Did the Heinkel He 162 Volksjäger Pilots Really had to Move a Spike Fore and Aft Inside the Nozzle Tube to Adjust Its Surface Area?

 [VSKYLABS Test-Pilot Notes] issued 27 August 2024

The answer is…YES!

The Heinkel He-162 A-2 Volksjäger was powered by the BMW 003 E-2 series turbojet, a 1st generation axial flow jet engine, which was equipped with a variable cross-section area exhaust nozzle.

The variable cross-section area mechanism featured an adjustable inner-diffuser cone, capable of shifting its position mechanically.

By shifting its position forward or aft, it increased or reduced the cross-section area of the exhaust jet-pipe. This mechanism allowed the utilization of the maximum allowable power during the flight, depending on the aircraft's speed and altitude, and prevented ‘choked nozzle’ at high flow velocities.

*Modern variable-area nozzles are capable of ‘transforming’ the exhaust nozzle into a ‘Converging-Diverging’ geometry, allowing the nozzle jet flow speed to exceed supersonic velocity. The early variable cross-section area mechanism of the BMW 003 turbojet operated only within the ‘converging’ range of nozzle geometry.

The adjustable nozzle control was manual, and the pilot had to set the nozzle position (cross-section) according to the given phases of flight. The index positions were marked on the dorsal mounting fin extension, located underneath and aft of the engine, allowing to recognize the nozzle position externally.

The adjustable exhaust nozzle had four positions, which the pilot set using a multi-position knob in the cockpit.

Adjustable nozzle position index:

A - Normal idle / Start-up.

H - Normal flight above 8 km (altitude).

S - Normal flight below 8 km (altitude).

F - High-speed flight from 0-4 km (altitude) and above 650 km/h (airspeed).






The First Ultralight, Junkers A50 Junior, Reborn by VSKYLABS!

[VSKYLABS Newsletter] issued 25 Aug 2024

It first got my attention last year, on the cover of Pilot magazine (March 2023 issue). At first sight, I assumed that the photo was of a unique replica/restored Junkers A50 Junior aircraft, brought back to flying condition as part of a historical recreation effort. Moments later, while reading the fascinating article I realized that it is an actual, modernized 'series production' S-LSA aircraft.


*Image source: Pilot Magazine March 2023

Following the detailed article, I initiated deep research, leading to the decision to develop the Junkers A50 Junior as a 'VSKYLABS' aircraft add-on for X-Plane 12. The main reason was that I really, really wanted to fly this aircraft, and a well-developed aircraft in X-Plane 12, optimized for the best VR experience, provides the closest flying experience one can get!

Next step was to acquire acknowledgement from ‘JUNKERS Aircraft GmbH’; The VSKYLABS development of the Junkers A50 Junior project for X-Plane flight simulator was approved by ‘JUNKERS Aircraft GmbH’. However, it is an independent VSKYLABS project which is not affiliated with ‘JUNKERS Aircraft GmbH’.

In this newsletter, we will go through a ‘short and effective’ presentation of the real-world Junkers A50 Junior aircraft, from 1929 to its rebirth as a modern S-LSA aircraft in 2022 and as an advanced and authentic flight simulation model for X-Plane 12.

If you are fascinated by the Junkers A50 Junior aircraft and wish to experience a close ‘look and feel’ flying of the modern S-LSA Junkers A50 Junior in X-Plane 12, you are welcome to visit the main project page on the VSKYLABS website in the link below!

Fly safe!

Huss - VSKYLABS.


The Historical Junkers A50 Junior

The Junkers A50 Junior, introduced in 1929, was a groundbreaking ultralight aircraft that perfectly captured the spirit of aviation innovation in the early 20th century. As one of the first sport aircraft designed with an all-metal structure, it featured a cantilever low-wing design made of a steel tube frame with duralumin corrugated skin. This design choice provided the aircraft with significant strength and reduced weight, enhancing its overall performance.

*Image source: Junkers Aircraft - History & Significant Milestones

*Image source: Junkers A50 Junior

Engine and Performance

The original A50 variants were powered by a variety of 5-cylinder radial engines (providing ~79–87 hp), paired with a wooden propeller. This configuration allowed the aircraft to reach a top speed of 170 km/h (105 mph/91 knots) and maintain a cruising speed of approximately 150 km/h (93 mph/81 knots). The aircraft had a service ceiling of ~4,000 meters (13,123 feet) and could cover a range of around 600-750 km. These specifications made the A50 Junior versatile, serving roles such as sport flying and pilot training.

