Truth Under Uncertainty

A Decision Integrity Analysis of the Tenerife Disaster

How unchallenged assumptions-not environmental conditions- led to the deadliest aviation tragedy in history

1.     Conditions did not cause the disaster.

Fog and reduced visibility, congestion, substandard communication equipment and language did not cause the disaster. Conditions created uncertainty, it was decisions that outpaced reality that crafted the outcome.

2.     Failure Mode: Loss of Decision Integrity (Deception)

Assumptions can replace any verified reality.

Breakdown 1: Runway clearance was assumed

Ambiguous ATC response interpreted as authorization. No explicit confirmation was given.

Failure: Assumption was treated as fact.

Breakdown 2: Uncertainty was Suppressed

First officer raised his concerns very weakly. Captain overrode them without any verification.

Failure: Uncertainty was not honoured or validated.

Breakdown 3: Facts were Missing

Pan Am was still on the runway. That information was not confirmed.

Failure: No Verification Loop

3.     The Missing Mechanism: Truth Alignment.

A.    Deception: Assuming that the runway is clear

B.    Truth: If we are wrong there will be a collision.

C.    Harsh Truth: This might have been a time to speak a harsh truth.

“If our assumption is wrong we will crash.”

Action: hold position

4.     Impact

This method stops assumption motivated actions. The process welcomes uncertainty. The engagement allows hierarchy to be challenged and anchors decisions in reality.

Catastrophic failure occurs when our actions outrun reality. Truth alignment connects actions with reality.

This is but one small part of our whole model. See Below.

This model is part of a decade long process.