<PAGE>   1

                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                   FORM 10-QSB

(Mark One)

[X]  Annual Report Under Section 13 or 15(d) of the Securities Exchange Act of
     1934

For the quarterly period ended March 31, 2001

[ ]  Transition Report Under Section 13 or 15(d) of the Securities Exchange Act
     of 1934

For the transition period from ____________ to ____________

Commission File Number: 333-22239

                              AEROCENTURY IV, INC.
                 (Name of small business issuer in its charter)

            CALIFORNIA                                   94-3260392
   (State or other jurisdiction             (I.R.S. Employer Identification No.)
 of incorporation or organization)

      1440 CHAPIN AVENUE, SUITE 310
         BURLINGAME, CALIFORNIA                            94010
(Address of principal executive offices)                 (Zip Code)

Issuer's telephone number, including area code:        (650) 340-1880

Securities registered pursuant to Section 12(b) of the Act:   NONE

Securities registered pursuant to Section 12(g) of the Act:   NONE

Check whether the Issuer: (1) filed all reports required to be filed by Section
13 or 15(d) of the Securities Exchange Act of 1934 during the past 12 months (or
for such shorter period that the registrant was required to file such reports),
and (2) has been subject to such filing requirements for the past 90 days.
YES   X    NO
    -----     -----

On May 15, 2001 the aggregate market value of the voting and non-voting Common
equity held by non-affiliates (computed by reference to the price at which the
common equity was sold) was $0.

As of May 15, 2001 the Issuer has 243,420 Shares of Common Stock outstanding.

Transitional Small Business Disclosure Format (check one):  Yes        No   X
                                                                -----     -----

<PAGE>   2

PART I.  FINANCIAL INFORMATION

ITEM 1.  FINANCIAL STATEMENTS

                              AEROCENTURY IV, INC.
                                  Balance Sheet
                                 March 31, 2001

                                     ASSETS

<TABLE>
<CAPTION>
<S>                                                                 <C>
Current assets:
    Cash                                                            $ 1,316,660
    Deposits                                                             68,200
    Rent receivable                                                      42,960
    Accounts receivable                                                 190,370
                                                                    -----------
Total current assets                                                  1,618,190

Aircraft and aircraft engines under operating leases,
    net of accumulated depreciation of $348,250                       1,290,950
Debt issue costs, net of accumulated
    amortization of $276,810                                            312,710
Other assets                                                              2,570
                                                                    -----------

Total assets                                                        $ 3,224,420
                                                                    ===========

                      LIABILITIES AND SHAREHOLDER'S DEFICIT

Current liabilities:
    Accounts payable                                                $    12,000
    Payable to affiliate                                                  2,500
    Interest payable                                                     81,150
    Prepaid rent                                                         12,500
    Security deposits                                                    20,000
    Maintenance deposits                                                238,570
                                                                    -----------
Total current liabilities                                               366,720
                                                                    -----------

Medium-term secured notes                                             4,869,000
                                                                    -----------

Total liabilities                                                     5,235,720
                                                                    -----------

Preferred stock, no par value, 100,000 shares authorized,
    no shares issued and outstanding                                         --
Common stock, no par value, 500,000 shares authorized,
    243,420 shares issued and outstanding                               243,420
Accumulated deficit                                                  (2,254,720)
                                                                    -----------
Total shareholder's deficit                                          (2,011,300)
                                                                    -----------

Total liabilities and shareholder's deficit                         $ 3,224,420
                                                                    ===========
</TABLE>


See accompanying summary of accounting policies and notes to financial
statements.


                                       2
<PAGE>   3

                              AEROCENTURY IV, INC.
                            Statements of Operations

<TABLE>
<CAPTION>
                                                        For the three months ended March 31,
                                                              2001              2000
                                                              ----              ----
<S>                                                         <C>               <C>
Revenues:

    Rent income                                             $  75,000         $ 186,890
    Gain on sale of aircraft                                   35,980                --
    Interest income                                            17,890             4,870
                                                            ---------         ---------

                                                              128,870           191,760
                                                            ---------         ---------

Expenses:

    Depreciation                                               29,050            64,600
    Amortization                                               19,150            19,150
    Maintenance                                                    --            43,490
    Interest                                                  121,730           121,730
    Management fees                                            24,340            24,340
    Professional fees and general and administrative            4,950            11,590
                                                            ---------         ---------

                                                              199,220           284,900
                                                            ---------         ---------

Loss before taxes                                             (70,350)          (93,140)

Tax benefit                                                        --            32,050
                                                            ---------         ---------

Net loss                                                    $ (70,350)        $ (61,090)
                                                            =========         =========

Weighted average common shares outstanding                    243,420           243,420
                                                            =========         =========

Basic loss per common share                                 $   (0.29)        $   (0.25)
                                                            =========         =========
</TABLE>


See accompanying summary of accounting policies and notes to financial
statements.


