As a result of its
first investigation of an accident involving an unmanned aircraft
(UA), the National Transportation Safety Board has issued a total
of 22 safety recommendations to address what NTSB Chairman Mark V.
Rosenker said were "a wide range of safety issues involving the
civilian use of unmanned aircraft."
The safety recommendations approved by the Board stemmed from
the April 25, 2006, accident in which a turboprop- powered Predator
B operated on a surveillance mission by the United States Customs
and Border Protection (CPB) crashed in a sparsely populated
residential area near Nogales, Arizona.
No one on the ground was injured; the remotely piloted 66- foot
wingspan aircraft was substantially damaged.
The Safety Board determined that the probable cause of the
accident was the pilot's failure to use checklist procedures when
switching operational control from a console that had become
inoperable due to a "lockup" condition, which resulted in the fuel
valve inadvertently being shut off and the subsequent total loss of
engine power, and a lack of a flight instructor in the Ground
At the Board meeting, the NTSB highlighted several areas of
particular interest including: the design and certification of the
unmanned aircraft system; pilot qualification and training; the
integration of UAs into the air traffic management system; and
audio records of all UA operations- related communications.
"This investigation has raised questions about the different
standards for manned and unmanned aircraft and the safety
implications of this discrepancy," said Rosenker. "Why, for
example, were numerous unresolved lock-ups of the pilot's control
console even possible while such conditions would never be
tolerated in the cockpit of a manned aircraft?"
Expressing concerns about how manned and unmanned aircraft will
share the same airspace, Chairman Rosenker said, "The fact that we
approved 22 safety recommendations based on our investigation of a
single accident is an indication of the scope of the safety issues
these unmanned aircraft are bringing into the National Airspace
The Safety Board's investigation also revealed that the pilot
was not proficient in the performance of emergency procedures,
which led to the accident. "The pilot is still the pilot, whether
he is at a remote console or on the flight deck," said Rosenker.
"We need to make sure that the system by which pilots are trained
and readied for flight is rigorous and thorough. With the potential
for thousands of these unmanned aircraft in use years from now, the
standards for pilot training need to be set high to ensure that
those on the ground and other users of the airspace are not put in
On the issue of UA operations-related communications, the Safety
Board noted that there is no equivalent of a cockpit voice recorder
at the pilot's control console and that the pilot's communications
with air traffic controllers and others were not recorded. To
enhance the efficacy of future investigations of UA incidents and
accidents, the NTSB recommended that the Federal Aviation
Administration (FAA) require all conversations, including telephone
conversations between unmanned aircraft pilots and air traffic
control, other UA pilots, and other assets that provide operational
support to unmanned system aircraft system operations, be recorded
Among the additional safety recommendations sent to the FAA
Require that established
procedures for handling piloted aircraft emergencies be applied to
unmanned aircraft systems.
- Require that all unmanned aircraft operators report to the FAA
all incidents and malfunctions that affect safety; require that
operators are analyzing these data in an effort to improve safety;
and evaluate these data to determine whether programs and
procedures remain effective in mitigating safety risks.
Among the 17 safety recommendations sent to U. S. Customs and
Border Protection, the operator of the unmanned aircraft involved
in the accident, are:
- Require that pilots be trained concerning the expected
performance and flight path of an unmanned aircraft anytime
communication with the aircraft is lost.
- Conduct face-to-face meetings between pilots of unmanned
aircraft and working-level air traffic controllers to clearly
define responsibilities and actions require for standard and
nonstandard UA operations.
- Identify and correct the causes of the lockups in the pilot's
- Revise the U. S. Customs and Border Protection's pilot training
program to ensure pilot proficiency in executing emergency
- Require that a backup pilot or another person who can provide
an equivalent level of safety as a backup pilot be readily
available during the operation of a UA system.
- Develop a safety plan, which ensure that hazards to the
National Airspace System and persons on the ground introduced by
the U. S. Customs and Border Protection UA system operation are
identified and that necessary actions are taken to mitigate the
corresponding safety risks to the public over the life of the
After adopting the safety recommendations, the Board voted to
convene a public forum on the safety of UA operations and the
methodologies to use when investigating UA accident and incidents.
The dates and agenda for the 2- to 3-day forum will be announced
once details are finalized.