Divraj Jain

The Unexpected Path to High-Speed Electric Flight

Thu, 21 May 2026 00:00:00 +0000

Most people associate drones with slow and stable aerial photography used for weddings or youtube videos. In reality high speed FPV drone racing has existed for years, with pilots flying through goggles at extreme speeds and accelerations closer to motorsport than photography.

Over the past decade, engineers and hobbyists have steadily pushed electric quadcopter performance further and further. Today electric quadcopters are reaching speeds once associated only with experimental aircraft. The fastest electric quad drone reached 685 km/h, surpassing rolls royce’s 623 km/h manned flight.

What began as a hobbyist ecosystem is rapidly becoming something much more important.

Driven by necessity in Ukraine, interceptor drones have evolved by borrowing heavily from the FPV racing world. These systems are becoming asymmetrically cheaper counters to threats like Shahed drones, with interceptors potentially costing around 1000 usd versus targets costing 10000–25000 usd. Unlike traditional aerospace programs that may take years between major hardware revisions, interceptor drone ecosystems can evolve in weeks. Motors, batteries, ESCs, radios, flight controllers, onboard compute, and manufacturing methods all benefit from global consumer electronics and EV supply chains. Small teams can rapidly prototype and test systems at a pace rarely seen in aviation.

Interceptor drones are also uniquely relevant to future high-speed electric flight.

Cinema drones optimize for stability. Delivery drones optimize for endurance and logistics. Urban eVTOLs primarily optimize for low-altitude passenger operations and certification constraints. Interceptor drones are different — they simultaneously demand extreme acceleration, very high power density, aerodynamic efficiency at high speed, autonomous guidance, survivability, operational turnaround, payload carrying capability, and thermal management under repeated stress cycles. That combination makes them unusually close to the engineering problems required for future high-speed electric aircraft.

A useful analogy is GPUs. GPUs were originally built for gaming. Crypto mining accelerated the hardware ecosystem further. Eventually the same hardware stack became foundational for modern AI. Something similar may happen in electric aviation: FPV racing drones created the high-performance ecosystem, interceptor drones are accelerating rapid real-world iteration, and future high-speed electric aircraft may eventually emerge from the same technological base.

One possible long-term outcome is ballistic electric flight, a concept described by Casey Handmer. Ballistic electric flight refers to aircraft that climb aggressively to very high altitude — potentially 50,000 to 80,000 feet — accelerate beyond Mach 1, and then coast along a ballistic arc before descending to their destination. Instead of cruising conventionally like an airliner, the aircraft trades altitude and momentum to travel efficiently at very high speed. Batteries are uniquely capable of delivering enormous amounts of power very quickly, while electric motors can convert that energy with extremely high efficiency and near instant torque response — enabling levels of acceleration and power delivery that are difficult to achieve with conventional combustion-based propulsion. Electric propulsors can also potentially be specialized for operation in thinner high-altitude air where traditional turbofan architectures become less effective.

This does not imply that today’s interceptor drones directly scale into passenger aircraft. The physics, certification burden, energy requirements, and reliability standards for human transport are vastly harder.

But reusable interceptor drones may become one of the first economically viable environments forcing engineers to solve many of the enabling problems. Current interceptor drones are mostly expendable. Future ballistic electric cargo and passenger aircraft will require airline-level reliability, redundancy, maintainability, operational safety, and long-cycle thermal management. Once an interceptor must survive repeated missions instead of a single engagement, the engineering problem changes fundamentally — designers are forced to optimize cooling systems, battery longevity, structural fatigue, redundancy, operational turnaround, fault tolerance, and reliability under repeated high-power cycles. A reusable interceptor becomes less like a munition and more like an extremely high-performance electric aircraft.

Reusable interceptors require compact, maneuverable airframes capable of carrying payloads. Initially those payloads may be small weapons. Later they could become sensors, cargo, and eventually people. The architectural principles remain similar even as the application changes.