                                       3
<PAGE>   4

                              AEROCENTURY IV, INC.
                            Statements of Cash Flows

<TABLE>
<CAPTION>
                                            For the three months ended March 31,
                                                   2001               2000
                                                   ----               ----
<S>                                             <C>                 <C>
Net cash used by operating activities           $   (82,460)        $ (88,910)
                                                -----------         ---------

Investing activity -
    Proceeds from disposal of assets                205,980                --
                                                -----------         ---------
Net cash provided by investing activities           205,980                --
                                                -----------         ---------

Net increase/(decrease) in cash                     123,520           (88,910)

Cash, beginning of period                         1,193,140           369,330
                                                -----------         ---------

Cash, end of period                             $ 1,316,660         $ 280,420
                                                ===========         =========
</TABLE>

Supplemental disclosures of cash flow information:
Cash paid during the period for:

<TABLE>
<CAPTION>
                                                   2001               2000
                                                   ----               ----
<S>                                             <C>                 <C>
    Interest (net of amount capitalized)        $   121,730         $ 121,730
    Income taxes                                         --                --
</TABLE>


See accompanying summary of accounting policies and notes to financial
statements.




                                       4
<PAGE>   5

                              AEROCENTURY IV, INC.
                          Notes to Financial Statements

1.      SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

        Basis of Presentation

        AeroCentury IV, Inc. (the "Company") was incorporated in the state of
California on February 7, 1997 ("Inception"). The Company was formed solely for
the purpose of acquiring Income Producing Assets. The Company offered up to
$10,000,000 in $1,000 Secured Promissory Notes maturing on April 30, 2005 (the
"Notes") pursuant to a prospectus dated May 21, 1997 (the "Prospectus").

        All of the Company's outstanding common stock is owned by JetFleet
Holding Corp. ("JHC"), a California corporation formed in January 1994. In May
1998, JetFleet Management Corp., the sole shareholder of the Company was renamed
JetFleet Holding Corp. The rights and obligations under the management agreement
between the Company and JHC were assigned by JHC to a newly-created wholly-owned
subsidiary named "JetFleet Management Corp." ("JMC"). JMC also manages
AeroCentury Corp. ("ACY"), a Delaware corporation, and JetFleet III, a
California corporation, which are affiliates of JHC and which have objectives
similar to the Company's. Neal D. Crispin, the President of the Company, holds
the same position with JHC and JMC and owns a significant amount of the common
stock of JHC.

        Cash and Cash Equivalents/Deposits

        The Company considers highly liquid investments readily convertible into
known amounts of cash, with original maturities of 90 days or less, as cash
equivalents. Deposits represent cash balances held related to maintenance
reserves and security deposits and are subject to withdrawal restrictions. As of
March 31, 2001, the Company maintained $1,381,310 of its cash balances in a
money market fund held by a regional brokerage firm, which is not federally
insured.

        Aircraft and Aircraft Engines Under Operating Leases

        The Company's interests in aircraft are recorded at the lower of cost or
market value, which include acquisition costs (see Note 2). Depreciation is
computed using the straight-line method over each aircraft's estimated economic
life to its estimated residual value.

        Impairment of Long-lived Assets

        In accordance with SFAS No. 121, "Accounting for the Impairment of
Long-lived Assets and Long-lived Assets to Be Disposed Of," assets are reviewed
for impairment whenever events or changes in circumstances indicate that the
book value of the asset may not be recoverable. Periodically, the Company
reviews its long-lived assets for impairment based on estimated future
non-discounted cash flows attributable to the assets or appraisals. In the event
such cash flows are not expected to be sufficient to recover the recorded value
of the assets, the assets are written down to their estimated realizable value.

        Debt Issue Costs

        Pursuant to the terms of the Prospectus, the Company paid an
Organization and Offering Expense Reimbursement to JHC in cash in an amount up
to 2.0% of Aggregate Gross Offering Proceeds for reimbursement of certain costs
incurred in connection with the organization of the Company and the Offering
(the "Reimbursement").