Records and Achievements

One of the A50 Junior’s notable achievements was its involvement in setting several world records, including long-distance flights. In 1931, Marga von Etzdorf became the first woman to fly solo from Berlin to Tokyo. She covered approximately 11,000 km using only compass and maps for navigation, unprotected from storms and rain in the open cockpit. Her journey took eleven days and demonstrated the aircraft's reliability and endurance over extensive distances.

*Image source: Flugpionierin Marga von Etzdorf: Rekordflug nach Tokio

Design and Structure

The A50's design was advanced for its time, emphasizing safety and pilot-friendly handling. Its all-metal construction marked a departure from the wood-and-fabric aircraft commonly used during that era, providing various advantages as an all-weather aircraft.

It featured a commonly Junkers convention of placing the pilot in the back-seat and the passenger in the front-seat.

*Image source: Junkers Aircraft - History & Significant Milestones


The Modern Junkers A50 Junior

Based on the historical model of the Junkers A50 Junior aircraft, businessman Dieter Morszeck and his design team developed the new, modern and innovative Junkers A50 Junior aircraft, incorporating the latest technology. The aircraft had its maiden flight in 2021 and became an extraordinary ultralight S-LSA aircraft.

*Image source: Junkers A50 Junior - Light Aircraft of the 1930s

Engine and Performance Upgrades

The modern A50 Junior is equipped with the fuel-injected Rotax 912iS engine that delivers 100 hp. This is a considerable upgrade from the original rotary engines, enhancing the aircraft's overall performance and safety margins.

Modern Avionics and Safety Features

While the original A50 was minimal in terms of avionics, the new aircraft incorporates state-of-the-art systems suitable for the common ‘21st century pilots’. The new Junkers A50 Junior features a high-tech cockpit interface that blends elegantly into the retro design. The back seat (the main cockpit used for flying the aircraft) is equipped with a Garmin G3X Touch 10", while the front cockpit can host the Garmin G3X Touch 7" or GI 275 / Winter altimeter / Winter airspeed indicators (analog cockpit configuration is available as well).

The aircraft features a Galaxy parachute system and Beringer brakes.

*Image source: Junkers A50 Junior - Light Aircraft of the 1930s

Certification: S-LSA

On November 25th 2022, the Junkers A50 Junior was certified by the German Ultralight Flight Association. Then on February 28th 2023, the A50 Junior received its Special LSA approval from the FAA. The WACO Aircraft Corporation produces the aircraft for American customers.

Here’s a link to the JUNKERS Aircraft GmbH A50 Junior website:

https://junkersaircraft.com/en/aircrafts/junkers-a50-junior/


The VSKYLABS Junkers A50 Junior for X-Plane 12 Flight Simulator

You are welcome to visit the project page at the VSKYLABS website: https://www.vskylabs.com/p/vskylabs-junkers-a50-junior-project/


Project Highlights:

  • VSKYLABS 'Test-Pilot' Project.
  • Superb Flight Dynamics: The VSKYLABS Junkers A50 Junior simulation is a highly engineered, robust tail-dragger S-LSA simulation model that makes use of X-Plane 12's sophisticated flight dynamics and physics simulation, pushing it to its limits.
  • Simulated Systems: The VSKYLABS Junkers A50 Junior features X-Plane 12's latest native features, systems, and physics. This ensures 'high airworthiness' in X-Plane throughout its update process. Some systems may be restricted to X-Plane's default systems algorithms.
  • General Cockpit Configuration: Equipped with a full-scale and fully-featured X-Plane 12 G1000 in a single-screen/dual-display configuration to allow maximum usability.
  • Equipped with Alpha Systems AOA 'Eagle' indicator replica.
  • Passenger Leaning-Aside Feature: For better takeoff and landing forward visibility (by demand via interaction/assignment).
  • Built for VR: Development was tailored specifically for VR and optimized for 2D usage.
  • Perfect Fit for Beginner and Expert Pilots: The aircraft is designed to be flown from the back-seat cockpit. This configuration requires higher piloting skills, and it will make you a better pilot! The front-seat cockpit is fully functional as well, with the limitations derived from the real-world Junkers A50 Junior front-seat operations.
  • Wonderful FMOD sound package that includes authentic Rotax 912 engine recordings and an interactive set of dynamic sound layers that will "wrap" your open-cockpit flying experience, setting a whole new level of immersion!
  • Autoupdater based on the SkunkCrafts autoupdater (XP12 only) - all updates are pushed smoothly without the need to re-download the entire base package (the base package will be updated every once in a while to minimize the gap).
  • Highly Responsive VSKYLABS Support Forums: VSKYLABS offers continuous professional support, from aircraft-related aspects (operating and flying) to X-Plane technical support: Junkers A50 Junior

