Breakthrough transportation technologies have often emerged first from environments where performance mattered more than efficiency or comfort. Motorsports like F1 accelerated automotive engineering. Rockets developed for defense eventually enabled space launch. Reusable interceptor drones may become a similar bridge technology for high-speed electric flight not because they are the final form of transportation, but because they force rapid iteration on exactly the technologies future ballistic electric aircraft may eventually require.

Electric Aviation is a Great Opportunity for Startups

Mon, 16 Dec 2024 00:00:00 +0000

No emissions and lower noise will make urban stops and favorable regulation possible.

Advances in composites and 3d printing will make structures simpler and faster.

Opportunity to own the whole stack = significant value can be captured in producing custom batteries and electronics for your own aircraft.

Electric motors are simpler, cheaper and lighter than jet engines. This versatility will make maintenance cheaper. Additionally multiple motors with unique placements on the aircraft will become feasible.

As the suppliers for the electric supply chain will be different it offers better avenues to negotiate margins and partnerships.

Progress in autonomous navigation will make smaller aircraft more viable.

Possibility to integrate assisted launch strategies as pressure to use incumbent infrastructure is not present.

Optimal number of motors for an Electric Supersonic Aircraft

Thu, 14 Nov 2024 00:00:00 +0000

An electric supersonic aircraft needs to minimize drag while also maintaining redundancy in case of engine failures. Electric motors make it feasible to have multiple units as fixtures are simpler and size can be varied easily. In spite of this ease adding multiple motors does add complexity in terms of cooling and wiring to the motors while also increasing drag surface area. For a single to four seater aircraft two motors could be considered optimal but this will add the need for control surfaces ( airlerons , rudders and elevators) incase the motors are fixed in orientation. To simplify control mechanisms while maintaining a sleek surface area four motors most likely powering ducted fans could be optimal as vectoring will be possible to achieve vertical takeoff and landing. In addition to VTOL there will be good redundancy and thrust for all phases of flight.

Open Propellers vs Ducted Fans for Electric Supersonic Aircrafts

Sat, 02 Nov 2024 00:00:00 +0000

Efficiency:- While open propellers are efficient for takeoff and initial climb once the aircraft reaches transonic speeds ducted fans are more efficient for propulsion.

Implementation:- Open propellers are easier to implement and weigh less than a ducted fan due to the lack of casing this lower weight could be critical where every gram counts.

Noise:- Ducted fans can control the noise created by the propellers specially at higher speeds.

Diameter Limitations:- Supersonic aircrafts typically require smaller diameter propulsive areas to reduce drag this is more easily achieved by ducted fans. Sophisticated inlet designs can also be done only by ducted fans not open propellers.

Motor Integration:- Ducted fans allow for better integration with the electric motor possibly reducing overall complexity.

Safety:- Ducted fans offer better containment incase of failure specially at supersonic speeds.

Ducted fans are superior to open propellers theoretically but are harder to implement and design for specially for a first prototype for a startup. Ducted fans will also likely require longer runways compared to open propellers an important constraint to keep in mind. Perhaps a compromise between the two is possible.

Single Handed Backhand is Alive and Well

Tue, 29 Oct 2024 00:00:00 +0000

Much is written about the demise of the single handed backhand. Federer himself apparently said he would encourage his children to adopt a two-hander. Many posts highlight the top 10 when there is no single hander in it. Yet with Mpetshi-Perricard surging , Musetti and Dimitrov also doing well the single handed backhand is alive and well. Despite apparent troubles returning high balls , the single hander also has several advantages. The single handed backhand offers greater reach requiring possibly one small step less at times. Second , on the run single handers have an advantage as they reach for the ball. Thirdly, single handed backhands is much more natural hence easier for late starters in tennis to pickup ( although not important for pro players having top players using it influences potentially tennis entrants). Fourthly , the single handed backhand has more style and is aesthetically pleasing to all watchers ( could be TV audiences or members at your club). Fifth , single handed players tend to have better slices and backhand volleys. Taking all these advantages into account we should encourage young players to adopt the single handed backhand !