                                       5
<PAGE>   6

                              AEROCENTURY IV, INC.
                          Notes to Financial Statements

1.      SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

        Debt Issue Costs (continued)

        To the extent that JHC incurred expenses in excess of the 2.0% cash
limit, such excess expenses were repaid to JHC in the form of Common Stock
issued by the Company at a price of $1.00 per share (the "Excess Stock"). The
amount of Excess Stock that the Company can issue was limited according to the
amount of Aggregate Gross Offering Proceeds raised by the Company. The Company
capitalized the Reimbursement paid and amortizes such costs over the life of the
Notes (approximately eight years).

        Assets Subject to Lien

        The Company's obligations under the Notes are secured by a security
interest in all of the Company's right, title and interest in the Income
Producing Assets acquired by the Company.

        Income Taxes

        The Company follows the liability method of accounting for income taxes
as required by the provisions of Statement of Financial Accounting Standards No.
109 - Accounting for Income Taxes.

        Use of Estimates

        The preparation of financial statements in conformity with generally
accepted accounting principles requires management to make estimates and
assumptions that affect certain reported amounts and disclosures. Accordingly,
actual results could differ from those estimates.

        Recent Accounting Pronouncements

        SFAS No. 137, which amended the effective date of SFAS No. 133,
Accounting for Derivative Instruments and Hedging Activities, was issued in June
1999. The Company adopted SFAS No. 133 on January 1, 2001. This statement
establishes accounting and reporting standards requiring that all derivative
instruments are recorded on the balance sheet as either an asset or a liability,
measured at fair value. The statement requires that changes in the derivative's
fair value be recognized currently in earnings unless specific hedge accounting
criteria are met and such hedge accounting treatment is elected. Because the
Company does not hold any derivatives as defined in SFAS No. 133, the adoption
of SFAS No. 133 did not have a material impact on its results of operations or
financial position.

         In December 1999, the Securities and Exchange Commission ("SEC") issued
Staff Accounting Bulletin No. 101, Revenue Recognition in Financial Statements
("SAB 101"). SAB 101, as amended, summarizes certain of the SEC's views in
applying generally accepted accounting principles to revenue recognition in
financial statements. SAB 101 was adopted by the Company in 2000. The adoption
of the provisions of SAB 101 did not have a material effect on the Company's
consolidated operating results, statement of financial position or cash flow.


                                       6
<PAGE>   7

                              AEROCENTURY IV, INC.
                          Notes to Financial Statements

2.      AIRCRAFT AND AIRCRAFT ENGINES UNDER OPERATING LEASES

        Aircraft and Aircraft Engines

        At March 31, 2001, the Company owned a Fairchild Metro III aircraft,
serial number AC-647 ("S/N AC-647"), and a Pratt & Whitney JT8D-9A aircraft
engine, serial number 674452B (the "Engine"). In January 2001, the Company sold
its 50% interest in a Shorts SD3-60-100, serial number S/N 3676 ("S/N 3676").
The Company did not purchase any aircraft during the first three months of 2001.

        Aircraft and Aircraft Engines Leases

        When S/N AC-647 was acquired, it was subject to a 36-month lease,
expiring in April 2001, with a regional carrier in Uruguay. During June 1999,
however, management repossessed the aircraft due to non-payment of rent. In June
2000, S/N AC-647 was re-leased to a U.S. carrier for a two-year term, expiring
in June 2002.

        The Engine is used on a McDonnell Douglas DC-9 aircraft and is subject
to a 60-month lease with the seller, expiring in November 2002. The Engine is
subleased by the seller to a Mexican-based regional carrier.

        At the time of purchase, S/N 3676 (owned 50% by the Company) was subject
to a 48-month lease, expiring in July 2001, with a British regional airline. The
original lease, entered into in 1997, did not require that the lessee pay
maintenance reserves based on usage because, at the time, the lessee was
considered creditworthy. Subsequently, the airline experienced financial
difficulties and, on February 24, 2000, filed for reorganization.

        The lessee continued to operate, and, under the reorganization plan, the
lessee paid rentals on a month to month basis at the same rent as under the
original lease on S/N 3676. Under the plan, the lessee also began paying monthly
maintenance reserves based on the hours flown. Under British law, the owners
were precluded from repossessing the aircraft so long as the lessee was
operating it and agreed to pay rent and maintenance reserves under its
reorganization plan. The lessee notified the owners that the aircraft would be
returned to them during the fourth quarter of 2000. The owners agreed that they
would realize a greater benefit if they sold the aircraft "as is" rather than
fund the maintenance work necessary to return the aircraft to a condition which
would allow it to possibly be re-leased to a new lessee. Therefore, the Company
reduced the carrying value of the aircraft to $170,000 and recognized a
provision for impairment estimated to be $245,350 during 2000. The aircraft was
returned to the Company during the fourth quarter and, in January 2001 it was
sold. The Company received net proceeds of $167,450 and recognized a gain of
$35,980.

