Black boxes are important elements of aircraft safety, used to record vital operational data which is useful in understanding crashes.
Whether or not aircraft need a black box depends on their size, not their ownership. If an aircraft can hold more than 20 passengers or more than six and requires two pilots, then it must have a black box. If the aircraft is smaller than this, it does not.
On most aircraft, black boxes are mandatory in order to provide information in the event of a crash. However, some smaller or less powerful aircraft are exempt.
What is a black box?
In essence, a black box is a heavily protected recording device which records operational data.
The black box is made up of the flight data recorder and the cockpit voice recorder, and having one is compulsory on all commercial flights and corporate jets.
The cockpit voice recorder can hold up to two hours of audio data, after which it starts recording over old material. The flight data recorder can hold up to 25 hours of data.
The flight data recorder tracks an astonishing variety of data – those on large aircraft record data to measure up to 146,000 parameters, from altitude to cabin pressure.
The data recorded by black boxes are used to answer questions about how and why aircraft accidents happen, such as the condition of the aircraft and the events on board.
Black boxes are usually kept in the tail of the aircraft where they stand a good chance of surviving a crash.
Black boxes are virtually indestructible, undergoing extensive tests such as durability underwater and impact tests, to ensure they would survive the stresses of a crash.
Are black boxes compulsory on all aircraft?
Initially, some governments expressed concern about making black boxes compulsory, arguing that they interfered with the privacy of the pilots.
However, after a fatal crash in 1960 Australia became the first to make flight data recording compulsory and the United States followed suit a few years later.
The United States has required any aircraft with more than 20 passenger seats, any turbine-powered craft with six or more passenger seats, and any aircraft requiring 2 pilots.
Small aircraft are not required to have black boxes, which is controversial as it means vital information about what causes small aircraft crashes remains unknown.
Some question the need for black boxes, arguing that our advanced technology, which allows us to track spacecraft, should also allow aircraft to stream the necessary data in real-time.
It can take months to find and then decode a black box after a crash and in some cases, it is never found, as with flight MH370.
Streaming the necessary data live would eliminate the delays hunting for the black box causes in investigations into accidents.
Because of this controversy, airline regulation authorities and even some governments want to eliminate the black box entirely, replacing it with a better system.
For now, however, the black box remains a mandatory presence on all large aircraft.
Do private aircraft need black boxes?
Business and corporate jets that can hold more than ten passengers are still required to have black boxes.
The same rule applies to any aircraft capable of holding more than six passengers and which requires two pilots must have a black box too, whether or not it is a private aircraft.
Private aircraft owners are often reluctant to install a black box because there are some concerns over who owns the data recorded, and what it can be used for.
For example, there are concerns that insurance companies could use the data to deny a claim, or that a private conversation might be recorded.
However, the data requires special software to read, making it an unpopular target for data theft or hacking.
Black boxes are also expensive, costing between $10,000 and $30,000, adding to the list of reasons to invest.
This investment is also unpopular because new data streaming technology is in development, and could make the black box obsolete in a few years.
Do private jets have black boxes?
Whether or not an aircraft is required to have a black box depends on its size rather than its ownership.
If an aircraft has more than 20 passenger holding seats, or more than six seats and requires two pilots, then it is required to have a black box.
Helicopters are not required to have black boxes, and aircraft small enough not to meet those parameters do not need to have one either.