During 2003-2010, the United States oil and gas (O&G) exploration industry had a collective fatality rate that was seven times higher than for all other categories of US workers. The Centers for Disease Control and Prevention that carried out this analysis also found that offshore transportation events were the leading cause of accidents. 75% of these transportation events involved helicopters that cumulatively caused 49 fatalities, all in the Gulf of Mexico.
Data from other parts of the world are not vastly different. An O&G UK report that analysed offshore helicopter transportation with other forms of transport in the UK for the period from 1995 to 2009 found that the safety record of offshore helicopter travel was less favourable than UK airlines, rail and car travel. There were a total of 25 offshore helicopter accidents in the UK between 1992 and 2013 out of which seven involved fatalities (51 deaths), prompting the UK Civil Aviation Authority (CAA) to order a review of helicopter operations in the North Sea.
It is an industry where traveling to the workplace appears to be the most dangerous part of the job.
In India, 23 O&G workers and four crew members perished in a Mi-172 helicopter crash at sea off Mumbai on 11 Aug 2003. This was the worst offshore helicopter crash in India and brought in sweeping changes in its wake. AS4 compliance, Performance Class 1 operations, underwater egress training, use of emergency breathing devices and many stringent criteria became the norm.
A High-Risk Industry
The O&G industry has traditionally been a high-risk industry. The July 1988 explosion and fire at Piper Alpha platform in the North Sea, UK is recorded as the worst offshore accident in history. 167 people were killed and it took three weeks to control the fire. Recent high profile accidents like the Deepwater Horizon explosion (2010, 11 fatalities) and Bombay High North fire (2005, 22 fatalities) are still fresh in the minds of industry workers. In this industry, SOPs are written in the blood and last breath of those who paid with their lives. After years of improvement through lessons learnt from mishaps, the industry today has reached a fairly high level of safety. Sharing of safety information forms a crucial part of the safety management program.
So when a helicopter and two crew are lost to the most fundamental accident causes that has bedeviled offshore crew for years, it is time to reflect if indeed we have made progress in real terms.
The Indian DGCA recently released the final report into the 04 Nov 2015 fatal accident of AS365N3 Dauphin VT-PWF off Mumbai. The helicopter was being operated on a training flight by Pawan Hans Helicopters Limited (PHHL) after embarking an offshore platform for night ambulance duties. The PIC who was the Pilot Monitoring (PM) was a 19500h veteran from the offshore industry. The trainee Pilot Flying (PF) with over one-third of the PIC’s experience was no stranger to offshore either. Yet, the two took off from the process platform on a dark night, made a direct approach to a rig ten miles away, and crashed into the sea after initiating a go-around. The accident investigation board attributed ‘spatial disorientation’ (SD) as the most likely cause.
Helicopters and the Night Sea
If offshore helicopter operations are among the most challenging for helicopter pilots, night flying offshore takes it a level higher. The deceptively calm and dark night seascape hides within it a terribly unforgiving and potentially disorienting environment. There are cardinal rules which must be respected and obeyed at all times. Currency is critical. Experience is no antidote. Eternal vigilance and strict adherence to standard operating procedures (SOP) are crucial to safety. A casual search on the internet will throw up several crashes of a similar nature that have taken place in the past. I will briefly touch upon just two.
Case 1 (G-REDU): On 18 Feb 2009, an EC225LP Super Puma helicopter bearing registration G-REDU belonging to Bond Offshore Helicopters Ltd departed Aberdeen, UK on a scheduled flight to the Eastern Trough Area Project (ETAP) offshore platform. Weather, visibility and cloud base at the ETAP were marginal by the time helicopter reached the platform at night. During approach to land, the crew apparently suffered oculogravic and somatogravic illusions. They remained fixated with the landing deck in reduced visibility while helicopter descended and impacted surface of the sea. Fortunately, speed was low and the helicopter remained upright on its flotation bags. Survivors were picked up by rescue boats from the freezing waters with no loss of life.
Case 2 (G-BLUN): On 27 Dec 2006, an AS365N Dauphin2 bearing registration G-BLUN of CHC Scotia Ltd crashed into the Irish Sea while attempting to land at night on the North Morecambe Gas Platform. As per the accident report, “the approach profile flown by the co-pilot suggests a problem in assessing the correct approach descent angle because of the limited visual cues available to him”. The approach was not stabilised as he was disoriented. Large oscillations in pitch, roll and collective pitch prompted the Captain to ask him if he was OK. The co-pilot sought assistance from the Captain who after a 4-second delay in taking over controls due to a non-standard call (“Yeah take…help us out”), couldn’t retrieve the situation. The helicopter crashed into the sea with seven fatalities (2+5). This was the third out of eight night sectors all of which were to be flown by the co-pilot as PF.