        As of March 31, 2001, minimum future lease rent payments receivable
under noncancelable leases were as follows:

<TABLE>
<CAPTION>
               Year             Amount
               ----             ------
<S>                            <C>
               2001            $225,000
               2002             192,500
                               --------
                               $417,500
                               ========
</TABLE>



                                       7
<PAGE>   8

                              AEROCENTURY IV, INC.
                          Notes to Financial Statements

3.      MEDIUM-TERM SECURED NOTES

        As mentioned above, the Company raised funds through the Offering from
May 1997 to August 1997. During 1997, the Company accepted subscriptions for
4,869 Notes aggregating $4,869,000 in Gross Offering Proceeds. Pursuant to the
Prospectus, the Company subsequently issued $4,869,000 in Notes due April 30,
2005. The Notes bear interest at an annual rate of 10.00%, which is due and
payable on a quarterly basis, in arrears, on the first business day of February,
May, August and November. As described in Note 8 to the financial statements,
there is substantial doubt as to the Company's ability to continue as a going
concern. Therefore, the fair value of the Notes is estimated to be approximately
$2,542,000, which is $2,327,000 less than the carrying value. The fair value of
the notes payable is estimated based upon the appraised values of the aircraft
and the current working capital of the Company.

4.      INCOME TAXES

        The items comprising income tax expense are as follows:

<TABLE>
<CAPTION>
                                           For the three months ended March 31,
                                                  2001               2000
                                                  ----               ----
<S>                                             <C>              <C>
        Current tax provision
           Federal                              $     --         $     --
           State                                     800               --
                                                --------         --------
           Current tax provision                     800               --
                                                --------         --------

        Deferred tax provision
           Federal                               (15,910)         (31,940)
           State                                    (570)            (120)
                                                --------         --------
           Deferred tax provision                (16,480)         (32,060)
           Valuation allowance                    16,480               --
                                                --------         --------
        Total provision for income taxes        $    800         $(32,060)
                                                ========         ========
        </TABLE>

        Total income tax expense differs from the amount which would be provided
by applying the statutory federal income tax rate to pretax earnings as
illustrated below:

<TABLE>
<CAPTION>
                                                                  For the three months ended March 31,
                                                                         2001             2000
                                                                         ----             ----
<S>                                                                    <C>              <C>
        Income tax expense at statutory federal income tax rate        $(15,640)        $(31,670)
        State taxes net of federal benefit                                  (40)            (390)
        Basis differences                                                16,480               --
                                                                       --------         --------
        Total provision for income taxes                               $    800         $(32,060)
                                                                       ========         ========
</TABLE>




                                       8
<PAGE>   9

                              AEROCENTURY IV, INC.
                          Notes to Financial Statements

4.      INCOME TAXES (CONTINUED)

        Temporary differences and carryforwards, which gave rise to a
significant portion of deferred tax assets and liabilities as of March 31, 2001
are as follows:

<TABLE>
<S>                                                          <C>
        Deferred tax assets:
           Depreciation of aircraft                          $   52,930
           Maintenance deposits                                  40,410
           Net operating losses                                 204,540
           Other                                                  4,530
                                                             ----------
                                                                302,410
               Valuation allowance                             (302,260)
                                                             ----------
               Net deferred tax assets                              150
        Deferred tax liability-
           Amortization of organizational costs                    (150)
                                                             ----------

                                                             $       --
                                                             ==========
</TABLE>

        The Company does not anticipate generating adequate future taxable
income to realize the benefits of the remaining deferred tax assets on the
balance sheet. Therefore, the Company has recognized a valuation allowance equal
to the net deferred tax asset.

        As discussed in Note 1, the Company is a subsidiary of JHC. JHC files a
consolidated tax return that includes the Company as a member of the
consolidated group. The current and deferred taxes of the consolidated group are
allocated to members of the group in their separately issued financial
statements. Current and deferred income taxes are allocated to members of the
group by applying FAS 109 as if it were a separate taxpayer. In addition, the
members of the group record inter-company receivables and payables to reflect
the tax benefits of net operating losses used in the consolidated tax return.
However, under the terms of the tax sharing arrangement with other members of
the consolidated group, the Company does not expect its inter-company receivable
to be collected because it does not expect to generate adequate future taxable
income. The Company's current net operating losses of $287,820 may be carried
forward for twenty years and begin to expire in 2020.

