THE FIRST TRUST GNMA, SERIES 109
                         TRUST AGREEMENT
                    Dated:  January 20, 2010
     This  Trust Agreement among First Trust Portfolios L.P.,  as
Depositor,  The Bank of New York Mellon, as Trustee, First  Trust
Advisors  L.P.,  as  Evaluator and Portfolio Supervisor  and  FTP
Services  LLC,  as FTPS Unit Servicing Agent, sets forth  certain
provisions in full and incorporates other provisions by reference
to  the document entitled "Standard Terms and Conditions of Trust
for  The  First  Trust  GNMA, Series 96  and  certain  subsequent
Series,  Effective January 20, 2005" (herein called the "Standard
Terms  and  Conditions  of Trust"), and such  provisions  as  are
incorporated  by  reference constitute a single  instrument.  All
references  herein to Articles and Sections are to  Articles  and
Sections of the Standard Terms and Conditions of Trust.
                        WITNESSETH THAT:
     In   consideration  of  the  premises  and  of  the   mutual
agreements  herein  contained, the Depositor,  the  Trustee,  the
Evaluator,  the Portfolio Supervisor and the FTPS Unit  Servicing
Agent agree as follows:
                             PART I
             STANDARD TERMS AND CONDITIONS OF TRUST
     Subject  to  the  Provisions of  Part  II  hereof,  all  the
provisions  contained  in the Standard Terms  and  Conditions  of
Trust are herein incorporated by reference in their entirety  and
shall  be deemed to be a part of this instrument as fully and  to
the  same extent as though said provisions had been set forth  in
full in this instrument.
                             PART II
            SPECIAL TERMS AND CONDITIONS OF TRUST FOR
                THE FIRST TRUST GNMA, SERIES 109
     The following special terms and conditions are hereby agreed
to:
    (A)   The  Securities defined in Section  1.01(5)  listed  in
Schedule  A hereto have been deposited in trust under this  Trust
Agreement and shall include any securities deposited in the  Fund
pursuant to Section 2.01 hereof.
    (B)   The  number  of  Units  in the  Trust  referred  to  in
Section   2.03   is  set  forth  under  "Summary   of   Essential
Information - Initial Number of Units" in the Prospectus.
    (C)  For the Trust the First General Record Date shall be set
forth under "Summary of Essential Information" in the Prospectus.
    (D)   For  the Trust the First Settlement Date shall  be  set
forth  under "Summary of Essential Information - First Settlement
Date" in the Prospectus.
    (E)    For  the  Trust the Record Dates and the  Distribution
Dates shall be set forth under "Summary of Essential Information"
in the Prospectus.
    (F)  First Trust Advisors L.P.'s compensation as referred  to
in Section 4.03 of the Standard Terms and Conditions of Trust and
FTP Services LLC's compensation as referred to in Section 3.17 of
the Standard Terms and Conditions of Trust shall collectively  be
an annual fee in the amount of $0.0060 per Unit.
                            PART III
     A.   Notwithstanding any provision to the  contrary  in  the
Standard Terms and Conditions of Trust, the Trustee may deem  and
treat  the  FTPS Unit Servicing Agent as the sole Unit holder  of
FTPS  Units  for all purposes of the Indenture and shall  not  be
affected by any notice to the contrary.
     B.   Section  1.01 of the Standard Terms and  Conditions  of
Trust shall be amended to include the following:
          "Section 1.01(18).  "FTPS Unit" shall mean Units  which
     are purchased through the Fund/SERV(R) trading system or  on
     a  manual basis through FTP Services LLC or for FTP Services
     LLC is acting as FTPS Unit Servicing Agent."
          "Section  1.01(19). "FTPS Unit Servicing  Agent"  shall
     mean  FTP  Services LLC or any successor FTPS Unit servicing
     agent appointed as hereinafter provided."
     C.   Section  3.05. of the Standard Terms and Conditions  of
Sub-Trust shall be amended to include the following at the end of
sub-section (a)-(d):
          "(e)   deduct  from  the Interest Account  or,  to  the
     extent  funds  are not available in such Account,  from  the
     Principal  Account and pay to the FTPS Unit Servicing  Agent
     the  amount  that  it  is entitled to  receive  pursuant  to
     Section 3.17."
      D.    Paragraphs  4 and 5 of Section 3.05 of  the  Standard
Terms and Conditions of Trust shall be replaced in their entirety
with the following:
          The share of the balance in the Interest Account to  be
     distributed  to  a Holder of Units shall be computed  as  of
     each  Record  Date,  commencing with the first  Record  Date
     subsequent  to the date of the Holder's Certificate  (or  in
     the  case of Units held in uncertificated form, the date  of
     the    Holder's   initial   transaction   statement),    and
     distribution made as provided herein on or shortly after the
     next  following Distribution Date; provided,  however,  that
     any  distribution  which would be made  in  respect  of  the
     Distribution Date occurring in December shall  be  made  not
     later  than  December 31.  In making such  computation,  the
     Trustee   shall  treat  as  received  the  interest  amounts
     receivable by the Trust Fund on the Securities prior to  the
     next following Distribution Date in respect of a record date
     for the Securities occurring on or before the Record Date on
     which  the  computation is being made based on estimates  of
     such   receivable  amount  provided  the  Trustee   by   the
     Evaluator,  determined  by  the  Evaluator  in  the   manner
     provided in Section 5.01, on which the Trustee is authorized
     conclusively to rely.
           Distributions  of  amounts  represented  by  the  cash
     balance  in  the Principal Account shall be computed  as  of
     each  Record Date.  In making such computation, the  Trustee
     shall  subtract  the amount of any unpaid advances  due  the
     Trustee  and  shall  treat  as  received  principal  amounts
     receivable by the Trust Fund on the Securities prior to  the
     next following Distribution Date in respect of a record date
     for the Securities occurring on or before the Record Date on
     which  the  computation is being made based on estimates  of
     such   receivable  amount  provided  the  Trustee   by   the
     Evaluator,  determined  by  the  Evaluator  in  the   manner
     provided in Section 5.01, on which the Trustee is authorized
     conclusively to rely and shall take into account any amounts
     identified for reinvestment pursuant to Section 3.13 hereof.
