Illustrative: a US Air Force weapons load crew member prepares a fuze well on a munition for fuze installation, RAF Fairford, 12 November 2024. The fuze well is the interface a height-of-burst sensor occupies; the aircraft and munition shown are not C-HOBS-specific. Photo: US Air Force, Airman 1st Class Laiken King / DVIDS, public domain.

The US Air Force has spent sixty million dollars on the part that decides how high a bomb goes off, and not on the bomb

L3Harris Technologies announced on 14 September 2026 a United States Air Force contract worth approximately $60 million to continue production of the DSU-43/B Cockpit Selectable Height of Burst Sensor, known as C-HOBS, at Cincinnati, Ohio. It is the second fuzing award on that site to be made public inside four months. For a weapons technical readership the point is not the money. It is that the constrained element in Western air-delivered munitions output is increasingly the fuzing and sensing assembly rather than the warhead it initiates.

Technical Summary

C-HOBS is a proximity sensing device, not a guidance kit and not a warhead. L3Harris describes the DSU-43/B as giving aircrew the ability to choose the precise detonation altitude so that the munition's effect can be tailored to different targets and mission environments, and credits the design with improved radar-guided performance alongside manual and cockpit-selectable burst heights. The company states that production will take place at its Cincinnati site, and that it is increasing proximity fuze and sensor capacity to meet demand for cost-effective counter-threat solutions on what its own statement calls a wartime footing. No contract number, quantity, unit price or delivery schedule appears in the announcement, and it names no weapon.

The programme record is less reticent than the press release. C-HOBS has been reported since August 2025 as an Air Force Life Cycle Management Center effort at Hill Air Force Base to replace the fielded Northrop Grumman DSU-33D/B height-of-burst sensor and to resolve obsolescence in it, maintaining the same form, fit and function as the DSU-33D/B while adding manual and cockpit-selectable burst heights and improved performance. Northrop Grumman has built the DSU-33D/B since 1999. The named host weapons are the Joint Direct Attack Munition and the Next Generation Area Attack Weapons, the Air Force has been reported as expecting as many as 60,000 units, and the detailed C-HOBS specifications are classified. The same reporting describes the device as a radar proximity sensor that provides a precise variable proximity function to the fuze system, which is the point a weapons reader needs: it is a sensor that tells a separate fuze when to function, not a fuze in its own right.

The reason a sensor of this class matters out of proportion to its cost is terminal. For a fragmenting warhead the height at which the charge functions determines the geometry of the fragment spray that arrives at the target, and therefore the density of effective fragments per unit area on the ground. Net explosive quantity, fragment mass distribution and initial fragment velocity are all fixed when the weapon is filled and assembled. Burst height is the last terminal variable still open once the aircraft is airborne, and making it selectable in the cockpit moves that decision from the weapon build standard to the mission. Against a soft or dispersed target set an airburst is the whole point of the weapon; against a hardened or buried target the same sensor has to be inhibited so the weapon can function on impact or with delay.

Proximity fuzes are precision electromechanical devices, and the lines that build them at scale are few. A warhead body can be made by any competent forging shop. The device that decides when it functions cannot. ISC Defence Intelligence standing assessment on fuzing capacity

Analysis of Effects

Read next to the June award on the same site, the September contract describes a pattern rather than an event. On 3 June 2026 L3Harris announced a contract worth up to $98 million from the Naval Surface Warfare Center Indian Head Division for the Mechanical Proximity Fuze, also known as the Fixed Wing, Air Launched, Counter-Unmanned Aircraft Systems Ordnance or FALCO fuze, for upgrades to the Advanced Precision Kill Weapon System. In that announcement the company stated it was increasing proximity fuze production sevenfold, with investment in tooling, inspection equipment and supplier expansion intended to enable a twentyfold capacity increase. Two customers and two distinct fuzing product lines inside four months resolve to one Ohio production base. The combined value is better stated as approximately $60 million plus an award of up to $98 million than as a single total, because the larger figure is a ceiling with options rather than booked work.

