USAF B-2 bomber lost after gear failure exposed deeper design flaw

A recently released US Air Force investigation has revealed how a cascading chain of mechanical and design failures led to the partial collapse of a Northrop Grumman B-2A Spirit stealth bomber during landing at Whiteman Air Force Base in December 2022.  

The incident resulted in over $300 million in aircraft damage, caused $27,500 worth of damage to the runway, and temporarily grounded the entire fleet. Consequently, the runway at Whiteman AFB was closed for 10 days. 

The aircraft was ultimately deemed beyond economical repair and removed from operational service, a significant loss given the B-2’s limited fleet size and irreplaceability. 

While the mishap was initially attributed to a hydraulic failure in the main landing gear, the full Accident Investigation Board (AIB) report paints a far more intricate and troubling picture, one that exposes hidden design vulnerabilities in the B-2’s systems. 

RELATED

B-2 Spirit strategic bomber damaged after emergency landing at Whiteman AFB

A routine flight turns into an emergency 

On December 10, 2022, the B-2A ‘Spirit of Hawaii’, tail number 90-0041, was returning to Whiteman AFB following a routine training sortie. The flight crew, flying solo after separating from a tanker formation, prepared for landing on Runway 01 under stable weather conditions. 

At 14:24 local time, the pilot initiated gear deployment at 200 KCAS, well within normal limits. But almost immediately, a failure occurred within the aircraft’s hydraulic system: a half-inch CryoFit coupling located in the right main landing gear’s sequence valve circuit separated from its fitting. This single-point failure released pressurized hydraulic fluid and triggered a cascade of automatic system responses. 

Within seconds, both primary and backup hydraulic systems attempted to compensate. The aircraft’s flight control computers cycled rapidly between the systems, attempting to extend the right main landing gear. But the open circuit continued to dump fluid overboard, rendering both systems ineffective. Only the nose landing gear and left main landing gear successfully deployed. 

An emergency extension, and a hidden flaw 

Facing an asymmetric gear configuration, the crew initiated emergency gear extension around 14:25. This procedure bypassed the main hydraulic systems and relied on accumulators and gravity to lower the right main landing gear. By 14:25:12, all three landing gears appeared “down and locked” on cockpit displays. 

But this was an illusion. 

The aircraft’s cockpit indicators rely on proximity sensors that detect gear position, not load-bearing integrity. While the left main landing gear appeared locked, its internal actuator had partially retracted during the pressure drop, causing it to sit at the edge of its tolerance limit. It looked locked, but it wasn’t mechanically secure. 

Touchdown, collapse, and fire 

The B-2A touched down smoothly at 14:29:01 local time. But as weight transferred to the left side of the aircraft, the compromised left main landing gear collapsed. The left wingtip struck the runway and began dragging, carving a deep gouge down the airstrip. 

The pilot not flying took over, using full right rudder and brake pressure to maintain directional control. Despite their efforts, the aircraft veered off the paved surface, dragging the left wing across the taxiway. At 14:30:20, it came to a stop, 9,062 feet down the runway, with the left wingtip in flames. 

The fire, fed by ruptured fuel tanks, ignited and led to multiple secondary explosions. Delayed application of fire-suppressant foam allowed the flames to spread before emergency crews brought them under control. 

System behaved as designed 

The AIB concluded that the mishap was triggered by the CryoFit coupling failure but exacerbated by systemic design flaws in the landing gear system. 

The Emergency Bypass Valve, used during emergency gear extension, unintentionally depressurized the system in a way that compromised the left main landing gear’s locking mechanism. 

A hydraulic pressure pulse caused by the shock of touchdown further weakened the actuator, pulling it fully out of the locked position. 

Throughout the process, cockpit indicators falsely reported the gear as locked, due to reliance on proximity sensors rather than load or pressure sensors. 

In short, the system worked exactly as designed, but that design failed to guarantee gear integrity in a dual-system hydraulic failure scenario. 

Crew exonerated 

While the mishap crew deviated slightly from the emergency gear checklist, initiating emergency extension 30 seconds after gear handle deployment instead of waiting the prescribed 60 seconds, the report explicitly clears them of any blame. 

Technical analysis confirmed that the design flaw, not timing, made the system vulnerable to collapse. The crew’s actions in landing and regaining control during the asymmetric drag were credited with preventing more serious damage or injury. 

Not an isolated incident 

This was not the first CryoFit coupling failure in the B-2A fleet. The report identifies 25 such failures, with 10 affecting the landing gear hydraulic system. In a notably similar case on September 14, 2021, the B-2A ‘Spirit of Georgia’ (tail number 89-0129) suffered a left main landing gear collapse while landing at Whiteman AFB. 

That incident followed an emergency gear extension after two hydraulic systems failed. Although all gear indicated “down and locked,” the left main landing gear collapsed shortly after touchdown at over 100 knots, causing the left wing to drag along the runway. The aircraft sustained at least $10.1 million in damage. Investigators blamed weak lock link springs, with a CryoFit coupling failure contributing to hydraulic isolation of the locking actuator. 

The incident prompted a Time Compliance Technical Order (TCTO) in early 2022, mandating the replacement of the springs and proximity sensor checks across the fleet. The B-2A lost in the December 2022 mishap had fully complied with the TCTO just six months earlier, indicating that the fix failed to address the system’s deeper design flaws. 

Implications for the fleet 

Following the incident, the entire B-2A fleet was grounded for inspection and testing. Flights resumed in May 2023, but the event cast a long shadow over the long-serving stealth bomber. With only 19 B-2As now operational and the aircraft no longer in production, every airframe remains critical to the US strategic deterrent. 

The B-21 Raider, the B-2’s successor, is being promoted as a solution to the Spirit’s long-standing sustainment issues. It promises better maintainability, improved diagnostics, and a larger fleet size, at least 100 aircraft, more than the B-1 and B-2 fleets combined. The post USAF B-2 bomber lost after gear failure exposed deeper design flaw appeared first on AeroTime.

Go to Source