     On  the  next  following  Distribution  Date,  or  within  a
     reasonable  period  of time thereafter,  the  Trustee  shall
     distribute by mail to each Holder of Units of record on  the
     Record  Date  at his post office address such  Holder's  pro
     rata  share of the cash balance of the Principal Account  as
     so computed on such Record Date; provided, however, that any
     distribution  which  would  be  made  in  respect   of   the
     Distribution Date occurring in December shall  be  made  not
     later  than December 31.  In the event the amount on deposit
     in  the  Principal  Account on a Distribution  Date  is  not
     sufficient for the payment of the amount of principal to  be
     distributed  on the basis of the aforesaid computation,  the
     Trustee shall advance out of its own funds and cause  to  be
     deposited  in  and  credited to the Principal  Account  such
     amount as may be required to permit payment of the principal
     distribution  to  be  made on such Distribution  Date.   The
     Trustee   shall  be  entitled  to  be  reimbursed,   without
     interest,  out of the principal received by the Trust  Fund,
     on  the first Record Date following the date of such advance
     on which such reimbursement may be made without reducing the
     balance  in  the Principal Account (calculated  treating  as
     received principal amounts receivable by the Trust  Fund  on
     the Securities prior to the next following Distribution Date
     as  provided in the first sentence of this paragraph) to  an
     amount   less  than  that  required  for  the  next  ensuing
     principal  distribution.  The Trustee shall not be  required
     to make a distribution from the Principal Account unless the
     cash  balance on deposit therein available for distribution,
     determined   as  provided  in  this  paragraph,   shall   be
     sufficient to distribute at least $1.00 per 1,000 Units.
     E.   Article  III  of the Standard Terms and  Conditions  of
Trust shall be amended to include the following section:
          "Section 3.17.  FTPS Unit Servicing Agent. FTP Services
     LLC  acts as record keeper, shareholder servicing agent  and
     distribution  agent for Units which are purchased  and  sold
     through the Fund/SERV(R) trading system or on a manual basis
     through  FTP Services LLC. ("FTPS Units").  (a) FTP Services
     LLC  shall  perform  all  of  the  duties  with  respect  to
     recordkeeping   of  FTPS  Units  and  FTPS   Unit   holders,
     distributions,  redemption of FTPS Units and  communications
     to and with FTPS Unit holders listed below.
          (1)   The  FTPS Unit Servicing Agent shall keep  proper
     books  of  record and account of all of the transactions  in
     the  FTPS  Units of each Trust under this Indenture  at  its
     corporate office, including a record of the name and address
     of,  and  the FTPS Units issued by each Trust and  held  by,
     every  FTPS Unit holder, and such books and records of  each
     Trust  shall  be  made  available to  the  Trustee  and  the
     Depositor  promptly upon request and open to  inspection  by
     any  FTPS  Unit holder of such Trust, with respect  to  such
     FTPS  Unit  holders  transactions, at all  reasonable  times
     during    usual  business   hours.   Without  limiting   the
     foregoing,  the  FTPS Unit Servicing Agent  shall  make  any
     records  or  documents described in Reg.  270.31(a)-1  under
     the Investment Company Act of 1940 available promptly to the
     Trustee and the Depositor upon request during usual business
     hours  and will preserve such records and documents for  the
     periods prescribed in Reg. 270.31(a)-2 thereunder.
          (2)  The FTPS Unit Servicing Agent shall distribute  on
     or  shortly  after the Distribution Dates specified  in  the
     Trust  Agreement to each FTPS Unit holder of record  on  its
     books  on  the  Record Date for each such Distribution  Date
     specified  in  the Trust Agreement such FTPS  Unit  holder's
     distribution  as  computed  under  the  Standard  Terms  and
     Conditions of Trust.
          (3)  In  connection with such distributions  set  forth
     above,  the  FTPS  Unit  Servicing  Agent  shall  furnish  a
     Distribution Statement to FTPS Unit holders of record on its
     books.   The  content  and frequency  of  such  Distribution
     Statements shall in no respect be less detailed or  frequent
     than  that  specified in Section 3.06 of the Standard  Terms
     and Conditions of Trust.
          (4)  The  FTPS Unit Servicing Agent shall  transmit  to
     each  FTPS  Unit  holder  of  record  any  notice  or  other
     communication received from the Trustee and shall be  solely
     responsible  for soliciting and transmitting to the  Trustee
     any notice required from FTPS Unit holders.
          (5)  The FTPS Unit Servicing Agent shall be responsible
     for  all  tax  reporting  required  from  time  to  time  by
     applicable  law and regulations with respect to  holders  of
     FTPS  Units, and reporting of cost basis in respect  of  the
     FTPS  Units  of such holders (including, without limitation,
     reporting  required  by  Section  6045(g)  of  the  Internal
     Revenue Code of 1986, as amended).
          (6)  For  purposes of permitting FTPS Unit  holders  to
     satisfy any reporting requirements of applicable federal  or
     state  tax law, the FTPS Unit Servicing Agent shall  provide
     the  Trustee  with the name, address, number of  FTPS  Units
     held  by,  and  such other information as requested  by  the
     Trustee, for every FTPS Unit holder so that the Trustee  can
     transmit to any FTPS Unit holder of record on the FTPS  Unit
     Servicing   Agent's  books  any  reports  required   to   be
     distributed  pursuant to Section 4.02 of the Standard  Terms
     and  Conditions  of  Trust.  The Trustee  may  rely  on  the
     accuracy and completeness of the information (including  any
     records or documents made available) provided to it  by  the
     FTPS  Unit  Servicing Agent and may accept such  information
     without  inquiry.  Each of the Depositor and the  FTPS  Unit
     Servicing  Agent  hereby agree, jointly  and  severally,  to
     indemnify  the  Trustee and hold Trustee harmless  from  and
     against  any  and  all costs, expenses, penalties,  damages,
     liabilities  or claims including attorneys' and accountants'
     fees  sustained  or  incurred by  or  asserted  against  the
     Trustee  by  reason  of  or  as  a  result  of  any  of  the
     information  provided  to  the  Trustee  by  the  FTPS  Unit
     Servicing  Agent  being  inaccurate  or  incomplete.    This
     indemnity  shall be a continuing obligation of each  of  the
     Depositor  and  the  FTPS Unit Servicing  Agent,  and  their
     successors  and assigns, notwithstanding the termination  of
     this Trust Agreement.
