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                                                                   EXHIBIT 10.6a


                          [AMERICAN MOBILE LETTERHEAD]




OPTIONEE:                                                   OPTION NO.


DATE OF GRANT                                               OPTION PRICE:
COVERED SHARES



                     AMERICAN MOBILE SATELLITE CORPORATION
                                STOCK AWARD PLAN

                      NONSTATUTORY STOCK OPTION AGREEMENT


1.   Definitions. In this Agreement, terms with initial capitals shall have the
meanings provided in the Plan, except as follows:

     (a)  "Agreement" means this Nonstatutory Stock Option Agreement.

     (b)  A "Change of Control" shall be deemed to have occurred if (i) any
person or group of persons (as defined in Section 13(d) and 14(d) of the
Exchange Act) together with its affiliates, excluding employee benefit plans of
the Corporation, is or becomes, directly or indirectly, the "beneficial owner"
(as defined in Rule 13d-3 under the Exchange Act) of securities of the
Corporation representing 40% or more of the combined voting power of the
Corporation's then outstanding securities; or (ii) individuals who at the
beginning of any two-year period constitute the Board, plus new directors of the
Corporation whose election or nomination for election by the Corporation's
shareholders is approved by a vote of at least two-thirds of the directors of
the Corporation still in office who were directors of the Corporation at the
beginning of such two-year period, cease for any reason during such two-year
period to constitute at least two-thirds of the members of the Board; or
(iii) the shareholders of the Corporation approve a merger or consolidation of
the Corporation with any other corporation or entity regardless of which entity
is the survivor, other than a merger or consolidation which would result in the
voting securities of the Corporation outstanding immediately prior thereto
continuing to represent (either by remaining outstanding or being converted into
voting securities of the surviving entity) at least 80% of the combined voting
power of the voting securities of the Corporation or such surviving entity
outstanding immediately after such merger or consolidation; or (iv) the
shareholders of the Corporation approve a plan of complete liquidation or
winding-up of the Corporation or an agreement for the sale or disposition by the
Corporation of all or substantially all of the Corporation's assets.

     (c)  "Covered Shares" means the Shares subject to the Option set forth as
the "Covered Shares" on page 1 of this Agreement.

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     (d)  "Date of Exercise" means the date on which the Company receives notice
pursuant to Paragraph 4(a) of the exercise, in whole or in part, of the Option.

     (e)  "Date of Expiration" means, subject to the provisions of Section 3 of
this Agreement, ten (10) years after the Date of Grant.

     (f)  "Date of Grant" means the date set forth as the "Date of Grant" on
page 1 of this Agreement.

     (g)  "Disability" means permanent and total disability of the Optionee.

     (h)  "Equivalent Option" means, in connection with a Change of Control, a
continuation of the Option by the Corporation, an agreement by the person or
persons acquiring the Corporation to honor or assume the Option following the
Change of Control, or the substitution of a new Option with an inherent value
equivalent to that of the original Option and on terms at least as beneficial to
the Optionee as those contained in the Optionee's original Option Agreement.

     (i)  "Insider" means an Optionee or Grantee who is subject to the reporting
requirements under Section 16(a) of the Exchange Act.

     (j)  "Involuntary Termination" means termination by the Corporation or a
Subsidiary of the Optionee's employment with the Corporation or a Subsidiary or,
in connection with or following a Change of Control, a substantial reduction by
the Corporation or Subsidiary in the salary, benefits or position of the
Optionee, but does not include any such substantial reduction as a result of the
commission of a felony by the Optionee or Termination for Good Cause.

     (k)  "Option" means the nonstatutory stock option granted to the Optionee
in Paragraph 2 of this Agreement.

     (l)  "Option Period" means the period during which the Option may be
exercised.

     (m)  "Option Price" means the dollar amount per Share set forth as the
"Option Price" on page 1 of this Agreement.

     (n)  "Optionee" means the person identified as the "Optionee" on page 1 of
this Agreement.

     (o)  "Plan" means the American Mobile Satellite Corporation Stock Award
Plan, amended and restated January 27, 2000.