As compared to the large variations in attitude and power that preceded the CHC Scotia Dauphin crash, the PHHL Dauphin went into the sea in a much steadier manner with very few words exchanged in the cockpit. The co-pilot, though seemingly disoriented, did not ask for assistance. Neither did the Captain take over controls while the aircraft breached decision height with unacceptable flight conditions. Outcome though was the same.
Preparing for the Night
Even as technology improves at a strident pace, failings arising from the human orientation triad continue to be the bane of night offshore flights, particularly in degraded visual environment (DVE). How do we remedy this? True, such accidents cannot be ruled out as long as humans are in the loop. But with a little preparation and the right aids, many traps can be avoided. Here are some factors which could serve as ‘food for thought’ for offshore helicopter operators trying to bridge that safety gap.
Use of Automation
Most of the helicopters flying offshore today have a fairly high level of automation built into them. Night flying over sea should utilize the highest level of automation appropriate to the phase of flight. Specifically, in the case of both Dauphin accidents described above, timely use of the ‘Go Around’ mode could have saved the day. Aircraft with 3-axis autopilot would require manual setting of power, but that is just one control you need to move. This will come only with practice and if it isn’t utilized by day, chances are you will forget to invoke it when it is needed at night. Pilot monitoring skills and autopilot ‘mode awareness’ have been particularly highlighted by CAA in a comprehensive review of offshore safety that resulted in CAP 1145.
Getting off the deck at night and immediately launching into a series of turns or bank reversals is an invitation for SD. Whenever situation permits, consider gaining your bearings with some overhead time before launching into pattern flying. This may not always be feasible while carrying out production tasks or multi-sector revenue flights. However, if it is a training flight like that of the PHHL Dauphin, allowing the trainee to gradually get his night adaptation and geographical / spatial orientation by some straight & level flying may have been a good idea. In other cases, maybe a dummy circuit would suffice. Even by daytime, offshore approaches need to be planned taking into account wind, obstructions, hot gases, clear getaway and deck access. More reason to dwell on these aspects with extra caution by night. The VT-PWF crew took off into a dark night, made a direct approach to the rig (in tailwinds as per the report), arrived low and fast, then decided to go around putting on bank at low height, all with a pilot who had last flown night almost a year ago. It is a deadly cocktail with all the ingredients for disaster.
The Airbus Flight Operations and Briefing Notes (FOBN) has a complete chapter on standard calls. While increasing the situational awareness and crew coordination at critical stages of flight, standard calls reduce the risk of errors in mode selection, aircraft configuration, changeover of controls, etc (e.g: the G-BLUN accident). It also helps in quickly drawing crew attention to an impending situation without distraction or confusion. While airlines have embraced this philosophy wholeheartedly, the same cannot be said about helicopter crews in general. One remedy is to train, practice and include this into the Line Proficiency Checks / IR syllabus. Only if followed diligently by day will it become second nature at night. The tendency to deviate by giving calls an individual ‘twist’ should be guarded against.
Call it ‘knock it off criteria’ or whatever, the need to mandate go-around conditions in company manuals and follow them meticulously is so important as evident from a long history of crashes where crew attempted to make a landing out of a poor approach. Deviation in parameters that call for either a take-over of controls by the non-handling pilot or for initiating go-around should be laid down in operating manuals and followed diligently. In the case of VT-PWF, the PF initiated a go-around but there were no standard calls, use of automation or take-over by the PIC even when the helicopter continued to descend past the decision height.
Visual Approach on Instruments
Most offshore approaches, even by night, are essentially visual approaches. As opposed to instrument approach procedures for fixed wing aircraft that provide clearance from terrain and obstructions, offshore approaches terminate in an area surrounded by obstructions. There are rarely any obstructions in the approach path. In a way, the sea below remains the main ‘obstacle’. The required visual references MUST therefore be obtained in level flight BEFORE commencing the approach and not during descent. Considering a roll-out on finals at 500 feet for a deck height of 150 feet, a glide slope of 5 degrees will intercept the Minimum Descent Height (MDH) of 500 feet at approximately 0.6 NM. This point is sometimes referred to as the Visual Descent Point (VDP). Simply put, the helicopter flies level at the MDH of 500 feet, picks up the visual references by VDP and then descends for landing. It is thus a small segment of about half a mile and 350 feet height (500-150) within which the descent, deceleration & decision to land or abort has to be taken. For night / DVE approaches, should there be another decision point before (above) the VDP or between VDP and committal point where the crew can review if it is safe to continue the approach? How about a two-step approach with the initial approach at 500 feet above deck level down to VDP (350 feet above deck level) and the second leg from VDP to committal point? One may argue that the crew is allowed to call off the approach at any point. However, leaving this decision open ended may encourage ‘pressonitis’ thereby continuing an unstabilised approach as it happened in the case of G-REDU.
