Aircraft Incidents and Accidents

Monday, September 11, 2000 1:13 PM ADT
ANCHORAGE, ALASKA 99502
ANCHORAGE INTERNATIONAL AIRPORT

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NTSB Probable Cause Narrative

The failure of the TRACON air traffic controller to issue a wake turbulence advisory to the pilot, and a wake turbulence encounter by the pilot. Factors in the accident were the pilot's inadequate visual lookout, the failure of the TRACON controller to notice an aircraft as a heavy jet, and insufficiently defined TRACON procedures used to facilitate prearranged coordination of aircraft through radar segments.

NTSB Narrative Summary Released at Completion of Accident

An airline transport pilot was returning from a charter flight in a twin-engine airplane and was in radio and radar contact with an FAA TRACON approach controller in Class C airspace. The pilot was given air traffic advisories for airplanes departing a satellite airport, but was not given an advisory about a McDonnell Douglas MD-11 airplane that was on final approach to land at the Ted Stevens Anchorage International Airport. The pilot said he did not specifically recall seeing the MD-11. The accident airplane encountered wake turbulence from the MD-11 that produced a violent vertical wind shear. The pilot then noticed the MD-11 airplane. After landing at a satellite airport, he notified the FAA of the wake turbulence event. Radar data revealed the MD-11 was on the glide path for landing at Anchorage, and the pilot of the MD-11 was in radio contact with the tower. The accident airplane crossed the flight path of the MD-11 at a 90 degree angle, about 900 feet msl, and about 55 seconds after the MD-11. When the accident airplane encountered the wake turbulence, it was 300 feet below the flight path of the MD-11 and separated by 2.47 miles. A postflight inspection of the airplane revealed substantial damage to the right wing. The Anchorage International Airport is within Class C airspace, which has a high volume mix of air carrier, general aviation, and military aircraft. Class D, Class E, and Class G airspace surround, and underlie the Class C area. In addition, the airspace is subject to Federal Aviation Regulation Part 93 (FAR 93). FAR 93 outlines geographic segments and special rules for operating at airports within the area. An air traffic controller is required to separate small aircraft operating behind heavy aircraft by 5 miles, and issue traffic advisories, and safety alerts including wake turbulence cautionary advisories. The TRACON utilizes certain prearranged coordination procedures to improve the traffic flow of aircraft through TRACON radar segments. Controllers are required to view a full data block on their radar screen when using prearranged coordination. The air traffic controller did not have a full data block displayed. The TRACON procedures manual does not contain a procedure for challenging, and verifying, the use or non-use of prearranged coordination between controllers. The air traffic controller did not notice that an aircraft designation symbol displayed on his screen indicated a heavy aircraft, and he did not issue a wake turbulence advisory. A heavy aircraft designator ('H' if assigned) is displayed on all radar data blocks (full or partial).

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Event Information
Type of Event	Accident
Event Date	9/11/2000
Event Day of the Week	Monday
Time of Event	1313
Event Time Zone	Atlantic Daylight Time
Event City	ANCHORAGE
Event State	ALASKA
Event Country	--
Zipcode of the event site	99502
Event Date Year	2000
Event Date Month	9
MidAir Collision Indicator	No
On Ground Collision occurred ?	No
Event Location Latitude	--
Event Location Longitude	--
Event Location Airport	ANCHORAGE INTERNATIONAL
Event Location Nearest Airport ID	PANC
Indicates whether the acc/inc occurred off or on an airport	Off Airport/Airstrip
Distance from airport in statute miles	4
Degrees magnetic from airport	320
Airport Elevation	144
Weather Briefing Completeness	Unknown
Investigator's weather source	Weather Observation Facility
Time of the weather observation	1300 Atlantic Daylight Time
Direction of event from weather observation facility (degrees)	140
Weather Observation Facility ID	PAN
Elevation of weather observation facility	144
Distance of event from weather observation facility (units?)	4
Time Zone of the weather observation	ADT
Lighting Conditions	Day
Lowest Ceiling Height	9000
Lowest Non-Ceiling Height	3100
Sky/Lowest/Cloud Conditions	Scattered
Sky Condition for Lowest Ceiling	Overcast
Visibility Runway Visual Range (Feet)	0
Visibility Runway Visual Value (Statute Miles)	0
Visibility (Statute Miles)	10
Air Temperature at event time (in degrees celsius)	11
Dew Point at event time (in degress fahrenheit)	6
Wind Direction (degrees magnetic)	140
Variable Wind Indicator	Unknown
Wind Speed (knots)	10
Wind Velocity Indicator	Unknown
Wind Gust Indicator	Not Gusting
Wind Gust (knots)	0
Altimeter Setting at event time (in. Hg)	29
Density Altitude (feet)	--
Intensity of Precipitation	Unknown
METAR weather report	--
Event Highest Injury	None
On Ground, Fatal Injuries	0
On Ground, Minor Injuries	0
On Ground, Serious Injuries	0
Injury Total Fatal	--
Injury Total Minor	--
Injury Total None	1
Injury Total Serious	--
Injury Total All	--
Investigating Agency	NTSB
NTSB Docket Number (internal use)	1073
NTSB Notification Source	FAA REGIONAL OPERATIONS CENTER
NTSB Notification Date	Sep 11 2000 12:00AM
NTSB Notification Time	1720
Fiche Number and/or location -used to find docket information	IMAGE
Date of most recent change to record	Jul 10 2001 3:51PM
User who most recently changed record	MONR
Basic weather conditions	Visual Meteorological Cond
FAA District Office	--

