**Exhibit 4.2**

|indianapolis power & light company


to


J.P. MORGAN TRUST COMPANY,
NATIONAL ASSOCIATION
Trustee




________________Fiftieth Supplemental
Indenture________________

Dated as of April 1, 2005


ESTABLISHING FIRST MORTAGE BONDS,

Variable Rate Series, Due 2023
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



Table of Contents*

of

FIFTIETH Supplemental Indenture

of

Indianapolis Power & Light Company

Page



PARTIES	1

RECITALS 	1

SECTION 1	Granting clauses	3

Part I   Electric Distributing Systems	4

Part II  Reserved	4

Part III Indeterminate Permits and Franchises	4

Part IV Other Property	4

General and after-acquired title	4



SECTION 2	Definitions	5

SECTION 3	Designation of Fiftieth series of bonds and kind and denominations
thereof	6

Designation of Company or J.P. Morgan Trust Company, National Association

as paying agent

Purpose of bonds

Redemption of bonds

Exchange of bonds

Transfer of bonds

Series limited to $30,000,000

SECTION 4	Form of fully registered bond 	12

Form of Trustee's certificate on bonds	12

SECTION 5	Temporary bonds	18

SECTION 6	Payment of principal and interest; credits	18

SECTION 7	Annual Payments for Maintenance and Improvement Fund	19

SECTION 8	Compliance with Section 47 of Original Mortgage with respect to
dividend restrictions	19

SECTION 9	Acceptance of trusts by Trustee and conditions of
acceptance	19

SECTION 10	Successors and assigns	20

SECTION 11	Limitation of rights hereunder	20

SECTION 12	Compliance with terms, provisions and conditions of
Mortgage	20

SECTION 13	Execution in counterparts	20



TESTIMONIUM	20



SIGNATURES AND SEALS	21



ACKNOWLEDGEMENTS	22



__________

*Table of Contents is not part of the Fiftieth Supplemental Indenture and should
not be considered such.  It is included herein only for purposes of convenient reference.



THIS FIFTIETH SUPPLEMENTAL INDENTURE, dated as of April 1, 2005, between
Indianapolis Power & Light Company, a corporation of the State of Indiana, hereinafter sometimes
called the "Company," party of the first part, and J.P. Morgan Trust Company, National Association,
as successor in interest to American National Bank And Trust Company Of Chicago, a national banking
association, as Trustee, hereinafter sometimes called the "Trustee," party of the second part;

Whereas, the Company by a Mortgage and Deed of Trust (hereinafter sometimes
called the "Original Mortgage" when referred to as existing prior to any supplement thereto or
modification thereof, and the "Mortgage" when referred to as now or heretofore supplemented and
modified) dated as of May 1, 1940, made to said American National Bank and Trust Company of Chicago,
as Trustee, to secure the payment of the bonds issued from time to time under the Mortgage for the
purposes of and subject to the limitations specified in the Mortgage, and to secure the performance
of the covenants therein contained, conveyed to the Trustee thereunder upon certain trusts, terms
and conditions, and with and subject to certain provisos and covenants therein contained, all and
singular the property, rights and franchises which the Company then owned or should thereafter
acquire, excepting the property expressly excepted by the terms of the Original Mortgage or any
indenture supplemental thereto, to which Mortgage reference is hereby made for greater certainty;
and

Whereas, the Original Mortgage has been supplemented and modified by supplemental
indentures dated as of May 1, 1942, as of February I, 1948, as of April 1, 1949, as of October 1,
1949, as of February 1, 1951, as of March 1, 1953, as of June l, 1956, as of March 1, 1958, as of
October 1, 1960, as of August l, 1964; as of April l, 1966, as of May l, 1967, as of May l, 1968, as
of October l, 1970, as of March l, 1972, as of March 15, 1973, as of February 15, 1974, as of August
15, 1974, as of September 15, 1975, as of June l, 1976, as of July 1, 1976, as of August 1, 1977, as
of September l, 1978, as of August 1, 1981, as of November l, 1983, as of November l, 1984, as of
December 1, 1984, as of September 1, 1985, as of October 1, 1986, as of June 1, 1989, as of August
1, 1989, as of October 15, 1991, as of August l, 1992, as of April 1, 1993 and as of October 1, 1993
(two), as of February 1, 1994 (two), as of October 1, 1995, as of October 1, 1995, as of August 1,
2001 (four), as of August 1, 2003, as of October 1, 2004 and as of April 1, 2005;

Whereas, Section 8 of the Original Mortgage provides, among other things, that
the form of each series of bonds (other than the initial issue of bonds) issued thereunder shall be
established by an indenture supplemental thereto authorized by resolution of the Board of Directors
of the Company; and that the form of each series, as established by the Board of Directors, shall
specify the descriptive title of the bonds and various other terms thereof, and may also contain
such other provisions as the Board of Directors may, in its discretion, cause to be inserted therein
expressing or referring to the terms and conditions upon which such bonds are to be issued and
secured under the Original Mortgage or any indenture supplemental thereto or in modification
thereof; and

Whereas, the Company has entered into a Loan Agreement, dated as of April l, 2005
(hereinafter called the Loan Agreement") with the City of Petersburg, Indiana (the "City"), in order
to obtain funds for the refunding of the aggregate principal amount of Thirty Million Dollars
($30,000,000) of the City's Pollution Control Refunding Revenue Bonds, Series 1993C (Indianapolis
Power & Light Company Project) issued by the City pursuant to a related loan agreement to pay a
portion of the cost of acquisition, construction, installation and equipping by the Company of
certain pollution control facilities, and pursuant to the Loan Agreement the Company has agreed to
issue a series of its bonds under the Mortgage and this Fiftieth Supplemental Indenture in order to
evidence and secure its indebtedness under the Loan Agreement; and