          (7)  The FTPS Unit Servicing Agent shall distribute  to
     redeeming   FTPS  Unit  holders  of  record  on  its   books
     redemption proceeds it receives pursuant to Section 5.02  of
     the  Standard Terms and Conditions of Trust from the Trustee
     as  the  sole  record owner of FTPS Units on  the  Trustee's
     books.
          (8)  The FTPS Unit Servicing Agent shall distribute  to
     FTPS  Unit holders of record on its books a pro rata portion
     of termination proceeds it receives pursuant to Section 8.02
     of  the  Standard  Terms and Conditions of  Trust  from  the
     Trustee  as  the  sole record owner of  FTPS  Units  on  the
     Trustee's books.
          (9)  In  connection with such termination distributions
     set forth above, the FTPS Unit Servicing Agent shall furnish
     a  Final  Distribution  Statement to FTPS  Unit  holders  of
     record on its books.  The content of such Final Distribution
     Statements  shall in no respect be less detailed  than  that
     specified  in  Section  8.02  of  the  Standard  Terms   and
     Conditions of Trust.
          (10)  As requested by the Depositor and/or the Trustee,
     the  FTPS  Unit  Servicing Agent shall  perform  such  other
     functions which, from time to time, are agreed upon  by  the
     parties hereto and which may give rise to additional fees.
     (b)   As  compensation for providing the services set  forth
herein,  of a character described in Section 26(a)(2)(C)  of  the
Investment  Company  Act of 1940, and to  the  extent  that  such
services  are in addition to, and do not duplicate, the  services
to  be  performed by the Trustee, FTP Services LLC shall receive,
in arrears, against a statement or statements therefore submitted
to the Trustee monthly or annually an aggregate annual fee in the
per  Unit amount set forth in Part II of the Trust Agreement  for
the  Trust,  calculated  based on the  largest  number  of  Units
outstanding  during the calendar year, except during the  initial
offering  period  as determined in Section 4.01 of  the  Standard
Terms  and  Conditions  of  Trust,  in  which  case  the  fee  is
calculated  based  on  the largest number  of  Units  outstanding
during the period for which the compensation is paid (such annual
fee  to  be pro rated for any calendar year in which FTP Services
LLC provides services described herein during less than the whole
of  such year).  Such fee may exceed the actual cost of providing
such services for the Trust, but at no time will the total amount
received by FTP Services LLC for rendering the services described
in this Section 3.17 and First Trust Advisors, L.P. for rendering
the  services described in Section 4.03 to unit investment trusts
of which the Depositor is the sponsor in any calendar year exceed
the  aggregate cost to FTP Services LLC and First Trust Advisors,
L.P.  of supplying such services in such year.  Such compensation
may,  from  time  to time, be adjusted by the Depositor  provided
that  the total adjustment upward does not, at the time  of  such
adjustment,  exceed the percentage of the total  increase,  after
the  date hereof, in consumer prices for services as measured  by
the  United  States  Department of  Labor  Consumer  Price  Index
entitled "All Services Less Rent of Shelter" or similar index, if
such  index  should  no  longer be  published.   The  consent  or
concurrence  of any Unit holder hereunder shall not  be  required
for  any such adjustment or increase. Such compensation shall  be
paid  by  the Trustee, upon receipt of an invoice therefore  from
FTP  Services  LLC, which shall constitute the representation  by
FTP Services LLC that the bookkeeping and administrative services
for  which  compensation  is  claimed  are  properly  compensable
hereunder  and that the aggregate cost incurred by  FTP  Services
LLC  of  providing FTPS Unit shareholder servicing hereunder  was
not less than the compensation claimed, upon which representation
the  Trustee may conclusively rely.  Such compensation  shall  be
charged  against  the  Interest  and/or  Principal  Accounts,  in
accordance with Section 3.05 of the Standard Terms and Conditions
of Trust.
     If  the  cash balance in the Interest and Principal Accounts
shall be insufficient to provide for amounts payable pursuant  to
this  Section 3.17, the Trustee shall have the power to sell  (i)
Securities from the current list of Securities designated  to  be
sold  pursuant  to  Section  5.02 hereof,  or  (ii)  if  no  such
Securities  have  been  so designated,  such  Securities  as  the
Trustee  may see fit to sell in its own discretion, and to  apply
the  proceeds of any such sale in payment of the amounts  payable
pursuant to this Section 3.17.
     All moneys payable to the FTPS Unit Servicing Agent pursuant
to  this  Section 3.17 shall be secured by a lien  on  the  Trust
prior to the interest of Unit holders, but no such lien shall  be
prior to any lien in favor of the Trustee under the provisions of
Section 6.04 of the Standard Terms and Conditions of Trust.
      (c)   The  FTPS  Unit Servicing Agent  shall  be  under  no
liability  for  any action taken in good faith on any  appraisal,
paper,  order, list, demand, request, consent, affidavit, notice,
opinion,    direction,   evaluation,   endorsement,   assignment,
resolution, draft or other document, whether or not of  the  same
kind,  prima  facie properly executed, or for the disposition  of
moneys,  pursuant to this Indenture, except by reason of its  own
negligence,  lack  of good faith or willful misconduct,  provided
that  the  FTPS Unit Servicing Agent shall not in any  event   be
liable or responsible for any evaluation made by the Evaluator.
