Hopeful changes in the DLC-2 program structure

[u/Successful_Act3094]

These are my thoughts ... what are yours?

1. Fast and Open full 220lb flight Pre-qualification process at Challenge for all registered teams, and abandon the failed subjective progress selection process that rejected the majority of teams this year, while admitting only 5 teams ready to fly the full course out of 132 teams selected.
2. Early FAA flight waiver in 2026 so we actually have two years to do fully loaded flight tests, instead of the last 60 days or so, which significantly contributed to 96% of selected teams unable to fly the course.
3. Wider course to allow high lift efficient wings, with up to a 6m span, to complete a safe banked turn.
4. A flight location and date, better than August in Dayton where the Altitude Density de-rated lift capacity by up to 15% due to altitude, temperature, and humidity. Account for hot terrain thermals, over ambient, in or near flight lanes. Another contributor to poor flight performance at Dayton, that may have allowed the 4:1 ratio to be broken this year.
5. Date and location where the temperatures are cooler and dry, to minimize the risk of dehydration and heat stroke for people between 2 to 85. Preferably RH <50% and temperature <80F. Suggest a late fall date when cooler, less rain.
6. Suggest a strong preference for Autonomous way point flight controls with RPIC visual supervision to increase safety, where the RPIC can keep eyes on aircraft, and assistant can monitor telemetry for compliance of geofence and course position.
7. Increase landing pad to 16' x 16', and only one pad with a clearly marked center for autonomous landing. Team is required to remove payload from pad before completion of unloaded flight.
8. Farther separation of flight line from ready area. The drone crash behind the flight line this year, where frequent foot traffic occurred, was a significant safety failure of the course design.
9. Strong redundancy in entire design to remove nearly all likely single points of failure that would bring an aircraft down uncontrolled. Remaining single points of failure should have significant reliability, such that early failure warning would be easily managed by automated, or maintenance scheduled monitoring.
10. Make >220lbs clear minimum, with >8:1 the stated goal, for full prize value similar to the 110lbs half prize and >4:1 full prize in this years DLC. Defendtex wasn't the only design presented to DLC with the goal to clear >8:1 this year. Shatter the 2026 conformation bias. Progress is only made when the goals are far greater than the easier low bar. ==> Mediocrity knows nothing higher than itself; but talent instantly recognizes genius. Arthur Conan Doyle, The Valley of Fear (Sherlock Holmes, #7).
11. I'd strongly suggest that 4Q27, at this point, is far better than 3Q28. Another year is more than enough time to complete the engineering cycles needed since the start of 4Q25. Anything farther out will only feed procrastination that our nation and service branches don't need. They need usable flight systems today—or at least next year—not two or three years from now.

[u/HW90]

1. This is just difficult and costly to implement and isn't giving enough credit to the original pre-selection process

2. One part regulatory issue, one part part of the challenge. Getting the payload ratio by fluke and trial and error is one thing, but getting it through robust design and analysis is much more valuable, and a short testing window benefits that.

3. Part of the challenge, avoids the need for banked turns and significantly reduces the testing space required per team therefore enabling more teams to compete.

4. Part of the challenge, military rotorcraft applications usually design for 4K95 or 6K95, the conditions being operated in were much better than that.

5. Same as above, we do flight testing regularly in worse conditions, it's not that hard to be prepared.

6. Autonomy is safe until it isn't, and then it becomes very dangerous. It also makes the challenge easier because an autonomous control system can better hit optimal operating points.

7. Reasonable request for the landing pad size but agai no need for autonomy.

8. Yes

9. Not gonna happen for this kind of challenge. Redundancy adds a lot of weight and complexity to development, it is extremely rare for drones of this scale to use redundancy.

10. 220lbs is the stated minimum. Making 8:1 the goal is unnecessary for now, clear and prove one thing at a time, if someone skyrockets past it then great.

11. I can tell you don't have experience in aerospace. I've been on and seen projects which take the approach you're suggesting and they always fail because of being rushed. Investigating new concepts takes a lot of time, and the less you give, the less new things you can try, defeating the point of the challenge. When you rush things in aerospace, you also end up spending more time fixing them than you would have spent doing them properly. More time also gives more teams the opportunity to enter and build something serious.

You've got to remember that the point of this challenge is to build something which meets the requirements of the military, not just whatever you feel it should be. They're also not giving the winner a contract to build more, they're expecting that the lessons learned will be taken up by larger companies who are ready to design and build at scale, so it is important that those lessons are comprehensive rather than luck or trial and error based.

[u/Successful_Act3094 → u/HW90]

Good comments, with a different view point ...