Style and Variety in Tennis

Thu, 24 Oct 2024 00:00:00 +0000

An underrated reason Federer was a fan favorite was his aesthetically pleasing technique on all shots, another was his variety of shots and strategies. Federer’s straight arm forehand and single handed backhand possesses the style that Djokovic and Sinner can’t match. Sinner’s bent arm forehand and backhand while currently effective looks very contorted and unnatural. Alcaraz similar to Federer has a straight arm forehand which is better stylistically and is also said to be more accurate in the long run. Both Federer and Alcaraz also have visible variety in their game coming to the net more often , employing drop shots and slices. While Sinner has improved his serve he is a more one dimensional player from the baseline whose success will likely be capped when Alcaraz becomes more consistent.

Assisted Takeoff Strategies for Supersonic Aircrafts

Wed, 23 Oct 2024 00:00:00 +0000

To offset the currently scarce battery density supersonic electric aircrafts could use assisted launch strategies to save upto 5 - 35% of battery capacity needed for takeoff and intial climb. Catapults are commonly used on aircraft carriers and are tried and tested , they could be installed in high volume airports owing to high infrastructure costs. Airship assisted launch if scaled well to could offer significant savings in the long run. 7-10% per takeoff is a massive saving. With companies like Airship Industries already building airships for cargo electric supersonic aircraft could be retrofitted to launch until high volume necessitates specially built airships.

1. Electromagnetic Catapult

Energy Savings: 35% (630 kJ/kg)
Initial Speed: 100-150 m/s
System Cost: $30-40M for infrastructure

Technical Requirements

Power substation: 15-20 MW peak
Track length: 200-300m
Acceleration: 3-4 G
Cooling systems
Control systems

Advantages

Highest energy savings
Weather independent
Repeatable launches
No onboard launch fuel/equipment
Precise control

Disadvantages

High initial infrastructure cost
Fixed location
High peak power demand
Complex maintenance

Operational Considerations

Launch cycle time: 15-20 minutes
Crew requirements: 3-4 technicians
Annual maintenance: 2-3 weeks
Power infrastructure needed

2. Hybrid Propulsion

Energy Savings: 25% (450 kJ/kg)
Initial Speed: 80-100 m/s
System Cost: $2-3M per aircraft modification

Technical Requirements

Fuel storage: 200-300 kg capacity
Dual propulsion systems
Modified fuel management
Enhanced cooling systems

Advantages

Flexible operations
No fixed infrastructure
Proven technology
Multiple launch locations

Disadvantages

Added weight penalty
System complexity
Fuel logistics
Reduced payload capacity

Operational Considerations

Pre-flight prep: 1-2 hours
Additional maintenance
Fuel availability needed
Dual certification required

3. Rocket-Assisted Take-Off (RATO)

Energy Savings: 20% (360 kJ/kg)
Initial Speed: 120-180 m/s
System Cost: $50-75K per launch

Technical Requirements

Solid rocket boosters
Launch attachment points
Jettison mechanisms
Safety systems

Advantages

Simple system
High thrust
Minimal aircraft modification
Location flexible

Disadvantages

Single-use boosters
High per-launch cost
Safety concerns
Recovery requirements

Operational Considerations

Setup time: 30-45 minutes
Special handling requirements
Hazardous materials
Recovery operations

4. Airship Assisted

Energy Savings: 7% (126 kJ/kg)
Initial Speed: 15-20 m/s
System Cost: $15-20M for airship system

Technical Requirements

Airship volume: 6,244 m³
Height capability: 25,000 ft
Release mechanism
Weather monitoring

Advantages

Zero-runway operations
Low noise
Environmentally friendly
Multiple launch locations

Disadvantages

Minimal energy benefit
Weather dependent
Complex operations
Large support team

Operational Considerations

Weather limitations: 70% of days
Setup time: 3-4 hours
Helium replenishment
Large ground crew required

5. Subsonic Climb (Baseline)

Energy Savings: 0% (baseline)
Initial Speed: 80-100 m/s
System Cost: No additional cost