     (d)  Except as the context otherwise requires, the FTPS Unit
Servicing  Agent  shall be subject to the provisions  of  Section
4.05  herein  in  the  same manner as it would  if  it  were  the
Evaluator.
     (e)   The  FTPS  Unit Servicing Agent shall  be  indemnified
ratably by the affected Trust and held harmless against any  loss
or  liability  accruing to it without negligence,  bad  faith  or
willful  misconduct on its part, arising out of or in  connection
with  the  operations  of  the Trust,  including  the  costs  and
expenses (including counsel fees) of defending itself against any
claim  of liability in the premises, including without limitation
any  loss,  liability or expense incurred in acting  pursuant  to
written directions to the FTPS Unit Servicing Agent given  by the
Trustee  or  Depositor from time to time in accordance  with  the
provisions of this Indenture or in undertaking actions from  time
to  time  which the FTPS Unit Servicing Agent deems necessary  in
its  discretion to protect the Trust and the rights and interests
of the FTPS Unit holders pursuant to the terms of this Indenture.
     (f)   The  FTPS  Unit  Servicing  Agent  shall  conduct  its
operations  in  a  manner  that is compatible  with  the  current
operational   procedures   and  requirements   of   the   Trustee
(including,  without limiting the foregoing,  the  provision  and
receipt  of  data  in  such  format and  meeting  such  technical
requirements  as the Trustee may specify) and shall exercise  its
best  efforts  to  accommodate any  changes  in  the  operational
procedures and requirements which the Trustee may make upon prior
notice   to  the  FTPS  Unit  Servicing   Agent.   The  Depositor
acknowledges  and  agrees  that the  default  of  the  FTPS  Unit
Servicing Agent in its obligations under this paragraph,  or  the
performance  by the FTPS Unit Servicing Agent of its  obligations
in   a   manner  which  shall  adversely  affect  the   Trustee's
performance of its duties, shall be a sufficient grounds for  the
Trustee  to  remove  the FTPS Unit Servicing  Agent  pursuant  to
Section 3.17(d) and Section 4.05.
     (g)   As used in this Section 3.17, FTPS Unit holder,"  when
referring to the records of the Trustee, shall mean the FTPS Unit
Servicing  Agent  and,  when  referring  to  the  records  to  be
maintained  by  the FTPS Unit Servicing Agent,  shall  mean  each
owner  of a FTPS Unit identified on the records of the FTPS  Unit
Servicing Agent."
     F.   Section  4.01 of the Standard Terms and  Conditions  of
Trust  shall be amended to include the FTPS Unit Servicing  Agent
among  the  parties who are furnished information concerning  the
Evaluation of each issue of Securities deposited in the Trust and
the Trust Fund Evaluation.
     G.  The last sentence of the first paragraph of Section 3.14
shall be replaced with the following:
          "Such fee may exceed the actual cost of providing  such
     services for the Trust, but at no time will the total amount
     received  by  First Trust Advisors, L.P. for  rendering  the
     services described in this Section 3.14 and FTP Services LLC
     for rendering the services described in Section 3.17 to unit
     investment  trusts of which the Depositor is the sponsor  in
     any  calendar year exceed the aggregate cost to FTP Services
     LLC  and  First  Trust  Advisors,  L.P.  of  supplying  such
     services in such year."
     H.   Section  4.04 of the Standard Terms and  Conditions  of
Trust  shall  be amended to include the Fund/SERV  Eligible  Unit
Servicing Agent replaced in its entirety by the following:
          "Section  4.04.  Liability of Evaluator.  The  Trustee,
     FTPS  Unit  Servicing Agent, Depositor and the Unit  holders
     may  rely  on any Evaluation furnished by the Evaluator  and
     shall have no responsibility for the accuracy thereof.   The
     determinations made by the Evaluator hereunder shall be made
     in  good  faith  upon  the  basis of  the  best  information
     available  to it.  The Evaluator shall be under no liability
     to  the Trustee, FTPS Unit Servicing Agent, Depositor or the
     Unit  holders  for  errors in judgement; provided,  however,
     that  this provision shall not protect the Evaluator against
     any  liability  to which it would otherwise  be  subject  by
     reason of willful misfeasance, bad faith or gross negligence
     in  the  performance  of its duties  or  by  reason  of  its
     reckless disregard of its obligations and duties hereunder."
     I.   The  second sentence of the first paragraph of  Section
5.01  shall be amended to delete subsection (ii) of such sentence
and replace it in its entirety with the following:
          "(ii)  amounts representing estimated accrued  expenses
     of  such Trust including but not limited to unpaid fees  and
     expenses  of  the  Trustee,  the  Evaluator,  the  Portfolio
     Supervisor, the FTPS Unit Servicing Agent, the Depositor and
     its  counsel, in each case as reported by the Trustee to the
     Depositor on or prior to the date of Evaluation,"
      J.    The  fifth sentence in the first paragraph of Section
5.01 shall be replaced in its entirety with the following:
          During  the period in any month prior to the time  when
     the  principal  to  be distributed on the next  distribution
     date  and  the  current outstanding principal  amount  of  a
     Security  is publicly available, the Trustee will  base  its
     calculation  of  (i) cash in the process of being  collected
     with respect to such Security and (ii) interest accruing  on
     the  outstanding  principal amount of such Security  on  the
     average  prepayment experience (as defined in  Section  4.01
     hereof)  with  respect  to such Security  during  the  three
     preceding  months (or since the issuance of the Security  if
     such  Security has been outstanding less than three  months)
     applied  to the principal amount outstanding at the  end  of
     the  second preceding month, as determined by the  Evaluator
     upon   which   determination  the  Trustee   is   authorized
     conclusively to rely.