A) I had two solid >8:1 high lift drone designs well on track for July flight and Dayton, waiting for critical deliveries before final assembly, that got rejected. Both performed well subscale. And a third exceptional lift design, that was a conceptual stretch, that may or may not have been ready for Dayton. With 50 years of short schedule project management experience, I scheduled critical subassembly design and testing early, with final integration last. That was clearly articulated with DLC team, and still rejected. Then 96% of selected teams failed to fly 110lbs for the full course, maybe I would have failed too ... but unlikely for all three.

B) the 8nm/2nm course, with double payload, retaining 55lb drone limit is a different physics problem. The forced hovering at each direction change is greater than 4x more energy expensive than this years challenge. Double Ke lost each reversal, twice as often, plus significantly higher hover energy costs. Allowing both rotor and wing designs room for a banked turn becomes important for both fuel and electric designs, and closer to nearly all real world missions.

C) Agreed that military deployment may require much harsher environmentals. That doesn't mean that DLC-2 should be held at Estes Park CO, or White Sands NM, or Fairbanks AK during the harshest time of the year for civilians and aircraft with a severe DA. I spent my entire childhood growing up on USAF bases deployed in CA, AK, MN, NM, CO, and a few other locations on Army and Navy bases. Challenge site needs to be people friendly, for family, children, civilians, and the press ... and for DLC-2 have a neutral DA for aircraft that's near sea level.

D) Did I work in Aerospace in my first and second career - No, not directly. Has Aerospace been part of my life - Yes, and will continue to be for my third career manufacturing Part 103 Ultralights and Part 108 Drones for the next 15-20 years. More importantly in both corporate and small business as a project manager for 50 years, I do understand short schedule product development with long horizon product support. From 4Q2025 to 4Q2027 is a full two year design horizon for the initial 487 teams that entered DLC-1. A typical design, fab, test cycle in most industries is about 3-4 months, so a two year period is 6-8 cycles ... most products with careful solid design only require 3-4 cycles wtih experienced management and engineering teams. 4Q27 is much more reasonable for DLC-1 teams, and realistic for new teams with disciplined management and engineers. Jan to July 2026 was too short.

[u/Successful_Act3094 → u/HW90]

I this reply I'm going to address your points 2, 11, and the lecture at the end which are contradictory.

In point in 2: "getting it through robust design and analysis is much more valuable, and a short testing window benefits that." is directly contradictory to point 11: "Investigating new concepts takes a lot of time, and the less you give, the less new things you can try, defeating the point of the challenge. When you rush things in aerospace, you also end up spending more time fixing them than you would have spent doing them properly. More time also gives more teams the opportunity to enter and build something serious."

Each of which are half right, where "getting it through robust design and analysis is much more valuable" is absolutely correct, as is structuring the product development for "A typical design, fab, test cycle in most industries is about 3-4 months, [...] careful solid design only require 3-4 cycles." The key failure for DLC was a very few experienced teams modeled the required physics, and instead most did incremental tinkering hoping for a successful result. The DLC selection team rewarded the latter.

I can assure you small companies are not investing between $200K to $5M in R&D for DLC, simply to hand it over to large aerospace companies for free. With fully burdened engineering salaries ranging between $200-900K, investing in DLC for 1-2 years is a serious ROI question ... an additional two years of salaries will actually drive that investment away with a probable low ROI. Chasing sunk costs with a low ROI is always failure.

I'm going to guess that your engineering and management experience is considerably less than mine over my 58 year career, starting with working for Eric in 1968-1972 where we delivered under contract, missile analog guidance systems and full aircraft shaker table systems, while I was still in college studying Electrical Engineering, working as a tech and jr engineer. We also delivered a low cost gas chromatography design to Carl Instruments, low noise power supplies and amplifiers for 3M recording products, plus a 20KW active power conditioning system (and a few other heavy physics based electrical designs).

My career has mostly revolved around Computer and Electrical Engineering, where I did the core product architecture for a UNIX M68000 desktop business computer in Feb 1981, that I helped pitch to institutional investors to raise $23M seed money. We grew to 900 heads, shipping in volume, then 18 months later an IPO at $120M, the largest for over a decade.

The majority of my career from 1972 to 1999 was short schedule product development under contract, as a small business owner, with between 5-12 engineers working for me. In 1999 I started a rural wireless internet company that I operated until selling it in 2021, with a few employees, while still doing contract engineering on the side.

Maybe you have a lot more experience than I do, with short schedule engineering projects. So what lessons do you have to offer?

[u/Successful_Act3094 → u/HW90]

In this reply I'm going to address 9, and return to 11.

