Austin Johnson 3-10-2016

Human Factors-Mangham Mid-Term

Q1- Expectancy bias is when evens are expected to happen a certain way. (Psychlopedia.

“Expectancy Bias” https://psychlopedia.wikispaces.com/Expectancy+Bias. Accessed 3/10/2016.)

Expectancy bias can come from experience with a particular system. For example, TCAS

(Traffic Collision Avoidance System) is a system that is designed to prevent collisions with other

aircraft and if a collision is near, the crew will get an aural alarm that says “Traffic, Traffic.” If

the aircraft continues to close-in, the TCAS system will give voice and visual commands to give

a RA (resolution advisory) where it will say directions like “climb, climb.” In addition, the pilot

on his//her vertical speed indicator (which tells how fast an aircraft is climbing or descending),

will get a green indicator zone to show how fast or slow to climb or descend and a red zone of

where to keep out of to avoid a collision. This can also be portrayed on the artificial horizon to

show which roll/pitch angle is need to avoid a collision (67.) TCAS is such an important system

in preventing mid-air collisions that aircrews are authorized and are expected to follow its

directions instead of that of ATC (Air Traffic Control). On July 1, 2002 TCAS would show the

human factor limitations of expectancy bias. On this day, a DHL Boeing 757 and a Bashkiran

TU-154 were involved in a mid-air collision near the border of Switzerland and Germany. As the

aircraft were nearing each other, both planes were issued TCAS RA advisories and the DHL

pilot followed the directions of his TCAS system however, the Bashkiran pilot did not follow

TCAS. When the ATC tried to get involved to avoid a collision, they issued clearances to the

Bashkiran aircraft which was opposite of the TCAS system. The Bashkiran pilots listened to the

ATC instead. As a result of the conflicting directions, the aircraft collided. Change blindness was

demonstrated when the DHL pilot followed TCAS and likely expected the Bashkiran pilot would

do the same. The TU-154 is one of the most commonly used aircraft in Soviet Russia. The

Bashkiran pilots may not have been fully aware of the limitations of TCAS or better yet, used to

the technology installed in the aircraft. Soviet aircrews in 2002 would have only recently been

exposed to the western ideas of TCAS and other advanced alerting systems. This would also

create a cultural barrier of understanding of technology utilization. Most soviet aircraft lacked

advanced technology and were not equipped to the same standards as western aircraft are. This

issue has shown itself in many third world countries when, aircraft have crashed for reasons that

would be unheard of in our country.

Q2-Systems theory is an interdisciplinary approach to the nature of complex systems. It can take

the forms of artificial or natural or even mathematical systems (27.). Aviation in itself is a large

system made up of many smaller systems including the national airspace system, training and

standards, regulatory, data infrastructure and even the aircraft themselves have many systems.

Relating to my concentration of avionics, we will examine some of the systems and how they are

interconnected. From a human factors standpoint over reliance on automation can be a dangerous

aspect of many younger pilots. Over-reliance on automation has resulted in many more accidents

compared to the design of modern aircraft systems. Many aircraft such as the Airbus A380 have

adopted a technology called fly-by-wire. We will examine the A380 to demonstrate the extreme

use of its dependence on fly-by-wire. The aircraft relies on three primary, three secondary, and a

back-up control module (in the case failure of all six flight control computers). In addition, the

aircraft has at least 3 modes of degraded operation for the fly-by-wire system. All of the flight

controls are commanded by computers, and actuated by local electrical-hydraulic backup (in the

case of hydraulic failure) or by one or both central hydraulic systems themselves. From a human

factors standpoint, an older pilot may not want to learn about all of the new technologies on this

aircraft and that may make it unpopular among older pilots. Older pilots tend to have some old

sayings like “If it isn’t broke don’t fix it.” or “More crap to break.” In a way that is true. If all

flight controls computers were to stop functioning in the A380 example, the aircraft would likely

crash because of the inability to move the flight controls. The A380 is also the largest of any

commercial aircraft; featuring two full-length double-decks it can carry comfortably almost 600

passengers. h If one of these monster jumbos were to crash, the legal litigation fall-out would be

incredible. In other words, Airbus may go bankrupt if an A380 were to crash due to a design

fault. Fortunately, the odds of that happening are tens of billions to one. In addition, I am not

aware of any incident of this magnitude in all of aviation history. Many newer pilots are

