Say The Magic Words
No, not the ones your parents
taught you"please" and "thank you." Rather, the ones
your flight instructor taught you"Cleared for...." These magic
words apply to instructions for taxi, takeoff, landing, and entry into
Class B airspace. Two reporters share their experiences of not verifying
receipt of the magic words:
- About 7
miles West of [the Class B airport], I called [Approach Control], and
stated our position and intentions. Controller responded with a squawk
number and ident, which was complied with. Approximately one minute
later [now inside the Class B boundary], the Controller came back with,
"I guess a clearance means nothing, but you are cleared into the
[Class B airspace]." I felt that once contact was made, the Controller
knew our intentions and a squawk and ident were given, that a clearance
Imminent does not mean "Cleared."
Contact with ATC and receipt of a squawk code constitutes permission to
enter Class C airspace, but Class B airspace requires the magic words.
Even when the pilots are clear on the rules, distractions can set the
stage for not receiving the magic words.
- Landed without
receiving landing clearance from Tower. The weather and traffic were
heavy.... Just prior to marker...we had a lightning strike which caused
a momentary loss of navigation instruments. I believe this event caused
the First Officer not to switch over to the Tower, and I forgot to verify
that we had received a landing clearance. I landed and rolled out normally,
and realized we were on Approach Control frequency. When...distracted
or startled, even experienced pilots can make fundamental mistakes.
Will the Last
One Out Please Turn Out the Lights?
- Normal single
engine taxi, [and] at the gate, ran normal engine shutdown checklist.
When external power came on line, APU was shut down and normal transfer
of power was observed on panel.... Cockpit cleanup was accomplished
and we departed to the next gate for [our next] flight.... Approximately
10-15 minutes later, we were notified of the left engine running on
[our previous] aircraft, and maintenance had shut down the engine.
Chances are the flight crew
substituted the APU shutdown for shutdown of the last engine. Apparently,
their thoughts were already on their next flight instead of clear communication
and proper coordination of cockpit duties.
According to the Pilot/Controller
Glossary of the Airman's Information Manual (AIM), "Roger" means,
"I have received all of your last transmission." It should not
be used by either pilots or controllers to answer a question that requires
a "yes" or "no" response. In this incident reported
to ASRS, the pilot of a small aircraft questioned a controller's use of
- We were
cleared by Tower to depart and climb northeastbound. [We noticed] an
aircraft approximately 50 feet below us...paralleling our course, and
climbing. I told the Tower we had traffic off our wing. The Tower acknowledged
by saying, "Roger." The aircraft began turning northbound
towards us, at which point we took evasive action to avoid [a mid-air
collision]. The aircraft continued climbing and departed northbound.
I questioned the Tower again about the traffic, and again the Tower
only answered, "Roger."
Upon landing, I telephoned the Tower to try to clear up several questions
about the Tower's responsibility. The Controller's response was that
once we had the traffic in sight, it was our responsibility to maintain
visual separation ...[and] that he was not in contact with the airplane
in question. The way the Controller stated "Roger" [on our
initial call] gave me the impression that the Tower was aware of the
traffic and it was under his control.
It appears that the pilot of the other aircraft was flying in Class
D airspace without contacting the Tower.
The report doesn't say whether
the Tower was radar-equipped. This does make a difference, since the conflict
was estimated to have occurred two miles from the airport, at 2,300 feet
MSL. If the Tower lacked radar, the controller's "Roger" may
have been appropriate. However, an optional message from ATC--"I'm
not in contact with the traffic"--would have been helpful to the
If the Tower did have radar,
the controller might have announced, "You have traffic at [clock
position]." However, the AIM notes that the issuance of a safety
alert is contingent upon the Controller's capability to have an awareness
of the situation. Controller workload, poor radar return of transponder
signals, and lack of aircraft transponders, can all reduce the Controller's
ability to have this awareness. In this incident, the Controller apparently
had no knowledge of a second aircraft until the call-out from the reporter.
Finally, the AIM and the FARs both state that the job of safely flying
the aircraft remains with the pilot. As the Controller observed, it was
the pilot's responsibility to practice the see-and-avoid concept and to
Editor's note: In April
1995, ASRS presented several research papers at The Ohio State University's
Eighth International Aviation Psychology Symposium. Brief summaries of
four papers are presented below.
