Exhibit 10.4


 


June 11, 2015


 


Chart Acquisition Corp.


555 5th Avenue, 19th Floor


New York, New York 10017


 


Deutsche Bank Securities Inc.


60 Wall Street, 4th Floor


New York, New York 10005


 


Cowen and Company, LLC


599 Lexington Avenue


New York, New York10022


 


Re:     Initial Public
Offering


 


Ladies and Gentlemen:


 


This third amended
and restated letter agreement (“Letter Agreement”) amends and restates that certain second amended and
restated Letter Agreement, dated as of March 11, 2015 (the “Original Letter Agreement”) by and among
Chart Acquisition Corp., a Delaware corporation (the “Company”), Deutsche Bank Securities, Inc. and Cowen
and Company, LLC, as the representatives of the underwriters (the “Underwriters”) and the Insiders (as
defined below). The Original Letter Agreement was delivered to you in accordance with the Underwriting Agreement (the “Underwriting
Agreement”) entered into by and between the Company and the Underwriters, relating to the Company’s underwritten
initial public offering (the “Offering”), of 7,500,000 of the Company’s units (the “Units”),
each comprised of one share of the Company’s common stock, par value $0.0001 per share (the “Common Stock”),
and one warrant exercisable for one share of Common Stock (each, a “Warrant”). The Units sold in the
Offering have been listed on the Nasdaq Capital Market pursuant to a registration statement on Form S-1 and prospectus (the “Prospectus”)
filed by the Company with the Securities and Exchange Commission (the “Commission”). Certain capitalized
terms used herein are defined in paragraph 16 hereof.


 


WHEREAS, the requisite
number of stockholders of the Company have approved an amendment to the Company’s amended and restated certificate of incorporation
to, among other things, extend the date before which the Company must complete a business combination from June 13, 2015 (the “Original
Termination Date”) to July 31, 2015 (the “Extended Termination Date”); and


 


WHEREAS, the parties
to the Original Letter Agreement desire to amend and restate the Original Letter Agreement to provide, among other things, that
any references to the Original Termination Date shall be replaced with the Extended Termination Date.


  


The Insiders and Underwriters hereby
agree with the Company as follows:


 


1. Each Insider
of the Company hereby agrees that if the Company seeks stockholder approval of a proposed Business Combination, then in connection
with such proposed Business Combination, such person shall vote, as applicable, all Founder Shares, Placement Shares and any shares
acquired by such person in the Offering or in the secondary public market in favor of such proposed Business Combination.


 


2. (a) Each Insider
of the Company hereby agrees that in the event that the Company fails to consummate a Business Combination by the Extended Termination
Date, such person, shall take all reasonable steps to cause the Company to (i) cease all operations except for the purpose of winding
up, (ii) as promptly as reasonably possible but not more than ten business days thereafter, redeem the Common Stock held by the
Public Stockholders, at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account,
including any amounts representing interest earned on the Trust Account less any interest released for working capital purposes,
payment of taxes or dissolution expenses, divided by the number of shares of Common Stock then outstanding, subject in each case
to the Company’s obligations under Delaware law to provide for claims of creditors and other requirements of applicable law
and (iii) as promptly as reasonably possible following such redemption, subject to the approval of Insiders and the Company’s
board of directors, dissolve and liquidate, subject in each case to the Company’s obligations under Delaware law to provide
for claims of creditors and the requirements of other applicable law.


 






    	 



    	 



    

 


(b) Each of the Company
and its officers and directors hereby agree they will not propose any amendment to the Company's amended and restated certificate
of incorporation that would affect the substance or timing of the Company's redemption obligation, as described in Section 9.1(a)
of the Company’s amended and restated certificate of incorporation.


 


(c) Each Insider
acknowledges that such party has no right, title, interest or claim of any kind in or to any monies held in the Trust Account or
any other asset of the Company as a result of any liquidation of the Trust Account with respect to the Founder Shares or Placement
Shares only.


