
The Israeli Air Force’s F-35I Adir not only flew over Syria but ventured 200 kilometers inside Syria to bomb Iran-backed militants groups. Israeli named F-35I “Adir” meaning “Strong One,” one of the names of God in Judaism.

The Israeli newspaper NZIV reported citing officials sources of Israeli Defense Forces (IDF) that Israeli F-35I Adir flew over the area covered by Russian-made S-300 and S-400 Surface-to-air missile system.
The F-35I Adir has been flying over Syrian territory covered by so called stealth-killer S-400 SAM advertised, spread propaganda brochures and sold to Turkey, Algeria, China and India, turn out to be another lame duck missile system manufactured by Almaz-Antey. The S-400 brochures says it can detect and engage interceptor missiles to a stealth fighter jet however, so far S-400 proved to be useless against stealth technology.
Previously, the Global Defense corp reported that the vulnerabilities of the search and fire control radar of S-400 can be fully exploited by the electronic warfare system of EA-18 Growler and F-35 stealth fighter jet. It’s a prove that the AN/ASQ-239 EW systems of F-35 successfully defeated the S-400 and S-300 radar systems.
It’s time to deconstruct Russian Radar and elaborate the performance of Russian radar in an actual combat. Let’s go through what Rostec, Almaz-Antey and Rosoboronexport brochure Says.
92N6E “Gravestone” (NATO code name Gravestone)
92N6E “Gravestone” is an I/J-Band multi-function phased-array trailer-mounted engagement radar with digital beam steering for use with the SA-21 “Growler” theatre defence missile (Russian designator: S-400 “Triumf”, Cyrillic: С-400 «Триумф»). It’s a direct successor of the engagement radar 30N6E “Flap Lid” in context of the S-300. A significant difference in appearance is that the 92N6E radar is mounted on a special MZKT-7930 (8×8) truck chassis, while the 30N6E is built on the MAZ-7910 (8×8). New processors and digital technologies allow the 92N6E to double the missile range compared to the older 30N6E variant.

The 92N6E uses a transmission type of space feeded phased-array antenna with a complex monopulse horn feed into the rear plane of the antenna, using a microwave lens. This antenna has low sidelobes as protection against noise jammers and anti-radar missiles. The 92N6E can control up to 12 missiles of type 40N6 against 6 aims in a range up to 400 km. Every missile is fitted with an active radar sensor and is involved in calculating of the precise target position (Track via Missile).
As acquisition radars can be used the multi-mode radar 96N6E “Cheese Board” for all altitude regions, or additionally a 76N6 “Clam Shell” FMCW radar for low altitude targets. Even passive radars can be used.
The 92N6E departs from the specialized engagement and fire control functionality of earlier radars in the Flap Lid family, redeveloped processor utilized in the 92N6E model.
It is intended to provide autonomous manual and automatic sector searchs, target acquisition and tracking, in adverse weather, Electronic Counter Measures, chaff and low altitude clutter environments. The radar is equipped with an IFF capability for domestic model.
The 92N6E Gravestone will automatically prioritise targets, compute Launch Acceptable Regions for missile launches, launch missiles, capture missiles, and provide midcourse guidance commands to missiles while tracking the target and missile. Missile guidance modes include pure command link, semi-active homing, and Track via Missile (TVM) /Seeker Aided Ground Guidance (SAGG), where missile semi-active seeker outputs are downlinked to the Grave Stone to support the computation of missile uplink steering commands.
The radar can track 100 targets in Track While Scan mode, and perform precision tracking of six targets concurrently for missile engagements. data exchanges between the 92N6E Grave Stone and 30K6E battle management system are fully automatic.
The 92N6E Gravestone data processing subsystem is designed around the Elbrus-90 mikro SPARC multiprocessor system, like the S-300PMU2 30N6E2 Tomb Stone variant. Computing power is exploited to support a diverse range of modes and waveforms. These including:
Sniffing waveforms at varying power levels to establish the presence of interfering emitters at a given angle and frequency; Adaptive beam control reflecting immediate operational conditions;
Variable PRFs and scan rates for missile and target tracking; Defeat of high-power active noise jammers by the use of “radical measures” in the design.
