Can the Russian S 400 shoot down a US B-2 Spirit Stealth Bomber in Syria?

B-2 Spirit, and F 35 LightningII

B-2 Spirit Stealth Bomber and the S-400:

Let's not confuse remote theoretical possibilities with practical feasibility, and also keep in mind the consequences of a possible shootdown.

Under normal circumstances, the radar cross-sections of the B-2 Spirit Stealth Bomber and the F-22 Raptor are below that of a small bird (F 35 LightningII does not have all-around stealth, only frontal stealth), At the altitudes where the B-2 Spirit fly, visualdetection from the ground is not possible.

This Stealth Bomber their radar cross-section for brief periods of time when releasing their weapons, because the B-2 Spirit uses its shielded Raytheon AN/APQ-181 radar only momentarily to identify a target just before attacking.

The B-2Spirit has a highly advanced, classified electronic warfare system. but that's too short to track or guide missiles. Besides, air-defense radars remain off most of the time (otherwise, their life span would be unenviable) whereas passive systems are inaccurate and way too easy to jam (say, just when the F-22 releases weapons).

S-400

There is some mythology about S 400's ability to track US stealth planes using the new radar Nebo-UM, This radar it is claimed that he can monitors the airspace, detects various targets and determines their coordinates. The station can detect and track both aerodynamic targets, including aircraft, helicopters and cruise missiles, and ballistic missile warheads. The radar detects a target, determines its coordinates and state affiliation and transmits information to air defense crews or the command and control post. Besides, it can take the bearings of jamming sources and determine their location. The station detects targets at a range of 600 km and at an altitude of up to 80 km.

it is claimed also the radar system Nebo-UM he can detect a hypersonic cruise missile with a RCS of 0.9 square meters can be detected at 250 kilometers flying at 10,000 meters of altitude or at 300 kilometers flying at 20,000 meters. A fighter aircraft with a radar cross section (RCS) of 2.5 square meters at 65 kilometers flying at 500 meters of altitude, at 310 kilometers flying at 10,000 meters or at 400 kilometers flying at 20,000 meters. And also the Nebo-UM radar has been provided with advanced digital techniques to suppress natural clutter and active jammers.

The Radar System Nebo-UM

But note that S-400 is based on trailers or mobile chassis, which limits the size, emit/receive frequency, and the energy of the radar (you would do better with a soccer-field size radar near a power station, or a much larger array like the one built by the Russia near the Chernobyl nuclear power plant - but such a stationary array is easier to target and sabotage). Russia only has such networks on some parts of its vast territory, and certainly not in Syria.

But let’s assume for a second that a Russian S 400 system managed to detect a US B-2 Spirit and locked a radar on it. This will be immediately detected by the B-2 Spirit and probably by the AWACS or NATO E-3 plane on duty. In response, the S 400 and the radar location will be targeted by any number of US assets nearby that carry cruise missiles, AGM-129 ACM or AGM-158 JASSM. The surface navy and submarines, the B-2 Spirit itself, and any F-35 Lightning II on patrol at the time (I can venture a guess that there will be a pair of B-2s, and they will be accompanied by two F-22s and two F-35 LightningII at a certain distance, with F-22s being invisible to other planes).

Just sticking it to the US isn’t a good purpose, as you can expect to be stuck from many sides in return. So, whoever goes for that, better have a good purpose.

Shooting down a large US plane might bring harsh response and loss of valuable property. So, before attempting to shoot down a B-2 Spirit, one needs to evaluate their goals, the chances of success, the cost, as well as the consequences in cases of success and failure.

To get close to a high-speed, high-altitude target such as B-2 Spirit before it goes out of range, a surface-to-air missile "S-400" needs to pick up altitude very quickly (while the target is cruising horizontally very quickly), which takes significant fuel, which takes significant energy, which makes the missile heavier, which requires more energy and fuel, and also limits the missile’s range and constrains maneuvers. Most importantly, a missile accelerating to several Mach from ground level (through relatively dense air) will be surrounded by hot plasma and can be easily detected by radar and thermal imaging. So, the B-2Spirit will have at least (20s of lead time, likely more), can deploy countermeasures and track the incoming missile.

In effect, whatever the US Military is trying to accomplish with the B-2Spirit, it is probably trying to accomplish in others ways too (The surface navy, submarine-launched cruise missiles, The US short-range ballistic missile system MGM-140 ATACMS, etc, etc).

The US short-range ballistic missile system MGM-140 ATACMS

So, the risks are high, the costs are high, (and bad PR for S 400 may undermine future sales), the chances to hit a B-2 Spirit questionable, and even if a B-2 Spirit is hit by an S 400 missile, Russia may lose the entire S 400 encampment as well as some choice outpost - that might be awkward (for example, if the Tartus wharf goes, the entire Russian story for Naval presence in the Mediterranean). The chances for embarrassment are significant.

On the other hand, Russia should not be underestimated. The lesson to be learnt by a silly observer is that, the F-117 Nighthawk, which is said to be stealthier compared to the B-2 Spirit (0.001sq.m Vs 0.1sq.m, that's 100 times stealthier for the F-117), was downed and another one severely damaged in 1999 by Yugoslvia using a 1960s era Soviet Isayev S-125 "Neva", and this whatever the excuse the US can seek in order to save their face of exceptionally advanced, and technologically unbeatable country.