 


(d) Each Insider
hereby further waives, with respect to any shares of the Common Stock or Placement Shares held by such undersigned party, any redemption
rights such party may have (i) in connection with the consummation of a Business Combination, (ii) if the Company fails to consummate
its initial Business Combination by the Extended Termination Date; provided, however, that if
any of the Insiders, should acquire public shares in or after the Offering, such Insiders will be entitled to redemption rights
with respect to such public shares if the Company fails to consummate a Business Combination by the Extended Termination Date,
(iii) in connection with an expired or unwithdrawn tender offer, and (iv) upon the liquidation of the Company prior to the Extended
Termination Date.


 


3. (a) To the extent
that the Underwriters do not exercise their over-allotment option to purchase an additional 1,125,000 shares of Common Stock (as
described in the Prospectus), the Insiders (except Messrs. Joseph R. Wright, Governor Thomas Ridge, Senator Joseph Robert Kerrey,
Timothy N. Teen and Manuel D. Medina) shall return to the Company for cancellation, at no cost, an aggregate number of Founder
Shares determined by multiplying 281,250 by a fraction: (i) the numerator of which is 1,125,000 minus the number of shares of the
Common Stock purchased by the Underwriters upon the exercise of their over-allotment option, and (ii) the denominator of which
is 1,125,000. The Insiders further agree that to the extent that: (A) the size of the Offering is increased or decreased and (B)
the Insiders have either purchased or sold shares of the Common Stock or an adjustment to the number of Founder Shares has been
effected by way of a stock split, stock dividend, reverse stock split, contribution back to capital or otherwise, in each case
in connection with such increase or decrease in the size of the Offering, then, (x) the references to 1,125,000 in the numerator
and denominator of the formula in the immediately preceding sentence shall be changed to a number equal to 15% of the number of
shares included in the Units issued in the Offering and (y) the reference to 281,250 in the formula set forth in the immediately
preceding sentence shall be adjusted to such number of shares of the Common Stock that the Insiders would have to return to the
Company in order that the Insiders will hold an aggregate of 20% of the Company’s issued and outstanding shares (which 20%
shall include any Founder Shares held by each of Messrs. Wright, Ridge, Kerrey, Teen and Medina) after the Offering (assuming the
Underwriters do not exercise their over-allotment option and excluding any Placement Shares).


 


(b) In the case
of any of the Founder Shares owned by the Insiders that are not subject to forfeiture pursuant to paragraph 3(a) above, until the
earlier of (A) one year after the consummation of the Business Combination or earlier if, subsequent to the Business Combination,
the last sales price of the Common Stock equals or exceeds $12.00 per share (as adjusted for stock splits, stock dividends, reorganizations,
recapitalizations and the like) for any 20 trading days within any 30-trading day period commencing at least 150 days after the
Business Combination, or (B) the date on which the Company consummates a liquidation, merger, stock exchange or other similar transaction
after the Business Combination that results in all of the Company’s stockholders having the right to exchange their shares
of Common Stock for cash, securities or other property (such applicable period being the “Founder Lock-Up Period”);
provided that, to the extent any Founder Shares remain subject to forfeiture as described in this paragraph 3(b)(i) and (ii) below,
the Founder Lock-up Period shall be automatically extended until such Founder Shares are no longer subject to forfeiture; the Insiders
shall not, except as described in the Prospectus, (i) sell, offer to sell, contract or agree to sell, hypothecate, pledge, grant
any option to purchase or otherwise dispose of or agree to dispose of, directly or indirectly, or establish or increase a put equivalent
position or liquidate or decrease a call equivalent position within the meaning of Section 16 of the Securities Exchange Act of
1934, as amended, and the rules and regulations of the Commission promulgated thereunder (the “Exchange Act”),
with respect to the Founder Shares, (ii) enter into any swap or other arrangement that transfers to another, in whole or in part,
any of the economic consequences of ownership of any of the Founder Shares, whether any such transaction is to be settled by delivery
of the Common Stock or such other securities, in cash or otherwise, or (iii) publicly announce any intention to effect any transaction
specified in clause (b)(i) or (b)(ii). Each of the Insiders, agrees, with respect to the Founder Shares that are the subject to
this paragraph 3(b), in the event the Company’s trading price of the Common Stock does not exceed the following price targets
subsequent to the Business Combination, such Insider acknowledges and agrees that it, he or she shall forfeit any and all rights
to a portion of the Founder Shares, as follows:


