<Page> Exhibit 99.4 LEASE INVESTMENT FLIGHT TRUST ("LIFT") C/O WILMINGTON TRUST COMPANY 1100 NORTH MARKET STREET RODNEY SQUARE NORTH WILMINGTON, DELAWARE 19890 ADJUSTED BASE VALUE OPINION 39 AIRCRAFT FLEET AISI FILE NO.: A1S007BVO DATE: 27 APRIL 2001 VALUES AS OF: 31 DECEMBER 2000 HEADQUARTERS, 26072 MERIT CIRCLE, SUITE 123, LAGUNA HILLS, CA 92653 TEL: 949-582-8888 FAX: 949-582-8887 E-MAIL: AISINEWS@AOL.COM 27 April 2001 Lease Investment Flight Trust ("LIFT") c/o Wilmington Trust Company 1100 North Market Street Rodney Square North Wilmington, Delaware 19890 Subject: Adjusted Base Value Appraisal for Fleet of 39 Aircraft as of 31 December 2000 Lease Investment Flight Trust ("LIFT") Portfolio AISI File number: A1S007BVO Ref: (a) Data--Previous AISI Reports A0S053BVO and A0S083BVO (b) Email messages 30/31 August 2000 (c) Technical Details / Maintenance Status Data Package 30 August 2000 (d) Technical Details / Maintenance Status Data Package 12 March 2001 (e) Technical Details / Maintenance Status Data Package 26 April 2001 II-1 <Page> Ladies and Gentlemen: Aircraft Information Services, Inc. (AISI) has been requested to offer our opinion of the adjusted base value appraisal as of 31 December 2000 of the Lease Investment Flight Trust ("LIFT") portfolio of 39 Aircraft as identified and defined in Table I and reference (a), (b), (c), (d) and (e) above (the "Aircraft'). 1. METHODOLOGY AND DEFINITIONS The standard terms of reference for commercial aircraft value are "base value' and "current market value' of an "average' aircraft. Base value is a theoretical value that assumes a balanced market while current market value is the value in the real market; both assume a hypothetical average aircraft condition. All other values are derived from these values. AISI value definitions are consistent with the current definitions of the International Society of Transport Aircraft Trading (ISTAT), those of 01 January 1994. AISI is a member of that organization and employs an ISTAT Certified and Senior Certified Appraiser. AISI defines a "base value' as that of a transaction between an equally willing and informed buyer and seller, neither under compulsion to buy or sell, for a single unit cash transaction with no hidden value or liability, with supply and demand of the sale item roughly in balance and with no event which would cause a short term change in the market. Base values are typically given for aircraft in "new' condition, "average half-life' condition, or "adjusted' for an aircraft in a specifically described condition at a specific time. An "average' aircraft is an operable airworthy aircraft in average physical condition and with average accumulated flight hours and cycles, with clear title and standard unrestricted certificate of airworthiness, and registered in an authority which does not represent a penalty to aircraft value or liquidity, with no damage history and with inventory configuration and level of modification which is normal for its intended use and age. AISI assumes average condition unless otherwise specified in this report. "Half-life' condition assumes that every component or maintenance service which has a prescribed interval that determines its service life, overhaul interval or interval between maintenance services, is at a condition which is one-half of the total interval. An "adjusted' appraisal reflects an adjustment from half life condition for the actual condition, utilization, life remaining or time remaining of an airframe, engine or component. Our opinion of the adjusted base values of the Aircraft are derived from information and specifications supplied by the client in the above referenced (a), (b) and (c) data. No physical inspection of the Aircraft or their essential records was made by AISI for the purposes of this report. It should be noted that AISI and ISTAT value definitions apply to a transaction involving a single aircraft, and that transactions involving more than one aircraft are often executed at considerable and highly variable discounts to a single aircraft price, for a variety of reasons relating to an individual buyer or seller. AISI defines a "current market value', which is synonymous with the older term "fair market value' as that value which reflects the real market conditions including short term events, whether at, above or below the base value conditions. Assumption of a single unit sale and definitions of aircraft condition, buyer/seller qualifications and type of transaction remain unchanged from that of base value. Current market value takes into consideration the status of the economy in which the aircraft is used, the status of supply and demand for the particular aircraft type, the value of recent transactions and the opinions of informed buyers and sellers. Current market value assumes that there is no short term time constraint to buy or sell. AISI encourages the use of base values to consider historical trends, to establish a consistent baseline for long term value comparisons and future value considerations, or to consider how actual market values vary from theoretical base values. Base values are less volatile than current market values and tend to diminish regularly with time. Base values are normally inappropriate to determine near term values. AISI encourages the use of current market values to consider the probable near term value of an aircraft. II-2 <Page> If more than one aircraft is contained in this report than it should be noted that the values given are not directly additive, that is, the total of the given values is not the value of the fleet but rather the sum of the values of the individual aircraft if sold individually over time so as not to exceed demand. 