Whereas, the Company now desires to provide for the establishment, execution,
authentication and delivery under the Mortgage of bonds of a series to be known as its "First
Mortgage Bonds, Variable Rate Series, due 2023" (the bonds of said series being hereinafter
sometimes referred to as the "2023 Bond"), limited to the aggregate principal amount of Thirty
Million Dollars ($30,000,000); and

Whereas, all things necessary to make the 2023 Bond hereinafter described, when
duly executed by the Company and authenticated and delivered by the Trustee, a valid, binding and
legal obligation of the Company, and to make this Fiftieth Supplemental Indenture a valid and
binding agreement supplemental to the Original Mortgage, have been done and performed; and

Whereas, the execution and delivery by the Company of this Fiftieth Supplemental
Indenture, and the terms of the 2023 Bond, have been duly authorized by the Board of Directors' of
the Company by appropriate resolutions of said Board; and

Whereas, it is provided in and by the Original Mortgage that the Company will
execute and deliver such further instruments and do such further acts as may be necessary or proper
to carry out more effectually the purposes of the Mortgage, and to make subject to the lien thereof
any property thereafter acquired and intended to be subject to the lien thereof; and

Whereas, the Company has, since the date of execution and delivery of the
Original Mortgage, purchased and acquired property and desires by this Fiftieth Supplemental
Indenture specifically to convey to the Trustee such property for the better protection and security
of the bonds issued and to be issued under the Original Mortgage, or any indenture supplemental
thereto;

Now, Therefore, This Indenture Witnesseth that, in consideration of the premises
and of the acceptance or purchase of the 2023 Bond by the registered owners thereof, and of the sum
of one dollar, lawful money of the United States of America, to the Company duly paid by the Trustee
at or before the execution and delivery of this Fiftieth Supplemental Indenture, the receipt of
which is hereby acknowledged, the Company and the Trustee, respectively, have entered into, executed
and delivered this Fiftieth Supplemental Indenture, for the uses and purposes hereinafter expressed,
that is to say:

SECTION 1. The Company has
granted, bargained, sold, released, conveyed, assigned, transferred, mortgaged, pledged, set over
and confirmed, and by these presents does grant, bargain, sell, release, convey, assign, transfer,
mortgage, pledge, set over and confirm (subject, however, to permitted encumbrances as defined in
the Original Mortgage), unto said J.P. Morgan Trust Company, National Association, as successor in
interest to American National Bank and Trust Company of Chicago, as Trustee, as herein provided, and
its successors in the trusts declared in the Original Mortgage and herein, all of the property,
real, personal and mixed, tangible and intangible, of every kind, character and description which
the Company has acquired since the execution and delivery of the Original Mortgage and now owns
(except property, rights and assets of a character similar to that excluded from the lien and
operation of the Mortgage by the Granting Clauses of the Original Mortgage, which property, rights
and assets are excluded from the lien and operation of the Mortgage only to the extent provided
therein), including, but without otherwise limiting the generality of the foregoing, the following
described property situated within the State of Indiana:

1. ELECTRIC DISTRIBUTING SYSTEMS.
2. [RESERVED].
3. INDETERMINATE PERMITS AND FRANCHISES.
4. OTHER PROPERTY.

All other property, whether real, personal or mixed (except any in the
Mortgage expressly excepted), now owned by the Company and wheresoever situated, including (without
in anywise limiting or impairing by the enumeration of the same the scope and intent of the
foregoing or of any general description contained in the Mortgage) all lands, flowage rights, water
rights, flumes, raceways, dams, rights-of-way and roads; all plants for the generation of
electricity by water, steam and/or other power, power houses, telephone systems, water systems,
steam heat and power plants, hot water plants, substations, transmission lines, distribution
systems, bridges, culverts and tracts; all offices, buildings and structures and the equipment
thereof; all machinery, engines, boilers, dynamos, machines, regulators, meters, transformers,
generators and motors; all appliances whether electrical, gas or mechanical, conduits, cables and
lines; all pipes whether for water, steam heat and power; or other purposes; all mains and pipes,
service pipes, fittings, valves and connections, poles, wires, tools, implements, apparatus,
furniture and chattels; all municipal franchises, indeterminate permits, and other permits; all
lines for the transportation, transmission and/or distribution of electric current, steam heat and
power or water for any purpose, including towers, poles, wires, cables, pipes, conduits and all
apparatus for use in connection therewith; all real estate, lands, leases, leaseholds; all
contracts, whether heat, light, power, water or street lighting contracts; all easements,
servitudes, licenses, permits, rights, powers, franchises, privileges, rights-of-way and other
rights in or relating to real estate or the occupancy of the same and (except as hereinafter or in
the Mortgage expressly excepted) all the right, title and interest of the Company in and to all
other property of any kind or nature appertaining to and/or used and/or occupied and/or enjoyed in
connection with any property hereinbefore described or referred to;

TOGETHER WITH all and singular the tenements, hereditaments and appurtenances
belonging or in anywise appertaining to the aforesaid property or any part thereof, with the
reversion and reversions, remainder and remainders and (subject to the provisions of Section 64 of
the Original Mortgage), the tolls, rents, revenues, issues, earnings, income, product and profits
thereof, and all the estate, right, title and interest and claim whatsoever, at law as well as in
equity, which the Company now has or may hereafter acquire in and to the aforesaid property,
indeterminate permits, franchises, ordinances, licenses and other authorizations and every part and
parcel thereof.

SECTION 2. Capitalized terms not otherwise defined in this
Fiftieth Supplemental Indenture shall have the following meanings:

"City" means the City of Petersburg, Indiana, a municipality and political
subdivision of the State of Indiana.

