Issue Number 231
September 1998
A Monthly Safety Bulletin from The Office of the NASA Aviation Safety Reporting System
P.O. Box 189, Moffett Field, CA 94035-0189

"Intersection Interactions"Some recent ASRS reports show that runway transgressions are often the result of confusion about taxi instructions at runway/taxiway intersections. In a report from a corporate aircraft First Officer, time pressure helped to fuel the misunderstanding:

The instruction to "cross the runway at Taxiway X" should have been a heads-up to the crew not to taxi onto the runway. In a callback conversation with an ASRS analyst, the reporter stated that in the future, the flight crew will verify any clearance to taxi onto a runway.

Absence of definitive ATC instructions lured another corporate flight crew into a runway transgression. The First Officer reports:

In the landing clearance, the absence of a "hold short" instruction was not permission for the flight crew to enter Runway 20 and stop there. In this case, there were intersecting taxiways shortly before and beyond the intersection with Runway 20 which could have provided appropriate turn-offs. The Aeronautical Information Manual (AIM) states that pilots should exit the runway at the first available taxiway or as instructed by ATC. The AIM Section 4-3-20 offers additional information on exiting the runway after landing.

Caution! Consruction ZoneA report from a Local (Tower) Controller points out the increased runway/taxiway confusion that can result during airport construction activities. In a subsequent conversation with the controller, the pilot indicated that he was unaware that there was a parallel taxiway available, and so turned onto the active runway. When airport construction or any other unusual activity renders runway and taxiway operations non-standard, both pilots and controllers need to use extra caution to ensure that taxi instructions are clearly understood and followed. Pilots can give themselves an edge by having airport diagrams close at hand to confirm taxi routes.
ELT Interference Portable Emergency Locator Transmitter

A situation commonly associated with GA pilots--an ELT false alarm--became a serious distraction to a commuter flight crew. The First Officer reports:

Pilots' quick responses to an ELT signal can save ATC and the Civil Air Patrol from scrambling to a false alarm, as well as save other pilots the frustration of trying to communicate over the sound of a transmitting ELT. The reporter does not indicate what, if any, repercussions resulted from this noisy flight.

"Helping Out" ATC

Air Traffic Controllers are constantly choreographing the ever-changing aerial and ground flow of traffic. They rely on pilots to provide accurate information and follow ATC clearances to keep the traffic movement progressing smoothly and safely. In our first report, the ground flow nearly came to a grinding halt when a training aircraft "stepped on the toes" of an air carrier jet. A Ground Controller reports:

In another report, marginal weather and rising terrain in the direction of flight should have encouraged the pilot to follow the vectors provided by the reporter, a Departure controller frustrated in his efforts to keep the pilot on course.

Helping Other Crew Members

ATC's choreography can also be disrupted due to flight crew distraction and subsequent loss of intra-cockpit coordination. A Captain's report provides an example.

The First Officer pinpoints the causes of the confusion:

Although the company communications might have been necessary, the timing of the conversation with the jump seat passenger was inopportune, interfering with the intra-cockpit communication that might have prevented the altitude deviation.

Another Captain likewise attributes an altitude deviation to workload and non-ATC communications.

Company communications are important but may need to be re-prioritized so that both crew members are available to confirm ATC clearances.

ASRS Recently Issued Alerts On...
Uncommanded disengagement of an EMB-145 autopilot
SAAB 340 brake failure attributed to a broken hydraulic line
DC-10 engine flameout attributed to the wake of a preceding jet
Reporters' advocacy of TCAS II equipment in cargo aircraft
SID-created traffic conflicts between two adjacent airports
July 1998 Report Intake
 Air Carrier Pilots 2,145
 General Aviation Pilots 832
 Controllers 79
 Cabin/Mechanics/Military/Other 161
 TOTAL 3,217