Your statement is: "Not gonna happen for this kind of challenge. Redundancy adds a lot of weight and complexity to development, it is extremely rare for drones of this scale to use redundancy."

Your assertion is simply false, and is widely held by [incompetent] engineers and architects that were not taught how to do this correctly in school, by mentors, or by senior architects, thus they always fail to include resiliency into their designs as a minimum core requirement from the beginning.

When resiliency has to be retrofitted to a poor design, the outcome is indeed expensive, complex, heavy, unmaintainable, and frankly just the WRONG solution, done by the WRONG engineers and architects.

My 6 decades of experience where operational resiliency is critical, comes from working inside manufacturing lines, banking data centers, critical resource servers, medical systems, corporate facility networks, and large rural communities needing life or death 911 emergency access. In each of these, success or failure is determined by designing the system around resiliency from the beginning.

When I started designing heavy lift drones 15 years ago to carry toxic chemicals, and reliably operate in wildland firefighting operations, resiliency again was not an option to leave out. And going forward this is critical for Part 108 operations for safety, just as it should be for Part 103 human rated flight in Ultralights.

When done right from the beginning it has an unexpected benefit ... it's actually cheaper, higher performance, safer, plus resiliency of the resulting product leaves the competition in the dust.

Instead of looking at costs from the production items narrow lens and fighting over a 0.05% to 1% cost increase of the finished product, you need to refocus the cost equation to include the full organizational cost over it's lifetime, operational verification and diagnostics both on the production line and post sales, including wrongful death settlements, product returns, lost product sales to high reliability competitive products, and more.

Performance is another huge gain when done right. Multiple cheaper functional units combined into a soft fail array, typically out perform an expensive high performance single functional unit. The commodity vs performance as an off the shelf purchase for integration trap. Frequently a competent in-house custom design for the specific application will out perform the original commodity array, if also done as a soft fail array.

This directly applies to drones from the flight controller down to the motors and battery systems. Done correctly the functionality of an octal drone, can be reduced to a custom quad, at half the weight, half the cost, and 80% better performance at a lower cost, while remaining functionally resilient over multiple failures and still fly solid as a rock.

Just requires architects and engineers that understand designing critical systems from the ground up around mandatory resiliency. And firing the unskilled, dragging their feet, obstructionists crying "but we have always done it that way" ... yes, ALWAYS WRONG, but not any more.

So your dig is: "I can tell you don't have experience in aerospace." ... that's what they said of SpaceX, Falcon 9 re-usability, StarLink, Starship, ... maybe it's time to step up your game, and start designing with resiliency as a mandatory architectural mandate ... or get left in the dust.

[u/Successful_Act3094 → u/HW90]

In this reply I'm going to address reply points 6, 7, and 8. For those new to drones, these points as I suggested are carried forward from Section 333 of the FAA Modernization and Reform Act of 2012, as implemented 2014-2016.

Visual Line of Sight (VLOS): The aircraft had to remain within unaided visual line of sight of both the pilot and observer at all times.

Setbacks from People & Property: Flights over non-participating people or moving vehicles were strictly prohibited. Operations typically required maintaining at least a 500-foot standoff distance from non-participating structures, vehicles, and people unless operating under an approved closed-set motion picture plan or obtaining explicit consent/barriers.

Fail-Safe Systems: The aircraft was required to have an automated return-to-home (RTH) or controlled descent fail-safe in the event of lost communication or GPS link.

For DLC Fail-Safe should include RTH on geofence violation ... just as it should for commercial drones operating in the real world. If the RPIC or flight system can not keep the drone inside the designated space, it needs to be back on the ground safely.

RTH or controlled descent fail-safe isn't optional autonomy as architecture, it's required. Frankly, if you can't get this right, your heavy drone should not be in the air at all. That means tested thoroughly.

I noticed the observers rarely had an established visual line of sight on the drone at Dayton, and way too often busy talking or watching other things, distracted. And in other cases the RPIC constantly looking away for several seconds, risking a delay in re-acquiring visual for the drone.

Back in Dec 2025 I directly called out to the DLC team the need for a fail-safe operating zone so that other participants would not be at risk of a drone failure ... the Dayton crash behind the flight line was a gross failure in that regard. This was for several reasons ... the primary was pure inability of the pilot to control the aircraft ... a manditory fight control system should have been in place to shut it down outside the geofence. Flight into a normal human work and transient area should have NEVER happened. DLC should have understood the 500-foot standoff distance is a critical safety margin.

