I am just starting conceptual design of a carbon fiber fixed wing UAV with zero payload that will have VTOL capability at a later stage. I’m struggling to find reputable empty weight fractions specifically for composite-structure fixed wing-only and VTOL aircraft that don’t also have some specified payload capacity - where can I find some representative numbers for my project?

I’ll also include some information about my configuration and design process for review since I am completely new to VTOL - besides this, I am referencing Raymer for my design workflow and am collaborating with someone that has more composite design experience for the structural design (we are both undergraduates).

Configuration: single pusher-motor, twin-boom, H-tail configuration with horizontal stabilizer mounted on top of the vertical stabilizers (for prop wash clearance). VTOL will be a quad-lifting motor design integrated with the booms. The goal is to build and fly just the fixed wing configuration for testing/trimming before adding the VTOL capability, but to account for the future extra weight/etc of VTOL in the initial design. Both configurations will use the same battery, 4-6S at 50+ C.

Initial design process (up to whats relevant for this post):

1. Choose a 4-6S battery sufficient for VTOL. Find an empty weight fraction for a fixed wing (FW) and a VTOL aircraft separately.
2. Estimate GTOW(FW) using battery weight. Use FW target wing cube load (WCL = 8.0 in my case) and AR (6:1) to find wing geometry
3. In parallel to step 2, create a BOM for all of the added VTOL equipment and sum all weights [we’ll call this W(VTOL-BOM)]. Find GTOW(VTOL) = GTOW(FW) + W(VTOL-BOM). Use GTOW(VTOL) to find WCL(VTOL).
4. Validate that WCL(VTOL)

,

1. GTOW(VTOL)

, and empty weight fraction for VTOL

1. are acceptable (I need to find references for these as well)
2. Proceed with FW design and manufacturing
3. VTOL integration and test

Exciting news for the aerospace community around Houston!

From November 4th-6th, students, industry professionals, and enthusiasts across disciplines are invited to the nation's longest-running space interest conference, SpaceVision, hosted by SEDS USA.

There will be expert panels on a variety of fields from Artemis to in space manufacturing, and even topics such as space medicine and science fiction. There are also thousands of dollars in competition prizes, exclusive networking events, and multi-day access to all of Space Center Houston.

I would definitely look up more information if you're nearby, even if you can only make it for one day I think it's super worth it!

Figured I would cross post this here if any of you can help!

hi guys!! Every satellite operator fighting tight radial and along-track deadbands in VLEO, LEO, MEO, and GEO knows the headache of empirical 1-cycle-per-revolution (1-CPR) residuals: between Solar Noon and the 180° anti-Sun Midnight wake, satellite orbits undergo a systematic radial dip and along-track strain shift. Standard autopilots and propagators (SGP4/GMAT/STK) either burn thruster propellant fighting this reversible diurnal oscillation or require constant empirical curve-fitting after every maneuver.

By debiasing 1,657 passive Satellite Laser Ranging (SLR) normal-point passes across Starlette ($r_1 = 7,190.1\text{ km}$, 860 passes) and LAGEOS-1 ($r_2 = 12,278.1\text{ km}$, 797 passes), we isolated two strict, zero-free-parameter radial power laws:

1. The Diurnal Noon-to-Midnight Dipole Trench ($\alpha = 2.635$): Satellites experience a deterministic, reversible radial altitude dip between Solar Noon and the Midnight Wake governed by $\Delta r(r) = -100.55\text{ m} \cdot (r_1 / r)^{2.635}$ (-110.9 m at 550 km VLEO, -100.55 m at Starlette). Tested blind out-of-sample on LARES ($r = 7,820\text{ km}$) and LARES-2 ($r = 12,270\text{ km}$), it predicts the radial dip within centimeters and cuts 7-day (168-hour) blind propagation drift on LARES from 4,913.3 m down to 11.86 m (99.8% error reduction with zero mid-course updates and zero empirical 1-CPR tuning).
2. Midnight Wake Strain Relief ($\beta = 4.445$) & The Anderson Effect ($V_{\text{A}} = 2\omega_\oplus\vert{}\Delta r_1\vert{} = 14.6644\text{ mm/s}$): Local along-track shear strain drops by 27.6% inside the 180° anti-Sun cavitation pocket, while non-orbital maneuvers ($v_r \neq 0$) experience a deterministic frame-transfer kick governed by the Anderson Constant $V_{\text{A}} = 14.6644\text{ mm/s}$(named in honor of Dr. John D. Anderson of NASA JPL).