 


(i) in the event
the last sale price of the Common Stock does not equal or exceed $11.50 per share (as adjusted for stock splits, share dividends,
reorganizations, recapitalizations and the like) for any 20 trading days within at least one 30-trading day period within 60 months
following the closing of the Business Combination, the Insiders (and Permitted Transferees) shall forfeit pro-rata any and all
rights to an aggregate of 2.5% of shares of Common Stock issued and outstanding (after exercise or expiration of the Over-allotment
Option and excluding any Placement Shares); and


 






    	 



    	 



    

 


(ii) in the event
the last sale price of the Common Stock does not equal or exceed $13.50 per share (as adjusted for stock splits, share dividends,
reorganizations, recapitalizations and the like) for any 20 trading days within at least one 30-trading day period within 60 months
following the closing of the Business Combination, the Insider (and Permitted Transferees) shall forfeit pro-rata any and all rights
to 2.5% of shares of Common Stock issued and outstanding (after exercise or expiration of the Over-allotment Option and excluding
any Placement Shares) in addition to any shares forfeited under Section 3(a)(i) above.


 


(c) Until 30 days
after the consummation of the Business Combination (“Placement Unit Lock-Up Period”), each of Sponsor,
Mr. Joseph R. Wright and Cowen shall not, except as described in the Prospectus, (i) sell, offer to sell, contract or agree to
sell, hypothecate, pledge, grant any option to purchase or otherwise dispose of or agree to dispose of, directly or indirectly,
or establish or increase a put equivalent position or liquidate or decrease a call equivalent position within the meaning of Section
16 of the Exchange Act with respect to the Placement Units, Placement Shares, Placement Warrants, Tendered Warrants or shares of
Common Stock underlying the Placement Warrants or Tendered Warrants, (ii) enter into any swap or other arrangement that transfers
to another, in whole or in part, any of the economic consequences of ownership of any of the Placement Units, Placement Shares,
Placement Warrants, Tendered Warrants or shares of Common Stock underlying the Placement Warrants or Tendered Warrants, whether
any such transaction is to be settled by delivery of the Common Stock or such other securities, in cash or otherwise, or (iii)
publicly announce any intention to effect any transaction specified in clause (c)(i) or (c)(ii).


 


(d) Notwithstanding
the provisions contained in paragraphs 3(b) and 3(c) herein, any Insider or Cowen may transfer, as applicable, the Founder Shares
and/or Placement Units, Placement Shares, Placement Warrants, Tendered Warrants or shares of Common Stock underlying the Placement
Warrants or Tendered Warrants: (i) to the Company’s officers or directors, to the other Insiders, any affiliates or family
members of any of the Company’s officers, directors or other Insiders, any member of Sponsor or partners, affiliates or employees
of members of the Sponsor, or partners of Cowen or any of their respective affiliates; (ii) by gift to a member of the Sponsor
or partners, affiliates, or employees of the members of the Sponsor, or a partner of Cowen or their immediate family or one of
the Insiders, an immediate family member of one of the members of the Sponsor or to a trust, the beneficiary of which is a member
of Sponsor or a family member of a member of the Sponsor or partners, affiliates or employees of the members of the Sponsor, or
partner of Cowen and their immediate family, or an Insider, or to a charitable organization; (iii) by virtue of the laws of descent
and distribution upon death of an Insider (including members of Sponsor) or a partner of Cowen; (iv) pursuant to a qualified domestic
relations order; (v) by virtue of the laws of the state of Delaware or the Sponsor’s limited liability company agreement
upon dissolution of the Sponsor or, in the case of Cowen, by virtue of the laws of the Cayman Islands or its controlling limited
partnership agreement; (vi) in the event of the Company’s liquidation prior to the completion of the Business Combination;
or (vii) in the event that the Company consummates a liquidation, merger, stock exchange or other similar transaction that results
in all of its stockholders having the right to exchange their shares of the Common Stock for cash, securities or other property
subsequent to the consummation of the Business Combination; provided, however, that, in the case of clauses
(i) through (v), these permitted transferees (each, a “Permitted Transferee”) enter into a written agreement
with the Company agreeing to be bound by the transfer restrictions in paragraphs 3(b) and 3(c) herein; provided, further that any
Placement Units, Placement Shares or Placement Warrants held by Cowen or any of its “related persons” under the rules
of the Financial Industry Regulatory Authority shall not be sold during the Offering or sold, transferred, assigned, pledged, or
hypothecated, or be the subject of any hedging, short sale, derivative, put, or call transaction that would result in the effective
economic disposition of any such Placement Units, Placement Shares or Placement Warrants by any person for a period of 180 days
immediately following the date of effectiveness of the registration statement of which the Prospectus forms a part.