It is not two product lines on that site but three. In June 2024 the US Army awarded L3Harris an indefinite delivery, indefinite quantity contract worth up to $871 million for M762A1 and M767A1 electronic-time fuzes for 105 mm and 155 mm artillery, manufactured by L3Harris Fuzing and Ordnance Systems at Union Township in Clermont County, the same Cincinnati-area operation. Air-delivered height-of-burst sensing, 2.75-inch rocket proximity fuzing and artillery electronic time fuzing therefore share one industrial footprint.

That concentration is the finding. Across NATO the public argument about munitions output is conducted almost entirely in terms of shell bodies, explosive fill and propellant, because those are the stages with visible factories attached. Fuzing is a smaller industrial footprint and a much harder one to duplicate, because it combines precision electromechanical assembly, radio-frequency sensing, lot-level quality control and an explosive safety qualification route that a general electronics manufacturer cannot simply enter. Europe has reached the same conclusion by a different road. In June 2026 the Czechoslovak Group announced electronic fuze contracts in two NATO states worth a total in the high tens of millions of euros and a joint venture with Reunert's Fuchs Electronics to produce electronic fuzes at Dubnica nad Vahom in Slovakia, on the stated reasoning that ammunition capacity means nothing without capacity in the components. Two alliance members, independently, have decided the fuze is the choke point.

Personnel and Safety Considerations

Two safety questions follow from the announcement and neither is answered in it. The first is the design safety architecture. In United States service fuzing systems are governed by MIL-STD-1316F, Fuze Design, Safety Criteria For, issued 18 August 2017 in supersession of MIL-STD-1316E of 10 July 1998, which sets requirements for independent safety features and for the conditions under which a system may arm. Programme reporting describes the DSU-43/B as providing a proximity function to the fuze system rather than performing the fuze function itself, which puts the weight of that standard on the fuze the sensor talks to rather than on the sensor. L3Harris has not published the architecture for this variant, so how much of the standard bears directly on the DSU-43/B remains a matter for the programme rather than for open source. The second question is storage and transport. If the assembly is wholly inert electronics it is an ordnance component; if it contains an explosive train or an initiating element it carries a hazard division and a compatibility group in its own right, and it has to be stored and moved accordingly. L3Harris has published neither, and a reader should not assume either case from the word sensor.

Data Gaps

Six gaps are recorded against this assessment. First, the contract number and contract type for this increment are unpublished; the contracting activity on the programme is the Air Force Life Cycle Management Center at Hill Air Force Base, but this award has not been tied publicly to a specific delivery order. Second, no quantity, unit price or delivery schedule is stated, so the $60 million figure cannot be converted into units or rate, and the 60,000-unit figure reported for the programme is a ceiling rather than an order. Third, the selectable burst-height range and its increments are unstated. Fourth, the sensing method is described only in the company’s own marketing terms, with no band, no aperture and no stated performance against terrain or countermeasures; the detailed specifications are reported to be classified, so this gap will not close in open source. Fifth, whether the assembly contains energetic material, and therefore its hazard division and compatibility group, is not published. Sixth, the internal interface between the DSU-43/B and the fuze it serves is not described beyond the general statement that it provides a proximity function to the fuze system, so no specific fuze designation is asserted here.

Editorial responsibility. This analysis is researched, written and published under the editorial responsibility of Steve Sawyers, MIExpE VR. Every technical claim is sourced to named open-source material and rated for reliability and accuracy under NATO STANAG 2022. ISC uses its own domain-trained research and drafting system under human direction; the analysis, the judgements and the accountability for them are ours. Corrections and updates welcome: if you hold open-source data that refines or corrects any parameter here, write to [email protected] citing the specific claim and your source. Verified corrections are incorporated and credited in the revision history. Full editorial and AI policy.