     K.   Section 6.01(c) of the Standard Terms and Conditions of
Trust shall be replaced in its entirety with the following:
          "(c)  The  Trustee shall not be responsible for  or  in
     respect  of the recitals herein, the validity or sufficiency
     of  this  Indenture or for the due execution hereof  by  the
     Depositor, the Portfolio Supervisor, the Evaluator,  or  the
     FTPS  Unit  Servicing  Agent, or for  the  form,  character,
     genuineness, sufficiency, value or validity of  any  of  the
     Securities (except that the Trustee shall be responsible for
     the  exercise of due care in determining the genuineness  of
     Securities  delivered to it pursuant to  contracts  for  the
     purchase  of  such Securities) or for or in respect  of  the
     validity or sufficiency of the Units or  of the Certificates
     (except for the due execution thereof by the Trustee) or for
     the  due execution thereof by the Depositor, and the Trustee
     shall  in  no event assume or incur any liability,  duty  or
     obligation to any Unit holder, the FTPS Unit Servicing Agent
     or  the  Depositor  other  than as  expressly  provided  for
     herein.   The  Trustee shall not be responsible  for  or  in
     respect of the validity of any signature by or on behalf  of
     the  Depositor, the Portfolio Supervisor, the  Evaluator  or
     the FTPS Unit Servicing Agent;"
      L.  Section 8.02(b) of the Standard Terms and Conditions of
Trust shall be replaced in its entirety with the following:
          "(b) deduct from the Interest Account of such Trust or,
     to  the extent that funds are not available in such Account,
     from  the  Principal Account of such Trust, and pay  accrued
     and  unpaid fees of the Evaluator, the Portfolio Supervisor,
     the FTPS Unit Servicing Agent, the Depositor and counsel  in
     connection with such Trust, if any;"
     M.   Section  8.05 of the Standard Terms and  Conditions  of
Trust shall be amended to add the following paragraph immediately
preceding the last paragraph of such section:
          "Any  notice,  demand, direction or instruction  to  be
     given  to the FTPS Unit Servicing Agent shall be in  writing
     and  shall be duly given if mailed or delivered to the  FTPS
     Unit  Servicing  Agent at ▇▇▇ ▇. ▇▇▇▇▇▇▇ ▇▇▇▇▇,  ▇▇▇▇▇  ▇▇▇,
     ▇▇▇▇▇▇▇,  ▇▇▇▇▇▇▇▇ ▇▇▇▇▇, or at such other address as  shall
     be  specified by the FTPS Unit Servicing Agent to the  other
     parties hereto in writing."
     N.    Section 6.01 shall be amended to add the following  as
paragraph (n):
          "(n)   The   Trustee  may  act,  and  may  engage   any
     corporation, partnership or other entity affiliated with The
     Bank of New York Mellon (an "Affiliated Entity") to act,  as
     broker  or  dealer  to execute transactions,  including  the
     purchase  or  sale of any securities currently  distributed,
     underwritten  or  issued  by  any  Affiliated  Entity,   and
     receive,  or  pay to the Affiliated Entity,  as  applicable,
     compensation for such services at standard commission rates,
     markups or concessions."
     O.     Notwithstanding  anything  to  the  contrary  in  the
Standard  Terms and Conditions of Trust, Section  3.14  shall  be
deleted in its entirety.
     P.     Notwithstanding  anything  to  the  contrary  in  the
Standard  Terms and Conditions of Trust, Section  4.03  shall  be
deleted in its entirety and replaced with the following:
          "   Section 4.03.   Compensation for Services Provided.
     As compensation for providing portfolio supervisory services
     in its capacity as Portfolio Supervisor, evaluation services
     in  its capacity as Evaluator, and for providing bookkeeping
     and  other  administrative  services  to  the  Trust  of   a
     character described in Section 26(a)(2)(C) of the Investment
     Company  Act  of 1940, and to the extent that such  services
     are in addition to, and do not duplicate, the services to be
     provided  hereunder  by the Trustee, First  Trust  Advisors,
     L.P.  shall  receive,  in arrears, against  a  statement  or
     statements  therefor  submitted to the  Trustee  monthly  or
     annually an aggregate annual fee in the per Unit amount  set
     forth  in  Part  II of the Trust Agreement  for  the  Trust,
     calculated  based on the largest number of Units outstanding
     during the calendar year, except during the initial offering
     period  as determined in Section 4.01 of this Indenture,  in
     which case the fee is calculated based on the largest number
     of  Units  outstanding  during  the  period  for  which  the
     compensation  is paid (such annual fee to be pro  rated  for
     any  calendar  year  in  which First  Trust  Advisors,  L.P.
     provides  services  described herein during  less  than  the
     whole of such year).  Such fee may exceed the actual cost of
     providing  such services for the Trust, but at no time  will
     the  total amount received by First Trust Advisors, L.P. for
     rendering  the services described in this Section  4.03  and
     FTP  Services  LLC for rendering the services  described  in
     Section  3.17  to  unit  investment  trusts  of  which   the
     Depositor  is  the sponsor in any calendar year  exceed  the
     aggregate  cost  to  First  Trust  Advisors,  L.P.  and  FTP
     Services LLC of supplying such services in such year.   Such
     compensation  may,  from time to time, be adjusted  provided
     that  the total adjustment upward does not, at the  time  of
     such adjustment, exceed the percentage of the total increase
     after  the  date hereof in consumer prices for  services  as
     measured  by the United States Department of Labor  Consumer
     Price Index entitled "All Services Less Rent of Shelter"  or
     similar  index, if such index should no longer be published.
     The  consent  or  concurrence of any Unit  holder  hereunder
     shall  not  be required for any such adjustment or increase.