 






    	 



    	 



    

 


(e) Further, each
Insider agrees that after the Founder Lock-Up Period or the Placement Unit Lock-Up Period, as applicable, has elapsed, the Founder
Shares and/or Placement Units, Placement Shares, Placement Warrants or shares of Common Stock underlying the Placement Warrants
owned by such Insider shall only be transferable or saleable pursuant to a sale registered under the Securities Act or pursuant
to an available exemption from registration under the Securities Act of 1933, as amended (the “Securities Act”).
The Company and each Insider acknowledges that pursuant to that certain registration rights agreement to be entered into among
the Company and certain securityholders of the Company, parties to the agreement may request that a registration statement relating
to the Founder Shares and/or Placement Units, Placement Shares, Placement Warrants or shares of Common Stock underlying the Placement
Warrants be filed by the Company with the Commission prior to the end of the Founder Lock-Up Period or the Placement Unit Lock-Up
Period, as the case may be; provided, however, that such registration statement does not become effective
prior to the end of the Founder Lock-Up Period or the Placement Unit Lock-Up Period, as applicable.


 


(f) Subject to the
limitations described herein, each Insider shall retain all of such Insider’s rights as a securityholder during, as applicable,
the Founder Lock-up Period and/or Placement Unit Lock-Up Period including, without limitation, the right to vote, as the case may
be, the Founder Shares and/or Placement Shares.


 


(g) During the Founder
Lock-Up Period and Placement Unit Lock-Up Period, all dividends payable in cash with respect to such securities shall be paid,
as applicable, to each security holder, but all dividends payable in Common Stock or other non-cash property shall become subject
to the applicable lock-up period as described herein and shall only be released from such lock-up in accordance with the provisions
of this paragraph 3.


 


(h)
Cowen agrees to purchase up to 1,312,500 Warrants, Joseph R. Wright agrees to purchase up to 125,000 Warrants, and the Sponsor
(together with Cowen and Joseph R. Wright, the “Warrant Purchasers”) agrees to purchase up to 2,312,500
Warrants, in each case, at a purchase price of $0.60 per Warrant in a tender offer which will occur after the announcement by the
Company of its having entered into a binding agreement with respect to its initial Business Combination (the “Warrant
Tender Offer”); provided, however, that the aggregate number of Warrants subject to the Warrant Tender Offer shall
be reduced at a ratio of one for every two Warrants tendered pursuant to the Warrant Extension Tender Offer (as defined below),
the tender offer consummated by the Warrant Purchasers on September 12, 2014 (the “Initial Warrant Tender Offer”)
and the tender offer consummated by the Warrant Purchasers on March 11, 2015 (the “Second Warrant Tender Offer”)
(rounded to the nearest number). In the event of any such reduction, the amount of Warrants each Warrant Purchaser agrees to purchase
shall be reduced pro rata. Each of the Warrant Purchasers further agrees not to tender any of its Placement Warrants or any public
warrants it may hold in the Warrant Tender Offer, which shall be consummated only upon, and simultaneously with, a Business Combination.
The Warrant Purchasers also agree to deposit with Continental Stock Transfer & Trust Company (“Escrow Account”)
an aggregate of $2,250,000 (representing $0.60 per Warrant for up to 3,750,000 of the Warrants), of which $ 2,053,440
remains following the consummation of the Initial Warrant Tender Offer and the Second Warrant Tender Offer. Each of the Warrant
Purchasers further agrees that in the event the Company is unable to consummate the initial Business Combination, Continental Stock
Transfer & Trust Company shall distribute to the holders of the Warrants the entire Escrow Account (as reduced by the amounts
distributed in connection with the Warrant Extension Tender Offer), as promptly as reasonably possible, but no more than five business
days after the Extended Termination Date.


