Indian carriers should compare themselves to the top 3 carriers in the world for safety and see where they fall short. They need to constantly strive to be among the top three and invest time, money, and effort to get it right.
Published Jun 21, 2025 | 4:00 PM ⚊ Updated Jun 21, 2025 | 4:00 PM
Continuous flight data transmission and collection within a five-mile radius of the airport — during takeoff and landing — is crucial. This will help in analysing errors and making corrections. (Supplied)
Synopsis: There can be no confusion about one principle in the aircraft industry: always putting safety above profit, and following processes with no deviations. Adequate planning and foreseeing problems are critical.
“Thrust not achieved…falling…Mayday! Mayday! Mayday!” Those were the final words from the cockpit of the ill-fated London-bound Air India Flight 171, soon after its takeoff from Ahmedabad on 12 June.
Moments after takeoff, the Boeing 787-8 Dreamliner with 242 souls onboard crashed into a medical college complex near the airport. The chilling final message that the Air Traffic Control received on that fateful day may lead investigators to the exact cause of the crash.
A probe is already underway into the aircraft not getting enough thrust. The cockpit’s final message underscores the need to understand aircraft dynamics, the play of technologies, the relationship between pilots and technologies, possible human error, technology failure, neglect and carelessness, the lack of application of the right procedures and protocols, shortcuts to manufacture aircraft and maybe even a possible sabotage.
Raghuvir Iyengar, a frontline structural aircraft and aviation researcher and engineer in the US for over 30 years, a professional who has worked with the world’s leading engine and aircraft manufacturers, offered clarity on how to understand aircraft dynamics and flying and the complex relationship between aircraft, technologies, and pilots.
He provided a perspective on the possibilities of preventing air crashes and loss of lives. However, despite every ounce of diligence, innovation, and expertise, crashes may occur.
In this interview, Iyengar shares with P Ramanujam some of his perspectives. Excerpts:
Q: Is perfection possible in aircraft design, manufacture, assembly, and flight, so that a technical or technological fault never occurs, preventing crashes in the future?
A. Perfection is not possible, although one should always pursue that goal. One can only — and should mandatorily — reduce the probability of an adverse occurrence to acceptably low numbers. Automation and human interaction/intervention should supplement and complement each other through elaborate infrastructure: networks of sensors, failsafe, damage-tolerant designs, feedback loops, service history, modeling, checklists, and timely intervention. And now, if it’s possible, through Artificial Intelligence (AI) decision-making, too, while working with relevant personnel and experts, engineers or pilots in real time.
Though not yet established, it is believed that AI could enable swifter and more precise and accurate decision-making at critical moments in aircraft dynamics that perhaps humans cannot execute. Research is on, and soon we will know how far AI can take over some complex, split-second decisions that pilots and humans have to make to avert crashes and save lives.
Q: Can complete and total automation and multiple technological back-ups prevent technological faults and crashes? Is technology flawless? Can the most advanced technology, the best conceptualised by humans, fail? If so, why? Any example?
A: Aircraft and flight history show us that there can be failure points with technology. We can only reduce the probability of failure by extensive testing and re-testing, and increasing the reliability of the system. Many crashes in the recent past, even when technologies have been far more advanced, demonstrate that complete technology perfection that prevents air crashes has not been achieved – be it a door being unhinged suddenly or the cockpit window breaking or the passenger window blowing apart or sudden hydraulic complications or part of a wing giving way — all of which have brought on sudden, sometimes, risky flight operations or perhaps error at the shop, and sometimes not.
Without doubt, we have achieved a great deal in aircraft technology and reduced the scale of crashes, but the technology loop hasn’t been completely closed. There are many instances of this in the last five years alone.
Q: Is human error inevitable even in the context of complete automation and advanced technological operations? If so, why? Is human-pilot error completely preventable by total automation in every aspect of an aircraft and from every standpoint – from takeoff to engine and wing operations to midair flight to landing and braking?
A. Human error is inevitable over a long period. Training, distractions, continuous diligence, and emergencies demanding multiple and simultaneous inputs and interactions in split seconds bring on pressure naturally. This is nobody’s fault: this is the nature of the relationship between humans and technology and pilots and cockpits, and the nature of humans themselves.
However, it’s possible that pilot error can be greatly minimised with automation. But over-reliance on automation will erode human capabilities over time, which is detrimental. The ideal solution is an optimal mix and level of human and automation-based controls. We need to identify specific areas of maximum benefit of technology that reduce pilot error.
Q: What are the reasons for an aircraft losing thrust and lift?
A: Aircraft lose thrust and lift for multiple reasons. If fuel is blocked and there is fuel starvation. Fuel pump failure, electrical failure, an unchecked fuel valve position, or even fuel contamination. Engine failure is a very obvious factor. Early takeoff without having gathered enough speed could contribute to thrust problems.
Q: What are the most critical factors just around and after takeoff?
