•HELIOS FLIGHT 522 AIRCRAFT ACCIDENT•ALOHA AIRLINES FLIGHT 243 ACCIDENT

SHEL FACTORS

MOHD FARID BIN MOHD FAUZI 53212215012FARAH SHAFINAZ BINTI AHMAD AZZAN 53212215030AFREENA AFIEN BINTI MOHD AZRI OOI 53212215008AMIRA ATIKAH BINTI RAUP 53212215007SITI NOR AIN BINTI HARIS 53212215026MOHAMMAD SUBAIL CHOWDHURY 53212215047

PREPARED BY:

PREPARED FOR:DR. MOHAMED IDRUS BIN ABD MOIN

5 CASES

1. Helios Airways Flight 5222. Aloha Airlines Flight 2433. Singapore Airlines Flight 0064. Tenerife airport disaster5. Crossair Flight 498

INTRODUCTION OF SHEL MODEL

A conceptual model using 4 blocks to represent interaction between the different components of “Human Factors”.

S – SoftwareH – HardwareE – EnvironmentL – Livewire 

1. Software Interaction with technology, system

rules and SOP’s2. HardwareControls / Surfaces, Displays and

functional systems3. EnvironmentThe “Climate”; Social / Economic, as

well as Natural v “Operating” Environments

4. LivewireHuman interaction; Flight crew ->

Cabin Crew -> Engineers etc. 

Interface between categories:

ANY IDEAS AS TO WHY THE “RAGGED” INTERFACE BETWEEN CATEGORIES?

Essentially it suggests that any interaction involving human beings is always less than “perfect” –

Hence the importance of; “HUMAN FACTORS”

CASE 1 :HELIOS FLIGHT 522 AIRCRAFT ACCIDENT

SEQUENCE OF EVENTS

• 14 AUG 05, crashed north of Marathon & Varnavas, Greece.• Wreckage located near Grammatiko community 40 km from Athens.• All 121 on board were killed.• Before take-off, crew failed to correctly set pressurisation system.• Result, gradual decompression. All on board suffering Hypoxia.• Captain’s conversation with engineer, confirmed he was suffering hypoxia.• When Greek air space entered, ATC not contacted. 2 Hellenic Air Force F-16 fighters scrambled.• F-16 pilots saw F/A Andreas Prodromou at controls, (trainee pilot), attempting control of aircraft, (consciousness due to portable oxygen).• Aircraft crashed due to lack of fuel. Engines failed in quick succession. 

SHEL MODEL ANDHUMAN FACTOR RELATIONSHIP

Liveware – Software(The interface between people and software) In this instance, none of significance

Liveware – Hardware(The interface between people and hardware) Pressurisation set to “Manual” instead of “Auto” - Importance of SOP’s! “Cabin altitude” horn misidentified as a take-off configuration warning An “Oxy ON” warning light misinterpreted as “systems” were

overheating.

Liveware – Environment(The interface between people and the environment) Attempt at cogitative thought in a “Hypoxic” environment, (loss of cabin

pressure) Re-enforces vital importance of recognition of symptoms and

adherence to drills

Liveware – Liveware(The interface between people and other people) Cultural differences, East German Captain, Cypriot First Officer, “lack

of common language” Engineer during discussion identified Hypoxia. Didn’t really “press

point” to the Captain 

CASE 2 :ALOHA AIRLINES FLIGHT 243 ACCIDENT

SEQUENCE OF EVENTS (AQ243)

Aircraft departed normally , bound to Honolulu No unusual occurrences were noticed during the pre-departure

inspection of the aircraft While flying, 18 feet of the upper cabin structure suddenly being

ripped away due to a structural failure Result in decompression in flight Able to land safely at Kahului Airport on Maui

SHEL MODEL ANDHUMAN FACTOR RELATIONSHIP

S – Software The engineering inspector might misinterpreted during his inspection or lack of focus

H – Hardware Possibility of not fully equipped of equipment during inspection

E – Environment The environment of the workplace might contributes and leads to a weak working performance

L – Liveware Lack of interactions between engineers and pilots during the pre flight checks