From Fast-Forward to Real-Time: F-19 Missions and Time Compression in Microprose vs. X-Plane 12!

[VSKYLABS Newsletter] issued 20 Aug 2024


*The VSKYLABS 'Test-Pilot': F-19 Stealth Fighter Project is an educational/research-based development effort that "brings to life" and realizes the hypothetical 80s Testor's F-19 concept in the most advanced flight simulation environment to date: X-Plane 12 by Laminar Research. It is not an 'arcade' aircraft, nor a 'generic jet fighter' that only looks like the F-19 externally. Extensive, professional real-world experience and knowledge of jet fighter design, systems, performance, handling, and operation were involved in the making of the VSKYLABS F-19. The result is a scientific, graceful, and powerful aircraft that also has a few weaknesses—just like any other real jet fighter. This makes flying it a true-to-life and fascinating experience, especially when exploring the flight envelope and its performance characteristics.

During the development of the VSKYLABS ‘Test-Pilot’: F-19 SF for X-Plane 12, several 80′s Microprose F-19 ‘game’ missions were flown in ‘real-time’ conditions in X-Plane 12, mainly to challenge the 80′s F-19 aircraft concept, as it was originally realized in the Microprose F-19 computer game, using nowadays state of the art simulated environment.

The first mission to be flown ‘operationally’ was the following one (down is a screenshot showing the mission screen vs. the general mission flight plan as measured on Google Earth).

IMPORTANT - quoted from Microprose F-19 80's manual:
"Our (Microprose) selection of regions for game scenarios is not intended to convey a political viewpoint, or promote antipathy toward any nationality or race. Military forces are required to fight whomever their governments says is the enemy (even other family members in a civil war). In this simulation (Microprose F-19), as in all our (Microprose) products, political circumstances of the day dictate who is hostile to whom." ..."In summary, military simulations like (Microprose) Project: Stealth Fighter allow us to experience the vicarious thrills of combat flying without have to declare war on anyone, much less hurt anybody."

The words quoted above reflect the VSKYLABS approach towards any of its military-oriented aircraft simulations. X-Plane is not a combat simulation, and the main focus of VSKYLABS projects has always been (and will continue to be) the joy of flying, the excitement of space and aviation flight, and the fascinating world of aircraft design.

Following the above, here are some of the first impressions and insights of a mission which was flown in a 1:1 scale using the VSKYLABS ‘Test-Pilot’: F-19 SF in X-Plane 12:



The mission presented here was measured at approximately 550 nautical miles in a 1:1 scale (real-world map), slightly above the game's 520 miles measurement (the suggested landing base in the game was at Sigonella, which is in practice located further inland when comparing the maps). However, it was generally quite similar.

The VSKYLABS simulated profile was flown with a fully loaded configuration (full internal fuel, 2xAIM-9X + 1xAGM-158A). No external fuel tanks, similar to the Microprose configuration.

The VSKYLABS F-19 real-time mission simulation included APU startup, taxi, takeoff (using afterburners), followed by non-afterburner acceleration to Mach 0.93 while maintaining low-level flight on the entire first leg to the first target (100 AGL).

After crossing to land, afterburners were enabled (but not operated), and another two-minute flight was made at low altitude. Then, full afterburner power was applied, followed by a pull-up and a simulated attack segment (not reflecting a proposed AGM-158 deployment but still faithful to the 80′s F-19 game).

The flight continued back at low altitude, with a couple of high-G turns, all with full afterburner, simulating a short engagement/evasive turns while accelerating to Mach 1.0 on the way out to the coastline.