A: A system of cameras — three cameras at each point, 20 points on either side of the runway, to automatically orient themselves depending on the size of aircraft and to monitor each takeoff and landing is vital. This records aircraft movement and corrections that can be introduced later in case of deviations.
Continuous flight data transmission and collection within a five-mile radius of the airport — during takeoff and landing — is crucial. This will help in analysing errors and making corrections. In Japan, the “pointing and calling” method, known as Shisa Kanko, is a safety protocol used to minimise errors by physically pointing at an object and verbally confirming its status. This technique, widely used in the Japanese railway system and other industries, involves a worker looking at a target, pointing a finger at it, calling out the target’s name or status, and then performing the related action.
Q: Why does an aircraft often require a longer runway than the normal length? Is it because the pilot senses a lack of thrust or because the pilot makes an error in judgment regarding when to takeoff? What is the significance of flaps in the lift of an aircraft?
A. No, flaps mean a longer runway required and lower lift. Also, wrong flap settings at the time of leaving the gate/at takeoff, and beginning of the runway generate inadequate lift. Pilot error — retracting flaps at takeoff or slats (metal, especially one of a series which overlap or fit into each other), not at the right position — or malfunction could also lead to inadequate thrust.
However, what enables and generates lift is airflow over the wings (airfoil cross-section). The slats at the leading edge of the wing and flaps at the trailing edge are high-lift devices that are controlled from the cockpit to dynamically change the area and curvature (camber- convex or arched) of the wing to generate additional lift at takeoff or reduce lift at landing.
Slats change the Angle of Attack (AoA – angle between airflow and airfoil chord line), thereby reducing the airplane’s speed required to generate high lift. Flaps at the trailing edge of the wing reduce the distance travelled on the runway to generate the lift. Flap extension at the rear of the wing increases surface area and lift by pushing the air below the wing, and the action-reaction principle generates lift in that part of the wing.
Q: Can you outline the significance of the acceleration of an aircraft on the runway and its connection with thrust, smooth takeoff, and cruise later on?
A: When an airplane accelerates on the runway and it reaches V1 speed, the pilot has to commit to takeoff. He cannot abort the takeoff. V1 is calculated based on weight, flap setting, wing span, temperature, engine power/thrust, altitude, air pressure, etc. After hitting V1, the airplane continues, and then the pilot depresses the elevator in the empennage/horizontal tail, and the airplane becomes airborne.
Once the speed is VR (Rotation speed at which the plane’s nose pitches up), the airplane moves up due to engine thrust. For a safe climb, an airplane has to achieve V2 speed, which is calculated. The airplane climbs and then goes into cruise. Achieving the V2 speed is crucial for thrust.
Q: What checks and balances and measures would you suggest to make an aircraft 100 percent safe technologically and to prevent sabotage?
A. Technology can be used to reduce the probability of failure to extremely low levels, that is, less than 1E-9, which is a failure rate of 1 in a billion for aircraft. As far as the sabotage factor is concerned, we need to try and have an automated check for every single human. This is the only way one can get a technological confirmation of the human check, undertaken or not.
Q: What are the best measures to ensure the structural integrity of an aircraft? Why is it crucial to avoid shortcuts in manufacturing, even if it takes time? And how best to tell customers that the long process is crucial to ensure quality and rigorous safe manufacturing protocols?
A. We need to understand that there are consequences of sloppy work that always show up in fatigue. Fatigue of structures is particularly insidious. Hence, experiences and previous air accident investigations provide crucial data to understand how to improve the manufacturing process. We need to develop a culture of integrity, continuous education, and awareness of multiple factors.
High-quality testing, analysis, periodic and scheduled inspection, and heavy maintenance checks are crucial. We also need strict metrics of quality and acceptance, and corrective action measures need to be in place. Compliance with regulations is non-negotiable.
Q: What technology do we have to save engines and aircraft from bird hits? How can this be done?
A. There is such a technology, but it is limited. Engines, fuselage, and wings are hardened for 8 8-lb bird impact (Canada goose), but it is difficult to develop a lightweight aircraft to handle a flock of geese. We need bird-strike prevention activities in place, and consortia are already in place.
Q: What is your assessment of the aircraft maintenance culture in India?
A. Indian carriers should compare themselves to the top 3 carriers in the world for safety and see where they fall short. They need to constantly strive to be among the top three and invest time, money, and effort to get it right.
We also need to understand where airports are placed in comparison to the top 10 airports of the world. There will always be corner points that are discovered during service. There’s been a long history of accidents and subsequent learning.
Q: How do we balance urgent customer demand and the need to avoid quick shortcuts that may compromise the quality and integrity of aircraft? Profit is important, but how does one ensure process rigour and transparency even if you make less money? Is trust in a company’s product at lower profits the ultimate goal of a company’s endeavor?
A: There can be no confusion about one principle in the aircraft industry: always putting safety above profit, and following processes with no deviations. Adequate planning and foreseeing problems are critical. Safety and reliability (must and should) always come before profit and schedule. You don’t have second chances, because you don’t.
(Edited by Majnu Babu).
