Aircraft · Air
KC-135 Stratotanker
Aerial-refueling aircraft supporting U.S. and allied aircraft.
by Boeing
- Milestones0
- Operators—
- Components—
- Programs—
- Capabilities—
- Inputs—
Photo: Balon Greyjoy via Wikimedia Commons · CC0 1.0 · Resized and reencoded as WebP with metadata removed; no additional crop.
Timeline
No milestones recorded for KC-135 Stratotanker yet. The timeline fills in as unveilings, tests, contracts and deliveries are sourced.
Cost to the Government
Aircraft · Boeing
KC-135R/T Stratotanker
Legacy tanker fleet; historical acquisition cost and maintenance-driven sustainment should be compared separately from replacement-aircraft procurement.
Published acquisition / aircraft
$39.6M
Undated fact sheet; reviewed 2026-10-09 · Constant FY1998 USD
Historical fact-sheet figure; not a current replacement quote.
U.S. Air Force ↗Published U.S. fleet snapshot
396
Undated fact sheet; reviewed 2026-10-09 · U.S. only
Source inventory snapshot; subsequent retirements, transfers and losses are not inferred.
U.S. Air Force ↗Program quantity
Not verified
A comparable total acquisition quantity has not been verified.
R&D program total
Not verified
A separately identified lifetime development total has not been verified. This is not a zero-cost estimate.
Reading the cost figures
The fact-sheet acquisition figure uses the dollar basis shown above. GAO’s annual operating and support cost includes a broader ownership scope than the Comptroller reimbursement rate. These figures should not be combined into a single inflation-free trend.
Operations & sustainment
Annual O&S / aircraft
$10.65M / yr
FY2018 · Constant FY2018 USD
Historical average for the source study population; not a marginal mission cost.
GAO ↗Reimbursement / flight hour
$20,959 / hr
FY2026 · Nominal USD; Other DoD Component
Published billing rate for use by another DoD component. It is not the fully burdened cost of ownership.
DoD Comptroller ↗Cost over time · 3 observations
Each row retains its original scope and dollar basis. Changing quantities, service life and inflation can change the estimate without changing the price of building one unit.
| Observation | Measure | Amount | Dollar basis | Evidence |
|---|---|---|---|---|
| FY2018 | Annual O&S / aircraft Historical average for the source study population; not a marginal mission cost. | $10.65M / yr | Constant FY2018 USD | GAO ↗ |
| FY2026 | Reimbursement / flight hour Published billing rate for use by another DoD component. It is not the fully burdened cost of ownership. | $20,959 / hr | Nominal USD; Other DoD Component | DoD Comptroller ↗ |
| Undated fact sheet; reviewed 2026-10-09 | Published acquisition / aircraft Historical fact-sheet figure; not a current replacement quote. | $39.6M | Constant FY1998 USD | U.S. Air Force ↗ |
Contracts & purchasing · 0 records
Award values, ceilings and purchase agreements have different meanings. These records are not added together as total spending.
No primary-source contract record verified in this review. This does not mean there are no contracts.
International buyers
No international purchase documented in this review.
Coverage & open research
- Figures retain the date and scope of the original source. A historical count, cumulative delivery or procurement plan is not today’s mission-capable inventory.
- A separately identified lifetime development total has not been verified. This is not a zero-cost estimate.
Unit costs and contract unit prices for this system, and budget figures for the programs that buy it. Each figure states its dollar basis and links its source; contract values are under Programs & awards.