The mission then proceeded at Mach 0.95, with no afterburner, approximately 100 AGL, northbound towards Sicily. After presumably being 'safe', the aircraft was gradually pulled up to 18,000 feet for long-range cruise and proceeded to Sigonella at Mach 0.74 until the top of descent, then proceeded for landing.

Just prior to descent, the 'Fuel Level Low' warning was triggered. A safe landing was achieved, but with a very uncomfortable, low fuel level.

Fuel consumption-wise, a lot of parameters are involved in such a comprehensive simulated mission. But in general, wow. Microprose’s 80s F-19 aircraft performance assumptions/predictions and tailored missions planning were truly impressive, in the light of modern analysis using advanced simulation technology, with only a few modifications to the F-19 concept (this will be presented in a dedicated VSKYLABS Newsletter, in the future).

To add that the original mission planning was extremely marginal; a short air-to-air encounter, or an additional 270 or 360 turn over the target area with afterburners, and safely reach to the planned destination would have been impossible. Yet, completing the mission in real-time simulation was extremely exciting!


*Screenshots above are of VSKYLABS ‘Test-Pilot’: F-19 SF v3.0, for X-Plane 12.

Time-Compression in the 80’s F-19 by Microprose:

When first flown the VSKYLABS F-19 in X-Plane 12, over the original 80’s Microprose F-19 missions, it was obvious that something was a bit ‘strange’ compared to the good-old memories of the 80’s F-19 game-play. Here’s why:

X-Plane 12 allows comprehensive real-time physics-based flight simulation over accurate world scenery. After taking off and heading towards the target area (sea or land), compared to the game memories from the 80’s, time seemed to stretch out.

In a 1:1 scale mission, it takes time to cross ~250+ miles to so-called enemy territory, then, bugging out at Mach 1.0 for a couple of minutes. Long minutes passes by... fuel is consumed... climbing to a more economical flight profile... reducing speed to ~Mach 0.7... over the sea, with no land on the horizon, just flying. Time... Flight takes Time!

Complete mission times in the 80′s F-19 game (covering a distance of ~500 NM) were not too long—about 20-30 minutes from takeoff to landing (this was also recreated by playing the original Microprose F-19 to confirm this).

Average simulated mission times in X-Plane 12 were about an hour for a ~500+ miles flight plan, when pushing the aircraft to Mach 0.9 from takeoff to preparations for landing (by a rough measurement).

In the Microprose F-19 game, distance coverage was highly accelerated compared to the 1:1 real-time scale—roughly up to ~8 times faster when reviewing the speeds and mileage in a full-mission profile, where actual average speed was not even close to Mach 0.9.

For more information regarding the VSKYLABS ‘Test-Pilot’: F-19 SF for X-Plane 12, visit: https://www.vskylabs.com/p/f19sf/

The development of the VSKYLABS F-19 for X-Plane flight simulator is approved by Testors/ITALERI S.p.A. However, it is an independent VSKYLABS development effort which is not endorsed and/or affiliated with/by Testors/ITALERI S.p.A

Stay tuned for more fascinating VSKYLABS Newsletters!

Fly safe!

VSKYLABS



Intel 14th/13th Gen CPU issue...This may SAVE your day??

[VSKYLABS Newsletter] issued 14th Aug 2024

Hello VSKYLABS Pilots!

This is an unusual topic, but since flight simulation involves *hardware* operations and setups, it may be relevant/useful for you!


Disclaimer:

The following information is brought here 'as is', and for information purpose only. VSKYLABS is not responsible for any damage or other consequences regarding any further use of the following information. Any action done in your PC is solely under your discretion and responsibility. If you don't know what you are doing, don't hassle with your bios settings without professional assistance.

OK here we go! Will start with the IMPORTANT information:

One of the main VSKYLABS development PC's was recently replaced with a brand new system, with the following core components:

  • Asus Z790 Gaming Plus WIFI mother board.
  • Intel i9 14900ks processor.
  • RTX 3080Ti

After 24 hours, system got unstable, sometimes could not even complete the booting process, with unexpected freezes every few minutes, under load or just while idling.

