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X-47B

Q: Why was the X-47B retired without production?

Several factors converged. Cost : developing a fully low-observable UCAV with internal weapons carriage was expensive, and the Navy budget could not support both an X-47B successor and competing priorities such as F-35C and MQ-25. Threat environment : the Navy concluded that aerial refuelling was a higher-priority near-term need than penetrating strike, driving selection of MQ-25 over a follow-on UCAV. Programme management : UCAS-D transitioned to UCLASS and then to CBARS/MQ-25, with each step narrowing the requirement. Industrial base : Boeing won MQ-25 while Northrop Grumman built the X-47B, so the demonstrator's design did not feed directly into MQ-25 production. The X-47B was retired in 2015 with its lessons informing — but not directly producing — the in-service follow-on.

Q: How does the X-47B compare to the RQ-170?

They sit in different size and mission classes. RQ-170 Sentinel : a 66 ft wingspan, single-engine stealth ISR UAV used by USAF and CIA for high-value intelligence collection, with 25-30 airframes in service. X-47B : a 62 ft wingspan, single-engine stealth UCAV demonstrator for U.S. Navy carrier operations, with two airframes built and the programme retired. The RQ-170 is in active service; the X-47B was a demonstrator. Both are flying-wing stealth UAVs, but they serve different services and doctrines. X-47B design work feeds potential future stealth UAV programmes.

Q: Where can I see the X-47B?

Two locations. X-47B AV-1 : Smithsonian Steven F. Udvar-Hazy Center in Chantilly, Virginia, on display since 2017 alongside Space Shuttle Discovery. X-47B AV-2 : Patuxent River Naval Air Museum in Lexington Park, Maryland, adjacent to NAS Patuxent River where the aircraft was based. Both airframes are accessible to the public; the Udvar-Hazy display is the higher-traffic of the two.

Northrop Grumman · Fixed Wing / Carrier UCAV technology demonstrator · USA · Digital Age (2010–present)

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The Northrop Grumman X-47B is an American twin-engine, low-observable unmanned combat aerial vehicle (UCAV) demonstrator designed by Northrop Grumman for the U.S. Navy and operated from 2011 to 2015. Two airframes were built. The aircraft never entered production, but the demonstrator flights proved the viability of unmanned carrier aviation in frontline use. Its headline achievement came on 10 July 2013, when an X-47B made the first arrested landing by an unmanned aircraft aboard a U.S. Navy aircraft carrier — USS George H.W. Bush — establishing the technical foundation for follow-on Navy unmanned carrier-aviation programmes, including the MQ-25 Stingray entering service from 2026.

Development took place under the U.S. Navy's UCAS-D (Unmanned Combat Air System — Demonstrator) programme. The airframe is a flying wing with no vertical control surfaces — in effect a small unmanned analogue of the much larger B-2 Spirit bomber. Low-observable features include the flying-wing planform optimised for radar-cross-section reduction, a blended body/wing fuselage, and internal weapons bays with no external stores. Power comes from a single Pratt & Whitney F100-PW-220 turbofan rated at 16,000 lbf with afterburner — the same engine family used in the F-15 and F-16. Maximum gross weight is 44,567 lb. The aircraft is 38.2 ft long with a 62 ft wingspan that folds to 30.9 ft for carrier hangar storage. Internal weapons load was rated at 6,250 lb in theory, though the X-47B itself flew unarmed.

The flight-test programme logged around 100 flights between 2011 and 2015. First flight took place on 4 February 2011 at Edwards AFB, California. The first runway-style landing on a carrier deck followed on 4 July 2013 aboard USS George H.W. Bush during sea trials, with the first arrested carrier landing six days later on 10 July 2013 from the same ship. In April 2015 an X-47B completed the first autonomous aerial-refuelling demonstration in the USS Theodore Roosevelt operations area, taking fuel from a KC-707 tanker. The programme retired without full production: the Navy chose the simpler MQ-25 Stingray refuelling tanker over an unmanned penetrating strike aircraft.

Lessons from the X-47B fed directly into the MQ-25 Stingray programme. The Navy's decision to retire the type without production reflected the high cost of developing a stealthy unmanned strike aircraft, a shifting threat environment that elevated tanker support over penetrating strike, and budget pressure on new-start procurement. Future U.S. Navy unmanned carrier aircraft — including F/A-XX-generation concepts and follow-on autonomous strike platforms — will build on the X-47B's technical groundwork. Both airframes are preserved: one at the Smithsonian Steven F. Udvar-Hazy Center in Chantilly, Virginia, alongside the Space Shuttle Discovery; the other at the Patuxent River Naval Air Museum.