"City Indenture" means the Indenture of Trust, dated as of April 1, 2005, by and
between the City and U.S. Bank National Association, as Trustee, and any indenture supplemental
thereto or amendatory thereof, pursuant to which the City of Petersburg Bonds and certain other
bonds are issued and secured.

"City of Petersburg Bonds" means the $30,000,000 City of Petersburg, Indiana
Pollution Control Refunding Revenue Bonds, Series 2005B (Indianapolis Power & Light Company
Project) issued under and pursuant to the City Indenture.

"City Trustee" means the person, corporation or association acting as trustee at
any time under the City Indenture.

"Loan Agreement" means the Loan Agreement dated as of April 1, 2005 between the
City and the Company, and any and all modifications, amendments and supplements thereof.

"Project" means the pollution control facilities comprising the Project as
defined in the Loan Agreement.

SECTION 3. There shall be
and is hereby established a series of bonds, limited in aggregate principal amount to Thirty Million
Dollars ($30,000,000) to be issued under and secured by the Mortgage, to be designated "Variable
Rate Series, due 2023", each of which shall also bear the descriptive title "First Mortgage Bonds";
said bonds shall mature on October 1, 2023, and shall be issued only as fully registered bonds
without coupons in the denomination of five thousand dollars and any larger denomination which is a
whole multiple of five thousand dollars; they shall bear interest at the rate from time to time
borne by the City of Petersburg Bonds, provided, however, that in no event shall the rate of
interest borne by the 2023 Bond exceed twelve percent (12%) per annum; interest shall be payable on
the interest payment dates specified in the City of Petersburg Bonds and principal of and premium,
if any, on said bond shall be payable on the dates for the payment of principal and premium, if any,
and in the amounts, specified in the City of Petersburg Bonds; and the principal of, premium, if
any, and interest on said bond shall be payable in lawful money of the United States of America at
the office of the Company in the City of Indianapolis, Indiana, or, if no such office is maintained,
at J.P. Morgan Trust Company, National Association, which is hereby designated and appointed the
office and agency of the Company in the City of Chicago, Illinois, for the payment of the principal
of, premium, if any, and interest on the 2023 Bond, if necessary, and for the registration, transfer
and exchange of such bond as hereinafter provided; all reference herein to the office or agency of
the Company in the City of Chicago, Illinois, for the payment of the principal of, premium, if any,
and interest on the 2023 Bond, or the registration, transfer or exchange thereof, being to J.P.
Morgan Trust Company, National Association. In event of the resignation or inability to act of J.P.
Morgan Trust Company, National Association, then a successor agent for all such purposes in the City
of Chicago, Illinois, shall be appointed by the Board of Directors of the Company.

The 2023 Bond shall be dated as of the date of authentication thereof, except as
otherwise provided in Section 10 of the Original Mortgage.

The 2023 Bond will be issued to evidence and secure a loan to the Company by the
City pursuant to the Loan Agreement of certain funds to be acquired by the City through the issuance
of the City of Petersburg Bonds, authenticated and delivered under and pursuant to the City
Indenture. Pursuant to the Loan Agreement, the 2023 Bond shall be issued to the City Trustee. All of
the proceeds of the City of Petersburg Bonds will be used for the refunding of the aggregate
principal amount of Thirty Million Dollars ($30,000,000) of the City's Pollution Control Refunding
Revenue Bonds, Series 1993C (Indianapolis Power & Light Company Project) issued by the City
pursuant to applicable loan agreements.

Upon the notice and in the manner and with the effect provided in this Section 3,
the 2023 Bond shall be redeemable prior to the maturity thereof under any one or more of the
following circumstances:

1. In whole, at the option of the Company, if the Project or Units 3 or 4 of the
Petersburg Generating Station shall have been damaged or destroyed (i) to such extent that they
cannot be reasonably expected, in the opinion of the Company, to be restored within a period of six
(6) months to the condition thereof immediately preceding such damage or destruction, or (ii) to
such extent that the Company, in its reasonable opinion, is thereby prevented from carrying on its
normal operations for a period of six (6) months or more, or (iii) to such extent that the
restoration thereof would not be, taking into consideration the net proceeds of any insurance
payable as a result of such damage or destruction, economic in the reasonable opinion of the
Company.
2. In whole, at the option of the Company, if title to, or the temporary use of,
all or substantially all of the Project or Units 3 or 4 of the Petersburg Generating Station shall
have been taken, under the exercise of the power of eminent domain, or should any governmental body
or agency exercise any right which it may have to purchase or designate a purchaser of the same, or
should such property be sold to any governmental body or agency so that the result of such taking or
takings is that (i) the Company, in its reasonable opinion, is thereby prevented from carrying on
its normal operations of either the Project or Units 3 or 4 for a period of six (6) months or more,
(ii) the restoration required as a result of the taking cannot be reasonably expected, in the
opinion of the Company, to be completed in a period of six (6) months, or (iii) the restoration
thereof, taking into consideration the net proceeds from such eminent domain award, would not be
economic in the reasonable opinion of the Company.
3. In whole, at the option of the Company, if, as a result of any changes in the
constitution or law of the State of Indiana or the Constitution or law of the United States of
America or of legislative or administrative action (whether state or federal) or by final decree,
judgment or order of any court or administrative body (whether state or federal) entered after the
contest thereof by the Company in good faith or the decision of the Company not to contest the same,
the Loan Agreement shall, in the reasonable opinion of counsel for the Company, have become void or
unenforceable or impossible of performance in accordance with the intent and purpose of the parties
as expressed in the Loan Agreement; or unreasonable burdens or excessive liabilities shall, in the
reasonable opinion of the Company, have been imposed upon the City or the Company, with respect to
the Project or operation thereof, including without limitation federal, state or other ad valorem,
property, income or other taxes not being imposed on the date of the Loan Agreement other than ad
valorem taxes presently levied upon privately owned property used for the same general purpose as,
the Project.
4. In whole, at the option of the Company, if changes in the economic
availability of raw materials, operating supplies or facilities necessary for the operation of the
Project or the operation of Units 3 or 4 of the Petersburg Generating Station shall have occurred or
technological or other changes shall have occurred which render the Project or Units 3 or 4
uneconomic for use in the reasonable opinion of the Company.
5. In part, at the option of the Company, to the extent of net proceeds received
from any condemnation award, taking or sale as stated herein, if title to, or the temporary use of
any portion of the Project shall have been taken under the exercise of the power of eminent domain,
or should any governmental body or agency exercise any right it may have to purchase or designate a
purchaser of the same, or should such property be sold to any governmental body or agency; provided
the Company shall furnish to the City and the City Trustee a certificate of an Independent Engineer
(as defined in the Loan Agreement) selected by the Company stating (i) that the property forming the
part of the Project that was taken by such condemnation, taking or sale is not essential to the
character or significance of the Project, or (ii) that the Project has been restored to a condition
substantially equivalent to their condition prior to the taking by such condemnation, taking or sale
proceedings, or (iii) that improvements have been acquired which are suitable for the operation of
the Project as Pollution Control Facilities (as defined in the Loan Agreement).
6. In whole or in part, at the option of the Company, upon the optional
redemption by the Company of a like principal amount of the City of Petersburg Bonds, so long as
there shall not have occurred any completed default (as defined in the Mortgage) which affects any
bond of any series outstanding under the Mortgage and which completed default has not been cured and
made good prior to such redemption date.
7. In the event all or substantially all of the mortgaged and pledged property
under the Mortgage, or all or substantially all such property used in the business of generating,
manufacturing, transporting, transmitting, distributing or supplying electricity, should be taken by
exercise of the power of eminent domain, or should any governmental body or agency exercise any
right which it may have to purchase or designate a purchaser of the same, or should such property be
sold to any governmental body or agency, the Company shall be obligated to redeem the 2023 Bond
outstanding as promptly as possible in accordance with paragraph B of Section 69 of the Original
Mortgage.
8. In the event that the Company is notified by the City Trustee that (i) an
event of default under the City Indenture has occurred and is continuing, and (ii) the City Trustee
has declared the principal of all the City of Petersburg Bonds then outstanding immediately due and
payable pursuant to the City Indenture, the Company shall call for redemption, on a redemption date
selected by it not later than forty-five (45) days following the date on which such notice is
mailed, the 2023 Bond outstanding, and shall on such redemption date redeem the same; provided,
however, that such requirement of redemption shall be deemed waived, if prior to the date fixed for
such redemption of the 2023 Bond (x) such event of default is waived or cured as set forth in the
City Indenture, or (y) there shall have occurred any completed default (as defined in the Mortgage)
which affects any bond of any series outstanding under the Mortgage and which completed default has
not been cured and made good prior to such redemption date, it being the intent of this proviso
that, in lieu of such right to redemption, the holder of the 2023 Bond shall be entitled only to
such rights as are available to the holders of bonds of any other series outstanding under the
Mortgage in the event of such completed default; and in case of any subsequent occurrence or
continuance of the events described in (i) and (ii) of this Section 3(viii), the Company shall have
the same obligation (subject to the same proviso) to redeem the 2023 Bond.
9. In the event the City Trustee notifies the Company and the City that the
interest payable on the City of Petersburg Bonds held by persons other than a "substantial user" or
a "related person" as those terms are used in Section 147(a)(2) of the Internal Revenue Code of
1986, as amended, has been determined by a court of competent jurisdiction or a formal ruling of the
Internal Revenue Service to be subject to federal income taxation by reason of a breach by the
Company of any covenant, agreement or representation in the Loan Agreement, the Company shall call
the 2023 Bond then outstanding to be redeemed on an interest payment date within one hundred eighty
(180) days after the date of such notice; provided, however, that such requirement of redemption,
whether in whole or in part shall be deemed waived if, prior to the date fixed for redemption of the
2023 Bond pursuant to this Section 3(i), there shall have occurred any completed default (as defined
in the Mortgage) which affects any bond of any series outstanding under the Mortgage and which
completed default has not been cured and made good prior to such redemption date, it being the
intent of this proviso that, in lieu of such right to redemption, the holder of the 2023 Bond shall
be entitled only to such rights as are available to the holders of bonds of any other series
outstanding under the Mortgage in the event of such completed default; but when any such completed
default shall have been cured and made good, if interest on the City of Petersburg Bonds shall still
be taxable as described above, the Company shall have the same obligation (subject to the same
proviso) to redeem the 2023 Bond on an interest payment date within one hundred eighty (180) days
after the curing and making good of such completed default; provided further, that the Company may
call for redemption such portion of the 2023 Bond, which in the written opinion of an attorney or
firm of attorneys of nationally recognized standing on the subject of municipal bonds, would allow
the City Trustee to redeem the City of Petersburg Bonds in part, which redemption would have the
result that the interest payable on the City of Petersburg Bonds remaining outstanding after such
redemption in part would not be subject to federal income taxation in the hands of persons other
than a "substantial user" or a "related person" as those terms are used in Section 147(a)(2) of the
Internal Revenue Code of 1986, as amended.

In case of redemption of 2023 Bond in whole for the purpose of prepayment under
the Loan Agreement pursuant to subsections (a), (b), (c), (d), (e), (f), (g), (h) or (i) above, the
amounts payable upon redemption of 2023 Bond shall be a sum sufficient, together with other funds
deposited with the City Trustee and available for such purpose, to pay the principal of (and
premium, in the case of redemption pursuant to (f) above), and interest on the 2023 Bond then
outstanding and to pay all reasonable and necessary fees and expenses of the City Trustee accrued
and to accrue through final payment of the 2023 Bond.