After an on-going hassle which took place for about a month, the following actions brought the system to become fully stable:

  1. We updated the bios with Intel's latest 0x129 microcode which was released last week (bios 1662 for the given Asus motherboard).
  2. We set the bios with Intel's recommended power settings for the i9 14900ks, found here: June 2024 Guidance regarding Intel Core 13th and 14th Gen K/KF/KS instability reports
  3. With regards to #2 above, it was set with the 'Performance' limits, not with the 'Extreme' limits (ICC MAX = 307A, PL1,PL2 = 253W).
  4. In the Bios settings, CPU Core Voltage Override was set to manual, 1.350V.

Following this, system seems to be fully stable, working in good and lower temps under load, completed thorough and prolonged stress and stability testings in Prime95 and multiple benchmarks in Cinebench with good scores. End of suffering???

Additional important information:
In the initial ~24 hours of operation of the NEW system (before any action was taken), all worked fine, however, CPU temps were running high under any light to moderate load (exceeding 100 degrees C, easily).

After the 1st ~24 hours of operation, PC suddenly froze, with the last 0.5 seconds of sound which was 'playing' at that moment, looping endlessly. Hard power-off and reset was required. The issue of freezing and hard-power off got worse and within a couple of hours, PC was total UNSTABLE and UNUSABLE.

As an immediate precaution, the CPU was set with Turbo disabled, bringing the P cores down to 3200 Mhz and the E cores down to 2400 Mhz (P cores ratios to 32, E cores ratios to 24).

The PC seemed to be stable, but hey...running an i9 14900ks at 3200/2400 Mhz is far from being acceptable...

Interestingly, with the Turbo mode being disabled, when performed high CPU-ONLY load tasks at base non-turbo 3200/2400 Mhz (say a prolonged 7-zip compression using all cores), CPU temps exceeded ~75 deg C.

Then, when performed a combined CPU/GPU load (running X-Plane, which doesn't use all cores), temps exceeded ~90-95 deg C, easily.

Updating to 0X125 microcode and following Intel's official recommended power settings as described above, did not assist; any operation with turbo enabled or above core ratio of 40 for the P and 24 for the E resulted with CPU freezes under load or just in idle.

Setting the bios as described up in this newsletter; updating to 0x129 microcode (Bios 1662 for Asus z790 Gaming plus WIFI + setting the power limits as described above + manually limiting the CPU Core Voltage Override to 1.350V....seems to hit the nail!

  • Working temps on idle got lower by ~10-15 deg c (~30-40 deg c peaking ~45 deg c).
  • Working temps when running X-Plane 12 at max settings got lower by ~10-15 deg c as well (now at ~60-70 deg c in average, peaking ~85c).
  • Temps under heavy stress (benchmarks and synthetic stress runs) never exceeding 95 deg C.

*Room temp at the 'labs is usually around 25 deg c.

Additional insights:

  • We believe that the fact that the CPU was immediately restricted to non-turbo mode, prevented permanent damage to the CPU, or heavily reduced the chances for damage, as the CPU is now passing prolonged heavy load stress testing without issues. CPU damage and degradation may still be a risk-factor or a given fact, as there is no way to know precisely what went within in those initial 24 hours, when it worked 'unleashed' though under low stress (mainly due to the installation process of the new development rig, so no benchmarks, only several times running X-Plane and other relevant software while preparing the system to its destiny).
  • Intel approved an RMA for the given CPU about two weeks ago, after we 'gave up' on the CPU, while trying to work this out for so long, including with the 0x125 microcode which was released for the motherboard and did not assist. The installation of 0x129 microcode was made with 'low motivation' and with low expectations, and indeed after the initial reboot with the default settings, CPU was not stable(!) and unusable (!!).
  • Only after going manually and setting the power restrictions as described above in the opening, it worked like magic. The most significant visible difference was the reduced in working temperatures of ~10-15 deg c, besides the stability.
  • Intel provides guarantee for the 13th and 14th gen CPU. At the present, this specific CPU remains 'operational' here at VSKYLABS, as it performs as expected and without issues. This will be the case until or if it will show signs of degradation. If not, then, it seems that this fiasco is over!
  • Reminder - Goal is not overclocking or exceeding more points in a benchmark. Goal is to have a 100% stable working station with the i9 14900ks installed, within its default/stock operation and limitations. It seems that this goal was achieved.

Hopefully this information is helpful to some.

VSKYLABS does not aim for providing PC/CPU/BIOS support. For professional support please contact your PC retailer, Intel, or other professional assistance.

Fly safe and stay tuned!

VSKYLABS