For Kids — a shorter, friendlier version

The Northrop Grumman X-47B is an American stealth combat drone built for the Navy. The X-47B first flew in 2011. Only two airframes were built, and the X-47B was a test program, not a production aircraft. Its goal was to show that drones could fly off Navy aircraft carriers, like manned jets.

The X-47B is shaped like a flying wing, with no separate tail, like a small B-2 stealth bomber. The drone is 38 feet long, about the length of a school bus, with a 62-foot wingspan that folds to fit in carrier hangars. One Pratt and Whitney F100 jet engine makes 16,000 pounds of thrust with afterburner. The same engine family powers the F-15 and F-16. Top speed is faster than a rifle bullet.

On July 10, 2013, an X-47B made the first arrested landing by an unmanned aircraft on a Navy carrier, the USS George Bush. The X-47B caught the carrier's tail-hook arresting cable, just like a manned jet. In April 2015, another X-47B made the first hands-off mid-air refueling by a drone, getting fuel from a KC-707 tanker. Both were big firsts in drone history.

The Navy retired the X-47B in 2015 without ordering a production version. The technology lived on in the MQ-25 Stingray, a smaller drone that refuels other Navy planes. The MQ-25 entered service in 2026. The two X-47Bs are now in museums, including one at the National Naval Aviation Museum in Pensacola, Florida.

Fun Facts

The X-47B is shaped like a flying wing, like a small B-2 bomber.
The X-47B is 38 feet long, about the length of a school bus.
The wingspan is 62 feet, folding down to 31 feet for carrier hangars.
Top speed is faster than a rifle bullet.
In July 2013, the X-47B made the first hands-off carrier landing by a drone.
In April 2015, the X-47B made the first hands-off mid-air refueling by a drone.
Only two X-47Bs were built, both retired in 2015.

Kids’ Questions

Why land on a carrier?

Aircraft carriers move around the world, getting Navy planes close to where they are needed. Until 2013, only manned jets could land on the rolling deck of a carrier. The X-47B showed that drones can do it too. This opens the door for future Navy drones to fly off carriers like manned jets, with no pilot at risk.

How does mid-air refueling work?

One plane flies underneath a tanker, which lowers a hose with a basket on the end. The receiving plane sticks a probe into the basket, fuel flows, and the planes part ways. In April 2015, the X-47B did this all by itself, with no human pilot. It was the first drone to refuel hands-off, a key step for long-range Navy missions.

What replaced the X-47B?

The Navy decided not to build the X-47B in large numbers. Instead, they ordered the smaller MQ-25 Stingray, a drone that refuels other Navy jets. The MQ-25 entered service in 2026. The MQ-25 is a tanker, not a combat drone, but it uses many lessons from the X-47B program.

Variants

X-47B (sole demonstrator build): Two airframes built, AV-1 and AV-2. First flight 4 February 2011. Around 100 flights through 2015. Both airframes preserved at U.S. museums after programme retirement.
X-47A Pegasus (predecessor demonstrator): Earlier Northrop Grumman X-47 demonstrator. Smaller airframe at roughly 5,000 lb gross weight, used for early autonomous-operations work between 2003 and 2005. Single airframe built; flown briefly after ground test.
X-47C (proposed full-scale UCAV): Proposed full-scale Northrop Grumman UCAV based on X-47B technology. Internal weapons load around 5,000 lb, longer endurance, expanded sensor suite. Not procured by the U.S. Navy.
MQ-25 Stingray (in-service successor): Boeing-designed unmanned aerial refuelling tanker for U.S. Navy carrier use. More on the MQ-25 Stingray. Service entry 2026; draws on lessons learned from X-47B development.
Future U.S. Navy unmanned carrier aircraft: Proposed unmanned strike and multi-role designs in development. The Navy's Future Naval Air Wing concept expands the unmanned-aircraft fleet through the 2030s, including loyal-wingman pairings with manned F-35C and F/A-18E/F.