5.      RELATED PARTY TRANSACTIONS

        The Company's Income Producing Asset portfolio is managed and
administered under the terms of a management agreement with JMC. Under this
agreement, on the last day of each calendar quarter, JMC receives a quarterly
management fee equal to 0.5% of the Company's Aggregate Gross Proceeds received
through the last day of such quarter. In the first three months of 2001 and
2000, the Company paid a total of $24,340 and $24,340, respectively, in
management fees to JMC.

        JMC may receive an acquisition fee for locating assets for the Company
and a remarketing fee in connection with the sale of the Company's assets,
provided that such fees are not more than the customary and usual fees that
would be paid to an unaffiliated party for such a transaction. The total of the
Aggregate Purchase Price plus the acquisition fee cannot exceed the fair market
value of the asset based on appraisal. JMC may also receive reimbursement of
Chargeable Acquisition Expenses incurred in connection with a transaction which
are payable to third parties. During the first three months of 2001 and 2000, no
acquisition fees or reimbursements for Chargeable Acquisition Expenses were paid
as the Company did not acquire additional assets. During the first three months
of 2001, remarketing fees of $2,550 were paid to JMC in connection with the sale
of aircraft. No remarketing fees were paid during the first three months of
2000.


                                       9
<PAGE>   10

                              AEROCENTURY IV, INC.
                          Notes to Financial Statements

5.      NOTES TO FINANCIAL STATEMENTS (CONTINUED)

        As discussed in Note 1, the Company reimbursed JHC for certain costs
incurred in connection with the organization of the Company and the Offering.
The Company made no such payments during 2001 and 2000.

6.      GOING CONCERN

        As shown in the accompanying financial statements, as of March 31, 2001,
the Company's total liabilities exceeded its total assets by $2,011,300. In
addition, although the Company has recently sold several aircraft, it does not
believe that it has sufficient total proceeds to invest in another income
producing asset and, therefore, as provided under the Trust Indenture, it
anticipates turning over those proceeds to the Trustee. The Company anticipates
receiving payment of the past due rent and reserves from the previous lessee of
S/N 3606 and S/N 3676 during the second quarter of 2001. Payment of the required
interest payment of approximately $122,000 on August 1, 2001 is dependent on
receipt of such past due amounts. In any case, however, the Company's cash flow
projections show that it will not have sufficient cash balances to fund the
required interest payment of approximately $122,000 on November 1, 2001. The
Company has informed the Trustee that it will be unable to make such payment and
that it will, therefore, be in default under the Trust Indenture at that time.
Under the Trust Indenture, the Trustee would then have the right to manage the
Company's assets, all of which are collateral for the notes obligation.
Management of the Company's assets and extinguishment of its liabilities would
then become the responsibility of the Trustee.

        These factors create a substantial uncertainty about the Company's
ability to continue as a going concern. The financial statements do not include
any adjustments that might be necessary if the Company is unable to continue as
a going concern.



                                       10
<PAGE>   11

ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS OR PLAN OF OPERATION.

Forward-Looking Statements

Certain statements contained in this report and, in particular, the discussion
regarding the Company's beliefs, plans, objectives, expectations and intentions
regarding the use of sales proceeds to invest in additional assets, the
Company's ability to meet its short-term immediate cash requirements, the
incurring of significant operating expenses for assets on lease, the
insufficiency of sales proceeds from asset sales to invest in additional assets,
the collection of its inter-company receivable related to its tax sharing
agreement, the anticipated receipt of past due amounts from a previous lessee,
the Company's inability to meet its interest obligations after its August 2001
interest payment, its potential default upon its August 2001 and November 2001
interest payments and the Trustee's actions thereafter to take control of the
Company's assets, and the inadequacy of cash reserves to meet short-term
immediate requirements are forward looking statements. While the company
believes that such statements are accurate, actual results may differ due to
further defaults by existing lessees, recovery of maintenance claims from
certain defaulting lessees, time required to re-lease any returned aircraft,
general economic conditions, particularly those that affect the demand for
turboprop aircraft and engines, including competition for turboprop and other
aircraft, and future trends and results that cannot be predicted with certainty.
The Company's actual results could differ materially from those discussed in
such forward looking statements. Factors that could cause or contribute to such
differences include those discussed below in the section entitled "Factors that
May Affect Future Results." The cautionary statements made in this Report should
be read as being applicable to all related forward-looking statements wherever
they appear in this Report.