I packaged this into a lightweight Python drop-in filter (Jiba) that sits between navigation sensors and the thruster controller:

• Strips the elastic Noon-Wake dipole from deadband boxes (eliminating false-alarm thruster firings).
• Schedules required orbit-raising burns inside the 180° Midnight Wake pocket (where local strain impedance is 27.6% lower).
• Pre-corrects non-orbital transfer burns using the exact Anderson Effect coupling.
• Result: Saves 15.2% to 35.0% of annual station-keeping $\Delta V$ propellant across VLEO, LEO, MEO, and GEO, extending satellite operational lifespan by +1.4 to +2.2 years.

GitHub Repository (Code + 7-Day Blind ILRS Benchmark + NORAD TLE Audit Generator):

https://github.com/fringeneering-jpg/Jiba

Day-One Evaluation & Licensing Terms:

• Free for Students & Academic Researchers: 100% free under GNU AGPLv3.
• Free for Enterprise Day-One Cost Benchmarking: Satellite operators and mission-control teams are invited to clone the repo and run python step4_tle_customer_audit.py with any NORAD Two-Line Element (TLE) from their own fleet to compare Jiba directly against their current station-keeping propellant costs and 7-day tracking residuals for free.
• Commercial Offers (Telemetry Data Only): Over the next month, Fringeneering is fielding commercial offers strictly for the purchase/licensing of the station-keeping telemetry data and orbital correction outputs only (the underlying Phase Wave Cosmology physical framework remains 100% retained by the author and is not for sale).
• Contact: Jaden Allison (Fringeneering — Western Australia) | [fringeneering@gmail.com.au](mailto:fringeneering@gmail.com.au)

feel free to test against your own station keeping programs let me know what you think.
Jaden.

hey, i submitted a post on this channel last week and it absolutely blew up. we had so many applications go through. a bunch of the job postings shut down in the days following my post because of the large influx of applications that were going in. i've gone ahead and updated the job links in this new link. please make sure to apply as soon as possible to ensure that your application is at the top of the pile. i've pulled the freshest job postings that i could.

aerospace jobs are spread across a lot of separate company career pages, so i pulled the ones open right now into lists, straight from employers' own job boards. everything's free and open access on github, no sign-up:

• 279 full-time aerospace and space engineering jobs, entry to mid level (spacex, the aerospace corporation, relativity space, boeing, true anomaly, blue origin): https://github.com/mehek-builds/Hiring-Now/blob/main/lists/aerospace-space-engineering.md
• 41 aerospace engineering internships and co-ops plus 13 new grad gnc and propulsion roles (the aerospace corporation, blue origin, astranis, zipline, mach industries): https://github.com/mehek-builds/Aerospace-Engineering-Internships

posting date on every row, rebuilt every monday.

comment which area you're looking for (propulsion, gnc, structures, new grad) and i'll send you a list for it.

Hi everyone!
I’m a final-year Aeronautical Engineering student, and for my graduation project, I need to design either an aircraft landing gear system or a braking system using CATIA V5.
The problem is that I’m not really sure where to start. I want to do a proper engineering project, not just model some parts in 3D without understanding the engineering behind them.
How should I approach a project like this from the beginning?
What should I include in my graduation thesis besides the CATIA models and technical drawings?
Are there any useful books, manuals, tutorials, or resources you would recommend?
If anyone has worked on something similar or studied aircraft landing gear design, I’d be very grateful for any advice on how to get started and what to focus on.
Thank you! Any help would mean a lot.

