Sec Form 3 Filing - FLEMING JAMES B JR @ NEXTNAV INC. - 2021-10-28

FORM 3 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person FLEMING JAMES B JR 2. Issuer Name and Ticker or Trading Symbol NEXTNAV INC. [ NN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 1775 TYSONS BLVD., 5TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 10/28/2021 (Street) MCLEAN,, VA22102 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 9,714,408 ( 1 ) ( 2 ) ( 3 ) I See footnote ( 1 ) ( 2 ) ( 3 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other FLEMING JAMES B JR 1775 TYSONS BLVD., 5TH FLOOR MCLEAN,, VA22102 X X Signatures /s/ Christian Gates, by power of attorney 10/28/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Consists of (i) 86,652 shares held of record by Columbia Capital Employee Investors IV, L.P. ("CCEI IV"), (ii) 8,572,962 shares held of record by Columbia Capital Equity Partners IV (ECI), LTD ("CCEP IV (ECI)") and (iii) 1,054,794 shares held of record by Columbia Capital Equity Partners IV (QPCO), L.P. ("CCEP IV (QPCO)"), (collectively, the "Columbia Entities"). Columbia Capital Equity Partners IV (QP), L.P. ("CCEP IV (QP)") is the sole shareholder of CCEP IV (ECI). Columbia Capital Equity Partners IV, L.P. ("CCEP IV") is the general partner of both CCEP IV (QP) and CCEP IV (QPCO). Columbia Capital IV, LLC is the general partner of both CCEI IV and CCEP IV. James B. Fleming, Jr. is the sole manager of Columbia Capital IV, LLC and as a result, he exercises shared voting and investment control over all the common stock held by CCEI IV, CCEP IV (ECI), and CCEP IV (QPCO) and may be deemed to have beneficial ownership over all those shares. ( 2 )Mr. Fleming disclaims beneficial ownership of the shares held of record by the Columbia Entities, except to the extent of their or his pecuniary interest therein, and this report shall not be deemed an admission that they or he is the beneficial owner of the securities for purposes of Section 16 or for any other purpose. Due to the limitations of the electronic filing system, Columbia Capital IV, LLC is filing a separate Form 3. ( 3 )Pursuant to the Agreement and Plan of Merger, dated as of June 9, 2021, by and among Spartacus Acquisition Shelf Corp (now known as NextNav Inc.), Spartacus Acquisition Corp., NextNav Holdings, LLC and the other parties thereto, the Reporting Persons became reporting persons of "NextNav Inc.", the as-renamed surviving corporation (the "Issuer") of the business combination, which business combination closed on October 28, 2021 (the "Business Combination"), the Reporting Person received shares of common stock of the Issuer in exchange for their holdings in NextNav Holdings, LLC as of the closing of the Business Combination.

Remarks: Exhibit 24: Power of Attorney

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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