“children of the magenta.” and while although comfortable with the newest of aircraft; they can

lack basic flying skills and not even understand older aircraft because, they expect automation to

preform and sometimes take place of basic flying skills.

Flight controls are not the only computerized systems in this aircraft. Everything from the

landing gear to the wheel brakes and even the emergency systems like emergency oxygen, and

emergency escape slides have some sort of computer control. The A380 is just one of dozens of

platforms using fly-by-wire. Aircraft such as the Boeing 747 have long featured traditional steel

cable flight controls. The traditional flight control setup has been used in aircraft from the 1910’s

to present day. These conventional flight controls can fail also. In August, 1985 a Boeing 747

crashed in Japan after it lost all four hydraulic systems that controlled flight controls and crashed

into a mountain. The aircraft had a improperly riveted bulkhead that ruptured and severed the

hydraulic lines. This accident was the worst accident in aviation history featuring a single plane

where over 500 people died.

Q3- Change blindness is failing to see large changes in front of you(About health, “What is

Change Blindess.”http://psychology.about.com/od/cognitivepsychology/f/change-blindness.htm,

Updated: 8/31/2015). Change blindness is relevant to aviation because, it can affect nearly every

area of aviation including ATC, pilots, and mechanics and has been a factor in some accidents.

In the accident of Eastern Airlines flight 401, an L-1011 was on approach to Miami airport. As

the crew lowered the landing gear they noticed that the nose landing gear was not confirmed to

be extended. On most aircraft equipped with a retractable landing gear, they are equipped with

red indicator lights meaning the gear is moving or is not locked and green lights which indicate

the landing gear is down. The lights are blank when the landing gear is up. In the case of flight

401, the two main landing gears were indicate to be down and the nose gear light was not

indicating that. The pilots attempted to change the burned-out light bulb for the nose gear. While

they were changing this, one of the crew getting out seat to go to the electronics bay to verify the

landing gear was extended by looking through a viewfinder, likely bumped the control wheel

which would have put the aircrafts’ autopilot in a different mode to hold a certain angle in

manual mode instead of holding 2,000 feet. The descent was so gradual, that nobody noticed

until seconds before impact that the aircraft was losing altitude. Change blindness in this case

was the fact that the crew was oblivious to the fact the aircraft was loosing altitude.

Some other examples of where change blindness could occur is in ATC. Most ATC radar

screens are monochromatic (1 color) and lack the ability for displaying planes in a vertical

dimension. If in a busy airspace area, a controller could let two planes overlap and could take a

chance of them being at different altitudes if they were distracted with other tasks. This change

blindness could result in a collision if for example a plane overflying the airport was confused

for a plane on the ground. This is especially true in periods of foul weather. If a controller cannot

see another aircraft the mental stress of this could be detrimental to a controllers’ performance.

As technology evolves, the concept of a virtual control tower was introduced. In this concept,

control tower windows are replaced with computer monitors. If a controller is not familiar with

the new display formats and symbols and is complaisant because they are used to a

monochromatic radar screen there is a possibility of accident. If for example a parked aircraft is

not giving any information to a controller because the datalink systems are powered down and

another plane taxis near it there could be a ground collision.