     Such compensation shall be paid by the Trustee, upon receipt
     of  an  invoice  therefor from First Trust  Advisors,  L.P.,
     which  shall  constitute the representation by  First  Trust
     Advisors,  L.P.  that  the  bookkeeping  and  administrative
     services  for  which  compensation is claimed  are  properly
     compensable  hereunder and that the aggregate cost  incurred
     by   First  Trust  Advisors,  L.P.  of  providing  portfolio
     supervisory,  evaluation and bookkeeping and  administrative
     services  hereunder  was  not  less  than  the  compensation
     claimed,   upon   which  representation  the   Trustee   may
     conclusively  rely.   Such  compensation  shall  be  charged
     against the Interest and/or Principal Accounts in accordance
     with Section 3.05."
     If  the  cash balance in the Interest and Principal Accounts
     shall   be  insufficient  to  provide  for  amounts  payable
     pursuant  to this Section 4.03, the Trustee shall  have  the
     power  to  sell  (i)  Securities from the  current  list  of
     Securities  designated to be sold pursuant to  Section  5.02
     hereof,  or  (ii)  if  no  such  Securities  have  been   so
     designated, such Securities as the Trustee may  see  fit  to
     sell in its own discretion, and to apply the proceeds of any
     such sale in payment of the amounts payable pursuant to this
     Section 4.03.
     Any moneys payable to First Trust Advisors, L.P. pursuant to
     this  Section 4.03 shall be secured by a lien on  the  Trust
     prior  to  the  interest of Unit holders, but no  such  lien
     shall be prior to any lien in favor of the Trustee under the
     provisions of Section 6.04 herein."
     Q.     Notwithstanding  anything  to  the  contrary  in  the
Standard  Terms and Conditions of Trust, Section  4.03  shall  be
deleted in its entirety and replaced with the following:
          "Section  4.05.  Resignation and Removal  of  Portfolio
     Supervisor  and/or Evaluator and/or Provider of  Bookkeeping
     Services Described in Section 4.03; Successor.
     (a)  First  Trust Advisors, L.P. and any successor appointed
     as  hereafter provided, in its capacity as Evaluator  and/or
     Portfolio Supervisor and/or provider of bookkeeping services
     described  in  Section 4.03, may resign  and  be  discharged
     hereunder  by  executing  an instrument  of  resignation  in
     writing  and  filing  the same with the  Depositor  and  the
     Trustee,  not less than sixty days before the date specified
     in  such  instrument when, subject to Section 4.05(e),  such
     resignation  is to take effect.  Upon receiving such  notice
     of  resignation,  the Depositor and the  Trustee  shall  use
     their  best  efforts to appoint a successor to  act  in  the
     capacity as to which the resignation applies, such successor
     to  have  qualifications and to be compensated at a rate  of
     compensation satisfactory to the Depositor and the  Trustee.
     Such   appointment  shall  be  made  by  written  instrument
     executed by the Depositor and the Trustee, in duplicate, one
     copy of which shall be delivered to the resigning party  and
     one copy to the successor.  The Depositor or the Trustee may
     remove  the  Evaluator  and/or Portfolio  Supervisor  and/or
     party performing bookkeeping and administrative services  at
     any  time  upon  thirty days' written notice and  appoint  a
     successor  to  act  in  the capacity to  which  the  removed
     applies,  such successor to have qualifications  and  to  be
     compensated  at a rate of compensation satisfactory  to  the
     Depositor and the Trustee, provided, however, that  so  long
     as  First Trust Portfolios L.P. is acting as Depositor,  the
     Trustee shall have no power to remove any affiliate  of  the
     Depositor  who  may  be  acting  in  any  such  capacity  or
     capacities.   Such  appointment shall  be  made  by  written
     instrument  executed by the Depositor and  the  Trustee,  in
     duplicate, one copy of which shall be delivered to the party
     removed  and  one  copy to its successor.   Notice  of  such
     resignation or removal and appointment of a successor  shall
     be  mailed  by  the  Trustee to each  Unit  holder  then  of
     record."
     (b)   Any  successor  evaluator and/or  successor  portfolio
     supervisor and/or provider of bookkeeping and administrative
     services   described  in  Section  4.03,   as   appropriate,
     appointed hereunder, shall execute, acknowledge and  deliver
     to  the  Depositor  and the Trustee an instrument  accepting
     such  appointment hereunder, and such successor without  any
     further act, deed or conveyance shall become vested with all
     the   rights,   powers,  duties  and  obligations   of   its
     predecessor  hereunder  with like effect  as  if  originally
     named  herein  and  shall be bound  by  all  the  terms  and
     conditions of this Indenture.
     (c)   The  Portfolio Supervisor may employ one or more  sub-
     Portfolio  Supervisors to assist in performing the  services
     set  forth  in this Section 4.05 and shall not be answerable
     for  the  default of any such sub-Portfolio  Supervisors  if
     such sub-Portfolio Supervisors shall have been selected with
     reasonable  care,  provided,  however,  that  the  Portfolio
     Supervisor  will indemnify and hold the Trust harmless  from
     and  against  any  loss occurring as  a  result  of  a  sub-
     Portfolio   Supervisor's   willful   misfeasance,   reckless
     disregard,  bad  faith,  or gross negligence  in  performing
     supervisory duties.  The fees and expenses charged  by  such
     sub-Portfolio  Supervisors shall be paid  by  the  Portfolio
     Supervisor  out  of  proceeds  received  by  the   Portfolio
     Supervisor in accordance with Section 4.03 hereof.
     (d)   In  case  at  any time the Evaluator and/or  Portfolio
     Supervisor and/or provider of bookkeeping and administrative
     services  described  in Section 4.03  shall  resign  and  no
     successor  shall  have  been  appointed  and  have  accepted
     appointment  within thirty days after notice of  resignation
     has  been  received by the Depositor and  the  Trustee,  the
     resigning  party may forthwith apply to a court of competent
     jurisdiction for the appointment of a successor.  Such court
     may  thereupon  after such notice, if any, as  it  may  deem
     proper and prescribe, appoint a successor.
