft-related long-term receivables represent the Company’s current estimate of future losses. The Company established these reserves based on an overall evaluation of identified risks. As a part of that evaluation, the Company considered certain specific receivables and considered factors including extended delinquency and requests for restruc- turing, among other things. Long-term receivables included com- muter aircraft receivables of $363 million and $680 million at December 31, 2003 and 2002, respectively.  The Company accrues interest on long-term aircraft customer receivables in accordance with the terms of the underlying notes. When a long-term aircraft receivable is over 90 days past due, the Company generally stops accruing interest. At December 31, 2003 and 2002, there were $37 million and $38 million, respec- tively, of long-term aircraft receivables on which the Company was not accruing interest. Interest payments related to these receiv- ables are credited to income when received. Once a receivable has been brought current, the Company begins to accrue interest again. Interest deemed to be uncollectible is written off at the time that determination is made.  In 2003, the Company sold an undivided interest in $337 million of general aviation finance receivables, received proceeds of $279 million, retained a subordinated interest in and servicing rights to the receivables, and recognized a gain of $2 million. In connec- tion with the sale, the Company formed a qualifying special purpose entity (QSPE) for the sole purpose of buying these receivables. The Future minimum lease payments from non-cancelable aircraft operating leases, which extend to 2014, amounted to $73 million at December 31, 2003 and were due as follows : In 1998, the Company entered into a $490 million property sale and five-year operating lease (synthetic lease) facility under which property, plant, and equipment was sold and leased back to the Company. In 2003, the lease facility expired and the Company bought back the assets remaining in the lease facility for $125 million.  Depreciation expense was $333 million, $305 million, and $289 million in 2003, 2002, and 2001, respectively. Accumulated depreciation of equipment leased to others was $25 million and $39 million at December 31, 2003 and 2002, respectively.  333 NOTE G: PROPERTY, PLANT, AND EQUIPMENT 333 NOTE H: OTHER ASSETS  Other assets, net consisted of the following at December 31:  (In millions) 2003 2002 Long-term receivables Due from customers in installments to 2015 $ 464 $ 969 Other, principally due through 2005 40 17 Sales-type leases, due in installments to 2013 50 135 Computer software, net 456 397 Pension-related intangible asset  199 217 Investments 146 154 Other noncurrent assets 498 344 Total $1,853 $2,233 (In millions) 2003 2002 Land $ 90 $ 91 Buildings and leasehold improvements 1,769 1,606 Machinery and equipment 3,592 3,083 Equipment leased to others 189 189 5,640 4,969 Less accumulated depreciation and amortization (2,929) (2,573) Total $ 2,711 $ 2,396 (In millions) 2004 $17 2005 11 2006 10 2007 8 2008 7 Thereafter 20