Aircraft Involved
	Aircraft #1
Aircraft Registration Number	N27179
NTSB Number	ANC00LA120
Missing Aircraft Indicator	N
Federal Aviation Reg. Part	Part 91: General Aviation
Type of Flight Plan filed	Company VFR
Flight plan Was Activated?	--
Damage	Substantial
Aircraft Fire	None
Aircraft Explosion	None
Aircraft Manufacturer's Full Name	Piper
Aircraft Model	PA-31-350
Aircraft Series Identifier	PA-31-350
Aircraft Serial Number	31-7752091
Certified Max Gross Weight	7250
Aircraft Category	Airplane
Aircraft Registration Class	U.S. Registered/U.S. Soil
Aircraft is a homebuilt?	No
Flight Crew Seats	--
Cabin Crew Seats	--
Passenger Seats	--
Total number of seats on the aircraft	8
Number of Engines	2
Fixed gear or retractable gear	Retractable
Aircraft, Type of Last Inspection	100 Hour
Date of Last Inspection	Jun 20 2000 12:00AM
Airframe hours since last inspection	39
Airframe Hours	4718
ELT Installed	Yes
ELT Activated	No
ELT Aided Location of Event Site	Unknown
ELT Type	--
Aircraft Owner Name	A.C.E. FLYERS INC.
Aircraft Owner Street Address	1842 MERRILL FIELD DR.
Aircraft Owner City	ANCHORAGE
Aircraft Owner State	AK
Aircraft Owner Country
Aircraft Owner Zipcode	99501
Operator is an individual?	--
Operator Name
Operator Same as Owner?	Yes
Operator Is Doing Business As	--
Operator Address Same as Owner?	Yes
Operator Street Address
Operator City
Operator State
Operator Country
Operator Zip code
Operator Code	JKWC
Owner has at least one certificate	Yes - certificate holder
Other Operator of large aircraft?	No
Certified for Part 133 or 137 Operation	Unknown
Operator Certificate Number	--
Indicates whether an air carrier operation was scheduled or not	--
Indicates Domestic or International Flight	--
Operator carrying Pax/Cargo/Mail	--
Type of Flying (Per_Bus / Primary)	Positioning
Second Pilot on Board	No
Departure Point Same as Event	No
Departure Airport Code
Departure City	SLEETMUTE
Departure State	AK
Departure Country
Departure Time	1100
Departure Time Zone	ADT
Destination Same as Local Flt	--
Destination Airport Code	PAMR
Destination City	ANCHORAGE
Destination State	AK
Destination Country
Specific Phase of Flight	--
Report sent to ICAO?	--
Evacuation occurred	--
Date of most recent change to record	Jun 3 2001 4:08AM
User who most recently changed record	dbo
Since inspection or accident	--
Event Location Runway Number and Location	0
Runway Length	--
Runway Width	--
Sight Seeing flight	No
Air Medical Flight	No
Medical Flight	--