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SF34 / PA27, Nassau Bahamas, 2018

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Summary
On 22 September 2018, a Saab 340B taking off in accordance with its clearance at Nassau came close to a midair collision over the main runway after a light aircraft began an almost simultaneous takeoff in the opposite direction of the same runway contrary to its received and correctly acknowledged non-conflicting takeoff clearance for a different runway without the TWR controller noticing. The light aircraft passed over the Saab 340 without either aircraft crew seeing the other aircraft. The Investigation noted that the light aircraft pilot had “forgotten” his clearance and unconsciously substituted an alternative.
Event Details
When September 2018
Actual or Potential
Event Type
Human Factors, Loss of Separation, Runway Incursion
Day/Night Day
Flight Conditions VMC
Flight Details
Aircraft SAAB 340
Operator Western Air
Domicile The Bahamas
Type of Flight Public Transport (Passenger)
Origin Nassau
Intended Destination Freeport/Grand Bahama International
Take off Commenced Yes
Flight Airborne Yes
Flight Phase Take Off
TOF
Flight Details
Aircraft PIPER Aztec
Operator
Domicile
Type of Flight Private
Origin Nassau
Intended Destination Great Harbour Cay Airport
Take off Commenced Yes
Flight Airborne Yes
Flight Phase Take Off
TOF
Location - Airport
Airport Nassau
General
Tag(s) Aircraft-aircraft near miss,
Inadequate ATC Procedures,
Ineffective Regulatory Oversight
HF
Tag(s) Distraction
LOS
Tag(s) Accepted ATC Clearance not followed,
Required Separation not maintained,
Near Miss,
VFR Aircraft Involved
RI
Tag(s) Accepted ATC Clearance not followed,
Incursion pre Take off,
Near Miss,
Wrong Active Runway
Outcome
Damage or injury No
Causal Factor Group(s)
Group(s) Aircraft Operation,
Air Traffic Management
Safety Recommendation(s)
Group(s) Aircraft Operation,
Air Traffic Management
Investigation Type
Type Independent

Description

On 22 September 2018, a Saab 340B (C6-KID) being operated by Western Air as WST 701 on a scheduled domestic passenger flight from Nassau to Freeport came very close to a mid air collision with a privately operated Piper PA27 (C6-JEF) overhead the main runway. The Piper was on a domestic VFR flight from Nassau to Great Harbour Cay. The near mid-air collision occured after the two aircraft begun their takeoffs simultaneously from opposite ends of the same runway in day VMC. Neither aircraft crew sighted the aircraft and the PA27 passed over the Saab 340 shortly after the latter had become airborne.

Investigation

An Investigation was carried out by the Bahamas Air Accident Investigation Department (AAID). Relevant recorded ATC communications data and security camera data were available.

It was noted that the Saab 340 PF at the time of the event was the First Officer and that the flight was being made under VFR with 25 passengers and three members of crew on board. The 53 year-old PA27 pilot was a PPL holder and the only occupant of that aircraft. No details of pilot experience were given. It was decided that with light winds prevailing, the Saab 340, which was taxiing from the main passenger terminal, would use the full length of runway 14 for its departure and that the PA27, coming from the south general aviation apron, would depart from runway 27 at its intersection with taxiway ‘K’ (see the illustration below). The PA27 was given its taxi instructions first and eight seconds later the Saab 340 was given its taxi instructions. Both instructions were read back correctly but without the controller noticing, the PA27 taxied instead to the intersection of taxiway ‘L’ with runway 32. When both aircraft were successively cleared for what the controller believed were non conflicting takeoffs, the PA27 began its takeoff on runway 32 heading directly towards the Saab 340.

After a takeoff roll estimated as “at least 10 seconds”, the PA27 became airborne first and came into view on the available security camera footage midway between the ‘B’ and ‘D’ taxiways at an estimated height of 50 feet agl. Approximately 12 seconds after the PA27 first appeared, the Saab 340 was observed to complete rotation just prior to taxiway ‘D’ and then passed beneath the PA27 as the two aircraft were abeam the control tower, by which time the PA27 was no longer visible on the available camera footage.