Technical Requirements

Standard runway
Normal takeoff systems
Standard aircraft systems
Regular maintenance

Advantages

Simple operations
Proven approach
No special equipment
Flexible locations

Disadvantages

No energy savings
Full battery weight
Longer acceleration phase
Higher energy usage

Operational Considerations

Standard flight operations
Normal maintenance
Regular crew requirements
Standard facilities

Comparative Metrics

Cost per Launch (USD)

Subsonic: $200-300
EM Catapult: $500-700
Hybrid: $1,000-1,500
Airship: $3,000-4,000
RATO: $50,000-75,000

Weather Dependency (% of Operable Days)

EM Catapult: 95%
Subsonic: 90%
Hybrid: 90%
RATO: 85%
Airship: 30%

Setup Time

Subsonic: 30 min
EM Catapult: 15 min
Hybrid: 90 min
RATO: 45 min
Airship: 240 min

Infrastructure Requirements (1-10 scale)

Subsonic: 3
RATO: 4
Hybrid: 5
EM Catapult: 8
Airship: 9

Maintenance Complexity (1-10 scale)

Subsonic: 3
RATO: 4
Hybrid: 7
EM Catapult: 8
Airship: 9

Technical Risk (1-10 scale)

Subsonic: 2
Hybrid: 4
RATO: 6
EM Catapult: 7
Airship: 9

Except for first paragraph commentary ,text and graph from claude.

Recommendations for Warm Humid Countries

Tue, 22 Oct 2024 00:00:00 +0000

Recommendations for warm toxically humid countries like India to combat the weather and improve future growth.

1) Create cooler charter cities which will replace commercial centers and the capital. E.g. in India only choice is areas with higher elevations like Leh and other hill stations

2) Change working hours to take advantage of relative coolness in the early morning, work hours should be moved to 0300 to 1100 hrs. Citizens can follow a biphasic sleeping schedule of sleep from 2100 to 0200 and then 1300 to 1600 in strong AC. In these hours of 0300 to 1100 due to relative coolness and lack of toxic sunlight workforce can move around easily by walk or public transport. Efficiency for hand based workers and factory workers will also be improved

3) Use nuclear power / solar to use AC abundantly. Create large AC spaces like mega malls, office blocks, stadiums and even outdoor AC like done in Doha.

The top inventions were all made in Cool Weather

Sat, 07 Sep 2024 00:00:00 +0000

Quoting anthropic , while it tries to stay neutral you can see that all inventions of significant importance are done in climates where part of the year is cool, nothing in warm humid climates .

Computers and the Internet: Much of the early development happened in temperate climates like California’s Silicon Valley (mild, Mediterranean climate) and the northeastern United States (varying seasonal climate).
Antibiotics: Alexander Fleming discovered penicillin in London, which has a temperate maritime climate with cool summers and mild winters.
Nuclear power/weapons: The Manhattan Project took place across several locations, including Los Alamos, New Mexico (arid climate with hot summers and cold winters) and Chicago, Illinois (humid continental climate with warm summers and cold winters).
Television: Early development occurred in various places, including New York (humid subtropical climate) and London.
Smartphones: Like computers, much development occurred in temperate climates like California and New England.
Genetic engineering: Key breakthroughs happened in various locations, including California and the UK.
Artificial intelligence: Major developments have occurred in diverse climates, from the temperate weather of the US East and West Coasts to the continental climate of Canada.
Space exploration technology: NASA’s work spans multiple climate zones, from Houston’s humid subtropical climate to Florida’s tropical climate.
Renewable energy: Innovations have come from many climates, though some testing of solar technology occurs in sunnier regions.
Transistors and integrated circuits: Bell Labs in New Jersey (humid continental climate) was a key site for early transistor development.

Top economically important cities all have Cool Weather

Wed, 21 Aug 2024 00:00:00 +0000

list of estimated gdp and size of cities

singapore doesn’t seem that impressive when you see this list

the top 22 cities all have cool weather yearly