Escape Routes for Depressurisation and Driftdown


Category: Flight Operations / Performance
Title: Escape Routes for Depressurisation and Driftdown
Date of Issue: March 2026
Applicability: CAT Operators

Background

Escape routing for depressurisation and driftdown scenarios is not explicitly mandated as a standalone requirement.

However, operators are required under EASA Air Operations to ensure the safe conduct of flights, including in abnormal and emergency situations.

For CAT operations, CAT.POL.A.215 En-route – one-engine-inoperative (OEI) requires that, in the event of an engine failure, the aircraft must be able to:

  • maintain adequate terrain and obstacle clearance, and
  • continue the flight to a suitable aerodrome.

In operations involving mountainous terrain or constrained airspace, this effectively requires a clear understanding of how a safe descent or drift-down can be achieved.

Impact on Operators

In a depressurisation or engine-out scenario, crews must react immediately.
The available options are often constrained by:

  • terrain and obstacle environment,
  • aircraft performance limitations,
  • and airspace structure.

Generic manufacturer procedures alone are not sufficient in these scenarios.
Without predefined routing or a clear escape concept, there is an increased risk of:

  • delayed or suboptimal decision-making,
  • loss of situational awareness in high-workload conditions,
  • or non-compliance with terrain and obstacle clearance requirements.

TRS Recommendation

Operators should assess whether escape routing for depressurisation and driftdown:

  • is defined for relevant routes and operational areas,
  • reflects aircraft-specific performance limitations,
  • considers terrain and airspace constraints,
  • and is usable in a time-critical scenario.

TRS Aviation Consulting offers the development of tailored escape routes for depressurisation and driftdown scenarios, based on aircraft performance and operational environment.

Further details:
https://www.trs-aviation.com/services/decompression/

Official Source

EASA Air Operations – CAT.POL.A.215 En-route – one-engine-inoperative (OEI)

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