In case of redemption in part pursuant to (e), (f) or (i) above, the amount
payable by the Company under this Fiftieth Supplemental Indenture, the Loan Agreement and the 2023
Bond shall be a sum sufficient, together with other funds deposited with the Trustee and available
for such purpose, to pay the principal of (and premium in the case of prepayment pursuant to (f)
above) and interest on the 2023 Bond so to be redeemed, which sum together with other funds
deposited with the City Trustee and available for such purpose shall be sufficient to pay the
principal of, premium, if any, and interest on the City of Petersburg Bonds and to pay all
reasonable and necessary fees and expenses of the City Trustee accrued and to accrue through such
partial prepayment.

The 2023 Bond and the City of Petersburg Bonds shall be redeemable at any time
within one hundred eighty (180) days following the event or events described as giving rise to an
option of the Company to redeem them in subsections (a), (b), (c), (d) or (e) above.

To exercise any of the options granted to redeem the 2023 Bond in whole or in
part or to comply with any obligations to redeem the 2023 Bond in whole or in part imposed in this
Section 3, the Company shall give written notice of the date of redemption to the City Trustee,
which date shall be not less than thirty (30) days nor more than ninety (90) days from the date the
notice is mailed. No further notice, by publication or otherwise, shall be required for redemption
of the 2023 Bond, and the requirements of Section 59 of the Mortgage for notice by newspaper
publication shall not apply to the 2023 Bond.

At the option of the holder, the 2023 Bond, upon surrender thereof at the office
or agency of the Company in Chicago, Illinois, together with a written instrument of transfer in
form approved by the Company duly executed by the holder or by his duly authorized attorney, shall
be exchangeable for a like aggregate principal amount of fully registered bonds of the same series
of other authorized denominations.

The 2023 Bond will be nontransferable except to the City Trustee and successors
thereto, if any, and to the Company. To the extent that it is transferable, it is transferable by
the registered holder thereof, in person or by attorney duly authorized in writing, on the books of
the Company at the office or agency of the Company in the City of Chicago, Illinois, upon surrender
thereof for cancellation at said office and upon presentation of a written instrument of transfer
duly executed. Thereupon, the Company shall issue in the name of the transferee, and the Trustee
shall authenticate and deliver, a new registered 2023 Bond or Bonds, in authorized denominations, of
equal aggregate principal amount. Any such transfer shall be subject to the terms and conditions
specified in the Mortgage and in this Fiftieth Supplemental Indenture.

The Company shall not be required to transfer or exchange the 2023 Bond for a
period of ten (10) days next preceding any interest payment date of said bond.

Except as set forth herein, no charge shall be made upon any transfer or exchange
of any of the 2023 Bond other than for any tax or taxes or other governmental charge required to be
paid by the Company.

The 2023 Bond shall be limited to an aggregate principal amount of Thirty Million
Dollars ($30,000,000) and shall be issued under the provisions of Article VII of the Original
Mortgage.

SECTION 4. The 2023 Bond, and
the Trustee's Certificate to be endorsed thereon, shall be in the following forms,
respectively:

[Form Of Face Of 2023 Bond]

This First Mortgage Bond, Variable Rate Series, due 2023 (hereinafter called the
"2023 Bond") is not transferable except to a successor trustee under the Indenture of Trust dated as
of April 1, 2005, between the City of Petersburg, Indiana and U.S. Bank National Association, as the
Trustee, or to Indianapolis Power & Light Company.

INDIANAPOLIS POWER & LIGHT COMPANY

First Mortgage Bond, Variable Rate Series, Due 2023
Due October 1, 2023

No.										$

INDIANAPOLIS POWER & LIGHT COMPANY, a corporation of the State of Indiana
(hereinafter called the "Company"), for value received, hereby promises to pay to U.S. Bank National
Association, as the Trustee (hereinafter called the "City Trustee") under the Indenture of Trust
between the City of Petersburg, Indiana (the "City") and the City Trustee, dated as of April 1, 2005
(the "City Indenture") or registered assigns, on October 1, 2023, at the office of the Company, in
the City of Indianapolis, State of Indiana, or if no such office is maintained at the time by the
Company, then at the office or agency of the Company for such purpose in the City of Chicago, State
of Illinois, principal in the amount set forth above and premium, if any, in the amounts and on the
dates for the payment of principal and premium, if any, specified in the $30,000,000 City of
Petersburg, Indiana Pollution Control Refunding Revenue Bonds, Series 2005B (Indianapolis Power
& Light Company Project) issued under and pursuant to the City Indenture (the "City of
Petersburg Bonds") in lawful money of the United States of America, and interest thereon at the rate
of interest from time to time borne by the City of Petersburg Bonds, provided, however, that in no
event shall the rate of interest borne by this Bond exceed twelve percent (12%) per annum, in like
lawful money at said office or agency, on the interest payment dates specified in the City of
Petersburg Bonds, until the Company's obligation with respect to the payment of such principal shall
have been discharged. The interest payable hereunder will be paid to the registered owner of this
2023 Bond at or before the close of business on such dates, or if such date shall be a Saturday,
Sunday, holiday or a day on which banking institutions in the City of Indianapolis or the city of
any paying agents are authorized by law to close, on or before the close of business on the next
succeeding business day on which such banking institutions are open for business.

REFERENCE IS MADE TO THE FURTHER PROVISIONS OF THIS 2023 BOND SET FORTH ON THE
REVERSE HEREOF. SUCH FURTHER PROVISIONS SHALL, FOR ALL PURPOSES, HAVE THE SAME EFFECT AS THOUGH
FULLY SET FORTH IN THIS PLACE.