New Electronic Countermeasures technology was employed in the design of the 92N6E Gravestone but was neither described nor named.
Application of 92N6E Gravestone
The Almaz-Antey advertised brochures say that the export variants of the S-400 and S-500 Triumf are intended to destroy opposing stand-off jammer aircraft, AWACS/AEW&C; aircraft, reconnaissance and armed reconnaissance aircraft, cruise missile armed strategic bombers, cruise missiles, Tactical, Theatre and Intermediate Range Ballistic Missiles, and any other atmospheric threats, all in an intensive Electronic Counter Measures environment. Lemanskiy et al describe the system composition as four core components:

The 30K6E battle management system, comprising the 55K6E Command Post and 91N6E Big Bird acquisition radar; Up to six 98Zh6E Fire Units, each comprising a 92N6E Gravestone “multimode” engagement radar, up to twelve 5P85SE2 / 5P85TE2 TELs, each TEL armed with up to four 48N6E2/E3 missiles; A complement of SAM rounds, comprising arbitrary mixes of the 48N6E, 48N6E2 and 48N6E3; The 30Ts6E logistical support system, comprising missile storage, test and maintenance equipment.
S-400 and S-500 System Integration
The communications and networking systems are designed with interfaces for operation over radio-frequency, and landline links, including analogue telephone cables. The 98Zh6E Fire Units can be located up to 100 km from the 55K6E Command Post. The 91N6E Gravestone can be installed on the 40V6MR mobile mast system for operation in complex or heavily forested terrain.

The 30K6E battle management system exploits much of the potential in a fully digital system, and can control: S-300PMU1 / SA-20A and S-300PMU2 / SA-20B fire units directly;S-300PMU1 / SA-20A and S-300PMU2 / SA-20B fire units via the respective 83M6E2 and 83M6E1 battle management systems;9K330/331 Tor / Tor M/M1/M2E / SA-15 point defence SAMs via the Ranzhir-M ADCP; 96K6 Pantsir S1 SPAAGM via the lead battery vehicle or battery ADCP where used.
Redundant 91N6E Big Bird acquisition and battle management radars; 96L6E acquisition radars; 67N6 Gamma DE acquisition radars; 59N6 Protivnik GE acquisition radars;83M6E2 and 83M6E1 battle management systems; 9S52M1 Polyana D4M1 Command Posts;73N6 Baikal E Command PostsOther 30K6E systems; Other Russian ADCP designs.
5N66/5N66M/76N6/76N6E “Clam Shell”
The Moscow based LEMZ (Lianozovo) company is now openly marketing the Clam Shell (5N66/5N66M/76N6/76N6E) low altitude search and acquisition radar for the SA-10A/B (S-300 PMU) Grumble SAM system. Representatives of the company distributed a technical brochure at the 1995 Avalon Airshow in Melbourne. The SA-10 is at this time the most potent of the late generation ex-Soviet strategic area defence SAM systems to be exported.
The Clam Shell remains a major part of existing Russian PVO IADS S-300P/PT/PS/PM SAM batteries. Moreover, large numbers of 76N6E Clam Shell radars have been exported to post-Cold War clientele, packaged with S-300PMU / SA-10B Grumble, S-300PMU1 / SA-20A Gargoyle and possibly some S-300PMU2 Favorit / SA-20B Gargoyle batteries, although the latter tend to employ the newer planar array 3D LEMZ 96L6 as a single replacement for the paired 5N59/36D6/ST-68U/UM Tin Shield and 76N6E Clam Shells used almost exclusively with earlier configurations of the S-300P series system.
What has been declassified and is now available on Russian websites is technical literature for the other widely deployed Almaz packaged CW radar, the 5N62 Square Pair, which is the CW engagement radar for the very long range S-200 / SA-5 Gammon SAM, first deployed in the late 1960s and a mainstay of the PVO and Warsaw Pact IADS. This semi-active homing SAM design, which still remains in use in many nations including Syria, Iran and the DPRK, is designed to kill high flying targets at ranges of up to 160 nautical miles.
The Square Pair has limited autonomous acquisition capability but is built to provide dual plane monopulse angle tracking, ranging and CW illumination in an ordinary environment.