 


(i) Cowen agrees
to purchase up to 2,395,680 Warrants, Joseph R. Wright agrees to purchase up to 228,160 Warrants, and the Sponsor agrees to purchase
up to 4,220,960 Warrants, in each case, at a purchase price of $0.30 per Warrant in a tender offer which will close on or about
the Original Termination Date (the “Warrant Extension Tender Offer”). Each of the Warrant Purchasers
further agrees not to tender any of its Placement Warrants or any public warrants it may hold in the Warrant Extension Tender Offer.


 






    	 



    	 



    

 


4. Without limiting
the provisions of paragraph 3 hereof, during the period commencing on the effective date of the Underwriting Agreement and ending
180 days after such date, each of the undersigned shall not (i) sell, offer to sell, contract or agree to sell, hypothecate, pledge,
grant any option to purchase or otherwise dispose of or agree to dispose of, directly or indirectly, or establish or increase a
put equivalent position or liquidate or decrease a call equivalent position within the meaning of Section 16 of the Exchange Act
with respect to any Units, Placement Units, shares of Common Stock, Warrants, Placement Shares, Placement Warrants or any securities
convertible into, or exercisable, or exchangeable for, shares of Common Stock owned by an undersigned party, (ii) enter into any
swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of any
Units, Placement Units, shares of Common Stock, Warrants, Placement Shares, Placement Warrants or any securities convertible into,
or exercisable, or exchangeable for, shares of Common Stock owned by the undersigned, whether any such transaction is to be settled
by delivery of such securities, in cash or otherwise, or (iii) publicly announce any intention to effect any transaction specified
in clause (i) or (ii).


 


5. In the event
of the liquidation of the Trust Account without the consummation of a Business Combination, each of Joseph R. Wright and Christopher
D. Brady (the “Indemnitors”) agree to jointly and severally indemnify and hold harmless the Company against
any and all loss, liability, claim, damage and expense whatsoever (including, but not limited to, any and all legal or other expenses
reasonably incurred in investigating, preparing or defending against any litigation, whether pending or threatened, or any claim
whatsoever) to which the Company may become subject as a result of any claim by (i) any third party for services rendered or products
sold to the Company or (ii) a prospective target business with which the Company has discussed entering into a transaction agreement
for a Business Combination (a “Target”) as described in the Prospectus; provided, however,
that such indemnification of the Company by the Indemnitors shall apply only to the extent necessary to ensure that such claims
by a third party for services rendered or products sold to the Company or a Target do not reduce the amount of funds in the Trust
Account to below $10.00 (or approximately $9.96 if the over-allotment is exercised in full) per share of the Common Stock sold
in the Offering (the “Offering Shares”), and, provided, further, that only if
such third party or Target has not executed an agreement waiving claims against and all rights to seek access to the Trust Account
whether or not such agreement is enforceable. In the event that any such executed waiver is deemed to be unenforceable against
such third party, the Indemnitors shall not be responsible for any liability as a result of any such third party claims. Notwithstanding
any of the foregoing, such indemnification of the Company by the Indemnitors shall not apply as to any claims under the Company’s
obligation to indemnify the Underwriters against certain liabilities, including liabilities under the Securities Act. The Indemnitors
shall have the right to defend against any such claim with counsel of its choice reasonably satisfactory to the Company if, within
15 days following written receipt of notice of the claim to the Indemnitors, the Indemnitors notify the Company in writing that
the Indemnitors shall undertake such defense.


 


6. Each of the undersigned
and the Company agrees that the Company will not engage any third party to render services, agree to purchase any products from
such third party, or enter into any discussion or any acquisition agreement with a Target unless (i) such third party or Target
has agreed to execute a waiver against any right, title, interest or claim of any kind in or to any monies held in the Trust Account
or any proceeds from the Trust Account that is acceptable to the Board of Directors of the Company (the “Board”) or
(ii) the Board has consented in writing to dispense with such waiver with respect to such services, product, discussions or acquisition
agreement, in each case with the written consent of each of the Indemnitors as part of the consent of the Board.


