NAT Error Summary, 2016

Approximately 460,000 flights cross the North Atlantic each year. The NAT Central Monitoring Agency is located adjacent to the Shanwick Oceanic Area Control Centre, in Prestwick, Scotland. Operational performance monitoring is one of the principle tasks of the NAT CMA. The primary source of operational safety reports are the air traffic control units responsible for the Oceanic Control Areas in the region, augmented by operator reports as available. The reports are reviewed by the CMA and a de-identified summary is available at year’s end. 

The numbers are in for 2016. Where indicated below, I have compared 2015 to 2016. Here are some of the "Threat Vectors" I pulled from the latest report.

WHAT IS REPORTABLE?

  • Gross Navigation Errors (>25NM from cleared route)
  • Lateral Deviations of Less than 25NM
  • ATC Interventions to Prevent Lateral Deviations
  • Large Height Deviations (+/-300ft from assigned Flight Level)
  • Erosion of Lateral or Longitudinal Separation
  • Time Errors (>2 mins or more between ETA and actual time)
  • Speed Errors – any change Mach/speed that results in a Time Error
  • Air Traffic Control inter-agency coordination errors
  • Communications failures
  • Non–approved (MNPS and/or RVSM) aircraft flying at RVSM levels
  • Diversions & Turnbacks
  • Adoption of a published contingency procedure

 

WHAT WAS REPORTED ?

                                                             2015                            2016

Total number off their clearance              375                              445

Large Height Deviations                          119                              105

ATC Interventions                                     97                              132

Lateral Deviations <25nm                         86                                55

Lateral Deviations >25nm                         12                                22

Climb/Descend w/o clearance, Loss of RLatSM and OCA to OCA coordination errors figure prominently

WHERE WERE THESE REPORTS LOCATED ?

                                                              2015                            2016

OTS                                                           73                              136

Random Routing                                      284                              307

Shanwick OCA,                                       205                              265

Gander OCA                                             77                                71

Reykjavik OCA                                          50                                47

New York OCA                                          21                                23

Santa Maria OCA                                      17                                28

Bodo OCA                                                   0                                  1

RESNO,SIVIR,PIKIL,GOMUP and DOGAL are intersections frequently mentioned in deviation reports

WHO WERE POSITIVELY RESPONSIBLE ?

Aircrew                                                     89                                38

ATC                                                          29                              230

Unknown/Undetermined                           47                              174

 Loss of RLatSM is tied to FANS failures and the high rate of Unknowns

WHAT WERE THE CAUSES?

Followed flightplan instead of clearance   70                              62

No comply w/ Conditional Clearance        30                               56

Weather Deviations                                  15                               12

ATC blunder errors                                   15                               27

ATC coordination errors                           14                               25

Medical diversion                                      1                                  2

Loss of FANS/LOGON Failed                   ?                                60

Weather, Turbulence, Icing and low-fuel temp were majority of divert reasons in 2016

WHEN DID THE ERRORS/DEVIATIONS OCCUR?

           25-35 Per month until summer

           50-60 Per month in June and July, 2X "Average"

           25-35 Per month until end of the year

           Same relative frequency for 2016

BOTTOMLINE...

         1. If you are operating in the NAT...

         2. In the Southeast corner of Shanwick OCA...

         3. Flying an airliner or BizJet...

         4. On a Random route...

         5. Heading East or West...

         5. Received your oceanic clearance via AFIS/ACARS

         6. In the months of June or July...

         7. And your SOP compliance is weak...

         8. You just know you are on the assigned FL

         9. And you just know you are a above average pilot

       10. Expect to have some explaining to do when you get home...or worse.