The Clam Shell is advertised as a low altitude FMCW (frequency modulated continuous wave) search and acquisition radar designed to detect and track approaching and receding low radar cross section (RCS) targets, particularly cruise missiles. The system will detect targets at extremely low altitudes in ground clutter under intense ECM conditions. This system is described as fully automatic and provides target track information for the fire control system of the static SA-10A or mobile SA-10B Grumble area defence SAM. Approaching and receding target velocity, range and bearing are provided, with selectable 1 or 6 degree vertical beamwidths, and selectable beam polarisation.
The FA-51MU antenna head subsystem combines a receive and transmit antenna, separated by a shielding structure, which prevents spillover from the transmitter into the receiver. The brochure states the antenna design includes sidelobe suppression features. The doubly curved transmit and receive reflectors each measure 9.2 ft per side. The antenna head is mounted on a hydraulically elevated mast which is supplied in two versions, the taller 127 ft 40V6MD and the shorter 78 ft 40V6M (see photo). The antenna mast and head are mated before elevation on a semi-trailer which is towed by a MAZ-537 tractor.
91N6E Big Bird Acquisition and Battle Management Radar
The design changes to the 91N6E were not detailed by Lemanskiy et al, other than to disclose its intended ABM acquisition role. The radar is tasked with acquiring and tracking aerial and ballistic targets, identifying targets, and performing angle measurements on standoff jamming aircraft.

The 91N6E is a Janus-faced symmetrical transmissive space fed passive phased array, with a range of conventional circular scan modes, and a number of fixed sector scan modes, using electronic beam steering in elevation and azimuth. In the latter modes, the antenna boresight can be mechanically tilted upward to extend achievable electronic beamsteering elevation coverage. The radar is a pulse-to-pulse agile frequency hopper, to maximise countermeasures resistance. Unique high duty cycle transmit waveforms are available for fixed sector electronically beamsteered search modes.
98Zh6E Fire Control Unit
The individual fire units in the battery are designated the 98Zh6E and comprise a single 92N6E Gravestone multirole engagement radar and a group of subordinate TELs.
55ZH6M “Nebo-M” TALL RACK Mobile multi-band radar complex (Early Warning Radar)
Russian industry is very actively marketing digital upgrades to the P-18 Spoon Rest, and new production digital 55Zh6 Nebo UE / Tall Rack and Nebo SVU VHF radars, specifically as a “Counter-Stealth” capability.

The fully digital Nebo SVU is a solid-state VHF band surveillance radar intended for the detection of airborne and ballistic targets. These include tactical and bomber aircraft, and low altitude and stealth aircraft targets. Capabilities include an integrated IFF array and the ability to track airborne noise jammers. Key features include:
Active phased array antenna design with a Transmit Receive Modules integrated with each of the antenna elements, analogue-to-digital conversion of each channel, with the option of digital beamforming in the vertical plane for ABM operating modes. Fully digital signal processing. Adaptive automatic operation to handle countermeasures and antenna element failures. Digital processing designed to handle adverse weather and intensive chaff bombing. Adaptive sidelobe cancellation. Height finding capability.
A key consideration when assessing the Nebo SVU is its greater mobility compared to other VHF radars. The Ural 4320 towed trailer arrangement has similar cross country and road mobility to the KrAZ-260 towed variants of the S-300PMU/S-400 TEL. More importantly, the ~20 minute deployment and stow times are much improved over earlier VHF radars in this class, more than twofold compared to the P-18 Spoon Rest or Nebo SV, and threefold over the legacy S-300PMU acquisition radar, the 36D6 Tin Shield. Currently the most mobile Russian acquisition radar is the 64N6E/91N6E series ESA, towed by a MAZ-543 derived tractor, and capable of “shoot and scoot” operations with times of minutes.
A self-propelled variant of the Nebo SVU has been developed as part of the new NNIIRT Nebo M Mobile Multiband Radar System, it is claimed to be equipped with a more advanced hydraulic stow/deploy mechanism to emulate the “shoot and scoot” capabilities of the 64N6E/91N6E series. What has not been disclosed about the Nebo SVU is the specific mechanism used for high precision angle tracking, it is likely that high speed electronic sequential lobing is employed to emulate amplitude monopulse techniques. Details of the active sidelobe cancellation and jammer nulling mechanisms have also not been disclosed. While reports have emerged of the integration of the 55Zh6 Nebo UE with the S-400 C3 system, none have been seen as yet on the integration of the Nebo SVU.
