Type: Prelims Only

Why in the News?

Authorities have recovered the black box from the crash site of the recent incident in Ahmedabad.

About Black Boxes:

• Purpose: Black boxes are essential flight data recording devices used in aircraft to aid in accident investigation and flight safety analysis.
• Development: Australian scientist David Warren in 1954, developed the first practical FDR after investigating mid-air explosions.
• Color and Visibility: Despite the name, black boxes are painted bright orange with reflective material to make them easily visible after a crash.
• Two Main Types: Aircraft typically have two black boxes:

1. 1. Cockpit Voice Recorder (CVR) and
   2. Digital Flight Data Recorder (DFDR).

• Single Unit: Some aircraft integrate both functions into a single combined unit.
• How does it work?
  • Cockpit Voice Recorder (CVR): The CVR records cockpit audio, including pilot conversations, radio transmissions, alarm sounds, and background noises like engine hum or warning tones.
  • Digital Flight Data Recorder (DFDR): The DFDR logs key flight performance data, including altitude, airspeed, direction, engine parameters, and system operations, capturing thousands of data points per second.
  • Installation Location: Black boxes are usually installed in the tail section of the aircraft, as this area is statistically more likely to remain intact in a crash.
  • Recording Capacity: The CVR records the last 2 hours of cockpit audio on a continuous loop, while the DFDR stores up to 25 hours of flight data.
  • Durability and Protection: Black boxes use solid-state memory chips housed in crash-survivable casings that can endure high-impact forces, extreme temperatures (up to 1,100°C), and deep-sea pressure.
  • Underwater Locator Beacons (ULBs): Each black box includes a beacon that emits signals for up to 30 days, aiding search teams in locating the devices in the event of a water crash.

Use of Black Boxes in India:

• Regulation in India: In India, aircraft crash investigations are conducted by the Aircraft Accident Investigation Bureau (AAIB) under the Ministry of Civil Aviation, using black box data as primary evidence.
• Recent Development (April 2025): India established its first dedicated Flight Recorders Laboratory in New Delhi, strengthening the country’s capability to analyze crash data independently and efficiently.

Why in the News?

The Union Ministry of Power is considering a policy to restrict the temperature range of new air conditioners (ACs) in India to between 20°C and 28°C.

How do Air Conditioners Work?

• Basic Idea: Air conditioners (ACs) work like a heat-moving machine. They take heat from inside your room and push it outside, making the room cooler. They do this using a special fluid called a refrigerant, and a system called the vapour-compression cycle.
• Main Parts and What They Do:
  • Evaporator: This part is inside your room. The refrigerant, which is very cold here, absorbs heat from the indoor air and turns into a gas. It also removes moisture, so your room feels less humid.
  • Compressor: This is outside the house. It squeezes the refrigerant gas, making it very hot (about 90°C) and high-pressure. This part uses the most electricity in the AC.
  • Condenser: The hot gas then flows through the condenser coil outside. It releases heat into the outdoor air and turns back into a liquid.
  • Expansion Valve: This part lowers the pressure of the liquid refrigerant, making it cold again before it goes back to the evaporator to repeat the cycle.
• Refrigerant: The refrigerant is a specially designed gas that changes state easily at low temperatures and pressures, making it ideal for absorbing and releasing heat rapidly. Modern refrigerants like R-32 or R-410A are more energy-efficient and environmentally safer than older ones like CFCs and HCFCs.

Why limit AC Temperature settings?

• Energy Efficiency Data: According to the Bureau of Energy Efficiency (BEE), setting an AC to 24°C instead of a lower setting can save 6% electricity per 1°C increase.
• National Impact: If adopted widely, this temperature setting could help India save 20 billion units of electricity annually.
• Health Risks at Low Temperatures: Temperatures below 18°C are linked to hypertension, asthma, and respiratory infections, especially among children, the elderly, and people with weakened thermoregulation.
• Evidence from Global Studies: Research in Japan, the UK, and New Zealand shows that slightly warmer indoor settings lead to better respiratory and cardiovascular health.
• WHO Recommendation: The World Health Organization advises 18°C as the minimum safe indoor temperature in temperate climates.
• Thermal Comfort Standards: Guidelines like ASHRAE-55 and ISO 7730 suggest optimal indoor temperatures between 20°C and 24°C for lightly clothed people, with adjustments based on local climate and culture.

Global Cooling Trends and the Need for Regulation:

• Global AC Usage Growth: As of 2022, there were an estimated 2 billion air conditioners in use worldwide, with residential units tripling since 2000, especially in India and China.
• Access Gap in Asia-Pacific: Despite this growth, 43% of the Asia-Pacific population still lacks access to adequate cooling solutions.
• Environmental Impact: Air conditioning significantly increases electricity use and carbon emissions, especially in countries with fossil fuel-dependent grids.
• India’s AC Load Projection: By 2030, India’s total connected AC load is expected to reach 200 gigawatts, requiring urgent demand management strategies.
• Consumer Awareness Tools: Initiatives like default settings at 24°C and energy labelling empower consumers to make informed energy-efficient choices.
• Benefits of Regulation: A regulated temperature range can help lower energy consumption, reduce peak power demand, and support public health.

Why in the News?

A new study from researchers at IISER Bhopal has revealed how a single protein called BBX32 helps plants time the critical moment they emerge from darkness into light.

What is BBX32? 

• Function: BBX32 is a plant protein that helps a seedling keep its protective hook closed as it pushes through the soil.
• Protection Mechanism: The hook shape shields the soft shoot tip in darkness; BBX32 extends this protection until it’s safe to open.
• Ethylene Activation: Underground, the plant hormone ethylene activates the BBX32 gene, signaling the seedling to stay protected.

How does it work?

• Light Stabilization: Once exposed to light, BBX32 is no longer broken down, allowing it to accumulate on one side of the hook.
• Protein Chain Reaction: BBX32 activates PIF3, which then activates HLS1, the protein that directly keeps the hook bent.
• Lab Testing: Plants were tested in different light types and sand to simulate real soil. Extra ethylene increased BBX32 activity.
• Mutant Comparison: Plants without BBX32 opened too early. Only 25% broke through sand, compared to 40% of normal and 80% with extra BBX32.
• Degradation Control: In darkness, COP1 breaks down BBX32. Ethylene slows this process. Light fully stabilizes BBX32.
• Coordinated Timing: The protein’s behavior is guided by light, hormone signals, and pressure, ensuring the hook opens at the right time.

Why is studying BBX32 important?

• Better Crop Survival: BBX32 can help develop crops that grow well in dense, wet, or compacted soils.
• Climate Adaptation: As climate change leads to tougher soil conditions, BBX32 can improve seedling emergence and survival.
• Boosting Yields: Supporting hook protection even slightly longer can lead to stronger early growth and higher productivity.
• Genetic Research: BBX32 is a potential target for gene editing in plants to improve resilience during germination.
• Broader Insight: Studying BBX32 helps us understand how plants balance internal signals with external cues for safe growth.