Notable Operators

United States Navy: Sole operator. UCAS-D programme ran 2008-2015, with flight test from 2011 to 2015. Operations were based at Naval Air Station Patuxent River and aboard USS George H.W. Bush and USS Theodore Roosevelt for carrier-based test deployments.
Northrop Grumman (manufacturer / contractor): Designed and built the X-47B at Northrop Grumman's Palmdale, California facility — the same plant that produced the B-2 Spirit. Contractor support continued through programme retirement, covering airframe maintenance for testing and final disposition.
NASA (limited test support): NASA's Armstrong Flight Research Center supported aerodynamic and autonomous-flight testing during the X-47B programme, contributing to test coordination at Edwards AFB.
Civilian / preservation: Both airframes preserved as museum exhibits. AV-1 is at the Smithsonian Steven F. Udvar-Hazy Center in Chantilly, Virginia, on display since 2017 alongside Space Shuttle Discovery. AV-2 is at the Patuxent River Naval Air Museum in Lexington Park, Maryland, adjacent to NAS Patuxent River where the aircraft was based for testing.

Frequently Asked Questions

What did the X-47B accomplish?

The X-47B set multiple U.S. Navy firsts for unmanned carrier aviation. First runway landing aboard an aircraft carrier: 4 July 2013, USS George H.W. Bush. First arrested landing aboard an aircraft carrier: 10 July 2013, USS George H.W. Bush — the first unmanned aircraft to do so in U.S. Navy history. First autonomous aerial-refuelling demonstration: April 2015, USS Theodore Roosevelt operations area, with a KC-707 tanker. First fully autonomous catapult launch and arrested-landing flights: integrated test programme 2013-2015. These results proved the technical viability of unmanned carrier aviation and laid the foundation for follow-on programmes.

Why was the X-47B retired without production?

Several factors converged. Cost: developing a fully low-observable UCAV with internal weapons carriage was expensive, and the Navy budget could not support both an X-47B successor and competing priorities such as F-35C and MQ-25. Threat environment: the Navy concluded that aerial refuelling was a higher-priority near-term need than penetrating strike, driving selection of MQ-25 over a follow-on UCAV. Programme management: UCAS-D transitioned to UCLASS and then to CBARS/MQ-25, with each step narrowing the requirement. Industrial base: Boeing won MQ-25 while Northrop Grumman built the X-47B, so the demonstrator's design did not feed directly into MQ-25 production. The X-47B was retired in 2015 with its lessons informing — but not directly producing — the in-service follow-on.

How does the X-47B compare to the RQ-170?

They sit in different size and mission classes. RQ-170 Sentinel: a 66 ft wingspan, single-engine stealth ISR UAV used by USAF and CIA for high-value intelligence collection, with 25-30 airframes in service. X-47B: a 62 ft wingspan, single-engine stealth UCAV demonstrator for U.S. Navy carrier operations, with two airframes built and the programme retired. The RQ-170 is in active service; the X-47B was a demonstrator. Both are flying-wing stealth UAVs, but they serve different services and doctrines. X-47B design work feeds potential future stealth UAV programmes.

What replaced the X-47B?

The Boeing MQ-25 Stingray, entering service in 2026. The MQ-25 is a much simpler unmanned aerial refuelling tanker, without the X-47B's stealth shaping or internal weapons bays. The U.S. Navy concluded that an unmanned tanker addressed a more immediate frontline need than a penetrating UCAV. Future stealth UCAV programmes for the Navy may follow through the 2030s as F/A-18E/F Super Hornet and F-35C carrier fleets are progressively augmented by unmanned strike and multi-role aircraft.

Where can I see the X-47B?

Two locations. X-47B AV-1: Smithsonian Steven F. Udvar-Hazy Center in Chantilly, Virginia, on display since 2017 alongside Space Shuttle Discovery. X-47B AV-2: Patuxent River Naval Air Museum in Lexington Park, Maryland, adjacent to NAS Patuxent River where the aircraft was based. Both airframes are accessible to the public; the Udvar-Hazy display is the higher-traffic of the two.

How much did the X-47B cost?

The total UCAS-D programme cost was around $1.4 billion USD over the 2008-2015 development and test period, covering both X-47B airframes plus support systems and test infrastructure. Per-airframe cost worked out at $400-600M USD. The high unit figure reflected the experimental nature of the programme; a production UCAV derived from X-47B technology would have been cheaper per airframe at scale. Even so, total programme cost was a major factor in the Navy's decision to retire the type without proceeding to production.

Sources

U.S. Navy — X-47B UCAS-D programme
Smithsonian Steven F. Udvar-Hazy Center — X-47B Pegasus
Wikipedia — Northrop Grumman X-47B — Source extract used for grounding; CC BY-SA attribution.