The 55ZH6M “Nebo-M” is a mobile radar complex of medium and high altitudes using radar of various types in a block-modular design. According to the R & D “Nebo-M”, the creation of an interspecific radio-location station [RLS] for detecting air targets in a wide range of wavelengths was carried out.
Drones, ballistic missiles, planes and even those employing stealth technology can’t hide from the Nebo-M. It’s a mobile radar station that spots and tracks airborne targets with two radar systems operating in different frequency ranges. The Nebo-M consists of three trucks carrying a giant, swimming-pool-sized antenna, a smaller one, and a command post module. Together they scan airspace at a range of 1,800 km and an altitude of 1,200 km. The Nebo-M takes just 15 minutes to deploy and its mobility enables positioning in any required direction. It also has strong jamming protection and works even if its radar systems get knocked out.
In the framework of the R & D “Sky-M” NIIIRT, work was underway to create a mobile interspecific multi-band radar location complex [RLK] of medium and high altitudes based on the BAZ-6909 chassis. The RLK is designed to detect prospective means of aerospace attack: aircraft, cruise missiles, ballistic missiles, etc. RLC 55ZH6M implements significant detection zones for small-sized and inconspicuous targets, including made using the “Stealth” technology, a short lead time for high-speed targets, a high rate of updating and issuing information, incl. on speeding and maneuvering targets, long-range detection of launches of ballistic missiles, large ceilings in the mode of tracking ballistic targets.
The RLK is made in the form of a meter-decimeter-centimeter complex, which provides for the operation of radars of different wavebands, not independently, but in adaptive interaction, allowing to combine the advantages of different wavelength ranges. RLK is made on the block-modular principle and contains a set of radar modules (RLM) meter, decimeter and similar in design, centimeter wavelengths, as well as, control cabins RLM work and their interaction.
The “Nebo-M” mobile multiband radar system is capable of detecting small-sized aerodynamic and hypersonic targets in difficult EW environment and bad weather conditions. It is also able to send data to the missile defence combat units. The system has Active Electronically Steered Array antennas which allow to work in difficult jamming situation that is why it is capable of detecting targets at larger distances and performing a quicker transmission of radar data concerning ballistic and hypersonic targets. Fully automatic data processing, target classification, functional-diagnostic monitoring and inquiry and communications systems allow to reduce the size of crew.
At present, the radio-location complex [RLK] includes four radar modules of various ranges, controls and power supply. All radar modules are mounted on the BAZ-6909-015 chassis with the wheel formula 8×8 and carrying capacity up to 22 tons. NNIIRT Nebo M System Components”
- KU – Central track processing and fusion system with multiple operator consoles.
- RLM-D – Self-propelled PESA radar based on L band Protivnik G design
- RLM-S – Self-propelled PESA radar based on S / X band Gamma S1 design
- RLM-M – Self-propelled PESA radar based on VHF band Nebo SVU design. Nebo-M RLM-ME is a 3-D acquisition radar. It is the successor to the 1L13 Nebo “Box Spring” and is easy to distinguish from it since the direction of polarization is vertical rather than horizontal. The system can be deployed or stowed in 40 minutes.
VHF-band and the L-band components are available, and it is not necessary to complete the Gamma S1 / S1E. The KU vehicle in the suite is the operator van. Each vehicle has an independent generator rated at 100 kiloWatts. It has been noted that the system will be able to complete the system. All radars are designed to ensure that they can be used in the field.
The Nebo M Mobile Multiband Radar System uses the BAZ-6909-015 8×8 all terrain 24 tonne chassis, self-propelled by BZKT BAZ-6909-015, is used as the SA-21 5P85TE2 TEL and the proposed wheeled SA-23 variant.
S-300PMU1 / 2, S-400 and S-300PMU systems, hosted on the BAZ-6909 S-300P / S-400 missile battery. NNIIRT 3D radars, the VHF band and the S / X-band Gamma S1 were designed for the 55Zh6 Nehir SVT AESA design. The L-band component antenna has been reduced size compared to the semi-trailer hosted 59N6E radar.
