# Project 634921 — Aircraft Propulsion Subsystems Int

**Program element:** 0603211F — Aerospace Technology Dev/Demo  
**Project:** 634921  
**Component:** U.S. Air Force  
**Appropriation:** 3600 — RDT&E, Air Force  
**Budget Activity:** 3 — Advanced Technology Development  
**Vintage:** President's Budget PB2027  
**Canonical URL:** https://hitchintel.com/programs/0603211F/634921  
**Parent:** https://hitchintel.com/programs/0603211F

## Summary

Project 634921 — Aircraft Propulsion Subsystems Int requests $0.0M in FY2027, 0.0% of the $260.2M requested for program element 0603211F, down 100% on FY2026. 4 R-2A activities decompose the request.

## Funding profile

| Fiscal Year | Estimate Type | Amount ($M) |
|---|---|---|
| FY2025 | Actual | 16.0 |
| FY2026 | Enacted | 19.7 |
| FY2027 | Request | 0.0 |
| FY2028 | Outyear | 0.0 |
| FY2029 | Outyear | 0.0 |
| FY2030 | Outyear | 0.0 |
| FY2031 | Outyear | 0.0 |

> Estimate types are not summed. This project is one leaf of PE 0603211F; the PE total is the sum of its projects, never added to them.

## What project 634921 buys

In FY 2027, within Program Element 0603211F/ Aerospace Technology Dev/Demo, all efforts and associated funding in this Project were transferred to 634920 / Flight Vehicle Tech Integration (now called Aerospace Systems Integration and Demonstration) to provide Congress with improved understanding and traceability of the discrete Aerospace Systems technology areas in Research, Development, Test & Evaluation (RDT&E), Air Force, Budget Activity (BA) 3. This project develops and demonstrates technology to increase military utility by improving turbine engine This project develops and demonstrates technology to increase military utility by improving turbine engine operational reliability, durability, mission flexibility, and performance while reducing weight, fuel consumption, and cost of ownership. This project includes demonstrator engines that address military specific needs for manned systems, autonomous vehicles and munitions applications. This project also focuses on integration of inlets, nozzles, engine- to-airframe compatibility, and power and thermal management subsystems technologies.

## Activities (R-2A) — 4

| Activity | FY2025 | FY2026 | FY2027 | Move | Page |
|---|---|---|---|---|---|
| Air Breathing Propulsion Integration and Demonstration | 0.0 | 19.7 | 0.0 | −100% | — |
| Expendable/Autonomous Vehicle Engine Capability | 11.6 | 0.0 | 0.0 | — | — |
| Core Engine Technologies | 4.3 | 0.0 | 0.0 | — | — |
| High Pressure Ratio Core Engine Technologies | 0.1 | 0.0 | 0.0 | — | — |

> Activities carry the prior, current and budget year only — no five-year plan. In the request year they partition this project exactly; in earlier years they can under-cover it.

### Air Breathing Propulsion Integration and Demonstration

**FY2027 planned work.** In FY 2027, the Air Breathing Propulsion Integration and Demonstration effort and associated plans & funding transferred within this Program Element to Project 634920 / Flight Vehicle Tech Integration (now called Aerospace Systems Integration and Demonstration) to provide Congress with improved understanding and traceability of the discrete Aerospace Systems technology areas in Research, Development, Test & Evaluation (RDT&E), Air Force, Budget Activity (BA) 3.

**FY2026 to FY2027 change.** FY 2027 funding decreased by $19.701 million due to the transfer of the Air Breathing Propulsion Integration and Demonstration effort and associated funding within this Program Element from Project 634921 / Aircraft Propulsion Subsystems Int to Project 634920 / Flight Vehicle Tech Integration (now called Aerospace Systems Integration and Demonstration).

**FY2026 plans — current year.** Continue new engine technologies to deliver reduced takeoff length, increased range, loiter, combat maneuverability, and lower cost for affordable unmanned aerial systems in contested environments. - Activities include affordable mass via advanced novel augmentor technology design. Complete studies for autonomous vehicles powered by air breathing propulsion for affordable mass - Activities include military utility studies. Continue advanced propulsion air frame integration experiments to enable embedded propulsion systems for affordable mass via embedded turbine engine propulsion. - Activities include model Based Systems Engineering for capturing advanced augmentor impacts to embedded fans and advanced augmentor preliminary design review.

### Expendable/Autonomous Vehicle Engine Capability

**FY2027 planned work.** Not Applicable

**FY2026 to FY2027 change.** Not Applicable

**FY2026 plans — current year.** - In FY 2026, this work transferred to the Air Breathing Propulsion Integration and Demonstration effort within this project.

### Core Engine Technologies

**FY2027 planned work.** Not applicable

**FY2026 to FY2027 change.** Not applicable

**FY2026 plans — current year.** In FY 2026, this work was transferred to the Air Breathing Propulsion Integration and Demonstration effort within this project.

### High Pressure Ratio Core Engine Technologies

**FY2027 planned work.** Not applicable

**FY2026 plans — current year.** Not Applicable

## What is NOT on this page

Congressional marks, the R-2 mission description and acquisition strategy, the industry vs government split of the whole request, and related program elements are recorded at **program-element** grain — an NDAA mark lands on a PE, never on a project. They are at https://hitchintel.com/programs/0603211F.

## Source & machine access

- **Source:** FY2027 Department of the Air Force RDT&E Budget Justification, Exhibits R-2/R-2A/R-3, PE 0603211F project 634921 (PB PB2027).
- **MCP:** `mcp.hitchintel.com` — `budget_get_program_element(pe="0603211F")`.

*HitchAI is an independent intelligence service, not affiliated with the U.S. Department of Defense. Budget figures are requests/estimates, not obligations.*