In plain English
FAR 52.211-10, Commencement, Prosecution, and Completion of Work, is a contract clause prescribed at FAR 11.404(b), most recently dated Apr 1984. The complete official text is reproduced below, verbatim, from GSA's published FAR source files.
Its text contains no sentence requiring insertion into subcontracts; see the flowdown section below for what that does and does not mean.
Does it flow down to subcontracts?
No flowdown mandate found in the clause text
We scanned the full clause text and found no sentence directing the contractor to insert this clause into subcontracts. That is a statement about the text, not legal advice: a prime contractor may still flow terms down contractually, an agency supplement (DFARS, VAAR, …) may add requirements, and clauses listed below (if any) may order this clause into subcontracts from the outside.
Where it's prescribed
As prescribed in 11.404(b), insert the following clause in solicitations and contracts when a fixed-price construction contract is contemplated. The clause may be changed to accommodate the issuance of orders under indefinite-delivery contracts for construction.
Prescribing reference: FAR 11.404(b).
The official text, verbatim
As prescribed in 11.404(b), insert the following clause in solicitations and contracts when a fixed-price construction contract is contemplated. The clause may be changed to accommodate the issuance of orders under indefinite-delivery contracts for construction.
Commencement, Prosecution, and Completion of Work (Apr 1984)
The Contractor shall be required to (a) commence work under this contract within _________ [Contracting Officer insert number] calendar days after the date the Contractor receives the notice to proceed, (b) prosecute the work diligently, and (c) complete the entire work ready for use not later than ______________.* The time stated for completion shall include final cleanup of the premises.
* The Contracting Officer shall specify either a number of days after the date the contractor receives the notice to proceed, or a calendar date.
(End of clause)
Alternate I (Apr 1984). If the completion date is expressed as a specific calendar date, computed on the basis of the contractor receiving the notice to proceed by a certain day, add the following paragraph to the basic clause:
The completion date is based on the assumption that the successful offeror will receive the notice to proceed by _______________ [Contracting Officer insert date]. The completion date will be extended by the number of calendar days after the above date that the Contractor receives the notice to proceed, except to the extent that the delay in issuance of the notice to proceed results from the failure of the Contractor to execute the contract and give the required performance and payment bonds within the time specified in the offer.