 


7. In order to minimize
potential conflicts of interest that may arise from multiple corporate affiliations, each officer and director hereby agrees that
until the earliest of the Company’s initial Business Combination, liquidation or such time as such party ceases to be an
officer or director of the Company, such person shall present to the Company for its consideration, prior to presentation to any
other entity, any suitable Business Combination opportunities of which such person or companies or entities which such person manages
or controls becomes aware, subject to any pre-existing fiduciary or contractual obligations such party might have as disclosed
to the Company.


 


8. As applicable,
the biographical information furnished to the Company by an officer or director of the Company is true and accurate in all material
respects and does not omit any material information with respect to such person’s background. Each of the questionnaires
furnished to the Company by an officer and director is true and accurate in all material respects.


 






    	 



    	 



    

 


9. Each undersigned
party represents and warrants that:


 


(a) such party is
not subject to or a respondent in any legal action for, any injunction, cease-and-desist order or order or stipulation to desist
or refrain from any act or practice relating to the offering of securities in any jurisdiction;


 


(b) such party has
never been convicted of, or pleaded guilty to, any crime (i) involving fraud, (ii) relating to any financial transaction or handling
of funds of another person, or (iii) pertaining to any dealings in any securities and the undersigned is not currently a defendant
in any such criminal proceeding; and


 


(c) such party has
never been suspended or expelled from membership in any securities or commodities exchange or association or had a securities or
commodities license or registration denied, suspended or revoked.


 


10. No Insider shall
receive any finder’s fee, reimbursement, consulting fee, monies in respect of any repayment of a loan or other compensation
prior to, or in connection with any services rendered in order to effectuate the consummation of the Business Combination (regardless
of the type of transaction that it is), other than the following:


 


(a) repayment of
$175,000 in loans made to the Company by the Sponsor in connection with the preparation, filing and consummation of the Offering;


 


(b) payment of an
aggregate of $10,000 per month to the Sponsor or an affiliate of the Sponsor, for office space, general office support, and receptionist,
secretarial and administrative services;


 


(c) reimbursement
for any out-of-pocket expenses related to identifying, investigating and consummating an initial Business Combination, provided
that no proceeds held in the Trust Account may be applied to the payment of such expenses prior to the consummation of a Business
Combination;


 


(d) repayment of
loans, if any, and on such terms as to be determined by the Company from time to time after completion of this Offering, made by
the Sponsor or an affiliate of the Sponsor or any Insider to finance working capital requirements of the Company; provided,
that, if the Company does not consummate a Business Combination, a portion of the working capital held outside the Trust Account
may be used by the Company to repay such loaned amounts so long as no proceeds from the Trust Account are used for such repayment;
and


 


(e) Promptly following
the consummation of the Company’s initial Business Combination, the Company shall reimburse the Warrant Purchasers for the
fees and expenses incurred in connection with the Warrant Tender Offer and the Warrant Extension Tender Offer.


 


11. Each undersigned
party acknowledges and understands that the Underwriters and the Company will rely upon the agreements, representations, and warranties
set forth herein in proceeding with the Offering.


 


12. To the extent
applicable, each undersigned party authorizes any employer, financial institution, or consumer credit reporting agency to release
to the Underwriters and their legal representatives or agents (including any investigative search firm retained by the Underwriters)
any information they may have about such undersigned party’s background and finances (“Information”),
purely for the purposes of the Offering (and shall thereafter hold such information confidential). Neither the Underwriters nor
its agents shall be violating such undersigned party’s right of privacy in any manner in requesting and obtaining the Information
and the undersigned hereby releases them from liability for any damage whatsoever in that connection.


 


13. Each officer
and director of the Company acknowledges and agrees that the Company will not consummate any Business Combination with any company
with which an officer or director has had any discussions in such person’s capacity as an officer or director of the Company,
formal or otherwise, prior to the consummation of the Offering, with respect to a Business Combination. Until the earlier of (i)
the entry into a definitive agreement by the Company for a Business Combination; (ii) the liquidation of the Company; or (iii)
the termination of such person as an officer or director of the Company, each officer and director of the Company agrees not to
become affiliated as an officer or director of a blank check company similar to the Company.