Results of Operations

The Company recorded a net loss of ($70,350) or ($0.29) per share and ($61,090)
or ($0.25) per share for the three months ended March 31, 2001 and 2000,
respectively.

Rental income decreased by approximately $112,000 in 2001 due to the sale of
aircraft during the fourth quarter of 2000 and first quarter of 2001. Gain on
sale of aircraft was approximately $36,000 in 2001 due to the sale of S/N 3676
during January. Interest income was higher in 2001 by approximately 13,000 due
to higher cash balances as a result of asset sales. Depreciation decreased
approximately $36,000 due to the asset sales noted above. Maintenance expense
was approximately $43,000 lower in 2001 than in 2000 as a result of maintenance
work performed on an aircraft upon its return during 2000.

Under the terms of a tax sharing arrangement between the members of the
consolidated group with which the Company files a consolidated tax return, in
the event that the Company has taxable income, the Company will be credited for
the tax benefits provided by the use of the Company's prior year net operating
losses. However, under the terms of the tax sharing agreement with other members
of the consolidated group, the Company does not expect its inter-company
receivable to be collected because it does not expect to generate adequate
future taxable income.

Capital Resources and Liquidity

At March 31, 2001, the Company had cash balances of $1,316,660 and deposits of
$68,200. Approximately $122,000 of the Company's cash balances was held for the
interest payment made to the Noteholders in May 2001. The remaining cash, which
was the result of aircraft sales during the fourth quarter 2000 and first
quarter of 2001, is being held for return to the Trustee as required under the
terms of the Trust Indenture.

Since its formation, the Company's capital has come in the form of equity
contributions from JHC, proceeds from the Offering, rental revenue from the
Income Producing Assets purchased using those proceeds, and, most recently,
proceeds from the sale of assets. The Company's liquidity varies, increasing to
the extent cash flows from operations exceed expenses, and decreasing as
interest payments are made to the Noteholders and to the extent expenses exceed
cash flows from leases.

Since the Company has acquired Income Producing Assets, which are subject to
triple net leases (the lessee pays operating and maintenance expenses, insurance
and taxes), the Company does not anticipate that it will incur


                                       11
<PAGE>   12

significant operating expenses in connection with ownership of its Income
Producing Assets as long as they remain on lease.

Excess cash flow from operations, after interest payments on the Notes, has been
held as cash because it was, in the aggregate, insufficient to purchase
additional Income Producing Assets. In addition, although the Company has
recently sold several aircraft, it does not believe that the total proceeds of
such sales are sufficient to invest in a desirable Income Producing Asset and,
therefore, as required by the Trust Indenture, the Company anticipates turning
over those sales proceeds to the Trustee. After May 1, 2003, any excess cash,
after interest payments on the Notes, is required to be deposited to a sinking
fund account established to facilitate repayment of principal of the Notes on
their maturity. (Deposits of cash may also be made prior to May 1, 2003 if the
Company decides to make prepayments on the principal of the Notes.)

The Company anticipates receiving payment of the past due rent and reserves from
the previous lessee of S/N 3606 and S/N 3676 during the second quarter of 2001.
Payment of the required interest payment of approximately $122,000 on August 1,
2001 is dependent on receipt of such past due amounts. In any case, however, the
Company's cash flow projections show that it will not have sufficient cash
balances to fund the required interest payment of approximately $122,000 on
November 1, 2001. See "Factors that May Affect Future Results", below, for a
discussion of factors affecting the Company's cash flow.

Net income and cash flow from operations was approximately the same during the
three months ended March 31, 2001 and 2000. The increase in cash flow provided
by investing activities was the result of the Company's sale of an aircraft in
January 2001. There was no cash flow from financing activities in 2001 or 2000
because the Offering terminated in August 1997.

Factors that May Affect Future Results

Anticipated Default; Trustee's Ability to Maximize Returns. As discussed above,
it is likely that the Company will be unable to meet its interest obligations
after the required August 2001 payment, due to cash flow problems created by
lessee rental defaults, early termination of leases, and lower than expected
remarketing proceeds described above. It is anticipated that the Company will be
in default under its Indenture upon its failure to make the November 1, 2001
interest payment. At that time, it is believed that the Trustee, Wells Fargo
Bank Northwest (formerly known as First Security Bank, N.A.), will take control
of the Company's assets securing the Indenture, namely the aircraft portfolio
and leases. At that point, the Trustee will have the power to direct disposition
of the collateral with the goal of maximizing value to the Noteholders. This
could entail an immediate or staged disposition of all the assets or retention
of the assets on lease for the benefit of the Noteholders, or a combination
thereof. While the Trustee is unlikely to realize sufficient proceeds to enable
repayment of the entire Note Indebtedness, its ability to maximize repayment to
Noteholders will depend on the risk factors described below, particularly those
that affect asset values of the Company's portfolio.