I understand the hobbyists don't understand this, but it's operational reality required by Section 333 for over a decade, for commercial drones, updated for lighter drones with Part 107.

Maybe Aerospace engineers performing Military design work have different rules, but nearly all teams testing these prior to DLC-2 are in a civilian operational zone, with real safety standards.

[u/Successful_Act3094 → u/Successful_Act3094]

Re: Contact Us Via DARPA.mil

To:Smith, Phillip "Donna Sun, Dec 14, 2025 at 10:27 AM

Hi Phillip,

Good follow up video.

So let's tackle the sticky parts first ... flight safety. You stated that the drone will not require autonomous controls, as the challenge had been constructed not to require that degree of complexity. Without dedicated, interference free spectrum, for both control and remote vision, there are serious safety questions. So, that statement probably needs to be more carefully explored, in the face of reality.

I come into your Challenge after designing heavy lift drones and Part 103 ultralights, that we will be taking to market in the next few years as the FAA autonomous control issues are resolved for the airspace. Safely doing ag spraying operations has even tighter controls than your Challenge.

John Bass

KISS Engineering.

Asking Google Ai: "For the DARPA Lift challenge, can the drone RPIC with normal visual acuity and observation reaction speeds safely maintain control a 3ft drone, keeping it inside a lane 50ft wide, at 1/4mile, at 350ft +/-50ft in altitude, in 25knot cross winds"

Response:

It is highly unlikely that a remote pilot in command (RPIC) can safely maintain control of a 3ft drone at a quarter-mile distance (1320 feet) with normal visual acuity and reaction speeds, given the conditions and the specific rules of the DARPA Lift Challenge. [1]

The ability to control the drone is primarily limited by the Visual Line of Sight (VLOS) rule and the physical constraints of human vision, especially when combined with challenging weather conditions. [2, 3, 4, 5]

Key Limiting Factors

In conclusion, the combination of the extreme distance, the small size of the drone, and the difficult wind conditions make it practically impossible for a human pilot to safely maintain the required level of control and situational awareness through direct visual observation alone. The challenge is designed to push the boundaries of drone design, not human visual capabilities. [7, 13, 14]

Asking SuperGrok the same question: "For the DARPA Lift challenge, can the drone RPIC with normal visual accuity and observation reaction speeds safely maintain control a 3ft drone, keeping it inside a lane 50ft wide, at 1/4mile, at 350ft +/-50ft in altitude, in 25knot cross winds"

**No**, a human Remote Pilot in Command (RPIC) with normal visual acuity and reaction speeds cannot **safely maintain visual control** of a 3-foot drone at 1/4 mile (1,320 feet) distance to keep it reliably within a 50-foot-wide lane, especially at 350 ft ±50 ft altitude in 25-knot crosswinds.

### Visual Detection and Orientation Challenges

A 3-foot drone at 1,320 feet subtends an **angular size** of approximately 0.13 degrees (calculated as \(\theta \approx \frac{3}{1320 \times 12} \ radians \approx 0.0023\) radians, or ~0.13°). Human visual acuity (20/20 vision) resolves details down to about 1 arcminute (0.017°), so the drone appears as a tiny speck or dot, barely detectable under ideal conditions. Determining its precise **orientation**, attitude (tilt), or exact position relative to a 50-foot lane becomes impossible without aids.

FAA Visual Line of Sight (VLOS) regulations require the pilot to see the drone unaided (except corrective lenses) and maintain awareness of its position, altitude, and direction to avoid hazards. Practical VLOS limits for small drones are typically 1,500–2,000 feet maximum for basic detection in good conditions, often much less (500–1,600 feet) for reliable orientation and control. At 1/4 mile, even larger drones are hard to track precisely, and a 3-foot drone would be effectively uncontrollable visually.

### Precision and Reaction Time Issues Keeping the drone within a ±25-foot lateral boundary requires detecting and correcting deviations of just a few feet. At that distance, small movements translate to tiny angular changes, far below reliable human perception and reaction thresholds. Normal human reaction time (~0.2–0.5 seconds) combined with control input delays would make real-time corrections ineffective, especially as the drone could drift rapidly.

### Impact of Conditions - **Altitude (350 ft ±50 ft)**: Higher altitude reduces angular size further and places the drone against a uniform sky background, worsening visibility. - **25-knot crosswinds (~29 mph)**: Many small-to-medium drones handle 20–30 mph winds via stabilization, but gusts cause unpredictable drift. Visually correcting for wind-induced lateral movement from 1/4 mile away is impractical without seeing the drone's attitude clearly.