 






    	 



    	 



    

 


14. Each undersigned
party acknowledges and agrees that the Company will not consummate any Business Combination that involves a company which is affiliated
with such undersigned party unless the Company obtains an opinion from an independent investment banking firm which is a member
of FINRA that the Business Combination is fair to the Company’s stockholders from a financial perspective.


 


15. Each officer
and director has full right and power, without violating any agreement to which such person is bound (including, without limitation,
any non-competition or non-solicitation agreement with any employer or former employer), to enter into this Letter Agreement and
to serve as an officer of the Company or as a director on the board of directors of the Company, as applicable, and hereby consents
to being named in the Prospectus as an officer and/or as a director of the Company, as applicable.


 


16. As used in this
Letter Agreement, (i) “Business Combination” shall mean a merger, capital stock exchange, asset acquisition,
stock purchase, reorganization or similar Business Combination, involving the Company and one or more businesses; (ii) “Founder
Shares” shall mean the 2,156,250 shares of the Common Stock of the Company acquired by Sponsor for an aggregate purchase
price of $25,000, or approximately $0.0116 per share, prior to the consummation of the Offering; (iii) “Public
Stockholders” shall mean the holders of securities issued in the Offering; (iv) “Placement Shares”
shall mean the shares of Common Stock sold as part of the Placement Units; (v) “Placement Warrants” shall
mean the aggregate of 375,000 Warrants to purchase up to an aggregate of 375,000 shares of the Common Stock that are
acquired as part of the Placement Units; (vi) “Placement Units” shall mean the aggregate of 375,000 Units
of the Company (each Placement Unit consists of one Placement Warrant and one Placement Share) sold in a private placement simultaneous
with the Offering for an aggregate purchase price of $3,750,000 to Sponsor, Joseph R. Wright and Cowen; (vii) “Trust
Account” shall mean the trust account into which a portion of the net proceeds of the Offering and the Private Placement
will be deposited; (viii) “Prospectus” shall mean the prospectus included in the registration statement
filed by the Company in connection with the Offering, as supplemented or amended from time to time; (ix) “Private Placement”
shall mean that certain private placement transactions occurring simultaneously with the closing of the Offering pursuant to which
the Company has agreed to sell (A) 231,250 Placement Units to Chart Acquisition Group LLC, a Delaware limited liability company
(the “Sponsor”), (B) 12,500 Placement Units to Joseph R. Wright and (C) 131,250 Placement
Units to Cowen Overseas Investment LP, a Cayman Islands limited partnership (“Cowen”); and (x) “Tendered
Warrants” shall mean the Public Warrants to be purchased by the Warrant Purchasers in connection with the Warrant
Tender Offer and the Warrant Extension Tender Offer; and (xi) “Insiders” shall mean the Sponsor, any
holder of the Placement Units, or its underlying securities or Founder Shares, any of their respective Permitted Transferees and
each officer and director of the Company.


 


17. This Letter
Agreement constitutes the entire agreement and understanding of the parties hereto in respect of the subject matter hereof and
supersede all prior understandings, agreements, or representations by or among the parties hereto, written or oral, to the extent
they relate in any way to the subject matter hereof or the transactions contemplated hereby. This Letter Agreement may not be changed,
amended, modified or waived (other than to correct a typographical error) as to any particular provision, except by a written instrument
executed by the parties hereto.


 


18. No party may
assign either this Letter Agreement or any of party’s rights, interests, or obligations hereunder without the prior written
consent of the other party. Any purported assignment in violation of this paragraph shall be void and ineffectual and shall not
operate to transfer or assign any interest or title to the purported assignee. This Letter Agreement shall be binding on each undersigned
party and each of such undersigned party’s, as applicable, heirs, personal representatives, successors and assigns.


 


19. This Letter
Agreement shall be governed by and construed and enforced in accordance with the laws of the State of New York, without giving
effect to conflicts of law principles that would result in the application of the substantive laws of another jurisdiction. Each
Insider and Cowen (i) agrees that any action, proceeding, claim or dispute arising out of, or relating in any way to, this Letter
Agreement shall be brought and enforced in the courts of New York, in the State of New York, and irrevocably submits to such jurisdiction
and venue, which jurisdiction and venue shall be exclusive and (ii) waives any objection to such exclusive jurisdiction and venue
or that such courts represent an inconvenient forum.


