Donna Murdoch Ph.D. CAsP
Human Systems Solutions, Inc.
Ramon, CA

This presentation was funded by Alaska
Airlines
The Reduced Oxygen Breathing Device 2 was supplied by Environics, Inc.
I would like to thank the aircrew members from Alaska Airlines who participated in this study and Gary Crawley my co-author.

HELIOS AIRWAYS FLIGHT HCY522


Alaska Airlines Aircrew Members

13 Pilots (average flight time = 6125)

7 had previous hypoxia training in an altitude chamber

3 reported being hypoxic in the aircraft

15 Experienced Cabin Crew Members

4 had previous hypoxia training in an altitude chamber

5 reported being hypoxic in the aircraft

All had a current physical and were qualified to fly




Pilots


Familiarization training for those with no previous hypoxia training

Up to 4 minutes at 25K ft
Data collection training run


3 minutes at 10K ft , immediately followed by to 4 minutes at 25K ft
Each subject performed a simulated flight using a desktop simulator with altitude changes, radio calls and frequency changes directed by a simulated air traffic controller
Cabin Crew


Familiarization training for those with no previous hypoxia training

Up to 4 minutes at 25K ft
Data collection training run


3 minutes at 10K ft while performing a simulated task requiring light exercise
Up to 4 minutes at 25K ft while performing a seated task simulating their flight duties
The student was encouraged to treat themselves and turn on their emergency oxygen when they felt hypoxic but if it became evident that they could not they were coached to turn on their oxygen by the instructor. The level of coaching was recorded.

All data was collected using the
Reduced Oxygen Breathing Device 2 computer controlled
SpO2 and heart rate monitor mass flow controller technology mixes nitrogen and air to get the desired altitude
100% emergency oxygen is available

N=1 78
25K/2:30
25K/2:00
N=1
N=1
25K/1:30
N=5
N=1
25K/1:00
N=10
N=7
25K/30 Sec
N=10
N=9
10K/3 Min
N=13
N=13
0 10 20 30 40 50
%SpO2
60 70
81
80
78
86
79
87
80
85
93
90
91
94
100
Cabin Crew
Pilots

80
%SpO2 78
76
74
72
70
86
84
82
Lowest working
%SpO2
Lowest Rec %SpO2
Pilots
Cabin Crew

18
16
14
12
10
8
6
4
2
0
Pilots
Cabin Crew
Total
None Mod Signif




Time to termination of training

Pilots - mean 66 (SD 24, range 0-197) Sec at 25K

3 of 13 terminated before 30 Sec at 25K

Cabin Crew – mean 56 (SD 59, range 0-210) Sec at 25 K

2 of 15 terminated at 10K and 4 more terminated just after arriving at 25K
Number feeling they were adequately trained 25

3 felt that they needed additional training
Interval of training required




17 thought that training should be given yearly
3 felt that it should be given more frequently than yearly
7 felt that it should be given between 2 and 5 years
1 felt that it should be given once in a career


Individual tolerances and workloads accounted for the wide range of exposure times and SpO2 levels.

A majority of the aircrew felt that they should receive this training at least yearly (20) thus indicating how valuable they thought it was.

A majority of the cabin crew members thought this training should be mandatory.

Hypoxia recognition and recovery training provides another defense against catastrophic events resulting from a loss of cabin pressurization when all crew members are trained and crew coordination procedures are in place.
This training should be conducted regularly for both pilots and cabin crew members.
A more time sensitive measure of SpO2 should be developed.

Donna Murdoch
Human Systems Solutions, Inc.
Murdochd.hss@cox.net
619-573-7106