2. VALUATION Adjustments from half life have been applied based on the current maintenance status of the Aircraft as indicated in the Aircraft Technical Details / Maintenance Status sheets supplied to AISI by the client in reference (a), (b), (c), (d) and (e) above and in accordance with standard AISI methods. Adjustments are calculated only where there is sufficient information to do so, or where reasonable assumptions can be made. With regard to airframe and gear maintenance, if no time between check/overhaul (TBO) or time since check/overhaul (TSO) information was provided, and if the total hours/cycles of the airframe do not exceed the TBO limits then the total hours/cycles of the airframe were assumed to be the TSO. This was typical of newer aircraft. If no information was provided and if the TSO could not be calculated, then half life was assumed. With regard to the engines, on aircraft where all engines total cycles equal the total cycles of the airframe, the engine's life limit CSOs and overhaul CSOs are assumed to be the same as the total cycles of the airframe. This is typical of newer aircraft. Where this assumption can not be made, the engines are considered to be in half life condition. All hours and cycle information provided for airframe, C Check, D Check, engines and gear have been projected from the Aircraft Technical Details / Maintenance Status sheet dates to 31 December 2000 based on a daily utilization factor calculated for each aircraft. It is our considered opinion that the 31 December 2000 adjusted base values of the Aircraft are as follows in Table I subject to the assumptions, definitions, and disclaimers herein. II-3 <Page> TABLE I <Table> <Caption> ADJUSTED BASE VALUE 31 DEC 2000 NO TYPE MSN DOM ENGINE MTOW US DOLLARS -- ---- --- --- ------ ---- ---------- 1 B767-300ER 29618 May-00 CF6-80C2B7F 412,000 $ 94,160,000 2 B767-300ER 30108 Nov-99 CF6-80C2B7F 412,000 $ 89,540,000 3 B767-300ER 30112 Sep-99 CF6-80C2B6F 412,000 $ 89,170,000 4 B737-300 28672 Jan-98 CFM56-3C1 139,500 $ 33,740,000 5 B737-300 28569 Feb-98 CFM56-3C1 139,500 $ 33,830,000 6 B737-300 28673 Feb-98 CFM56-3C1 139,500 $ 33,700,000 7 B737-300 23384 Aug-87 CFM56-3B2 138,500 $ 19,030,000 8 B737-400 24469 Jul-89 CFM56-3C1 142,500 $ 22,900,000 9 MD82 49513 Apr-90 JT8D-217A 149,500 $ 18,690,000 10 MD82 49515 Oct-90 JT8D-217A 149,500 $ 18,760,000 11 MD82 49511 Mar-90 JT8D-217A 149,500 $ 18,580,000 12 A320-200 1093 Oct-99 CFM56-5B4 169,750 $ 43,250,000 13 A320-200 1108 Nov-99 CFM56-5B4 169,750 $ 43,290,000 14 B737-300 23376 Nov-86 CFM56-3B2 138,500 $ 18,790,000 15 B737-300 29338 Jul-99 CFM56-3C1 139,500 $ 36,250,000 16 B737-400 24512 Sep-89 CFM56-3C1 150,000 $ 22,900,000 17 B737-300 28602 Sep-99 CFM56-3C1 139,500 $ 36,550,000 18 B737-300 28606 Oct-99 CFM56-3C1 139,500 $ 36,650,000 19 A320-200 879 Dec-98 CFM56-5B4 169,750 $ 40,600,000 20 MD82 49419 Aug-87 JT8D-217A 149,500 $ 15,830,000 21 MD11F 48523 Jun-92 PW4460 630,490 $ 73,040,000 22 B737-700 28609 Nov-99 CFM56-7B24 154,500 $ 38,690,000 23 B747-400 28427 Mar-98 PW4056 870,490 $ 139,630,000 24 MD82 53147 Aug-93 JT8D-217C 149,500 $ 22,150,000 25 B737-800 28591 Apr-99 CFM56-7B26 174,200 $ 45,890,000 26 B737-800 28628 Jun-00 CFM56-7B26 174,200 $ 49,470,000 27 B737-500 28565 Nov-97 CFM56-3C1 133,500 $ 27,270,000 28 B737-800 28592 May-99 CFM56-7B26 174,200 $ 45,500,000 29 B737-300 28570 Mar-98 CFM56-3C1 139,500 $ 34,170,000 30 MD82 49501 Oct-87 JT8D-217A 149,500 $ 16,820,000 31 MD82 49509 Aug-89 JT8D-217A 149,500 $ 18,420,000 32 MD82 49519 Dec-90 JT8D-217A 149,500 $ 19,400,000 33 MD83 49578 Mar-88 JT8D-219 160,000 $ 18,150,000 34 MD82 49507 Nov-87 JT8D-217A 149,500 $ 15,910,000 35 B767-300ER 26208 Sep-94 PW4060 407,990 $ 68,040,000 36 B737-300 28671 Nov-97 CFM56-3C1 139,500 $ 31,540,000 37 B737-700 28584 Dec-98 CFM56-7B24 154,500 $ 36,050,000 38 A320-200 1152 Feb-00 CFM56-5B4 169,750 $ 45,860,000 39 B767-300ER 30110 Dec-99 CF6-80C2B7F 411,990 $ 85,340,000 ---------------- TOTALS................................................................... $ 1,597,550,000 ================ </Table> II-4 <Page> Unless otherwise agreed by Aircraft Information Services, Inc. (AISI) in writing, this report shall be for the sole use of the client/addressee. This report is offered as a fair and unbiased assessment of the subject aircraft or equipment. AISI has no past, present, or anticipated future interest in the subject aircraft or equipment. The conclusions and opinions expressed in this report are based on published information, information provided by others, reasonable interpretations and calculations thereof and are given in good faith. Such conclusions and opinions are judgments that reflect conditions and values which are current at the time of this report. The values and conditions reported upon are subject to any subsequent change. AISI shall not be liable to any party for damages arising out of reliance or alleged reliance on this report, or for any parties action or failure to act as a result of reliance or alleged reliance on this report. Sincerely, AIRCRAFT INFORMATION SERVICES, INC. John D. McNicol Vice President Appraisals & Forecasts II-5