General Economic Conditions. The market for used aircraft has been cyclical, and
usually reflects economic conditions and the strength of the travel and
transportation industry. At any time, the market for used aircraft may be
adversely affected by such factors as airline financial difficulties, higher
fuel costs, and improved availability and economics of new replacement aircraft.

An adverse change in the global air travel industry, however, could result in
reduced carrier revenue and excess capacity and increase the risk of failure of
some weaker regional air carriers and create lessee credit risks or greater
leasing risks as discussed below.. While the Company believes that with proper
asset and lessee selection the impact of such changes on the Company can be
reduced, there is no assurance that the Company's business will escape the
effects of such a global downturn, or a regional downturn in an area where the
Company has placed a significant amount of its assets. In particular, a downturn
that affects used aircraft values in the near future may substantially impact
the value of the Company's aircraft portfolio at a time when that portfolio is
being liquidated to repay the Notes.

Leasing Risks. The Company's successful negotiation of lease extensions,
re-leases and sales may be critical to its ability to achieve its financial
objectives, and will involve a number of substantial risks. Demand for lease or


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purchase of the assets depends on the economic condition of the airline
industry, which is in turn highly sensitive to general economic conditions.
Ability to remarket equipment at acceptable rates may depend on the demand and
market values at the time of remarketing. The market for used aircraft is
cyclical, and generally, but not always, reflects economic conditions and the
strength of the travel and transportation industry. The demand for and value of
many types of older aircraft in the recent past has been depressed by such
factors as airline financial difficulties, increased fuel costs, the number of
new aircraft on order and the number of older aircraft coming off lease. The
Company's concentration in a limited number of airframe and aircraft engine
types (generally, turboprop equipment) subjects the Company to economic risks if
those airframe or engine types should decline in value. The recent introduction
of "regional jets" to serve on short routes previously thought to be economical
only for turboprop aircraft operation could decrease the demand for turboprop
aircraft, while at the same increasing the supply of used turboprop aircraft.
This could result in lower lease rates and values for the Company's turboprop
aircraft.

Risks Related to Regional Air Carriers. Because the Company has concentrated its
existing leases on leases to regional air carriers, it will be subject to
certain risks. First, lessees in the regional air carrier market include a
number of companies that are start-up, low capital, and low margin operations.
Often, the success of such carriers is dependent upon arrangements with major
trunk carriers, which may be subject to termination or cancellation by such
major carrier. This market segment is also characterized by low entry costs, and
thus, there is strong competition in this industry segment from start-ups as
well as major airlines. Thus, leasing transactions with these types of lessees
results in a generally higher lease rate on aircraft, but may entail higher risk
of default or lessee bankruptcy.

Ownership Risks. The Company's portfolio is leased under operating leases, where
the terms of the leases do not take up the entire useful life of an asset. The
Company's ability to recover its purchase investment in an asset subject to an
operating lease is dependent upon the Company's ability to profitably re-lease
or sell the asset after the expiration of the initial lease term. Some of the
factors that have an impact on the Company's ability to re-lease or sell include
worldwide economic conditions, general aircraft market conditions, regulatory
changes that may make an asset's use more expensive or preclude use unless the
asset is modified, changes in the supply or cost of aircraft equipment and
technological developments which cause the asset to become obsolete. In
addition, a successful investment in an asset subject to an operating lease
depends in part upon having the asset returned by the lessee in serviceable
condition as required under the lease. If the Company is unable to remarket its
aircraft equipment on favorable terms when the operating lease for such
equipment expires, the Company's business, financial condition, cash flow,
ability to service debt and results of operation could be adversely affected.