I opened VSPAERO on my model, there were no graphs in the convergence or any other tab, and in the viewer tab my model is fully purple and it does not change when i change the AoA. Any advice would be helpful, i heard there might be a problem with vertical the stabilizers but there should not be the problem since i dont have one in my model. I have a basic model with only a stock fuselage and a lightly modified wings, i only wanted to test VSPAERO but i did not expect to run i to such problems on my first try. I also tried a more advanced model but i ran into the same issues.

I wanted to share an original, open-source conceptual design I developed for a next-generation exoplanetary rover that completely throws out the traditional wheeled "buggy" model.

Traditional rovers easily get trapped in loose sand, and their external steering joints are easily destroyed by abrasive planetary dust. My design, the Autonomous Inertial-Tumbling Interplanetary Scout (ATIS), solves this by sealing all mechanical components inside a singular, heavy-coin-shaped cylindrical rim.

How the core mechanics work:

1) Locomotion & Mid-Air Correction: It moves using internal angular momentum. A variable-radius gyroscope (I = mr²) spins freely on low-friction tracks inside the core. For a massive brute force jump, the electromagnet turns on all at once, locking the flywheel to the outer shell to deliver an instantaneous torque spike. Unlike a normal, unguided projectile, it can actively spin its gyroscope and alter its internal radius in mid-air. By changing the distribution of mass while airborne, it manipulates its angular momentum to dynamically alter its trajectory, change its jump height, or control how it tumbles backto the surface and with varying the position of gyroscope from left to right it becomes an multi directional rover for sample collection

2) Station-Keeping: When at rest, the gyroscope actively maintains balance, allowing the entire unit to stay perfectly still and upright without rolling away.

3) Suspension: The outer rim features a hermetically sealed pneumatic chamber filled with compressed exoplanetary gases collected directly from the target atmosphere. This acts as a non-linear gas cushion to absorb heavy impacts from ballistic drops.

4) Energy Efficiency: The rolling motion of the outer rim down slopes can reverse the clutch to spin the flywheel back up, acting as a kinetic energy battery. Thermoelectric Generators (TEGs) capture heat from the internal clutch and motor, feeding it back into the battery and using the trapped warmth as a thermal blanket to survive freezing space nights.

5) Science Axis: Cameras and drills are mounted sideways on the central axis. While the outer rim spins violently, the internal gyroscope keeps the side instrument panels perfectly level, stable, and protected from ground impacts.

I am releasing this publicly as Prior Art to ensure the concept remains open to the space exploration community under my name. I welcome any feedback on the physics!

(Attached: My original engineering design sketches from my tablet)

Disclaimer: I am a conceptual designer, not a systems engineer. I developed the physics framework for this architecture just for fun on my tablet. I have no plans to build a prototype, run math models, or commercialize this. Feel free to use this as inspiration or build upon it-I just wanted to put the idea out into the open-source community

Recently rediscovered this and thought I’d share. This was my father’s first place of employment following his graduation from Bucknell.

Hi everyone,

I'm an aerospace engineering student at Iowa State University conducting customer discovery research to better understand challenges engineers face in their day-to-day work.

We're looking to learn about:

• Workflow bottlenecks
• Documentation and communication challenges
• Project coordination issues
• Technical tools and software frustrations
• Other recurring pain points engineers encounter

If you're a practicing engineer, engineering manager, project engineer, or technical lead, we'd greatly appreciate your perspective.

The survey takes approximately 3-5 minutes:

https://forms.gle/kpwzNgwwCMUGXUbc7

Thanks for your time. I'm happy to share a summary of the results with the community once the research is complete.

Hey everyone! I'm a BE Aerospace Engineering student looking for cool, original ideas for my Fundamentals of Programming II Course lab project.

I need to pitch a 1-page proposal this week detailing a specific aircraft or aerospace problem to analyze, along with what our code will compute and plot.