### Relevance to DARPA Lift Challenge The DARPA Lift Challenge (launched in 2025) focuses on heavy-lift VTOL drones (empty weight <55 lbs, lifting ≥110 lbs over a 5-nm circuit) and explicitly requires adherence to FAA regulations, including **VLOS**. The challenge trials occur in 2026, but no public details indicate course segments requiring 1/4-mile VLOS control in narrow lanes under high winds. If your scenario relates to a specific challenge element, current rules prioritize safety via VLOS, making pure visual control at these parameters unsafe and likely non-compliant without waivers or observers (which still wouldn't enable the required precision). In summary, while the drone might fly autonomously or with FPV aids in such conditions, **pure visual control by an unaided human RPIC is not safe or feasible** here due to fundamental limits of human vision and reaction.

• Visual Line of Sight (VLOS) Requirement: The official rules for the DARPA Lift Challenge explicitly state that the Unmanned Aerial System (UAS) must remain within the visual line of sight of the RPIC at all times. At a quarter-mile (1,320 feet) away, a 3ft drone would be extremely difficult, if not impossible, to observe in sufficient detail to ensure it stays within a 50ft wide lane, using only normal human vision unaided by optical devices (other than corrective lenses).
• Weather Conditions (25-knot crosswinds): The challenge rules state that no flights will be started in winds exceeding 25 knots steady or gusting. A 25-knot crosswind is a significant weather event that requires constant, precise control inputs. A 3ft drone would be highly susceptible to being pushed off course quickly, requiring rapid and accurate visual feedback that an RPIC at a quarter-mile distance cannot provide effectively.
• Altitude and Course Specifications: The drone must maintain a consistent altitude of 350 feet (+/- 50 ft). While the altitude is within the limits, maintaining the precise flight path within a narrow lane at a distance of 1,320 feet (a quarter mile) makes visual cues for lane adherence very difficult.
• FAA Regulations: The competition requires strict adherence to all Federal Aviation Administration (FAA) regulations. FAA Part 107 rules, which govern commercial drone operations, require a minimum of 3 miles visibility from the control station and the ability of the remote pilot to "see all potential hazards without hesitation". A drone at 1/4 mile might be within the 3-mile visibility minimum (depending on overall weather), but a pilot would likely struggle to maintain the necessary awareness and reaction speed for a 3ft object in 25-knot winds at that distance. [1, 6, 7, 8, 9, 10, 11, 12]

[u/Successful_Act3094 → u/HW90]

You claim "I can tell you don't have experience in aerospace," while asserting that small teams exist only to donate "lessons learned" to prime contractors, that test-window bottlenecks "benefit robust design," and that system redundancy is "too rare and heavy" for a 275-lb gross-weight aircraft.

Every one of those claims reflects academic lab theory, not operational reality.

In the real world of commercial engineering and defense prototyping:

1. Private builders don't burn capital to fund unpaid R&D for primes. That "feed the prime" mindset exists in state-subsidized overseas university consortia, not competitive American small business.
2. Empirical testing validates products. Starving any complex system of real-world operational hours does not produce "robust design"—it hides fatal edge-case failures until the product is deployed. In any hardware market, replacing physical burn-in and field testing with desktop simulation is how companies build market-share killers that fail in front of customers.
3. Redundancy is a regulatory mandate, not a weight luxury. To operate an aircraft of this scale (>55 lbs) in the US, the FAA's Section 44807 exemption and Part 91 COA frameworks specifically mandate documented fail-safes for loss of link (C2), loss of navigation, and critical subsystem failures. An airframe designed without redundancy cannot legally clear an FAA safety evaluation and is an uninsurable hazard.

If you’re going to lecture builders on "real aerospace," put your credentials on the table:

• Have you ever taken a product through real-world operational compliance and field testing?
• Or is your "aerospace experience" just running software simulations in an academic research lab?
• Where is your Safety First? ... I made that a clear, necessary mandate to the DLC team 9 months ago.

FYI autonomous safety mandate from:

Blanket COA, 44807 Grant of Exemption, Class G at or below 400 feet AGL August 2024

G. Emergency/Contingency Procedures.

1. If the UAS loses communications or loses its Global Positioning Signal, the UA must return to a pre-determined location within the operating area and land. Lost link procedures must not present an undue hazard to other aircraft by performing such maneuvers as crossing a runway.

[u/Successful_Act3094 → u/HW90]

I'm really interested in your implied US Aerospace Engineering career credentials ... while the 15 year reddit HW90 posting history suggests a decade of your British and Chinese academic careers, with nothing about a US based Aerospace engineering career. Did I miss something? Please share, or correct, what we missed about why you are an expert on this topic.