1. Airport Ramp Safety
and Crew Performance Issues
This study examined 182 Part
121 and Part 135 ramp operations incident reports from the Aviation Safety
Reporting System (ASRS) database, to determine the areas of operations
in which damage is most likely to occur, the types of damage that occur,
and the role of flight and ground crew performance errors in ramp incidents.
It was found that ramp damage incidents occurred more often during aircraft
arrivals than during departures. The damage incidents occurred most frequently
at the gate stop area (within 20 feet of the nose wheel parking line);
next most frequently at the gate entry/exit areas, where taxi lines lead
into and out of the gate area; and least frequently on the ramp fringe
Damage most frequently occurred to ground equipment (in 64% of the incidents).
In more than one third of the damage incidents, there was only one ground
crew member available to attend the aircraft. Pilot reporters attributed
error to ground crew personnel in more than half the incidents, but also
faulted themselves almost as frequently. The authors offer suggestions
relevant to both airline management and flight crews for preventing ramp
2. Flight Crew Performance
During Aircraft Malfunctions
Past research has shown that
a large number of aircraft accidents attributed to human error began with
an aircraft malfunction. Several of these accidents were caused by the
flight crew's fixation on the malfunction, which resulted in their loss
of overall situational awareness. The objectives of this study were to
develop a better understanding of the factors that can affect performance
when flight crews are faced with inflight malfunctions, and to offer recommendations
designed to improve crew performance during these conditions.
The study examined 230 reports in NASA's Aviation Safety Reporting System
(ASRS) database. Each report was placed into one of two categories, based
on the severity of the malfunction. Report analysis was conducted to extract
information regarding crew procedural issues, communications, workload
management, situational awareness, and safety problems. A comparison of
these factors across malfunction types was then performed. This comparison
revealed significant differences in the ways that crews dealt with serious
malfunctions compared to less serious malfunctions. These differences
may be due to crew perception of the malfunction severity, as well as
training. The authors offer recommendations for improving crew performance
when faced with inflight aircraft malfunctions.
3. The Use of ASRS
Incident Reports in AQP (Advanced Qualification Program) Training
The FAA's Advanced Qualification
Program (AQP) is a recent approach to flight crew training that can be
customized to an air carrier's unique operational needs. The goal of AQP
is to introduce real-world conditions into training situations that require
trainees to apply a range of technical and flight management skills. AQP
emphasizes the use of scenario-based training in Line Oriented Flight
Training (LOFTS), ground school, Flight Training Devices (FTDs), and simulators,
to ensure that trainees learn to apply the information they are expected
However, scenario development requires creativity and high-fidelity attention
to detail on the part of curriculum designers. The Aviation Safety Reporting
System (ASRS) database is a repository of a wide variety of incident reports
that can be used as a basis for AQP training scenarios. ASRS incident
reports cover such areas as breakdown of CRM, maneuvers specific to a
particular aircraft, and crew response to deviations and malfunctions.
The ASRS database is now available on CD-ROM. This paper suggests search
strategies likely to produce reports that can be used in LOFTs or other
4. Measuring Safety
with Flight Data
For more than two decades,
airlines outside of the U.S. have routinely measured safety by screening
flight data for deviations from prescribed procedures. In 1993, the FAA
and NASA began a joint five-year program, known as the Automated Performance
Measurement System (APMS), to develop a set of highly automated tools
that will enable the large-scale analysis of flight data by U.S. airlines.
The goal of the APMS program is to develop a prototype system that uses
powerful data retrieval, analysis, and presentation tools to address industry's
and government's questions relating to operational performance and safety.
In addition to measuring specific safety parameters, the APMS research
program will develop techniques for determining why an unsafe event occurs.
APMS does not, however, involve the actual implementation of a nationwide
flight data collection system.
This paper provides a brief overview of the APMS approach to developing
a prototype flight data analysis system. This approach consists of a user-needs
study, creation of a common graphical user interface, development of powerful
data visualization features, and a library of statistical procedures that
support cluster analysis and pattern recognition.
Readers may obtain free copies of papers of interest by requesting
specific titles from the following address: Aviation Safety Reporting
System, c/o Administrative Staff, P. O. Box 189, NASA Ames Research Center,
Moffett Field, CA, 94035-0189.
ASRS Recently Issued Alerts
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in an RCO below FL170
- Failure of a backup battery
system at San Juan CERAP
- Uncommanded yawing during
a Fokker F-28 ferry flight
- A BA-31 emergency attributed
to a chafed hydraulic line
July 1995 Report Intake
- Air Carrier Pilots--2028
- General Aviation Pilots--817