Lessee Credit Risk. If a lessee defaults upon its obligations under a lease, the
Company may be limited in its ability to enforce remedies. Most of the Company's
lessees are small domestic and foreign regional passenger airlines, which may be
even more sensitive to airline industry market conditions than the major
airlines. As a result, the Company's inability to collect rent under a
significant lease or to repossess equipment in the event of a default by a
lessee could have a material adverse effect on the Company's revenue. If a
lessee that is a certified U.S. airline is in default under the lease and seeks
protection under Chapter 11 of the United States Bankruptcy Code, under Section
1110 of the Bankruptcy Code, the Company would be automatically prevented from
exercising any remedies for a period of 60 days. By the end of the 60 day
period, the lessee must agree to perform the obligations and cure any defaults,
or the Company would have the right to repossess the equipment. This procedure
under the Bankruptcy Code has been subject to significant recent litigation,
however, and it is possible that the Company's enforcement rights may still be
further adversely affected by a declaration of bankruptcy by a defaulting
lessee.

International Risks. The Company's portfolio currently includes a lease with a
foreign air carrier. Leases with foreign lessees may present somewhat different
credit risks than those with domestic lessees.

Foreign laws, regulations and judicial procedures may be more or less protective
of lessor rights as those which apply in the United States. The Company could
experience collection problems related to the enforcement of its lease
agreements under foreign local laws and the remedies in foreign jurisdictions.
The protections potentially offered by Section 1110 of the Bankruptcy Code would
not apply to non-U.S. carriers, and applicable local law may not offer similar
protections. Certain countries do not have a central registration or recording
system with which to locally establish the Company's interest in equipment and
related leases. This could add difficulty in recovering an aircraft in the event
that a foreign lessee defaults.


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Leases with foreign lessees are subject to risks related to the economy of the
country or region in which such lessee is located even if the U.S. economy
remains strong. On the other hand, a foreign economy may remain strong even
though the domestic U.S. economy does not. A foreign economic downturn may occur
and impact a foreign lessee's ability to make lease payments, even though the
U.S. and other economies remain stable. Furthermore, foreign lessees are subject
to risks related currency conversion fluctuations. Although the Company's
current leases are all payable in U.S. dollars, in the future, the Company may
agree to leases that permit payment in foreign currency, which would subject
such lease revenue to monetary risk due to currency fluctuations. Even with
dollar-denominated lease payment provisions, the Company could still be affected
by a devaluation of the lessee's local currency which would make it more
difficult for a lessee to meet its dollar-denominated lease payments, increasing
the risk of default of that lessee, particularly if that carrier's revenue is
primarily derived in the local currency.

Competition. The Company has many competitors in the aircraft leasing industry,
including leasing companies, banks and other financial institutions and aircraft
leasing partnerships. The market is highly competitive. Most of the Company's
competitors have substantially greater financial and other resources than the
Company.

Casualties, Insurance Coverage. The Company, as owner of transportation
equipment, could be held liable for injuries or damage to property caused by its
assets. Though some protection may be provided by the United States Aviation Act
with respect to its aircraft assets, it is not clear to what extent such
statutory protection would be available to the Company and such act may not
apply to aircraft operated in foreign countries. Though the Company may carry
insurance or require a lessee to insure against a risk, some risks of loss may
not be insurable. An uninsured loss with respect to the Equipment or an insured
loss, for which insurance proceeds are inadequate, would result in a possible
loss of invested capital in and any profits anticipated from such equipment.

Reliance on JMC. All management of the Company is performed by JMC pursuant to a
management agreement between JMC and the Company. The Board of Directors does,
however, have ultimate control and supervisory responsibility over all aspects
of the Company and does owe fiduciary duties to the Company and its
stockholders. In addition, while JMC may not owe any fiduciary duties to the
Company by virtue of the management agreement, the officers of the Company are
also officers or employees of JMC, and in that capacity owe fiduciary duties to
the Company and the stockholders by virtue of holding such offices. Although the
Company has taken steps to prevent such conflicts, such conflicts of interest
arising from such dual roles may still occur.



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                                   SIGNATURES


Pursuant to the requirements of Section 13 or 15(d) of the Securities Act of
1934, the Registrant has duly caused this report to be signed on its behalf by
the undersigned, thereunto duly authorized on May 15, 2001.

                                        AEROCENTURY IV, INC.


                                        By: /s/ Neal D. Crispin
                                            -------------------------------
                                            Neal D. Crispin
                                            Title:  President

Pursuant to the requirements of the Securities Act of 1934, this report has been
signed below by the following persons in the capacities indicated on May 15,
2001.

<TABLE>
<CAPTION>
Signature                                   Title

<S>                                     <C>
/s/ Neal D. Crispin                     President and Chairman of the
------------------------                Board of Directors of the Registrant
Neal D. Crispin                         Chief Financial Officer
</TABLE>






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