Here are the project requirements & constraints:

• Group Size: 3–4 students (everyone has to contribute to data collection, coding, and analysis).
• Language: Either Python or MATLAB.
• Allowed Tools/Concepts: Variables, conditionals, nested loops, user-defined functions, arrays/matrices, NumPy, Pandas, and plotting tools. We can also go beyond the syllabus as long as we can explain how the code works during our individual viva.
• Scope: It needs to solve or analyze a real aerospace problem with meaningful calculations and engineering significance—basic data plotting or generic coding exercises won't be accepted. The prompt gave standard examples like aircraft performance, aerodynamic analysis, lift/drag, range, or efficiency, but encouraged us to explore more original ideas.
• Deliverables: Working code, a presentation, an individual viva, and a technical report that includes at least 4 properly labeled plots showing our results.

What are some interesting aerospace problems or specific aircraft analyses that are a step above basic textbook formulas, can generate at least 4 cool plots, and are doable for a 3–4 person undergrad team?

Thanks in advance!

Same as question

We moved a batch of fixture brackets and adapter plates for a component vibration test to a new CNC machining supplier, mostly 6061 with a few 17-4 parts. Their quote came back with a long list of features where our callouts were tighter than anything the test setup needed, and that meant extra setups plus a bigger inspection package. Most of those numbers were copied straight off flight part drawings. How do you decide which tolerances on ground test hardware stay at flight level?

I am part of a high school team developing a simple payload PCB to go to space. We are going to be adding a temperature sensor to the PCB, and we were wondering how we could tell from the numbers alone if the sensor is rather low-power-consuming. Specifically TMP75. I asked AI and it gave me some thresholds, but I couldn't find any sources supporting these numbers. Any insights would be greatly appreciated - thanks!

I recently had a job interview for an aerospace engineering-related position in the aerospace industry. One question caught my attention: “What would you do if a stakeholder didn’t respond to your emails?”

The hiring manager mentioned that people don’t always respond, almost as if this were normal and acceptable.

It got me thinking. Back in the early 2000s, when I worked in engineering, people showed up for meetings and responded to emails. Those were our main communication channels, and somehow, communication seemed more effective.

Fast-forward to today. We have emails, Teams, instant messaging, video calls, and countless other ways to connect, yet getting a simple response can feel like a challenge.

Have we become so overwhelmed with communication tools that we’ve forgotten how to communicate?

What concerns me is that if I receive and accept an offer, I might be setting myself up for failure in an environment where I spend more time chasing stakeholders than actually doing the job I was hired to do. How can someone be held accountable for deadlines and deliverables when progress depends on people who don’t respond?

I’m curious about other people’s experiences. Is this the new workplace culture? Should I see the manager’s comment as a potential red flag, or is this simply how things work nowadays?

So I'm currently helping my friend designing some UAV cargo aircraft like the HH-200 from China and I found some difficulties regarding take-off weight calculation for this aircraft.
For the context, the UAV is not small like a typical UAV but rather large in size.

And so for these UAV, my friend decided to make an UAV cargo similar to these. The UAV will only use single engine (turboprop engine) and this where it start to make a problem.

So in these section, Sadraey explain that the equation used is the equation on 4.26. He explain that the a and b value is obtained from the table 4.8 that based on data he obtained.

Because there are no UAV classification yet in the table 4.8, he use the a and b value for General Aviation with single engine. I also think that the GA-single engine classification is the closest one we know for his UAV design. The a and b value is presented on table 4.8

When he calculate the take-off weight for the aircraft, the output from the formula does not generate a convergent value at all presented by the image below.

I also have tried to check the formula using quadratic formula from the his 2nd edition book about Aircraft Design and only getting this.

The take-off weight showing error because the value inside the square root is negative thus the quadratic formula can't be solved.

But when we change the a value from positive to negative, all of the equation resulting in normal result like these one.

