MiG-23ML or MiG-23MLA? A pedantic🧵 I see a lot of people using the term "MiG-23MLA" when referring to the MiG-23ML equipped with Sapfir-23MLA radar. To be fair, I've also noticed a few former pilots/mechanics using this term to differentiate between the MiG-23ML/Sapfir-23ML & MiG-23ML/Sapfir-23MLA.

MiG-23ML or MiG-23MLA? A pedantic🧵 I see a lot of people using the term "MiG-23MLA" when referring to the MiG-23ML equipped with Sapfir-23MLA radar. To be fair, I've also noticed a few former pilots/mechanics using this term to differentiate between the MiG-23ML/Sapfir-23ML & MiG-23ML/Sapfir-23MLA.

MiG-23 high AoA aerodynamics🧵 Most books & articles will tell you that the early MiG-23s had poor handling at high angles of attack (AoA), limiting manoeuvrability, and that the MiG-23MLD improved this by, among other things, the addition of dog-tooth vortex generators at the wing-root.

Soviet MiG-23ML (изд. 23-12).

Libyan MiG-23MS and UB aircraft in the 1980s.

Libyan MiG-23MS with R-3S missiles.

Iraqi Air Force, MiG-21F-13 (изд. 74), № 533.

You can calculate total air temperature using the formula: T₂=T₁×(1+0.2×M²) T₂ - total air temperature (Kelvin) T₁ - static air temperature (Kelvin) H=11 km, t=-56.5 °C (T=216.65K) ATAR 9K50: M=2.10; t=135 °C J79: M=2.00; t=121 °C J79: M=2.40; t=193 °C R35: M=2.50; t=215 °C D-30F6: M=2.83; t=290 °C

Throttle response at high Mach numbers🧵 Years ago, with the appearance of Steve Davies’ first edition of “Red Eagles: America's Secret MiGs" in 2008, I learned of an interesting phenomenon, related to the R29-300 engine of the MiG-23MS.

MiG-23 №2 fuel tank🧵 The MiG-23's №2 fuel tank is made of VNS-2 (ВНС-2) precipitation-hardening stainless-steel (PHSS). Other than housing 870 litres of internal fuel, it was also the wing pivot support structure.

The F-14's Wing Center Section🧵 The F-14’s Wing Center Section (WCS) is made of Ti-6Al-4V α–β titanium alloy in the annealed state (UTS ≈ 896 MPa), probably the most commonly used titanium alloy in the aerospace industry. The structure assembled by electron-beam welding (EBW).

The F-111's Wing Carry-Through Box🧵 The General Dynamics F-111's Wing Carry-Through Box (WCTB) is made of D6AC medium carbon, low-alloy, ultra-high strength steel, refined by vacuum arc remelting. D6AC was developed by the Ladish Corporation.

MiG-23/F-4 air intake design🧵 Whenever somebody brings up the MiG-23's intakes, there is always that one person who just has to say: "yeah, it's just a copy of the F-4's intakes, they even copied the number of boundary-layer bleed holes".

When redesigning the MiG-21 from the small nosed day fighter version, the MiG-21F-13 (изд. 74, with СРД-5М "Квант" rangefinder), into the all-weather MiG-21PF (изд. 76, with ЦД-30ТП radar), to fit the larger radar in the nose, the inlet had to be completely redone.

For a long time I wondered if the redesign was a compromise or an improvement in terms of thrust & drag, the fact that it had increased empty aircraft weight being clear.

Iraqi MiG-21F-13 (706) at the aviation museum in Baghdad.

F-106 Delta Dart pictures.

Convair TF-102A & F-102A.

Convair TF-102A & F-102A.

Egyptian Air Force F-7A.

MiG-21F-13 with R-3S missiles.

DPRK AF MiG-21F-13 afterburner.

Red Eagles 4477th MiG-21F-13.

Early production MiG-21F-13 (narrow chord tail).

The lift generated by the forward fuselage (nose) is proportional to its span (or diameter in the case circular cross-sections) squared, as opposed to platform area for the wings found on most aircraft. The thing is that the nose's lifting characteristics do not change with Mach number.

Bulgarian MiG-21F-13.

Back to the MiG-21.

Despite it being considered a Mach 2.05 airplane, according to "Arab MiGs, Volume 2, by Tom Cooper & David Nicolle" the MiG-21F-13 could actually reach Mach 2.2.

E-6T/1 had the new R11F2-300 (6200 kgf) & increased inlet cone travel length. Mosolov on October 31, 1958 set a world speed record of 2388 km/h. A year later, it reached a speed of 2504 km/h (M = 2.38). In 1960, Kokkinaki set a world speed record of 2148.66 km/h on a closed circuit of 100 km.

End of 🧵

Romanian MiG-21F-13 at Deveselu air base, 1964.

MiG-21F-13 inlet cone.

End of 🧵

Romanian MiG-21F-13

Polish MiG-21F-13

I've previously discussed, in an earlier thread, the basic working principle of axisymmetric supersonic inlets with external compression, and the differences between the small & large nosed MiG-21s.

Bulgarian MiG-23ML makes high-speed pass in afterburner at Dobroslavtsi, 1994.

Polish Air Force MiG-23MF makes a low pass. Słupsk 1989. Wings swept at 45 degrees.

Polish Air Force MiG-23MF makes a low pass. Słupsk 1989. Wings swept at 72 degrees.

Three Polish MiG-23MFs.

Damn logo placement. 😒

Bulgarian MiG-23ML making fly-by.

Iraqi MiG-23ML in the USSR/Russia in the early 90s. High resolution version, credit to Славян for finding it.

Iraqi MiG-29 (type 9-12B) at the Baghdad air show.

Iraqi MiG-21F-13 (706) at the aviation museum in Baghdad.

Impressive images. "Interferometric synthetic aperture sonar images of the seafloor. (a) Wreck of a barge on a sediment substrate with boulders. (b) Offshore energy production infrastructure. » 🔗📷📑 tos.org/oceanography...