Q4- The term safety culture was introduced after the 1986 Chernobyl incident. In a blame

culture, everyone is encouraged to report all incidents. This can be detrimental to workers

because, in the event of a problem somebodies name and reputation will be at stake. A blame

culture also does not promote confidentiality because, the last person at an incident is blamed. In

a blame culture everybody is at risk of retribution from lack of confidential safety reporting. In a

secret society such as Apple or Google, safety culture is a strictly-closed loop system. In my

opinion, this is not a good model of business when it comes to safety culture because, in some

cases some secretive companies may think they are above the law. For example, a company

could take short cuts on maintenance of aircraft ad fail to disclose it. One such company called

Sabre Tech was involved in one such incident. On May 11, 1996 a Valu Jet DC-9 crashed after a

massive in-flight fire swept through the plane killing 110 people. An documentary I watched on

the accident, showed that oxygen generators that were improperly packaged by Sabre Tech

caused an inflight fire. Oxygen generators are a device that is used to create a chemical reaction

for emergency oxygen masks for airliners for passengers. When activated, these devices generate

heat in excess of 500 degrees F. These generator were stored in bubble wrap and some had no

safety caps to prevent activation because they were not all available. These were packaged in a

box labelled “aircraft parts” and were stored around an airplane tire in the cargo hold. To make

matters worse, in 1996 aircraft were not required to have a fire detection and extinguishing

systems in cargo holds. For some reason one of the oxygen generators activated and started an

intense fire due to the intense heat that was put off by oxygen generators. As the smoke became

unbearable, the fire burned through the cabin floor of the plane and the pilots lost control of the

aircraft and crashed. After the accident most commercial aircraft are required to have smoke

detection and fire suppression systems in cargo holds and there are much stricter regulations

regarding hazardous materials be shipped onboard aircraft. Some of the Sabre Tech employees

that were involved loading the hazardous material on the aircraft were convicted of

manslaughter. This shows that when a company is lax and does not supervise its employees and

thinks it is above the law that people have lost their lives with this course of thinking.

Finally, the preferable alternative is to have a just culture where employees can report

unsafe conditions and do so with confidence and without fear of reprisal or retribution In a just

culture, productivity is higher because employees are able to focus on the task at hand and not

focus on blaming others for mistakes.

Q5- On August 13. 2005, a Helios airlines B737 crashed after running out of fuel. The aircraft

flew for nearly 3 hours on autopilot after the plane lost cabin pressure. The pilots lost

consciousness after the cabin pressure was set incorrectly for flight. On a previous flight the crew

observed that one of the aircrafts doors did not look correct. After pressurizing the plane for a

ground leak check the pilot left the cabin pressure mode selector in the wrong position and did

not switch it back to automatic for the next flight. As a result of this mistake some of the

mechanics were criminally charged (129.) A high reliability organization (HRO) is a designation

given to a company who has operations that are very dependable. If a company is highly

dependable, they may let a lack of problems lend way to them getting complacent when it comes

to safety. This idea lends itself to the school of thinking that since nothing bad happened in the

past that, an accident will not happen in the future. An example of this would be the company of

Qantas Airlines. Even though that company has not had a fatal accident, they have had a few

close-calls of incidents that Ingenerated some close encounters with a major accident. A Qantas

747 lost electrical power after all four generators failed in flight. The cause was water from the

galley draining and getting into the electronics in the equipment bay which was below. In

another incident, a Qantas A380 suffered an un-contained engine failure. As a result of the large

amount of degraded systems, the aircraft could have had an accident had the engine blow-up had

been worse. My point is no matter how safe your airline or company is, you can always have an

accident if you are allowed to be complacent when it comes to safety. Helios airlines may have

had a good safety record before the accident however, complacent thinking by the mechanics

sent 121 people to their deaths. Another company that had high reputation for safety that

probably does not is Asiana Airlines. This airline has had three fatal wrecks including the San

Francisco incident where the aircraft ran off the end of the runway. The crew in this case allowed

the aircraft to approach too slowly and crashed. The aircraft was engulfed in flames and three

people died. A flight crew with a good amount of experience can be the difference between a

successful flight and crashing.