The AirSafe Journal
Issue 1 - July 4, 1996
Welcome to the first issue of the AirSafe Journal, a publication which I hope will shed some light on the sometimes serious, but often comic world of aviation safety. This journal is intended primarily for airline passengers the world over who are looking for factual information that can help them make informed decisions about their safety when they travel by air.
- Risk vs. Safety - You Be the Judge
- Traveling with a Child Seat - Not Worth the Hassle
- Oxygen Generators and the ValuJet Crash
Whenever someone asks me if a certain airline, aircraft, or airport is safe, I am always unable to give a nice short answer. Safety, or perhaps more precisely whether a particular situation is considered safe, depends on who is asking the question. For example, an individual would usually consider an icy street to be unsafe, but will not do anything about it if only strangers will drive on it. However, that same person may be driven to action if buses filled with school children regularly drove on that street.
An easier concept to define is risk. One can decide that a certain objective measure would define risk so that anyone looking at the same situation could objectively define the risk. For example, let risk be defined as the loss of human life. In a hypothetical aviation situation, imagine that there are three distinct hazards facing the airlines of the world and that some responsible air safety authority were to decide which hazard to address first. Imagine that the risked faced by passengers is the loss of life due to an accident. The relevant experts analyze the three situations and conclude the following:
- the first hazard will kill 30 passengers each year over the next decade, but that no more than five will die in any single accident;
- the second problem will kill about 60 people at a time in five different accidents over the next decade;
- the third problem will cause one fully loaded jumbo jet to crash sometime in the next decade, killing 300 people.
If you had to decide which problem should be addressed first, which problem would you pick? The normal inclination would be to address the third problem 300 people dying at one time, first. Note that the risk - 300 deaths - is the same in all three cases, but the third would be perceived as the greater "safety" issue by most people.
Let's take the hypothetical situation one step further. Imagine that the aviation authorities of country X, the most important economic power in this imaginary world, had to choose from these same three hazards. Because every other airline in the world needs to meet the safety standards of country X to be considered acceptably safe, the decision will affect every airline. Now imagine that the second and third hazards only happen in countries beyond X's boarders and only to non-country X airlines. Which do you think would be chosen the most important safety issue now?Back to Contents for this Issue
At this writing, last April's crash of a ValuJet DC-9 is still being actively investigated by the U.S. National Transportation Safety Board. While the Board has had many public comments about the accident investigation, the Board has not reached any final conclusions as to what factor or factors may have led to the accident. It is not, nor will it ever be, my intention to second guess the NTSB in this Journal or in any other public venue. However, I will make comments about ongoing investigations in the AirSafe Journal where appropriate.
The investigators in the ValuJet accident have confirmed that there were a number of oxygen generators present in the forward cargo area of the DC-9. Several media sources have speculated that these generators may have been involved in the sequence of events that led to the accident. While searching the publicly available files of the NTSB, I have discovered a rather interesting accident summary involving the destruction of a DC-10 due in part to an oxygen generator. The report is available at the NTSB Web site and is reproduced here in full (with changes made for clarity).
Aircraft: McDonnell Douglas DC-10-40, registration: N184AT
Injuries: None of the seven ground crew were injured.
A charter flight arrived and deplaned without incident and with no indication of smoke, fumes or heat. Company maintenance personnel had placed damaged passenger seat backs (incorporating solid-state chemical oxygen generators) in the forward cargo compartment with seat covers and oil. A company mechanic examined the seat backs to find a serviceable unit. He found a loose oxygen canister and handled it improperly by its oxygen hose. Such handling can release the firing pin, fire the percussion cap, trigger a chemical reaction, and generate oxygen. This can generate up to 430 degrees of heat outside the canister. A fire began in the fwd cargo compartment in the vicinity of where an oxygen canister was found (later) with a dented striker plate. The seat covers ignited, fire burned through the cabin floor, and subsequently, it spread throughout the entire cabin. Company maintenance personnel did not know that oxygen generators, carried as company supplies, were hazardous materials. The mechanic was not familiar with the repair or installation of the passenger supplemental oxygen equipment.
Oxygen system: Information insufficient - Company maintenance personnel
Supervision: Improper - Company/operator management
Lack of familiarity with aircraft: Company/operator management
Tie down: Improper - Company/operator management
Oxygen system: Not understood - Company maintenance personnel
Lack of familiarity with aircraft: Company maintenance personnel
In June, 1996, the FAA published a set of recommendations on traveling with small children. In brief, the FAA suggests that children weighing less than 40 pounds use an appropriate and approved child restraint system. I had an opportunity to put those suggestions into use recently, and I have come away with an appreciation of some practical problems with the FAA suggestions.
The car seat is not designed to travel :Car seats are not designed to be frequently moved. It has no convenient handles or rollers to make it easy to travel through a terminal. Also, the car seat may have problems fitting through the x-ray machine at the security checkpoint.
It is an extra hassle: In addition to maneuvering down a narrow aisle with one or more bags and a child, one has to buckle the car seat into the seat. For an adult traveling alone with a child, it may mean buckling the seat in a very tight space while simultaneously keeping the child under control or buckling the seat with the child sitting in the seat. Both options take more than a little bit of talent.
Changing planes: On a round trip consisting of two non-stop flights, most people will have to put the car seat into four different vehicles, a car at the origin and destination and an aircraft coming and going. Add a change of planes each way and the number goes up to six.
Seating restrictions: In addition to the normal restrictions on where children can sit, one is further restricted when one has a car seat. On a single aisle aircraft, the child seat had to be by the window on my flight. If I am traveling alone and the row has to be filled, that means that the child and guardian have to climb over someone for the inevitable trip to the lavatory.
Use of the seat is not guaranteed unless you buy a ticket: An adult traveling with a child less than two years old does not have to buy a ticket. However, if one plans to use an approved child restraint system and the plane is full, then the child has to sit on your lap.
My opinion - not worth the hassle: After my one experience with traveling with my child and a car seat. I'd have to say that the inconvenience of using a child seat on an aircraft will keep most people from doing so more than once, especially adults who have no one to help them with the child and the child seat. Unless the FAA requires the use of child restraint systems, I think that most people would ignore the FAA suggestions and continue to plan on putting children less than two in their laps and buckling children older than two in regular airline seats and not in a child restraint system.
Note: When I first wrote this, my child was a toddler. Sixteen years later, my child is now in college, but my opinion on child seats has not changed. Back to Contents for this Issue
http://airsafe.com/journal/issue1.htm -- Revised: 10 November 2012