# Presentation: 252534

## VLTA Emergency Requirements 
Research Evacuation Study

Rebecca L. Wilson, Lauren J. Thomas 
& Helen C. Muir

Human Factors Group
School of Engineering
Cranfield University, UK

**Research Evacuation Study**
**Rebecca L. Wilson, Lauren J. Thomas **
**& Helen C. Muir**
*Human Factors Group*
*School of Engineering*
*Cranfield University, UK*

## Consortium & funding

- The VERRES programme was a European Commission & DG Tren funded project.
- The aim of the project was to examine some of the issues relevant to evacuation from next generation VLTA.
- The study was general in nature, and not related to any specific VLTA type.
- The consortium included Sofréavia, CAA/SRG, JAA, Airbus, University of Greenwich, Cranfield University, Virgin Atlantic Airways and SNPNC.

## Programme of study

- The study covered three major domains:
- The configurational aspects of aircraft cabin design and the evacuation implications.
- The use of analysis supported by relevant small-scale evacuation tests and evacuation modelling software.
- The human aspects such as cabin crew co-ordination and training and the mental representation layout of the aircraft for the passenger.

## Scope of project

- Analyses on the trial data were conducted independently by three VERRES partners, each using a different approach and reaching their own conclusions.
- The Cranfield University analysis focussed on passenger evacuation times and data from post evacuation questionnaire.
- A summary report, providing an overview of the whole programme, has been published by the JAA on behalf of the consortium (Greene & Friedrich, 2003).

## Potential research areas

- During the development of the test plan for the experimental tests, the VERRES consortium identified a large number of areas of interest.
- Areas were classified into high or low priority within the specification of the project.
- High priority issues included staircase size, staircase configuration, staircase flow management, upper deck slides and crew co-ordination.

## Research areas for testing

- However, it became evident that consortium members were unable to limit the number of variables for testing.
- Therefore, instead of an experiment, it was proposed to conduct the evacuation trials as a series of demonstration evacuations.
- It was accepted that because of the lack of experimental control, trials would only be used to explore possibilities for future research, and no conclusions could be drawn from the work.

## Design of demonstrations

- Three variables related to passenger movement in three types of situations:
- Free choice of exits between decks
- Lower deck exits unavailable
- Upper deck exits unavailable
- Variables related to the cabin crew at the staircase:
- Additional cabin crew at staircase
- Cabin crew at exits only

## Test facility

- Test facility – Large Cabin Evacuation Simulator located at Cranfield University, United Kingdom.
- Both decks of the simulator were to be used during the trials, all seats were at 31” pitch.
- Lower deck had 172 seats, with three fitted exits (LL1, LL2 & LR2), with platforms available outside for evacuation.
- Upper deck had 88 seats, two fitted exits (UL1 & UR1). UL1 had a platform for evacuation and UR1 was fitted with a dual lane evacuation slide.

## Lower deck of LCES

## Upper deck of LCES

## Internal staircase

## Volunteers

- Up to 168 volunteers were recruited for each day, with four demonstrations held on each day.
- Volunteers were split into two groups of 84, to manipulate staircase naiveté.
- Volunteers were members of the public who were recruited using either the HFG aviation research database or via local and regional advertising.
- All demonstrations were video recorded, to allow data relating to passenger and cabin crew behaviour to be extracted.

## Demonstration scenarios

- Movement between decks was of interest, as was the presence or absence of additional cabin crew at the internal staircase.
- Four demonstrations were the moving downwards scenario, two with additional crew at internal staircase.
- Two demonstrations utilised the moving upwards scenario, one with and one without additional crew.
- Two demonstrations were free choice scenarios, neither with additional crew at the internal staircase.

## Order of demonstrations

| Trial number | Day 1 (25 Jan 03) | Day 2 (1 Feb 03) |
| --- | --- | --- |
| 1 | Free choice | Moving downwards with additional crew at staircase |
| 2 | Moving downwards, no additional crew at staircase | Moving upwards, no additional crew at staircase |
| 3 | Moving upwards, additional crew at staircase | Moving downwards without additional crew at staircase |
| 4 | Moving downwards, with additional crew at staircase | Free choice |

## Conduct of demonstrations

- After pre-trial paperwork and briefing, volunteers boarded simulator via external staircases to ensure naïve use of internall staircase.
- Seats allocated according to a pre-defined seating plan on a random basis, with each volunteer sitting on each deck twice.
- Ten members of cabin crew were involved in the evacuations.
- Prior to the evacuation all cabin crew (except those located at UR1) were unaware of which exits were available for evacuation.

