Issue Number 237
March 1999
A Monthly Safety Bulletin from The Office of the NASA Aviation Safety Reporting System
P.O. Box 189, Moffett Field, CA 94035-0189

Incidents Involving Flight Toward TerrainAnalysis of a recent controlled flight into terrain (CFIT) accident revealed that the flight crew errors could be grouped into those that involved a failure of group interaction skills, and those that involved individual errors in thinking, planning, recognizing, preparing, or remembering (FSF Flight Safety Digest, May-June 1998). An air carrier Check Airman's report to ASRS provides examples of both error types -- even though the aircraft involved was equipped with the latest terrain-avoidance technology:

Enhanced GPWS is a second-generation terrain avoidance system that is much prized by pilots. But it's no substitute for proper training, clear communications among crew, and a primary focus on flying the airplane.

Rules One Through Ten

The flight crew of a Turbo Commander rediscovered a basic flying rule while trying to troubleshoot a problem on an IFR approach over mountainous terrain. The First Officer (the flying pilot) reports:

Flight crew distraction is a factor in many accidents. Our reporter's analysis is accurate. In addition, pilots must be trained to recognize when they are rushed, distracted, and susceptible to error.

Spin CityA pilot practicing aerobatics over a private pasture learned why air show performers don't attempt some maneuvers:

We're also glad that our reporter survived his ordeal and was willing to share this experience with others.

Expectant Pilots

The Pilot/Controller Glossary defines an "Expect" altitude as one to be used in the event of radio communications failure, and as information to assist a pilot in planning. But some pilots take the information past the planning stage, as a General Aviation reporter did:

This report highlights the importance of pilot readbacks in maintaining good pilot/controller communication. It also points out how easily an "expect" instruction can be interpreted as an actual instruction in the mind of an expectant listener.

Another reporter, an air carrier Captain, provided the necessary readback, but did not wait for acknowledgment from the busy controller.

A pilot's best defense against this sort of altitude deviation is to verify instructions before taking any action. In this case, there was no obvious rush to start the enroute climb.

PEDs: A Continuing SagaThe new rules governing Passenger Electronic Devices (PEDs) seem to have lessened the frequency of PED-related reports to ASRS. But we still occasionally hear about PEDs, including this unusual incident experienced by an air carrier Captain:

The Captain adds that an extensive check of the autoflight system was performed later to confirm that there was no mechanical anomaly.


In another incident, a First Officer reports that the suspected source of interference with his jet's navigation system involved a passenger's "guessing game."

ASRS Recently Issued Alerts On...
Runway visibility obstruction at a Minnesota airport
MU-2 cockpit smoke attributed to failed cockpit heat valve
Inadequate taxiway signage/markings at a Wisconsin airport
Three incidents of electrical smoke and fumes in BE-1900Ds
Confusing charting of a holding pattern for a Canadian airport
January 1999 Report Intake
 Air Carrier/Air Taxi Pilots
 General Aviation Pilots