Even the quadratic formula used to check the equation also result in normal value

I just wanna ask, is there something wrong with the equation or the value that substituted into the equation? Thanks for reading all of this.

Thats the question thats all just with kraft paper liner. And please recommend how to make the nozzle.

I thought this was cool and wanted to share it here, This here is a NACA 0012 wing at 8° run in it The mesh is about 149k cells with a wake refinement box and 3 prism layers. The particles are coloured by pressure, and you can see the suction peak and the tip flow.

Anyway I wanted to show it because I finally believe it is a bit presentable now, it is basically a gui with openFOAM, and additionally I added TENO schemes from Fu et al, I thought of adding higher order schemes for more accuracy.

Most of the code is human slop, otherwise known as "spaghetti code" I have yet to clean it up so apologies for any bugs that may arise.

Source code: https://github.com/CakeCFD/cake-studio

Website: https://cakecfd.org/

note that a variant of this post was also posted in r/CFD

I would like opinions from fellow engineers on how to improve this further and make this better, or more specifically what validation case would you trust before using the TENO schemes?

am an independent researcher exploring high-pressure supersonic closed-loop fluid dynamics. I am looking to connect with a simulation expert who has access to CFD tools to discuss and test a kinetic-to-electrical energy conversion module under strict confidentiality. If anyone is interested, please DM me.

I'm building a transforming drone inspired by the M4 morphobot for my project, but simplified to just two modes: flight and ground mode. I know the main argument for adding ground mode is power saving. In the M4 paper, their robot consumed 3000W in flight mode but only 30W driving on the ground which is a huge 100x difference if you need to stay deployed longer or navigate indoor spaces.

The issue is I'm still really struggling to find a solid real-world application that justifies the trade-off. The morphing mechanism adds a ton of weight and mechanical complexity, which hurts flight time. Plus, ground mode is super slow. It feels like in 99% of cases, you'd be better off using a regular drone or a cheap rover. What kind of application would actually justify this design? Like a scenario where a pure drone fails AND a pure rover fails, so a hybrid is strictly required?

I've pretty much run out of ideas and I'm starting to feel like I'm building a gimmick looking for a problem. Am I cooked or is there a legit use case here?

I am an A&P mechanic and always wonder why engineers design stuff the way they, especially when it makes my job incredibly difficult. I understand there are outside factors, like the engineer wanted it one way to make it easier to access, but budget or bosses won’t allow it. I’m not complaining about that at all.

My question is, are spacecraft designed with LESS maintainability since their tolerances are even tighter than aircraft? Looking for any input on the subject, I’m genuinely curious.

TLDR: Are spacecraft even more of a pain in the ass to work on than planes?

I have refined the aeroacoustic/vibration-based aircraft simulation that I posted previously:

https://www.reddit.com/r/AerospaceEngineering/comments/1tqoq9m/oscillatory_propulsion_simulation_and_simple/

It is now more versatile, featuring both "jellyfish" and "fish" modes. The underlying principle remains the same: the fluid does not act directly on the craft's surfaces; instead, the forces derived from the fluid are converted into thrust via an accumulator. However, thrust is no longer generated simply as a phase-shifted inversion of drag. Rather, energy is captured from low-pressure regions—stored as potential energy—and then released through a "collapse" mechanism, with dynamically evaluated recovery and shock coefficients.

This approach yields a more realistic relationship between propulsion efficiency and parameters such as frequency and amplitude, expressed via Strouhal numbers. The feedback loop between internal oscillations and drag acts as an automatic frequency-tuning mechanism.

Additionally, the model incorporates simplified lift and drag forces acting perpendicular to the thrust vector.

The code can be found here:

https://github.com/MasterOgon/Aeroacoustic-Flying-Saucer-Oscillating-Resonator-CFD-Simulation-LBM-/blob/main/README.md

A question thats been in my mind for a few days. I wondered if it is powerful and long enough to make it take off. Taking off like a plane not a rocket tho so it will be a glider after take off.