     (e)    Any  corporation  into  which  the  Evaluator  and/or
     Portfolio  Supervisor  and/or provider  of  bookkeeping  and
     administrative services described in Section 4.03  hereunder
     may  be merged or with which it may be consolidated, or  any
     corporation  resulting from any merger or  consolidation  to
     which  the  Evaluator  and/or  Portfolio  Supervisor  and/or
     provider   of   bookkeeping   and  administrative   services
     described in Section 4.03 hereunder shall be a party,  shall
     be  the successor under this Indenture without the execution
     or filing of any paper, instrument or further act to be done
     on  the part of the parties hereto, notwithstanding anything
     to  the  contrary  contained  herein  or  in  any  agreement
     relating  to  such  merger  or consolidation  by  which  the
     Evaluator  and/or  Portfolio Supervisor and/or  provider  of
     bookkeeping   and  administrative  services   described   in
     Section  4.03 may seek to retain certain powers, rights  and
     privileges for any period of time following such  merger  or
     consolidation.
     (f)   Any  resignation  or removal of the  Evaluator  and/or
     Portfolio  Supervisor  and/or provider  of  bookkeeping  and
     administrative  services described  in  Section  4.03  shall
     become  effective  upon  acceptance of  appointment  by  the
     successor as provided in subsection (b) hereof."
     R.     Notwithstanding  anything  to  the  contrary  in  the
Standard Terms and Conditions of Trust, Section 3.05 (b) shall be
deleted  in  its  entirety and Section  3.05(d)  shall  refer  to
Section 4.03 rather than Section 3.14.
      S.    Notwithstanding  anything  to  the  contrary  in  the
Standard Terms and Conditions of Trust, Section 1.01(3) shall  be
amended to delete the reference to Securities Evaluation Service,
Inc. and replace it with First Trust Advisors L.P.
      T.    Notwithstanding  anything  to  the  contrary  in  the
Standard Conditions of Trust, paragraph (e) of Section 6.05 shall
be amended by adding the following sentence at the end thereof:
      "The  Trustee's  and  each  successor  Trustee's  right  to
indemnification shall survive its resignation or removal."
      U.    Section 6.04 of the Standard Terms and Conditions  of
Trust  shall be amended to add the following sentence at the  end
of the First paragraph thereof:
          "The Bank of New York Mellon, or any of its affiliates,
     may perform services in any capacity for any exchange traded
     fund,  investment company, investment trust or other  entity
     whose shares are held as an asset of the Trust, and the Bank
     of New York Mellon, as Trustee, shall be entitled to receive
     the     foregoing    compensation,    without     reduction,
     notwithstanding  that  the Bank of New  York  Mellon  or  an
     affiliate  is  receiving compensation for services  to  such
     exchange  traded fund, investment company, investment  trust
     or other entity."
      V.    All  references  to  The  Bank  of New  York  in  the
Standard  Terms and  Conditions  of Trust shall be replaced  with
"The Bank of New York Mellon."
     W.    Any  notice,  demand, direction or instruction  to  be
given  to either the Depositor, Portfolio Supervisor or Evaluator
shall  be  in  writing  and  shall be duly  given  if  mailed  or
delivered  to  such party at ▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇,  ▇▇▇▇▇  ▇▇▇,
▇▇▇▇▇▇▇,  ▇▇▇▇▇▇▇▇ ▇▇▇▇▇, or at such other address  as  shall  be
specified by the Depositor, Portfolio Supervisor or Evaluator  to
the other parties hereto in writing.
      X.    Article  IV of the Standard Terms and  Conditions  of
Trust shall be amended to add the following:
          "Section 4.06.  Liability of Portfolio Supervisor.  The
     Portfolio Supervisor shall be under no liability to the Unit
     holders  for  any  action taken or for refraining  from  the
     taking  of  any  action  in good  faith   pursuant  to  this
     Indenture  or  for errors in judgment, but shall  be  liable
     only  for  its own willful misfeasance, bad faith  or  gross
     negligence in the performance of its duties or by reason  of
     its   reckless  disregard  of  its  obligations  and  duties
     hereunder."
      Y.    Notwithstanding  anything  to  the  contrary  in  the
Standard  Terms  and Conditions of Trust, the  last  sentence  of
Section 3.01 shall be replaced with the following:
           "As used herein, the Depositor's reimbursable expenses
     of  organizing  the  Trust shall include  the  cost  of  the
     initial  preparation  and typesetting  of  the  registration
     statement,      prospectuses     (including      preliminary
     prospectuses),  the indenture, and other documents  relating
     to  the Trust, SEC and state blue sky registration fees, the
     cost of the initial valuation of the portfolio and audit  of
     the  Trust, the costs of a portfolio consultant, if any, the
     initial   fees  and expenses of the Trustee, and  legal  and
     other  out-of-pocket  expenses  related  thereto,  but   not
     including   the  expenses  incurred  in  the   printing   of
     preliminary prospectuses and prospectuses, expenses incurred
     in  the  preparation  and printing of  brochures  and  other
     advertising materials and any other selling expenses."
      Z.  Section  2.03 of the Standard Terms and  Conditions  of
Trust  is  amended by adding the following paragraph to  the  end
thereof:
          "Notwithstanding any provisions of the Indenture to the
     contrary, Units shall be held solely in uncertificated  form
     evidenced by appropriate notation in the registration  books
     of  the Trustee, and no Unit holder shall be entitled to the
     issuance of a Certificate evidencing the Units owned by such
     Unit holder.  The only permitted registered holders of Units
     shall be (i) Depository Trust Company (or its nominee,  Cede
     &  Co.),  (ii) the FTPS Unit Servicing Agent, or (iii)  Unit
     holders  who purchase or otherwise hold their Units  through
     Advisor  Direct  ("Advisor  Direct holders");  consequently,
     individuals who are not Advisor Direct holders or holders of
     FTPS Units must hold their Units through an entity which  is
     a  participant  in  Depository  Trust  Company.   Except  as
     provided by the preceding provisions of this paragraph,  the
     rights  specified  in  this Indenture of  holders  of  Units
     evidenced by a Certificate shall apply to holders  of  Units
     held in uncertificated form."