     (p)  "Retirement" means termination of employment with the Corporation or a
Subsidiary at age 65 or thereafter, or at such other age as provided by
Corporation policy.

     (q)  "Termination for Good Cause" means termination as a result of the
commission of a felony by the Optionee.

2.  Grant of Option. Pursuant to the Plan and subject to the terms of this
Agreement, the Corporation hereby grants to the Optionee or his successors the
Option to purchase from the Corporation that number of shares of Common Stock
equal to the Covered Shares, exercisable at the Option Price.

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3.   Terms of the Option.

     (a)  Type of Option. The Option is intended to be a nonstatutory stock
     option, and is not intended to be an incentive stock option under section
     422 of the Code.

     (b)  Option Period. During the period commencing on the Date of Grant and
     terminating on the Date of Expiration, the Option may be exercised with
     respect to all or a portion of the Covered Shares (in full shares), to the
     extent that the Option has not been previously exercised with respect to
     such Covered Shares, subject to the following limitations:

          no portion of the Option may be exercised during the first year
          following the Date of Grant;

          during the second year following the Date of Grant, the Option may be
          exercised to a maximum of 33 1/3% of the Covered Shares;

          during the third year following the Date of Grant, the Option may be
          exercised to a cumulative maximum of 66 2/3% of the Covered Shares;

          thereafter the Option may be exercised in full.

     (c)  Exercise after termination of employment: Except as provided in
     paragraphs (d) and (e) of this Section 3, if the Optionee's employment is
     terminated during the Option Period, the Option may be exercised for a
     period of six (6) months after termination in the event of an Involuntary
     Termination or for a period of three (3) months after termination in the
     case of a voluntary termination, and the Option Period shall expire at the
     end of such six (6) month period or three (3) month period, respectively.
     An Option will terminate immediately, and may no longer be exercised, in
     the event of a Termination for Good Cause.

     (d)  Exercise in the event of Death, Disability or Retirement: If the
     Optionee's employment is terminated during the Option Period in the event
     of death, Disability or Retirement, the Option may be exercised in whole or
     in part, by the Optionee, the authorized representative of the Optionee's
     estate or by his properly appointed attorney-in-fact, guardian, trustee, or
     conservator, for a period of one year after the Optionee's death,
     Disability or Retirement.

     (e)  Limitation on exercise after termination: No portion of an Option
     which is unexercisable at the termination of the Optionee's employment may
     thereafter be exercised under this Section 3 except that an Option may be
     exercised in full upon termination of other Optionee's employment with the
     Corporation or a Subsidiary by reason of the Optionee's death or Disability
     (other than Disability during the six-month period following the Date of
     Grant).

     (f)  Change of Control. Notwithstanding the provisions of Section 3(b), if
     a Change of Control occurs during the period commencing on the Date of
     Grant and terminating on the Date of Expiration, the Optionee shall be
     entitled to receive an Equivalent Option. If, despite the best efforts of
     the Corporation, the Optionee cannot receive an Equivalent Option in
     connection with such Change of Control, (i) the Optionee shall be entitled
     to receive immediately prior to such Change of Control, and in exchange for
     his or her Option, cash in an amount equal to the excess of the highest
     price paid for a Share in connection with the

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    Change of Control over the Option Price, multiplied by the total number
    of Covered Shares subject to the Option, including all of the Covered Shares
    with respect to which the Option has not yet become exercisable under the
    provisions of Section 3(b) but excluding any of the Covered Shares with
    respect to which the Option has been previously exercised, or (ii) if the
    Optionee is an Insider who would be subject to suit under Section 16(b) of
    the Exchange Act if the Optionee were to receive the cash payment described
    in Section 3(c)(i), the Option may be exercised in full beginning on the
    date two weeks before such Change of Control. If the Optionee receives an
    Equivalent Option in connection with a Change of Control, and the Optionee's
    employment with the Corporation or a Subsidiary is terminated within two
    years following the Change of Control by reason of Involuntary Termination,
    the Equivalent Option may be exercised in full beginning on the date of such
    termination if and for such period as the Committee, in its sole discretion,
    so determines.