It is a clear idea that it provides a counter-VLO capability. A track fusion system in the KU vehicle will be required, providing a capability of the Navy CEC (Cooperative Engagement Capability) system. This technology was previously developed. It is a controlled leakage pattern. It is a very significant advancement to make it possible.
In 2010, the newer NNIIRT-designed 1L119 Nebo SVU and Nebo M RLM–M radars are self-propelled and designed from the outset to support SAM batteries in the field. The Nebo M RLM–M is the much more powerful and accurate self-propelled offspring of the Nebo SVU. Using a similar but much larger hydraulically deployed and stowed AESA design with 168 active elements, this system is carried on the same 8×8 all-terrain BAZ–690915 chassis as SA–21 SAM system launchers. It provides around 40 percent more range and much more accurate angle measurement than the Nebo SVU, retaining the electronic beam steering agility of its predecessor.
The RLM–M is a formidable modern radar in its own right. It is intended for use as part of the Nebo M multiband counter-stealth radar system, which employs the VHF-band RLM–M, the L-band RLM–D, and the S-band RLM-S AESA radars, all networked together via the RLM–KU command post.
Proper deployment of the Nebo M would see the VHF-band radar painting incoming aircraft head on and the flanking L-band and S-band components painting the target from the often less stealthy sides. Also unstated is that with an operational networked Cooperative Engagement Capability (CEC) “CEC-like” track fusion system resident in the RLM–KU command post, other more potent configurations with multiple radars are feasible—for instance, networking and fusing tracks from several RLM–M or RLM–D systems.
The “Nebo-M” mobile multiband radar system is capable of detecting small-sized aerodynamic targets in difficult EW environment and bad weather conditions. It is also able to send data to the missile defence combat units. The system has Active Electronically Steered Array antennas which allow to work in difficult jamming situation that is why it is capable of detecting targets at larger distances and performing a quicker transmission of radar data concerning ballistic targets. Fully automatic data processing, target classification, functional-diagnostic monitoring and inquiry and communications systems allow to reduce the size of crew.
67N6E GAMMA DE
Designed and built in 1990s, the 67N6E GAMMA DE is a radar system developed by VNIIRT for the Russian Armed Forces and exported to the numerous countries.

The Gamma-DE is a Soviet-era modular phased array surveillance radar is designed to effectively detect, identify, measure 3D coordinates, and track a wide range of current and future air threats, including high-altitude low-signature air-launched missiles in a heavy .electronic countermeasures and clutter environment, as well as to receive data from aircraft equipped with ICAO-code transponders.
The radar can be used in automated and non-automated Air Force and Air Defence command and control systems and also as an air route surveillance radar in air traffic control and monitoring systems. The GMMA-DE can be provisioned for the delivery of a remote control equipment kit, enabling the operation of the radar at up to 15 km from the command & control post via a radio link, as well as the possibility to move the equipment cabin by 1,000 m away from the rotating antenna unit. The advertised detection range of aerodynamic object of jumbo jet sized aircarft, 15sqm RCS up to 200km. The detection range is significant lower if the aerodynamic object is less than 5sqm RCS.
Kasta-2E2
Designed and built in 1990s, the Kasta-2E2 is a 3D surveillance radar is designed to conduct air surveillance, find range, azimuth, altitude, and track air targets like airplanes, helicopters, unmanned aerial vehicles, and cruise missiles, including low- and extremely low-level and stealthy air targets, in a heavy clutter environment.

The Kasta-2E2 mobile automated solid-state low-level radar can be employed in various military and civilian systems, including Air Defense, Air Force, Coast Guard, border surveillance, and air traffic control and monitoring systems. At Customer request, the radar can be delivered in the container configuration for operation with a mast antenna.
The radar features long detection ranges for small-sized low-level targets, including low-speed ones, and good jamming immunity. It is economic, reliable, operationally safe, and easy in maintenance. It can be carried by various means of transportation.
The advertised detection range of aerodynamic object of 15sqm RCS up to 150km. The detection range is significant lower if the aerodynamic object is less than 5sqm RCS.
