More than a year after the loss of Air India Flight AI-171, the central issue is no longer simply whether the Aircraft Accident Investigation Bureau is continuing its work. The more pressing question is whether the investigation will ultimately yield a technically convincing and publicly accessible explanation of what happened.
The Ministry of Civil Aviation has stated that the investigation is being conducted in accordance with the Aircraft (Investigation of Accidents and Incidents) Rules and with applicable ICAO Standards and Recommended Practices. It has also said that the AAIB has undertaken an extensive examination of the technical, operational, organisational and human factors associated with the accident, and that significant progress has been made in analysing aircraft systems, flight-recorder data and other evidence.
The AAIB, for its part, has reiterated its commitment to professionalism, transparency and investigative rigour.
Those assurances are welcome, but they also invite an obvious question: where is the transparency?
The preliminary report issued in July of last year was necessarily limited in scope and largely factual. This is entirely normal. Preliminary reports are not intended to establish probable cause or provide a complete analysis.
What is more difficult to understand is why, after such an extended period of investigation, so little substantive information has emerged regarding the direction of the technical inquiry.
We are told that aircraft systems have been examined, flight-recorder data analysed and forensic work undertaken. Yet fundamental questions remain unanswered.
Which components were subjected to detailed examination? Which systems were considered potentially relevant? Were any parts sent overseas for specialist analysis? Have those examinations been completed? Has the AAIB received the findings? Have investigators identified any mechanical, electrical, software or system anomalies? More importantly, have significant technical failure modes been conclusively ruled out?
These questions are not speculative distractions. They go directly to the purpose of an aircraft accident investigation.
At the heart of the AI-171 investigation lies a critical, still unresolved issue: how and why did both fuel-control switches move from RUN to CUTOFF shortly after take-off?
Everything else is secondary to that question.
The loss of thrust occurred during one of the most vulnerable phases of flight. If the switches changed state because of a technical or electrical malfunction, investigators must establish and explain the mechanism. If the possibility of a technical malfunction has been excluded, the basis for that exclusion must be demonstrated.
If human action is involved, the conclusion must rest on evidence rather than assumption.
And if the evidence does not allow investigators to determine with certainty how the switches moved, the final report should state this plainly.
There is nothing professionally unacceptable about an inconclusive finding when the evidence genuinely does not permit a definitive conclusion. What would be unacceptable is leaving the central causal question unanswered while relying on confidentiality provisions to avoid discussing the evidence.
This is where the issue of the Cockpit Voice Recorder is particularly important.
There is a sound and well-established reason for protecting raw CVR recordings. Cockpit recordings may contain private conversations, incidental remarks and information entirely unrelated to the accident. Unrestricted publication would serve little safety purpose and could seriously undermine the principles on which protected safety information is collected.
The aviation community should therefore resist simplistic demands that the complete CVR recording be released publicly.
But that is not the real issue.
The crucial distinction is between protecting a raw cockpit recording and withholding information about the safety significance of what that recording reveals.
ICAO provisions protecting CVR material were never intended to prevent investigators from explaining relevant cockpit events in a final accident report. On the contrary, if a statement, action or exchange recorded on the CVR materially assists in understanding the accident sequence, that information forms part of the evidential basis of the investigation.
The public does not need to hear every second of cockpit conversation. But the aviation community needs to understand what the recorder evidence establishes about the accident.
CVR confidentiality must therefore not become a convenient shield behind which critical causal evidence is concealed.
The same principle applies to the Flight Data Recorder and to any forensic examinations of aircraft components or systems.
A professional accident report should not merely state that no technical defect was identified. It should explain how investigators reached that conclusion.
What failure modes were considered? What tests were conducted? What physical evidence was recovered? Which electrical or electronic pathways were examined? Which system logic was assessed? Were switch mechanisms physically inspected? Were wiring, control systems, software functions, or associated components tested? Did the recorder data support or contradict any technical hypotheses?
The credibility of the investigation depends on the ability of technically qualified readers to understand the reasoning.
This is particularly important when a conclusion may point away from mechanical failure and towards human action.
Such conclusions carry significant consequences. They affect the reputation of crew members who cannot speak for themselves. They may influence litigation, manufacturer liability, airline accountability and public perception.
That makes evidential transparency even more important, not less so.
If human action is implicated, the report must establish the sequence convincingly. It should examine not only what appears to have happened but also the circumstances in which it happened: workload, cockpit interaction, procedural design, system ergonomics, possible inadvertent action, startle, cognitive factors, and any relevant organisational influences.
Accident investigation is not strengthened by prematurely reducing a complex event to a single cockpit action.
Nor is it strengthened by excluding technical explanations without demonstrating how they were eliminated.
The recent reports that a copy of the AAIB report may be submitted to the Supreme Court in a sealed cover add another dimension to the debate.
