|Safety features||- Safety|
The twin tail configuration InView displays many safety critical features.
Above: all InView pre-flight operations and test flights are recorded on video for the records and any subsequent analyses. Pre-flight check lists and flight logs are also kept for each flight.
A plan for pilotless aircraft to begin operating routinely from ordinary airports in the US is being greeted with alarm by aviation safety campaigners. They say such operations would put at risk the safety of other planes, passengers on the ground and people living near the airports.
The plan, which also involves giving unmanned aerial vehicles (UAVs) easier access to US civil airspace, is the result of a powerful partnership led by the Pentagon, NASA, Lockheed-Martin, Northrop Grumman and Boeing. Called Access 5, the group aims to loosen restrictions on where UAVs can operate within 5 years.
For most of their flight, UAVs are controlled by a pilot on the ground via a satellite radio link. At present, anyone wanting to fly one in civilian airspace has to file a detailed flight plan with the Federal Aviation Administration (FAA) at least 30 days in advance.
Access 5 wants UAVs to be allowed to fly on the day the plan is filed, like any other aircraft. The group hopes that this rapid approval for UAV flights will allow the craft to fly more flexible missions. But critics fear it may eventually pave the way for pilotless cargo flights.
" Totally opposed"
The prospect of UAVs sharing runways with passenger planes is raising serious concerns. " What happens if a pilotless plane hits an airport terminal or another plane?" asks Gail Dunham of the National Air Disaster Alliance, an airline safety pressure group based in Washington DC. " We are totally opposed to this plan."
Warren Morningstar at the Aircraft Owners and Pilots Association in Frederick, Maryland, says avoiding collisions with other aircraft is the major concern. " How do you accomplish that when you don't have a pilot on board?" he asks.
UAVs have been used for military scouting and attack missions in Iraq, Afghanistan, Kosovo and elsewhere. But they will also become important to civilian scientists performing environmental monitoring, volcanic observation and atmospheric sampling because they can stay aloft far longer than piloted planes.
A group led by Glenn Hamilton of NASA's Dryden Flight Research Center in Edwards, California, has modified a military Predator UAV for such applications. Called the Altair, the craft made its maiden flight earlier in June.
But before such a UAV is allowed to fly in civilian airspace, its operator has to prove to the FAA that it has an equivalent level of safety to a piloted aircraft. This is a lengthy process that currently takes between 30 and 60 days.
The operator files a detailed flight plan with the FAA, listing every detail of the craft's journey: where it will be flying, how it is controlled and, perhaps most importantly, what will happen if the radio link with the pilot on the ground is lost. Only then will the FAA allow it to take off. These restrictions mean that UAVs only fly in controlled US airspace about 10 times a year.
Advocates of UAVs say these controls are far stricter than they need to be. The Pentagon admits that the Global Hawk UAV has a crash rate more than 50 times that of F-16 piloted fighter jets, and has set a target to reduce this by 2009 (see graph). Even then, the 25 crashes per 100,000 flying hours that the Pentagon is aiming for will still exceed that of piloted planes.
But the UAV's proponents claim these figures can be misleading. For example, when a military UAV fails to return from a mission it can be impossible to tell whether it was shot down, or crashed because of a systems or communications failure.
One crucial question for safety campaigners is what will happen if the link between the ground pilot and the UAV is interrupted while the craft is taking off or landing.
Hamilton describes the chances of this happening as " minuscule" , because for these operations there are two direct line-of-sight radio links, rather than just a satellite link.
But airline safety analyst Todd Curtis of Airsafe.com insists that plans must always be in place to deal with the loss of the control link, however unlikely that is.
Denis Chagnon of the International Civil Aviation Organization in Montreal believes global civil UAV operations are, ultimately, unstoppable. " Pilotless aircraft are coming," he says. " We just have to be ready for them."
An interesting suggestion that small UA should be treated as birds was made by Olle Hagner in his presentation on " Inherently safe UAS by design ..." at the UAV 2007 Conference in Paris. The bird statistics are for Sweden.
However, as pointed out by Cliff Whittaker of the U.K. CAA in his presentation of " UK-CAA policy for light UAS systems" at the UAV 2007 Conference in Paris by D Haddon and C Whittaker, the larger birds can inflict some severe damage on aircraft (with the aircraft inflicting even more damage to the bird). Below, a copy from the same presentation.