Nebo-SVU
The Nebo-SVU radar is designed for use in Air Defence forces and provides automatic detection, positioning, and tracking of a wide range of current air targets, including ballistic and low-signature stealthy targets; identification friend-or-foe interrogation; location of active jammers; target identification when operating as part of both advanced automated Air Defence command and control systems and non-automated control systems.
The Nebo-SVU Radar design features an active electronically scanned array (AESA) with analog-to-digital data signal conversion in each array row; digital space-time signal processing; flexible adaptation of the signal processing system to the electronic environment and radar’s condition; a high-performance digital moving-target indication system, enabling reliable tracking of air targets under moisture target and passive jamming conditions; adaptive side lobe suppression.
Battlefield Results: Fact Checked In Syrian War
Nebo-M Cannot Detect Stealth Fighter Jet
Many VHF radars will be able to track stealthy fighters at tactically useful distances, albeit much smaller compared to legacy fighters. A fighter’s ability to survive is then determined by its ability to deny launch opportunities through speed and altitude, evade any launched SAMs through high turn rate maneuvering, and compromise terminal SAM seeker guidance by stealth and electronic countermeasures.

The F–22A Raptor and F-35 are in a strong position because its high penetration altitude and supersonic cruise capability place it out of reach of all but the best long-range SAMs. Its stealth is effective from all key aspects, and its shaping is well designed to defeat threat radars from the Ku -band down to the L-band, negating all but the VHF-band radars. The aircraft’s high supersonic turn rate maneuver capability will provide it with an excellent ability to spoil SAM endgame maneuvers. The aircraft is large enough to accommodate internal electronic countermeasures equipment for superior self-defense and radar defeat capability.
Russian Radar Cannot Detect Anti-radiation/Cruise Missile
Currently, Russian radar may be able to detect a low observable object under 50km at 20km altitude, whereas the most Western anti-radiation missile, loitering munitions and cruise missile have a range beyond 200km. The stealth cruise missile like the LRASM have range beyond 1000km.
The Storm Shadow and Scalp missile have range beyond 400km. The Scalp cruise proved deadly against Syrian regime and failed detect by Pantsir-S1 and S-300/S-400 missile defense systems.
The detection range of low observable objects makes the VHF waveband radar vulnerable to current and future anti-radiation missiles such as HARM, Storm Shadow/Scalp, Delilah, MALD-J and Stand-In Attack Weapon (SiAW).
The US, UK, and France conducted air strikes against the Syrian government at around 9:00 PM EST on April 2018.
Secretary of Defence Jim Mattis said at a press conference on Friday night that double the amount of weapons were used compared with the strike in April 2017, which consisted of 59 Tomahawk missiles. The Pentagon confirmed Saturday morning that 105 total weapons were used against three Syrian targets.

French participation in strikes against three chemical-weapons sites in Syria in the early hours of Saturday morning marked the most significant military operation ordered by President Emmanuel Macron since he took office, in May 2017.
France fired 12 Scalp cruise missiles that struck the installations. Operation Hamilton, as the French called their part of the joint operation with the United States and United Kingdom, involved six ships and 17 aircraft.
Russian Radar Has Low Detection Probability Against Drones
According to the media Yeni Akit, they [the military] have material, which, in fact, is an infographic of the effectiveness of the Russian S-400.
As follows from the data presented, the Russian S-400 air defense system can indeed track targets at distances up to 400 kilometers (under the condition of a suitable terrain).

However, under the condition that the target will be at an altitude of 20 kilometers. When the target is located below the altitude of 5 kilometers, the efficiency drops several times, allowing, among other things, to attack the S-400 positional area.
One of the S-400 positioning areas in Turkey covers most of the Turkish territory and airspace, however, if the target is at an altitude of 5 kilometers, its detection efficiency drops by 30-40%.
Read More Israeli Kamikaze Drones Are Destroying Russian-made Air Defense Systems in Syria:
When an air target is located at an altitude of 1 kilometer, the effective range of its detection and destruction is only 70-180 kilometers (depending on the terrain), And when the target is at an altitude of less than one kilometer, we are talking about defeat aerodynamic targets only a few kilometers away.