Neither aircraft was aware of the near miss until advised by the TWR controller after it had occurred. The PA27 pilot subsequently admitted that he “forgot” to follow the acknowledged instructions issued for departure from runway 27. It was noted that another aircraft was lined up at the threshold of runway 14 at the time the near miss occurred. It was noted that that as a result of the investigated event, the ANSP, the Bahamas Air Navigation Service Division (BANSD), had established their own three-member ‘Internal Review Board’ to examine procedures to determine whether an ‘operational deviation’ had taken place and if so, to determine its cause(s) and recommend corrective measures and to review the Industrial Agreement between the Government of the Bahamas and the Bahamas Air Traffic Controllers’ Union as the basis and guidelines for the review. This Review produced 14 Recommendations but “due to the nature and sensitivity of those concerns and recommendations” they were not adopted as formal Safety Recommendations by the Investigation or otherwise included in this Report. It was nevertheless noted that these recommendations have been identified in the Investigation Department’s safety tracking system “for follow up at prescribed intervals to determine whether they are being addressed by BANSD management, as the BAAID finds the findings and recommendations credible and critical to safety and air traffic management” and capable of negatively impacting safety if not addressed.

An annotated version of the Nassau Aerodrome diagram. [Reproduced from the Official Report]

The Investigation determined that the Probable Cause of the near miss was “the poor decision making exercised by the PA 27 pilot in not following directions issued by ATC, despite advising he understood the instructions given”.

Two Contributory Factors were also identified as:

  • the TWR Controller losing visual contact with the PA27 which he had issued instructions to.
  • the failure of the Saab 340 crew to notice that another aircraft was on the same runway at the same time before commencing their takeoff roll.

It was further considered that:

  • the loss of visual contact with the aircraft by the controller may have been as a result of distraction due to the ongoing shift change at the time and the fact that the controller was manning two separate radio frequencies during a time of high traffic volume, while using a system that required additional training and frequent data input to allow all systems to function properly with adequate current information.
  • the failure of the Saab 340 crew to notice the PA27 may have been the result of distractions or preoccupation with completing final checks while on the runway, before takeoff.

It was also observed that “Pilot training, qualification and air traffic controller training, licensing and record keeping practices had been investigated and while not directly contributing to the incident were noteworthy and required action”. This included that the TWR controller’s Medical Certificate had expired and that several other controllers were operating without current medical certificates, that neither the TWR Controller nor any other ATCO had been issued with an ATCO Licence, that the ANSP had no documented process to track medical status of ATCOs and that there was no record that the PA27 pilot had completed his required annual recurrent training.

Ten Safety Recommendations were made as a result of the Investigation as follows:

  • that the Safety Oversight Department of the Bahamas Civil Aviation Authority (BCAA) should re-examine the PA27 pilot for his competence to hold a Bahamas-issued pilot licence.
  • that the Safety Oversight Department of the BCAA should, based on additional information obtained post-incident, have the PA27 pilot reassessed by a medical assessor for medical fitness.
  • that the Safety Oversight Department of the BCAA should issue all ATC personnel with ATC Licences as required by the Civil Aviation General Regulations.
  • that the Bahamas Air Navigation Services Division (BANSD) should institute policies which will address controllers’ medical certificate validity.
  • that the BANSD should put in place a process to ensure that ATC schedulers are aware of the medical status of ATC personnel prior to scheduling them for active duty.
  • that the BANSD should liaise with the BCAA to ensure that all personnel are issued with the required ATC licences.
  • that the BANSD should address the practise of dual position assignment by one controller during busy periods of the day unless there is additional manpower to assist with entries required of its new system.
  • that the BANSD should ensure that ANS refresher classes are conducted on a more structured and frequent basis (as no refresher had been conducted for the controller involved since 2007, more than 11 years earlier).
  • that the BANSD should conduct refresher classes on the ‘AIRCON2100’ traffic management system for all controllers using the system.
  • that the BANSD should address the manpower shortage or institute a shift system as outlined in the recommendation made by their three-member Internal Review Board tasked with reviewing their procedures generally and the increased workload for a single controller if made responsible for combined positions and frequencies during busy periods, which constitutes a serious safety risk.

The Final Report of the Investigation was published on 8 April 2019.

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