TL;DR
The Su-57 has some fifth-gen traits (planform alignment, internal bays, distributed apertures), but persistent issues—finish quality, exposed engine aspects, current engines lacking true supercruise, and mixed evidence on LO upkeep—keep it short of F-22/F-35-class low observability. Combat employment to date has emphasized standoff missile shots from Russian airspace, not penetrating strikes. RUSI+2The War Zone+2
1) Airframe shaping vs. finish: what the jet gets right—and wrong
- Pros (5th-gen-like): planform-aligned edges, saw-toothed panel lines, internal weapon bays, partial S-duct masking with a compressor-face blocker, and RAM coatings—all standard LO measures. Wikipedia
- Cons (where it lags): repeated open-source assessments note rough production finish, panel gaps, and fasteners seen on test/airshow airframes; analysts argue the baseline design/quality limits true VLO (very-low observability). RUSI’s long-running critique: Su-57 lacks several “basic design features” for genuine LO. Wikipedia+1
Bottom line: Geometric stealth is there on paper; repeatable, fleet-wide LO execution is questionable.
2) Engines & supercruise: status check
- In service Su-57s chiefly fly with AL-41F1 (izdeliye 117). Multiple analyses indicate this engine does not deliver reliable supercruise (>Mach 1 without afterburner) on production jets. The izdeliye 30/AL-51F-1 is intended to fix that, but has been flight-tested on prototypes and is not yet fielded fleet-wide. The War Zone+2The War Zone+2
Bottom line: Until izdeliye 30 equips operational squadrons in numbers, true supercruise remains aspirational.
3) Sensors, fusion, and electronic warfare
- Radar suite: the N036 “Byelka” package integrates a nose X-band AESA, cheek arrays, and L-band leading-edge arrays (IFF/EW roles), enabling wide-angle coverage and multi-target tracking. (Module counts and exact performance remain partly opaque.) Wikipedia+1
- EO/IR & IRST: the OLS-50M family provides passive IR search/track; paired with distributed apertures to support non-emitting tactics. Global Security
- Teaming: Russia has signaled S-70 Okhotnik UCAV teaming to expand radar coverage and roles with Su-57, but this is developmental. Aviation Week Network
Bottom line: Ambitious sensor architecture—but maturity/debug timelines are unclear in open sources. Wikipedia
4) Signature management: radar and IR realities
- Radar-band LO: The inlet blocker + partial S-duct help, yet no full deep serpentine like F-22/F-35; rear-aspect shaping and conventional circular nozzles also leave RCS/IR vulnerabilities, especially from beam/aft quarters. Wikipedia
- IR signature: Big, hot engines + TVC nozzles complicate sustained IR suppression; modern IRST resurgence erodes a “radar-only stealth” approach.
Bottom line: Multi-spectral LO (RF+IR+EMCON discipline) is the 5th-gen bar; Su-57 shows partial delivery.
5) Weapons & bays: what fits inside
- Two tandem main bays (~4.4 m x 0.9 m) + two side bays for WVR missiles. Internal AAMs cited: R-77M (BVRAAM), R-74M2 (WVR), with reports of a compact R-37M-derived izd. 810 for long-range shots; standoff Kh-69/PGMs also referenced for strike. (Details vary; some loads external when stealth isn’t required.) Wikipedia
6) Combat use to date: how Russia actually flies the Su-57
- Since 2022, UK MoD-cited reporting and multiple outlets say Russia has used Su-57s to launch long-range weapons from Russian airspace, avoiding dense Ukrainian SAM belts—not as deep-penetration LO assets. UK Defence Journal
- In June 2024, Ukraine released satellite imagery showing a Su-57 hit at Akhtubinsk—a rare and reputationally painful incident for a low-density fleet. Major outlets corroborated the strike with imagery. Reuters+1
Bottom line: Operational behavior implies Moscow is risk-averse with the type; it’s treated more like a standoff shooter/test bed than a day-one penetrator.
7) Verdict: So…how “5th-gen” is it?
- Design intent: 5th-gen-style shaping, internal carriage, AESA-centric avionics, and teaming concepts.
- Execution gaps (today): LO finish and seams, engine maturity/supercruise, rear-aspect/IR management, and limited combat profiles suggest it’s not a peer to F-22/F-35 in VLO survivability—at least not yet. RUSI
If—and it’s a big if—izdeliye 30 arrives in numbers, LO finish tightens across production airframes, and Byelka/ECM mature, the Su-57M arc could close some gaps. For now, its most credible role is networked standoff and limited LO strike rather than deep, repeated penetrations against modern IADS.
FAQs
Does the Su-57 supercruise today?
Open sources indicate no reliable, fleet-level supercruise with AL-41F1; izdeliye 30 aims to provide it but is not widespread operationally. The War Zone+1
Is its radar really multi-aperture with L-band?
Yes, that’s the stated architecture (nose X-band AESA + cheek arrays + L-band leading-edge arrays) under the N036 “Byelka” suite—though practical performance remains hard to verify publicly. Wikipedia
Has it been used in Ukraine?
Yes—primarily for standoff strikes, according to UK-cited reporting; and one Su-57 was imaged damaged at Akhtubinsk in June 2024. UK Defence Journal+1
Publish checklist (Yoast/SEO)
- Keyphrase placement: title, intro, H2 (“Engines & supercruise”), conclusion, and 1–2 captions.
- Synonyms to sprinkle: Su-57 Felon stealth, Su-57 supercruise, Su-57 radar Byelka, Su-57 IR signature, Su-57 engines izdeliye 30.
- Internal links:
- Airpower & Defense hub
- Missiles & Counter-Air (PL-15/AMRAAM context piece)
- Engines & Propulsion (adaptive vs. variable cycle primer)
- Alt-text ideas: “Su-57 Felon rear-aspect nozzles (IR/LO trade-offs)”; “N036 Byelka AESA arrays—concept graphic (X+L band)”.
Sources
- RUSI assessment of Su-57 LO/credibility; commentary on damaged Su-57 at Akhtubinsk (2024). RUSI+1
- Engine & supercruise context (AL-41F1 limits; iz. 30 testing). The War Zone+1
- N036 “Byelka” architecture & L-band arrays. Wikipedia
- Combat employment & UK-cited briefings on standoff use. UK Defence Journal
- Imagery-corroborated strike on Su-57 (June 2024). Reuters+1