Russian Radar Has Product Reliability Issues
MTBF (Mean Time Between Failures) and MTTR (Mean Time To Repair) are two very important indicators when it comes to availability of an application. Despite its importance in the performance of the processes, most managers do not make full use of these key performance indicators (KPIs) in their control activities. Find out in the next few lines the differences between these two metrics and how they can be used to improve the efficiency of the processes in your company.
MTBF, or Mean Time Between Failures, is a metric that concerns the average time elapsed between a failure and the next time it occurs. These lapses of time can be calculated by using a formula.
Whereas the MTTR, or Mean Time To Repair, is the time it takes to run a repair after the occurrence of the failure. That is, it is the time spent during the intervention in a given process.
Remember that we are dealing with systems, facilities, equipment or processes that can be repaired. If we were talking about something irreparable, the correct KPI would be the MTTF (Mean Time To Failure). Differentiating these concepts is essential for businesses of all sectors, especially those working with high-availability environments where failures can result in large losses with sales forgone or with loss of confidence in the delivery of services.
For example: a system should operate correctly for 9 hours During this period, 4 failures occurred. Adding to all failures, we have 60 minutes (1 hour). Calculating the MTBF, we would have:
MTBF = (9-1)/4 = 2 hours
This index reveals that a failure in the system occurs every 2 hours, leaving it unavailable and generating losses to the company. The opportunity to spot this index allows you to plan strategies to reduce this time.
Using the same example, we come to the MTTR, by using the following formula:
MTTR = 60 min/4 failures = 15 minutes
Above, we have the average time of each downtime. Therefore, the company knows that every 2 hours, the system will be unavailable for 15 minutes. Being aware of our limitations is the first step to eliminate them.
The uptime calculation involves MTTR and MTBF. We can get to the uptime of a system, for instance, using these 2 KPIs. Let’s check the formula:
uptime = MTBF/(MTBF + MTTR)
To be more clear, nothing better than a practical example. Imagine the following situation:
- How long the system should work: 36 hours
- How long the system was not working: 24 hours
- How long the system has been available: 12 hours
- A total of 4 failures occurred.
uptime: (A-B/D) / [(A-B/D) + (B/D)] = (36-24/4) / [(36-24/4) + (24/4)] = 3 / 9 = 33%
The effect of the quality of components on the reliability of a radar system, measured as MTBF, is examined. It is shown that to achieve an MTBF of 1000 hr for radar used in ground mobile applications, only certain selective combinations of various professional grade components are permissible. A portion of the additional cost of these components is compensated in the form of a reduction in the number of likely repairs during the warranty period. The use of components, such as switches, semiconductor devices, and ICs, of commercial grade deteriorate the system MTBF to a considerable extent and therefore should be avoided. A proper choice of the type of soldering is also important in optimizing the system MTBF.
The Russian radar has a very low MTBF, less than 500hr compared to western radars, as a result of the PESA technology used. The most western radar is using AESA technology with GaN electronics. Russia still uses monopulse and pulse Doppler radar.
Performance Indicators
In general, a computer may have MTBF between 2000-4000hrs and computer mouse may have a MTBF up to 200000hrs. An airborne ISR and navigation radar can have MTBF up to 2000hrs and 4500 hrs respectively. An western GaN based AESA radar is highly reliable with extended MTBF up to 4500hrs comparing Russian radar’s MTBF is only 500hrs.
MTTR and MTBF are two indicators used for more than 60 years as points of reference for decision-making. MTBF is a basic measure of the reliability of a system, while MTTR indicates efficiency on corrective action of a process.

If the MTBF has increased after a preventive maintenance process, this indicates a clear improvement in the quality of your processes and, probably, in your final product, which will bring greater credibility to your brand and trust in your products. The MTBF increase will show that your maintenance or verification methods are being well run, a true guide to support teams.
In the case of MTTR, the effort should be exactly the opposite: to reduce it as much as possible to avoid loss of productivity for system unavailability. A lower mean-time-to-repair indicates that your company has quick answers to problems in their processes, which demonstrates a high degree of efficiency.
As it can be noticed, MTTR and MTBF are two powerful performance indicators that should be used to expand the company’s knowledge about processes and reduce losses in productivity or quality in the products offered.
© 2020 – 2022, GDC. © GDC and www.globaldefensecorp.com. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to www.globaldefensecorp.com with appropriate and specific direction to the original content.
Be the first to comment