 






    	 



    	 



    

 


20. Any notice,
consent or request to be given in connection with any of the terms or provisions of this Letter Agreement shall be in writing and
shall be sent by express mail or similar private courier service, by certified mail (return receipt requested), by hand delivery,
electronic or facsimile transmission.


 


21. This Letter
Agreement shall terminate on the earlier of (i) the later of the expiration of the Founder Lock-Up Period or Placement Unit Lock-Up
Period, as applicable, or (ii) the liquidation of the Trust Account; provided, however, that this Letter Agreement
shall earlier terminate in the event that the Offering is not consummated; and, provided, further, that
paragraph 5 of this Letter Agreement shall survive any liquidation of the Company.


 


 


[Signature page follows]


 






    	 



    	 



    

 


	 	Sincerely,
	 	 
	 	
        COMPANY:

        CHART ACQUISITION CORP.

        a Delaware corporation

         

	 	By:  	 


  


	 	
        CHART ACQUISITION GROUP LLC

        a Delaware limited liability company

	 	 
	 	By:  	
        THE CHART GROUP L.P.,

        a Delaware limited partnership, as the managing member of
        Chart Acquisition Group LLC



 


	 	By:  	 
	 	Name:  	Christopher D. Brady
	 	Title:	Manager 


 


	 	
        COWEN INVESTMENTS LLC,

        a Cayman Islands limited partnership

	 	 
	 	By:  	RCG LV PEARL, LLC, its general partner 


 


	 	By:  	 
	 	Name:  	 
	 	Title:	 


 


	 	
        THE CHART GROUP L.P.,

        a Delaware limited partnership

         

	 	By:  	 
	 	 	Christopher D. Brady
	 	 	Manager


 


	 	
        THE KENDALL FAMILY INVESTMENTS

         

	 	By:  	 
	 	 	 


 


 


Signature
Page to Third Amended and Restated Letter Agreement


 






    	 



    	 



    

 


	 	 	 
	Joseph R. Wright	 	Governor Thomas Ridge
	 	 	 
	 	 	 
	Senator Joseph Robert Kerrey  	 	Timothy N. Teen
	 	 	 
	 	 	 
	David Collier  	 	Christopher Brady
	 	 	 
	 	 	 
	Michael LaBarbera  	 	Charlene Ryan
	 	 	 
	 	 	 
	Matthew McCooe   	 	Christopher Brady Jr.
	 	 	 
	 	 	 
	Cole Van Nice  	 	 
	 	 	 
	 	 	 
	Young-Gak Yun	 	Geoffry Nattans
	 	 	 
	 	 	 
	H. Whitney Wagner	 	Abdulwahab Al-Nakib
	 	 	 
	 	 	 
	Joseph Boyle 	 	
        Khaled El-Marsafy

        (Fourth and Market)

	 	 	 
	 	 	 
	Deirdre Kilmartin	 	Margaret Saracco
	 	 	 
	 	 	 
	Manuel D. Medina	 	 


 


 


Signature
Page to Third Amended and Restated Letter Agreement


 






    	 



    	 



    

 





Agreed to and accepted on the date
first above written (which also constitutes written consent under Section 7.3 of the Underwriting Agreement):


 


DEUTSCHE BANK SECURITIES INC.


COWEN AND COMPANY, LLC


 


Acting severally on behalf of themselves and the several
Underwriters named in Schedule A hereto


 


DEUTSCHE BANK SECURITIES INC.


 


	By:	 	 	 	 
	 	Name:	 	 	 
	 	Title:	 	 	 
	 	 	 	 	 
	By:	 	 	 	 
	 	Name:	 	 	 
	 	Title:	 	 	 
	 	 	 	 	 
	COWEN AND COMPANY, LLC	 	 	 
	 	 	 	 	 
	By:	 	 	 	 
	 	Name:	 	 	 
	 	Title:	 	 	 


 


 


Signature Page to Third Amended and
Restated Letter Agreement