No recourse shall be had for the payment of the principal of or interest on this
2023 Bond against any incorporator or any past, present or future subscriber to the capital stock,
stockholder, officer or director of the Company or of any predecessor or successor corporation, as
such, either directly or through the Company or any predecessor or successor corporation, under any
rule of law, statute, or constitution or by the enforcement of any assessment or otherwise, all such
liability of incorporators, subscribers, stockholders, officers and directors, as such, being waived
and released by the terms of the Mortgage, as herein defined.

This 2023 Bond shall not become obligatory until J.P. Morgan Trust Company,
National Association, the Trustee under the Mortgage, as herein defined, or its successor
thereunder, shall have signed the form of certificate endorsed hereon.

In Witness Whereof, Indianapolis Power & Light Company has caused this 2023
Bond to be signed in its name by its President or one of its Vice-Presidents, by his signature or a
facsimile thereof, and its corporate seal to be affixed hereon, attested by its Secretary or one of
its Assistant Secretaries, by his signature or a facsimile thereof.

|                     | Indianapolis Power & Light
Company
|-------------------- | ----------------------------------
|Dated:

Attest:

By: | By:                               





[Form Of Trustee's Certificate On 2023 Bond]

Trustee's Certificate

This 2023 Bond is one of the bonds, of the series herein designated, provided for
in the within-mentioned Mortgage and Fiftieth Supplemental Indenture thereto.



|J.P. Morgan Trust Company, National Association, as successor in interest to American National
Bank And Trust Company Of Chicago
Trustee

By:
Authorized Signature
|------------------------------------------------------------------------------------------------------------------------------------------------------------------







[Form Of Reverse Side Of 2023 Bond]

INDIANAPOLIS POWER & LIGHT COMPANY

First Mortgage Bond, Variable Rate Series, Due 2023 
Due October l, 2023

This 2023 Bond is one of an issue of bonds of the Company, issuable in series,
and is one of a series known as its First Mortgage Bonds, Variable Rate Series, due 2023 (herein
called the "2023 Bond") limited in aggregate principal amount to Thirty Million Dollars
($30,000,000) and established by a Fiftieth Supplemental Indenture dated as of April 1, 2005, all
bonds of all series issued and to be issued under and equally secured (except insofar as any sinking
or other fund, established in accordance with the provisions of the Mortgage hereinafter mentioned,
may afford additional security for the bonds of any particular series) by a Mortgage and Deed of
Trust, dated as of May 1, 1940, executed by the Company to American National Bank and Trust Company
of Chicago (predecessor to J.P. Morgan Trust Company, National Association), as the Trustee (which
Mortgage and Deed of Trust as supplemented and modified by all supplemental indentures thereto is
hereinafter referred to as the "Mortgage"), to which Mortgage reference is made for a description of
the property mortgaged and pledged, the nature and extent of the security, the rights of the bearers
or registered owners of the bonds in respect of such security, the duties and immunities of the
Trustee and the terms and conditions upon which the bonds are secured.

This 2023 Bond evidences and secures a loan made by the City of Petersburg,
Indiana (the "City") to the Company, pursuant to a Loan Agreement, dated as of April 1, 2005,
between the City and the Company (the "Loan Agreement"). In order to obtain funds for such loan, the
City, contemporaneously with the issue of this 2023 Bond, will issue Thirty Million Dollars
($30,000,000) principal amount of its Pollution Control Refunding Revenue Bonds, Series 2005B
(Indianapolis Power & Light Company Project) (the "City of Petersburg Bonds") under and pursuant
to the Indenture of Trust between the City and U.S. Bank National Association, as trustee (the "City
Trustee"), dated as of April 1, 2005 (the "City Indenture"). The City of Petersburg Bonds are
payable from payments made by the Company of principal of, premium, if any, and interest on this
2023 Bond and from moneys in the Bond Fund created under the City Indenture. The obligation of the
Company to pay the principal of, premium, if any, and interest on this 2023 Bond shall be discharged
to the extent that any moneys in said Bond Fund are available for payments on the City of Petersburg
Bonds and are directed by the Company to be applied thereto, all as provided in the Fiftieth
Supplemental Indenture.

This 2023 Bond is not subject to redemption, except as provided in Section 3 of
the Fiftieth Supplemental Indenture, to which reference is made for full description of redemption
provisions.

With the consent of the Company and to the extent permitted by and as provided in
the Mortgage, the rights and obligations of the Company and/or of the holders of the bonds and/or
coupons and/or the terms and provisions of the Mortgage and/or any instruments supplemental thereto
may be modified or altered by affirmative vote of the holders of at least sixty-six and two thirds
per centum (66-2/3%) in principal amount of the bonds affected by such modification or alteration
then outstanding under the Mortgage (excluding bonds disqualified from voting by reason of the
Company's interest therein as provided in the Mortgage); provided that no such modification or
alteration shall permit the extension of the maturity of the principal of this 2023 Bond or the
reduction in the rate of interest hereon or any other modification in the terms of payment of such
principal or interest without the consent of the holder hereof. The principal hereof may be declared
or may become due and payable prior to the stated date of maturity hereof, on the conditions, in the
manner and at the time set forth in the Mortgage, upon the occurrence of a completed default as in
the Mortgage provided.

No reference herein to the Mortgage, and no provision of this 2023 Bond or of the
Mortgage, shall alter or impair the obligation of the Company, which is absolute and unconditional,
to pay, subject to the provisions of the Fiftieth Supplemental Indenture, the principal of, and
premium, if any, and interest on this 2023 Bond at the place, at the respective times and at the
rate and the manner herein prescribed.

This 2023 Bond is issuable only in full registered form without coupons in
denominations of Five Thousand Dollars and any larger denomination which is a whole multiple of Five
Thousand Dollars.