There may be perfectly legitimate reasons for a court to receive certain material confidentially. Judicial proceedings often require sensitive information to be protected, particularly where statutory restrictions apply to recordings, personal information or other investigative material.
But a confidential submission to the Supreme Court and a public aviation accident report serve very different purposes.
a) One serves a judicial process.
b) The other serves aviation safety.
c) A sealed report does not, in itself, prevent a recurrence.
d) It does not inform flight crews.
e) It does not change operating procedures.
f) It does not alert engineers to a system vulnerability.
g) It does not lead manufacturers to modify a design.
h) It does not enable regulators to improve oversight.
And it does not provide the wider aviation community with the lessons that accident investigation is intended to yield.
For that reason, a sealed submission can never be regarded as a substitute for a comprehensive public report.
The primary objective of a safety investigation is not to determine guilt behind closed doors. Its purpose is to reconstruct the sequence of events, identify causal and contributory factors, and recommend measures to reduce the likelihood of recurrence.
That purpose can only be fully achieved when the findings become accessible to those who must act upon them.
a) This is also why prolonged opacity is dangerous.
b) It inevitably creates suspicion.
If no technical defect has been identified, people will naturally ask what the remaining evidence indicates. If investigators have access to the CVR, FDR, physical evidence and forensic results, but the public continues to receive little more than assurances of progress, speculation will fill the vacuum.
Questions will arise about whether the crew, the manufacturer, the airline, the regulator or Government itself has an interest in limiting disclosure.
At present, there is no verified evidence that any of these parties is being protected.
That must be stated clearly.
Criticism of secrecy is justified. An allegation of a deliberate cover-up requires evidence.
But investigative authorities must also recognise that secrecy carries its own consequences. The longer crucial questions go unanswered, the more public confidence erodes.
Trust cannot be sustained indefinitely by statements about professionalism and rigour.
It has to be earned through evidence.
The final report must therefore do far more than announce a conclusion.
a) It must show its work.
b) If a technical failure was considered and rejected, the report should explain the basis for rejection.
c) If an electrical malfunction was investigated, the relevant findings should be presented.
d) If the fuel-control switch design or operation was examined, the results should be discussed.
e) If overseas forensic examinations were commissioned, their significance should be explained.
f) If recorder information establishes a particular sequence, the relevant parameters should be presented clearly enough for informed readers to follow it.
g) If human factors were involved, the analysis should be proportionate, detailed and evidence-based.
h) If organisational, training, regulatory or procedural weaknesses contributed, they should not be obscured by an excessive focus on the final seconds in the cockpit.
i) And if investigators remain unable to determine exactly why the decisive event occurred, the report should say so.
j) There is no need to manufacture certainty simply to produce a neat conclusion.
In aviation safety, an honest admission of limitation is far more valuable than an unsupported assertion.
Transparency should not be confused with indiscriminate disclosure. There is no need to publish irrelevant cockpit conversations or to invade personal privacy. Nor should incomplete or unverified evidence be released prematurely.
But once an investigation reaches its final stage, the evidence required to understand the accident must be disclosed in sufficient detail to withstand technical scrutiny. That is the standard by which the AI-171 investigation should ultimately be judged.
a) The families of those who died deserve meaningful answers.
b) Pilots need to know whether there is an operational lesson.
c) Engineers need to know whether there is a technical vulnerability.
d) Airlines need to know whether procedures require modification.
e) Manufacturers need to know whether design or system changes are necessary.
f) Regulators need to know whether certification, training or oversight require reform.
g) Passengers have a legitimate expectation that a catastrophic accident will result in a clear explanation and tangible safety improvement.
h) These interests are not secondary to the investigation.
i) They are the reason the investigation exists.
j) The public does not need the raw CVR.
k) It does not need speculation dressed up as fact.
l) It does not need premature accusations.
What it needs is a technically complete and intellectually honest account of the accident.
a) If a technical failure has been ruled out, show how.
b) If a system malfunction remains possible, explain why.
c) If human action is implicated, establish this rigorously.
d) If forensic analysis has produced important findings, disclose their safety significance.
e) And if uncertainty remains, acknowledge it.
The AAIB has repeatedly emphasised transparency, professionalism and investigative rigour.
The final report will offer an opportunity to demonstrate all three.
A sealed report may satisfy a procedural or judicial requirement.
But aviation safety is not advanced by sealing away evidence. It advances when evidence is examined rigorously, conclusions are explained convincingly, and lessons are shared openly.
The real test of the AI-171 investigation will therefore not be whether the AAIB says it conducted a thorough investigation. It will be whether the final report shows the aviation community that it did.
a) The investigation must answer the central questions.
b) It must subject its reasoning to professional scrutiny.
c) And above all, it must explain the accident — not bury it.
Author: GR Mohan