Currency or Proficiency?
Areas like the North Sea where offshore helicopter operations continue unabated by day and night are the real crucibles of night offshore. For countries like India that are blessed with 12-hour daylight, night offshore flights are undertaken only for training or Medevac. Such opportunities are few and far between and it is difficult to build or maintain a high level of proficiency. While pilots who have formerly flown in the navy may bring relevant experience from their ship-borne days, others have to learn from the available windows of opportunity, mostly on the job. Stage-wise training, a slow build-up and continuous practice are therefore crucial. Here are some suggestions to increase the available opportunities for countries like India (subject to weather and visibility minima):
- Pre-dawn crew-change shuttles (shore to offshore or vice-versa)
- Extend the landing time restrictions to permit offshore landings into dusk
- Incorporate periodic practice diversions to shore & alternate decks by night
- Equip and nominate few ‘easy’ decks with all night landing facilities as ‘practice decks’
Alas, a closer scrutiny will reveal that watch hours of Juhu (0730-1800) need to change to facilitate night offshore flying activity at Mumbai. Traffic congestion and restrictions at the Mumbai International Airport make even actual Medevac flights by night tedious and complicated.
Incentivising Night Halts
Night offshore operations are decidedly tough and everybody may not be up to it. The prevalent system by some operators of incentivising night flying while not solving the bigger jigsaw of improving night proficiency is counterproductive and detrimental to flight safety. I will let it rest at that.
Visual Landing Aids
As a former naval helicopter pilot used to gliding down a slope beamed by the ship’s Glide Path Indicator (GPI) or Stabilised Glide Slope Indicator (SGSI), the abject lack of visual landing aids on offshore decks has always struck me as odd. The cultural lighting of an offshore platform, inky darkness around the elevated deck and the poor visual cuing environment provided by only a set of perimeter lights can create illusions like the ‘black hole’ effect. Countries like India should be particularly watchful that the ’12-hour daylight’ syndrome doesn’t relegate night flying to secondary importance. CAA, vide Safety Directive SD-2016/005, has mandated lighting comprising lit touchdown / positioning marking and helideck identification marking (‘H’ marking) as per the latest CAP 437 from 01 April 2018 for offshore installations under its purview. Trial results of this lighting scheme have reportedly been encouraging. Hopefully, this will become the norm in other parts of the world as well.
Automated Rig Approach
Sikorsky (now Lockheed Martin) in collaboration with PHI, Inc. had successfully developed, tested and certified a GPS-based automated ‘Rig Approach’ system on the S-92 in 2013. Airbus has also developed a similar system called the Rig’ N Fly and it is EASA certified on the H225. CAA, on its part, has sought funding for research into DGPS-guided approaches as an industry initiative. However, such systems are yet to become the industry-wide standard. Again, borrowing from my naval experience, autonomous approach to a predetermined point-in-space hover (for dipping sonar operations or sea rescue) is a standard feature on modern naval helicopters like the Merlin, NH-90 or Seahawk. I hope it is only a matter of time (& not money) before the offshore industry adapts the technologies and best practices from the navy to improve safety of night / DVE rig approaches.
Comprehensive Audit of Offshore Operations
After a series of five offshore accidents in four years, the CAA undertook a review of offshore helicopter operations in the North Sea in 2013. The mandate of this review was “to study current operations, previous incidents and accidents and offshore helicopter flying in other countries to make recommendations aimed at improving the overall safety of offshore flying”. The output of this study is CAP 1145. A similar review is perhaps needed in India by a joint team of all stakeholders with participation from an international team of experts. And we do not have to wait for a spate of accidents to commission such a study as is usually the norm. The question “who has the controls?” when it pertains to regulating offshore aviation safety and bringing about the required change also needs to be clearly answered.
Don’t Wait Until Dark
In case you missed it, there is a common thread running through G-BLUN, G-REDU, VT-PWF and other helicopters that crashed during night offshore flights – the maxim that “It is safe only if you understand how dangerous it is”
So if you want to be completely ready for that dark night landing offshore, rehearse and fine tune those procedures by day. Don’t wait until dark. It may be too late.
© KP Sanjeev Kumar, 2017. All rights reserved.
Views expressed are personal and written with a view to contribute to safety of offshore helicopter operations. Feel free to debate and contribute to the discourse. I can be reached at firstname.lastname@example.org. Cover photo from open source (original source unknown, please advice if identified)