This 2023 Bond will be nontransferable except to the City Trustee and successors
thereto, if any, and to the Company. To the extent that it is transferable, it is transferable by
the registered holder thereof, in person or by attorney duly authorized in writing, on the books of
the Company at the office or agency of the Company in the City of Chicago, Illinois, upon surrender
thereof for cancellation at said office and upon presentation of a written instrument of transfer
duly executed. Thereupon, the Company shall issue in the name of the transferee, and the Trustee
shall authenticate and deliver, a new registered 2023 Bond or Bonds, in authorized denominations, of
equal aggregate principal amount. Any such transfer shall be subject to the terms and conditions
specified in the Mortgage and in the Fiftieth Supplemental Indenture.

[End Of 2023 Bond Form]



SECTION 5. Until the 2023
Bond in definitive form is ready for delivery, the Company may execute, and upon its request in
writing the Trustee shall authenticate and deliver, in lieu thereof, a fully registered 2023 Bond in
temporary form, as provided in Section 15 of the Original Mortgage. Such bond may, in lieu of the
statement of the specific redemption prices required to be set forth in such bond in definitive
form, include a reference to this Fiftieth Supplemental Indenture for a statement of such redemption
prices.

SECTION 6. The Company covenants and agrees that it will duly and punctually pay
to the holder of the 2023 Bond the principal thereof, premium, if any, and interest on said bond at
the dates and place and in the manner mentioned therein; provided, however, that:

1. The obligation of the Company to pay the principal of, and premium, if any,
and interest on the 2023 Bond shall be discharged to the extent that any moneys in the City of
Petersburg Bond Account within the Bond Fund (as defined in the City Indenture) created under and
pursuant to the City Indenture are available for the payment of the principal of, or premium, if
any, or interest on the City of Petersburg Bonds and are directed by the Company to be applied to
the payment thereof in the manner provided in the City Indenture on or prior to the dates on which
the Company is required to pay the principal of, or premium, if any, or interest on the 2023
Bond.
2. Except as otherwise provided in this Section 6, the principal amount of any
City of Petersburg Bond acquired by the Company and delivered to the City Trustee, or acquired by
the City Trustee and cancelled, shall be credited against the obligation of the Company to pay the
principal of the 2023 Bond.

As the principal of, premium, if any, and interest on the 2023 Bond is paid or
deemed paid in full, and upon its receipt by the Company, such bond shall be delivered to the
Trustee for cancellation. The Company shall promptly inform the Trustee of all payments made and
credits availed of with respect to its obligations on the 2023 Bond. The Trustee shall not be
required to recognize any payment made or credit availed of with respect to any 2023 Bond unless it
has received (a) the bond for cancellation by it, or (b) a certificate signed by a duly authorized
officer of the City Trustee specifying the amount of such payment or credit and the principal amount
of the 2023 Bond with respect to which the payment or credit was applied. In the absence of receipt
by the Trustee of any 2023 Bond, any such certificate shall be controlling and conclusive.



SECTION 7. The covenant of the Company to make annual payments to the Trustee for
a Maintenance and Improvement Fund as contained in Section 41 of the Original Mortgage and in the
first twenty-four Supplemental Indentures to the Original Mortgage creating the several series of
First Mortgage Bonds presently outstanding under such Supplemental Indentures shall not apply to nor
be for the benefit of the 2023 Bond, and the Company reserves the right, without any consent of, or
other action by, the holder of the 2023 Bond, to amend, modify or delete the provisions of the
Mortgage relating to such Maintenance and Improvement Fund and by acceptance of the 2023 Bond the
holder thereof waives any right or privilege so to consent or take any other action with respect
thereto.

SECTION 8.

1. The Company covenants that, so long as the 2023 Bond shall remain
outstanding, it will (i) comply with all of the provisions of Section 47 of the Original Mortgage,
including the provisions with respect to limitations on dividends and distributions and the purchase
and redemption of stock, and (ii) use the maximum interest rates payable on the 2023 Bond (twelve
percent (12%) per annum) as the interest rate borne by the 2023 Bonds for purposes of preparing the
net earnings certificate or calculating the amount required to defease the 2023 Bonds under the
terms of the Mortgage.



SECTION 9. The Trustee hereby accepts the trusts herein declared, provided and
created and agrees to perform the same upon the terms and conditions herein and in the Mortgage set
forth and upon the following teens and conditions:

The recitals contained herein and in the bonds shall be taken as the statements
of the Company and the Trustee assumes no responsibility for the correctness of the same. The
Trustee makes no representations as to the validity or adequacy of the security worded hereby, or as
to the validity of this Fiftieth Supplemental Indenture or of the 2023 Bond issued hereunder.



SECTION 10. Whenever in this Fiftieth Supplemental Indenture either of the
parties hereto is named or referred to, this shall, subject to the provisions of Article XVII of the
Original Mortgage, be deemed to include the successors or assigns of such party, and all the
covenants and agreements in this Fiftieth Supplemental Indenture contained by or on behalf of the
Company, or by or on behalf of the Trustee, shall, subject as aforesaid, bind and inure to the
benefit of the respective successors and assigns of such parties, whether so expressed or not.



SECTION 11. Nothing in this Fiftieth Supplemental Indenture expressed or implied,
is intended or shall be construed to confer upon, or to give to, any person, co-partnership or
corporation, other than the parties hereto and the holders of the bonds and coupons outstanding
under the Mortgage, any right, remedy; or claim under or by reason of this Fiftieth Supplemental -
Indenture or any covenant, condition or stipulation hereof; and all the covenants, conditions,
stipulations, promises and agreements in this Fiftieth Supplemental Indenture contained by or on
behalf of the Company shall be for the sole and exclusive benefit of the parties hereto and of the
holders of the bonds and of the coupons outstanding under the Mortgage.