    (g)   Other Terms of Option. Notwithstanding the provisions of Section 7.B
    of the Plan, no Shares may be used to pay any portion of the Option Price
    unless those Shares shall have been held by the Optionee for a period of not
    less than six months prior to the Date of Exercise, provided that the
    holding period may be extended by the Committee at any time or times, by
    written notice to the Optionee, to any other holding period not exceeding
    two years prior to the Date of Exercise.

4.  Exercise.

    (a)   Notice. Until the Committee notifies the Optionee to the contrary, the
    forms attached to this Agreement as Exhibit A shall be used to exercise the
    Option.

    (b)   Effect. The exercise, in whole or in part, of the Option shall cause a
    reduction in the number of Covered Shares equal to the number of shares of
    Common Stock with respect to which the Option is exercised.

5.  Restriction Upon Shares of Common Stock Issued Upon Exercise. By accepting
this Option, the Optionee agrees to the conditions specifically set forth in
Section 6.C of the Plan.

6.  Rights as Stockholder. The Optionee shall have no rights as a stockholder
with respect to any Shares subject to the Option until and unless a certificate
or certificates representing such Shares are issued to the Optionee pursuant to
this Agreement. Except as provided in Article 11 of the Plan, no adjustment
shall be made for dividends or other rights for which the record date is prior
to the issuance of such certificate or certificates.

7.  Employment. Neither the granting of the Option evidenced by this Agreement
nor any term or provision of this Agreement shall constitute or be evidence of
any understanding, express or implied, on the part of the Corporation or any of
its Subsidiaries to employ the Optionee for any period. Whenever reference is
made in this Agreement to the employment of the Optionee, it means employment by
the Corporation or a Subsidiary.

8.  Subject to the Plan. The Option evidenced by this Agreement and the exercise
thereof are subject to the terms and conditions of the Plan, which are
incorporated herein by reference and made a part hereof. In addition, the Option
is subject to any rules and regulations promulgated by the Committee consistent
with the terms of the Plan.

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IN WITNESS WHEREOF, the Corporation has caused this Agreement to be signed on
its behalf effective as of the Date of Grant.




ATTEST:                                    AMERICAN MOBILE SATELLITE CORPORATION


                                           By:
-----------------------------------           ----------------------------------


Accepted and agreed to as of the Date of
Grant.


-----------------------------------
Optionee
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                                   EXHIBIT A



                               EXERCISE OF OPTION



Board of Directors
American Mobile Satellite Corporation
10802 Parkridge Boulevard
Reston, Virginia  20191-5416


Gentlemen:


The undersigned, the Optionee under the Nonstatutory Stock Option Agreement
identified as Option No.        , granted pursuant to the American Mobile
                        --------
Satellite Corporation Stock Award Plan, hereby irrevocably elects to exercise
the Option granted in the Agreement to purchase shares of Common Stock of
American Mobile Satellite Corporation, par value $.01 per share, and herewith
makes payment of $       in the form of                       [cash, Common
                  ------                ----------------------
Stock, cash plus Common Stock] for the shares purchased and $        in the
                                                              ------
form of                        [cash, Common Stock, cash plus Common Stock] to
       -----------------------
cover the Corporation's withholding tax liability in respect of the purchase.
(Please complete.)

The Optionee hereby represents, warrants, and acknowledges the following:

     A.  The Optionee has received and reviewed the statutory prospectus
relating to the Stock Option Plan prior to making this election.

     B.  The certificate for such stock may be legended, for certain officers
who may be deemed affiliates of the Company, to the effect that such officers
may not reoffer or resell shares of Common Stock in a transaction which is not
registered under the Securities Act of 1933, as amended ("the Act"), except
pursuant to the Securities and Exchange Commission's Rule 144 under the Act, or
another exemption thereunder.

[Note: Shares of Common Stock being delivered in payment of all or any part of
the exercise price must be represented by certificates registered in the name of
the Optionee and duly endorsed by the Optionee and by each and every other
co-owner in whose name the shares may also be registered.)





Dated:                                       Name of Optionee:
      --------------------                                    ------------------


                                             -----------------------------------
                                             Signature of Optionee


Received by American Mobile Satellite Corporation:


By:                                                   Date:
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