     AA. Notwithstanding anything to the contrary in the Standard
Terms  and Conditions of Trust, Section 3.15 shall be amended  by
adding the following sentences at the end thereof:
            "To  the  extent  permitted  by  applicable  law  and
     regulatory  authorization, unpaid portions of  the  deferred
     sales  charge  shall be secured by a lien on  the  Trust  in
     favor  of  the Depositor, provided that such lien  shall  be
     subordinate  to the lien of the Trustee granted  by  Section
     6.04 of the Standard Terms and Conditions of Trust.  To  the
     extent  of such lien, the Trustee shall hold the assets   of
     the  Trust  for the benefit of the Depositor, provided  that
     the  Trustee  is  authorized to dispositions,  distributions
     and   payments  for expenses in the ordinary course  of  the
     administration of the trust without regard to such lien."
      BB.   Notwithstanding  anything  to  the  contrary  in  the
Standard  Terms  and  Conditions of Trust, Section  6.02  of  the
Standard Terms is amended to add the following as the penultimate
paragraph:
          Cost-basis  reporting for Unit holders who purchase  or
     hold  their  Units  through the First Trust  Advisor  Direct
     system  ("Advisor  Direct"). The  Depositor  shall  maintain
     information required for the reporting of the cost basis  of
     Advisor  Direct holders (as defined in section  2.03(b))  as
     may  be  required  from  time  to  time  by  applicable  law
     (including,  without  limitation,  Section  6045(g)  of  the
     Internal  Revenue Code of 1986, as amended) and regulations,
     and the Depositor shall be responsible for the reporting  of
     such  information  to  the Advisor  Direct  holders,  or  if
     reporting  by  the Depositor is not permitted by  applicable
     law  or regulation or if the Depositor and Trustee otherwise
     agree  that  the Trustee shall report such information,  the
     Depositor shall provide the Trustee such information as will
     permit   the   Trustee   to  provide   required   cost-basis
     information to the Advisor Direct holders and shall  provide
     the  information  at  such times and in  such  form  as  the
     Trustee may reasonably request. The Depositor will be solely
     responsible  for the accuracy of such cost-basis information
     and  the  reporting thereof to Advisor Direct  holders    as
     provided  above. The Trustee may rely conclusively upon  the
     cost-basis  information  provided  by  the  Depositor   with
     respect  to Advisor Direct holders, and shall be indemnified
     in  accordance  with Section 6.04 of the Indenture   against
     any loss or liability, including any penalty or other charge
     imposed  by  any taxing authority in respect of  such  cost-
     basis information or reporting thereof made by the Depositor
     as provided in this paragraph.
    IN  WITNESS WHEREOF, First Trust Portfolios L.P., The Bank of
New  York  Mellon and First Trust Advisors L.P. and FTP  Services
LLC  have each caused this Trust Agreement to be executed and the
respective  corporate seal to be hereto affixed and attested  (if
applicable) by authorized officers; all as of the day, month  and
year first above written.
                                 FIRST TRUST PORTFOLIOS L.P.,
                                       Depositor
                                 By:   ▇▇▇▇▇ ▇. ▇▇▇▇▇
                                       Senior Vice President
                                 THE BANK OF NEW YORK MELLON,
                                       Trustee
                                 By:   ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                       Managing Director
[SEAL]
ATTEST:
▇▇▇▇ ▇. ▇▇▇▇▇▇
Vice President
                                 FIRST TRUST ADVISORS L.P.,
                                       Evaluator
                                 By:   ▇▇▇▇▇ ▇. ▇▇▇▇▇
                                       Senior Vice President
                                 FIRST TRUST ADVISORS L.P.,
                                       Portfolio Supervisor
                                 By:   ▇▇▇▇▇ ▇. ▇▇▇▇▇
                                       Senior Vice President
                                 FTP SERVICES LLC,
                                       FTPS Unit Servicing Agent
                                 By:   ▇▇▇▇▇ ▇. ▇▇▇▇▇
                                       Senior Vice President
                  SCHEDULE A TO TRUST AGREEMENT
                      SECURITIES DEPOSITED
                               IN
                   THE FIRST TRUST, SERIES 109
(Note: Incorporated  herein and made a  part  hereof  is  the
       "Portfolio"  for  Series  109  as  set  forth  in  the
       Prospectus  and  any  other  securities  that  may  be
       deposited  subsequent to the Initial Date  of  Deposit
       pursuant to this Trust Agreement.)
                  SCHEDULE B TO TRUST AGREEMENT
                THE FIRST TRUST GNMA, SERIES 109
           NOTICE OF DEPOSIT OF ADDITIONAL SECURITIES
     Dated: ____________, 2010
     Pursuant  to  Section  2.01  of the  Trust  Agreement  dated
January 20, 2010 among First Trust Portfolios L.P., as Depositor,
The  Bank  of  New York Mellon, as Trustee, First Trust  Advisors
L.P.,  as  Evaluator, and First Trust Advisors L.P., as Portfolio
Supervisor   (the   "Trust  Agreement"),  the  Depositor   hereby
certifies to the Trustee as follows:
          (a)    The  additional securities listed in Appendix  A
     hereto   are   hereby  deposited  in  trust   and   have   a
     substantially  equal  percentage  relationship  between  the
     principal  amounts  of the Securities of specified  interest
     rates  and  years of maturity as specified  in  the  Trust's
     prospectus dated January 20, 2010.
          (b)    In  accordance with Section 2.03  of  the  Trust
     Agreement,  an  additional ______________  Units  should  be
     issued  as a result of the deposit referred to in (a) above.
     Taking  into  account the above Units, the total  number  of
     Units  in  the  Trust issued as of the date of  this  notice
     is_____________
          (c)    Taking  into account that Units  issued  in  (b)
     above, the fractional undivided interest in and ownership of
     the Trust represented by each Unit is _________
                              FIRST TRUST PORTFOLIOS L.P.
                              By