SECTION 12. The Company covenants that all of the terms, provisions and
conditions of the Mortgage shall be applicable to the 2023 Bond issued hereunder, except as herein
otherwise provided and except insofar as the same may be inconsistent with the provisions of this
Fiftieth Supplemental Indenture.

SECTION 13. This Fiftieth Supplemental Indenture is
dated as of April 1, 2005, although executed and delivered on the date of the acknowledgement hereof
by the Trustee; and shall be simultaneously executed and delivered in several counterparts, and all
such counterparts executed and delivered, each as an original, shall constitute but one and the same
instrument.



IN WITNESS WHEREOF, INDIANAPOLIS POWER & LIGHT COMPANY, party of the first
part, has caused its corporate name to be hereunto affixed and this instrument to be signed and
acknowledged by its President or a Vice-President, and its corporate seal to be hereto affixed and
attested by its Secretary or an Assistant Secretary, for and on its behalf, and J.P. MORGAN TRUST
COMPANY, NATIONAL ASSOCIATION, AS SUCCESSOR IN INTEREST TO AMERICAN NATIONAL BANK AND TRUST COMPANY
OF CHICAGO, party of the second part, as Trustee, has caused its corporate name to be hereunto
affixed and this instrument to be signed and acknowledged by one of its Authorized Officers, and its
corporate seal to be hereto affixed and attested by one of its Authorized Officers, all as of the
day, month and year first above written.

INDIANAPOLIS POWER & LIGHT

COMPANY



By /s/ Hamsa Shadaksharappa

(SEAL)	HAMSA SHADAKSHARAPPA,

Senior Vice President Financial Services,

Chief Financial Officer and Secretary

Attest:



By: /s/ Connie Horwitz

CONNIE R. HORWITZ,

Treasurer and Assistant Secretary

J.P. MORGAN TRUST COMPANY, NATIONAL ASSOCIATION, AS SUCCESSOR IN INTEREST TO
AMERICAN NATIONAL BANK AND

TRUST COMPANY OF CHICAGO



By /s/ Derick Rush

Derick Rush,

Authorized Officer

Attest:
																	(SEAL)

By: /s/ Perette Ogrizovich

Perette Ogrizovich,

Authorized Officer

STATE OF INDIANA	)

) SS:

COUNTY OF MARION	)

On this 8th day of April, in the year 2005, before me, a Notary Public in and
for the County and State aforesaid, personally came HAMSA SHADAKSHARAPPA, Senior Vice President
Financial Services, Chief Financial Officer and Secretary and CONNIE R. HORWITZ, Treasurer and
Assistant Secretary, of Indianapolis Power & Light Company, one of the corporations described in
and which executed the foregoing instrument, to me personally known and known to me personally to be
such Senior Vice President Financial Services, Chief Financial Officer and Secretary and Treasurer
and Assistant Secretary, respectively. Said HAMSA SHADAKSHARAPPA and CONNIE R. HORWITZ being by me
severally duly sworn did depose and say that the said HAMSA SHADAKSHARAPPA resides in Marion County,
Indiana and the said CONNIE R. HORWITZ resides in Hamilton County, Indiana; that said HAMSA
SHADAKSHARAPPA is Senior Vice President Financial Services, Chief Financial Officer and Secretary
and said CONNIE R. HORWITZ is Treasurer and Assistant Secretary of said Indianapolis Power &
Light Company; that each of them knows the corporate seal of said corporation; that the seal affixed
to said instrument and bearing the name of said corporation is such corporate seal; that it was so
affixed by order of the Board of Directors of said corporation; and that each of them signed his
name thereto by like order; and each of them acknowledged the execution of said instrument on behalf
of said corporation to be his free and voluntary act and deed and the free and voluntary act and
deed of said corporation, for the uses and purposes therein set forth.

IN WITNESS WHEREOF, I have hereunto set my hand and affixed my official seal
this 8th day of April, 2005.



/s/ Catherine McDaniel

Catherine McDaniel,

Notary Public

My Commission Expires:

August 17, 2009

My County of Residence is:

Shelby

(NOTARIAL SEAL)





STATE OF INDIANA	)

) SS:

COUNTY OF MARION	)

On this 11th day of April, in the year 2005, before me, a Notary Public in
and for the County and State aforesaid, personally came Derick Rush and Perette Ogrizovich,
Authorized Officers of J.P. Morgan Trust Company, National Association, as successor in interest to
American National Bank and Trust Company of Chicago, one of the corporations described in and which
executed the foregoing instrument, to me personally known and known to me personally to be such
Authorized Officers. Said Derick Rush and Perette Ogrizovich, being by me severally sworn did depose
and say that the said Derick Rush resides in Hamilton County, Indiana, and that the said Perette
Ogrizovich resides in Hamilton County, Indiana; that said Derick Rush and Perette Ogrizovich, are
Authorized Officers of said J.P. Morgan Trust Company, National Association, as successor in
interest to American National Bank and Trust Company of Chicago; that each of them knows the
corporate seal of said corporation; that the seal affixed to said instrument and bearing the name of
said corporation is such corporate seal; that it was so affixed by authority of the Board of
Directors of said corporation; that each of them signed his name thereto by like authority; and each
of them acknowledged the execution of said instrument on behalf of said corporation to be his free
and voluntary act and deed and the free and voluntary act and deed of said corporation, for the uses
and purposes therein set forth.

IN WITNESS WHEREOF, I have hereunto set my hand and affixed my official seal
this 11th day of April, 2005.

/s/ Lucas Nathaniel Burgin

Lucas Nathaniel Burgin,

Notary Public

My Commission Expires:

June 23, 2011

My County of Residence is:

Hancock

(NOTARIAL SEAL)

This instrument was prepared by

Steven W. Thornton, Barnes & Thornburg,

11 South Meridian Street, Indianapolis, IN 46104