The B-2 Spirit Bomber is the most expensive aircraft ever conceived, with an average unit cost exceeding $2 billion (when adjusted for inflation). It is also an incredibly costly aircraft to operate and maintain, costing approximately $30 million per year to fly and over 100 hours of maintenance per hour flown.

The bomber also has a very high fuel consumption given its heavy maximum takeoff weight (MTOW) and four high-thrust jet engines, and it is even more fuel-hungry if fully loaded with armaments. So just how much fuel does a B-2 Spirit bomber consume?

The B-2 Spirit: How Many Miles Per Gallon?

According to the Air Force, the B-2 Spirit has a fuel capacity of 167,000 pounds and an unrefueled range of 6,900 miles (9,600 km, or 6,000 NM). Using a standard rate of 6.7lb/gal for jet fuel, this amounts to 0.28 miles per gallon, or just over 0.24 nautical miles per gallon. To put this the other way around, it works out at approximately 4.2 gallons per mile flown.

Other unofficial sources give similar numbers. Aero Corner states the bomber’s fuel efficiency to be 0.24 nautical miles per gallon, which converts to 0.276 miles per gallon. On an episode of the Trending Globally podcast, a similar figure is given by Neta Crawford, professor of political science at Boston University. This is just the cost of what the B-2 burns, and doesn’t take into account the fuel consumption of getting tankers into the air to refuel them. Crawford said,

« The aerial refueling tankers that supply them in the air are getting an estimated 2.9 gallons per mile. So they’re carrying thousands of gallons of fuel to be put into that B-2 bomber so that it can continue its mission without landing, and then return again without landing. So it is a very fuel-intensive activity to fly aircraft. And of course, they’re not just flown for missions, they’re flown for training, and for teaching people how to fly them. »

While the United States Air Force (USAF) is more concerned with capability than it is with fuel consumption, operating costs and fuel consumption are still valid factors in determining the usefulness of an aircraft. After all, higher fuel consumption means less range, more frequent midair refueling maneuvers, or more takeoff and landings to refuel on the ground, all of which are not exactly ideal during a conflict.

Comparing The B-2 Spirit’s Fuel Consumption

With one of the highest operating costs of any aircraft in the USAF fleet, the B-2 is a highly effective yet expensive stealth bomber. Its estimated fuel consumption of 0.28 miles per gallon is a lot for a two-person aircraft, when you consider a 180-seater commercial jet like the Boeing 737 MAX gets over 0.6 miles per gallon.

Looking at other bomber jets in the USAF fleet, the B-2 is not the least efficient. That would be the B-1B Lancer, which has a fuel efficiency of under 0.20 miles per gallon, calculated by its 265,000-lb (39,493 gallons) fuel capacity and maximum range of 6,500 NM (7,480 miles). Even the B-52H Stratofortress – an eight-engined strategic bomber that has been in service since the 1950s – has a better mileage than the B-1B Lancer at around 0.22 miles per gallon.

This mileage goes down considerably if the aircraft are fully loaded for combat. In comparison to fighter jets, the B-2 Spirit is also a lot less efficient (if the fighter jet is at cruise speed, of course). However, with the afterburners on, fighter jets guzzle fuel at a rapid rate and can only fly at this speed for several minutes before exhausting fuel reserves. The B-2 Spirit doesn’t have afterburner capacity, a decision made to keep its high-stealth abilities intact.

Hourly Costs Of Flying A B-2 Spirit Bomber

A lot of money goes into getting a B-2 Spirit in the air and keeping it flying. This includes fuel and manpower costs, as well as maintenance and storage. With the B-2, a significant chunk of its operating overheads are dedicated to its exhausting maintenance requirements, which are estimated at up to 120 maintenance hours per hour of flight.

As such, the stealth bomber’s hourly operating costs are said to be upwards of $130,000 per flight hour. Fuel consumption is a major overheard, and given that B-2 missions can often exceed 30 hours, the bomber requires multiple refueling maneuvers to top up its tanks. In comparison, a large widebody like the Boeing 747 or Airbus A380 typically costs around $25,000 per flight hour.

The B-2 Spirit also requires specialized climate-controlled hangars due to its unique stealth coating, which is highly sensitive to heat and humidity. This stealth coating can be quite costly to maintain and replace, making up a lot of the overall maintenance costs. The bomber also needs to undergo a complete programmed depot maintenance (PDM) overhaul, a process that typically takes around 470 days to complete.

The Engines Powering the B-2 Spirit

There are four General Electric F118-GE-100 turbofan engines powering the B-2 Spirit, and these are very different to the engines you’d typically find on a military jet. Because of the stealth profile of the B-2 Spirit, the jet engines were designed to emit minimal heat signature and are placed a lot deeper within the blended wing to minimize detection from adversaries.

The engine can deliver up to 17,300 lbf (77 kN) of thrust, meaning the B-2 Spirit has a total thrust capacity of 69,200 lbf. Notably, these engines lack afterburners, a design choice to maximize the jet’s stealth capabilities. The B-2 was also designed with fuel optimisation in mind given its high fuel demands, with its cruise speed of 900 km/h (560 mph) optimal for fuel consumption.

Alongside the B-2 Spirit, the F188 engine also powers the re-engined version of the U-2S spy plane, although this version of the engine delivers 17,000 lbf of thrust.

What Makes The B-2 So Special?

When the B-2 debuted in the late 1980s, it was revolutionary for its time and remains unsurpassed in terms of stealth capabilities. It has the smallest radar cross section (RCS) of any bombing aircraft ever built, making it extremely difficult for adversaries to spot or track. On radar, the B-2 is essentially as visible as a small bird. As the Air Force states,

« The B-2’s low observability is derived from a combination of reduced infrared, acoustic, electromagnetic, visual and radar signatures. These signatures make it difficult for the sophisticated defensive systems to detect, track and engage the B-2. Many aspects of the low-observability process remain classified; however, the B-2’s composite materials, special coatings and flying-wing design all contribute to its stealthiness. »

It also has a large payload of 40,000 lbs, meaning it can be equipped with the largest armaments in the US arsenal, including nuclear bombs. The bomber recently demonstrated its high value to US strike capabilities when it dropped 30,000-lb bunker-busting GBU-57 bombs on Iranian nuclear facilities last month.

With its combination of extreme stealth, long-range and payload capacity, the B-2 enables the US to strike pretty much any location in the world. The B-2 can stay in the air for over 40 hours if needed, and is equipped with living quarters to ensure its two-man crew is well-rested and prepared for their mission.

Only 19: Inside The US B-2 Fleet

With fewer than 20 B-2 Spirit bombers under its command, the stealth bomber is a sparse yet crucial asset to the United States. A total of 22 airframes were built by Northrop Grumman, one of which was a test aircraft, meaning the USAF took delivery of 21 bombers.

However, two of these bombers were put out of action, meaning it now has 19 B-2 Spirit bombers at its disposal. One of these crashed in Guam in 2008, leading to the entire aircraft being written off, while another was involved in an accident and deemed too costly to repair.

The B-2 Spirit won’t be in service for too much longer with the arrival of the B-21 Raider, an improved stealth bomber scheduled to enter service by the mid-2030s. USAF expects to acquire over 100 of these bombers during its production run at a cost of almost $700 million per plane. Details about the upcoming stealth bomber have understandably been kept under wraps, with USAF describing it as « a long-range, highly survivable, penetrating strike stealth bomber. » Until the B-21 arrives, USAF’s B-2 fleet will be the most advanced long-range stealth bomber in the world.