Exhibit 3.28

DELAWARE

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The First State

I, Harriet Smith Windsor, Secretary of State of the State of Delaware, do hereby certify the attached are true and correct copies of all documents on file of
"Worldwide Recruiting and Staffing Services LLC" as received and filed in this office.

The
following documents have been certified:

Certificate
of Formation, filed the twenty-second day of April, A.D. 2005, at 11:17 o'clock A.M.

Certificate
of Amendment, changing its name from "Dyncorp International of Nigeria LLC" to "Global Recruiting and Staffing Services LLC", filed the fifteenth day of March, A.D. 2006, at
4:07 o'clock P.M.

Certificate
of Amendment, changing its name from "Global Recruiting and Staffing Services LLC" to "Worldwide Recruiting and Staffing Services LLC", filed the second day of June, A.D.
2006, at 12:59 o'clock P.M.

And
I do hereby further certify that the aforesaid certificates are the only certificates on record of the aforesaid limited liability company, "Worldwide Recruiting and Staffing
Services LLC".

|[SEAL]3959170 8100H
070727561 |  | /s/HARRIET SMITH WINDSORHarriet Smith Windsor, Secretary of State
Authentication: 5773873
Date: 06-19-07
|----------------------------- |  | --------------------------------------------------------------------------------------------------------

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CERTIFICATE OF FORMATION    OF    DYNCORP INTERNATIONAL OF NIGERIA LLC

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FIRST:The name of the limited liability company is DynCorp International of Nigeria LLC.

SECOND:The address of its initial registered office in the State of Delaware is 1209 Orange Street, Wilmington, Delaware
19801. The name of its registered agent at such address is The Corporation Trust Company.

THIRD:The address of its principal office is 8445 Freeport Parkway, Suite 400, Irving, TX 75063.

IN WITNESS WHEREOF,the undersigned has executed this Certificate of Formation this 22nd day of April, 2005

| |  | DYNCORP INTERNATIONAL OF NIGERIA LLC
| |  | ------------------------------------
| |  | By:                                 

| | State of Delaware
Secretary of State
Division of Corporations
Delivered 11:19 AM 04/22/2005
FILED 11:17 AM 04/22/2005
SRV 050326202 - 3959170 FILE
| | --------------------------------------------------------------------------------------------------------------------------------------------------

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CERTIFICATE OF AMENDMENT TO    THE CERTIFICATE OF FORMATION OF    DYNCORP INTERNATIONAL OF NIGERIA LLC

DynCorp
International of Nigeria LLC, a limited liability company organized and existing under the laws of the State of Delaware (the "Company") hereby certifies as follows:

FIRST:
That the Certificate of Formation of the Company was filed with the Secretary of State of the State of Delaware on April 22, 2005.

SECOND:
That the sole Manager of the Company, by written consent in lieu of a meeting, adopted the following resolution:



THIRD:
That in lieu of a meeting of the Members of the Company, the sole Member of the Company has given its written consent to said amendment.

FOURTH:
That the aforesaid amendment was duly adopted in accordance with the applicable provisions of the Limited Liability Company Act of the State of Delaware.

Executed
as of the 15th day of March, 2006.

|                                                                                                                                                   |  | DynCorp International of Nigeria LLC
|-------------------------------------------------------------------------------------------------------------------------------------------------- |  | ------------------------------------
|                                                                                                                                                   |  | By:                                 
|State of Delaware
Secretary of State
Division of Corporations
Delivered 04:10 PM 03/15/2006
FILED 04:07 PM 03/15/2006
SRV 060251688 - 3959170 FILE |  |                                     

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|State of Delaware
Secretary of State
Division of Corporations
Delivered 02:05 PM 06/02/2006
FILED 12:59 PM 06/02/2006
SRV 060535905 - 3959170 FILE |  |  |  | 
|-------------------------------------------------------------------------------------------------------------------------------------------------- |  |  |  | 

CERTIFICATE OF AMENDMENT TO    THE CERTIFICATE OF FORMATION OF    GLOBAL RECRUITING AND STAFFING SERVICES LLC

Global
Recruiting and Staffing Services LLC, a limited liability company organized and existing under the laws of the State of Delaware (the "Company") hereby certifies as follows:

FIRST:
That the Certificate of Formation of the Company was filed with the Secretary of State of the State of Delaware on April 22, 2005.

SECOND:
That the sole Manager of the Company, by written consent in lieu of a meeting, adopted the following resolution:



THIRD:
That in lieu of a meeting of the Members of the Company, the sole Member of the Company has given its written consent to said amendment.

FOURTH:
That the aforesaid amendment was duly adopted in accordance with the applicable provisions of the Limited Liability Company Act of the State of Delaware.

Executed
as of the 1st day of June, 2006.

| |  | GLOBAL RECRUITING AND STAFFING SERVICES LLC
| |  | -------------------------------------------
| |  | By:                                        

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