## Results

- Data were available from 8 demonstrations, with a total of 336 volunteers.
- A person was deemed to have evacuated when they placed their 1st foot over the exit threshold.
- Inferential statistical analyses between different scenarios could not be conducted, since insufficient data were available for comparison.
- Differences between additional/no additional cabin crew scenarios may not be clear due to crew behaviours.

## Free choice demonstrations

| Free choice | N | Mean evac time (secs) | Evac rate (pax per min) | Overall exit time (secs) |
| --- | --- | --- | --- | --- |
| 25 Jan 03 Trial 1 |  |  |  |  |
| UR1 | 33 | 42.4 | 25.4 | 75.6 |
| LL2 | 62 | 31.2 | 56.7 | 64.5 |
| LR2 | 74 | 33.4 | 63.3 | 69.2 |
|  |  |  |  |  |
| 1 Feb 03 Trial 4 |  |  |  |  |
| UR1 | 36 | 29.9 | 46.4 | 45.3 |
| LL2 | 65 | 22.9 | 92.3 | 41.6 |
| LR2 | 68 | 25.3 | 79.4 | 50.6 |

## Free choice results

- Differences are apparent between demonstrations. Faster evacuation rates, lower evacuation times and lower overall evacuation times were obtained on the last trial of programme.
- Inferential statistical analysis cannot be conducted, since insufficient data are available for comparison.
- The observed differences are likely to be a function of passenger and cabin crew learning.

## Moving upwards demonstrations

| Moving upwards | N | Mean evac time (secs) | Evac rate 
(pax per min) | Overall exit time (secs) |
| --- | --- | --- | --- | --- |
| 1 Feb 03 Trial 2 |  |  |  |  |
| No additional crew |  |  |  |  |
| UL1 | 112 | 43.9 | 78.9 | 84.4 |
| UR1 (slide) | 57 | 47.5 | 38.8 | 86.5 |
|  |  |  |  |  |
| 25 Jan 03 Trial 3 |  |  |  |  |
| Additional crew |  |  |  |  |
| UL1 | 119 | 45.3 | 91.1 | 77.7 |
| UR1 | 49 | 45.4 | 36.8 | 78.2 |

## Moving upwards results

- Two demonstrations were conducted within this scenario, one with and one without additional crew.
- Marked differences are apparent in evacuation rates between UR1 and UL1.
- Inferential statistical analysis cannot be conducted, since insufficient data are available for comparison.
- Observed differences are likely to be a function of the extreme caution exercised by cabin crew at UR1

## Moving downwards demonstrations – without additional crew

| Moving downwards
Without additional crew | N | Mean evac time (secs) | Evac rate 
(pax per min) | Overall exit time (secs) |
| --- | --- | --- | --- | --- |
| 25 Jan 03 Trial 2 |  |  |  |  |
| LL2 | 80 | 28.3 | 83.0 | 57.1 |
| LR2 | 88 | 29.4 | 92.9 | 56.2 |
|  |  |  |  |  |
| 1 Feb 03 Trial 3 |  |  |  |  |
| LL2 | 81 | 27.5 | 90.7 | 52.9 |
| LR2 | 88 | 28.1 | 98.3 | 53.1 |

## Moving downwards demonstrations – with additional crew at staircase

| Moving downwards
With additional crew | N | Mean evac time (secs) | Evac rate 
(pax per min) | Overall exit time (secs) |
| --- | --- | --- | --- | --- |
| 25 Jan 03 Trial 4 |  |  |  |  |
| LL2 | 81 | 28.8 | 90.2 | 53.2 |
| LR2 | 87 | 28.2 | 99.0 | 52.1 |
|  |  |  |  |  |
| 1 Feb 03 Trial 1 |  |  |  |  |
| LL2 | 86 | 29.9 | 89.9 | 56.7 |
| LR2 | 83 | 31.1 | 83.5 | 58.9 |

## Moving downwards evacuations

- Four demonstrations were conducted within this scenario – two with and two without additional crew.
- Mean evacuation times, evacuation rates and overall evacuation times do appear to be broadly similar across the different demonstrations.
- Inferential statistical analysis cannot be conducted, since insufficient data are available for comparison.

## Conclusions

- Post demonstration questionnaires revealed that cabin crew had a major influence on passenger exit choice.
- Cabin crew variable was uncontrolled – as crew moved to give additional assistance at staircase. Reasons may be highlighted in Sofréavia analysis - research crew can be more flexible.
- As demonstrations were not scientifically controlled, no firm conclusions can be drawn.
- Future research could include passenger exit choice behaviours, interaction between passengers and crew, and investigation of internal features e.g. staircases.