12-Oct-2016 Source: Allan Blake
It must have been with some trepidation that Airbus anticipated attending Helitech this year. For the second time in three years their flagship offshore helicopter, the H225 along with the AS332L2, had been grounded following a tragic accident in Norway on 29th April 2016, leading to an idle fleet of 111 H225s and over $3billion of assets.
A Preliminary Report of the Accident Investigation Board Norway (AIBN) on 28th June stated:
“the accident most likely was the result of a fatigue fracture in one of the second stage planet gears. What initiated the fatigue fracture has not yet been determined.”
The AIBN Report also stated that it was:
“most likely that the fatigue fracture of this planet gear subsequently resulted in loss of the main rotor. It is considered unlikely that this fatigue crack propagated as a consequence of a structural break-up of another component”
There have been no more reports from the AIBN since this Preliminary Report in June, which implies that there have been no new major findings, but it was still a surprise to see the announcement of EASA on 7th October that they had lifted their grounding of the H225 and AS332L2 with effect from 13th October, albeit subject to a daily inspection regime.
The EASA Airworthiness Directive (AD) states:
“…Airbus Helicopters (AH) have investigated possible accident contributory factors and determined that the likely cause relates to the rupture of the second stage planet gear, which was found with fatigue and surface degradation. Although the root cause of this failure is still not fully understood, it involved cracking of the planet gear bearing outer race, some spalling and propagation of a crack into the rim of the gear, finally resulting in its rupture…By limiting the type design to the gear configuration with lower stress levels and better reliability and specifying a reduced life limit, combined with more effective oil debris monitoring procedures and other operational controls, an acceptable level of safety can be restored.”
However, at Helitech, Ricardo Genova Galvan, Flight Standards Director at EASA stated that, after working closely with Airbus, EASA have identified the cause of the accident as the defective planet gear. An Airbus source explained that they had conducted over 20,000 bench hours of tests to identify the cause of the accident, the results of which were passed to EASA. It appears that there are two different manufactured planet gears, both made to the same Airbus specification. One of these gears is more resilient than the other and is now being retro-fitted into the H225 before any aircraft resumes service. This includes military aircraft.
Meanwhile, the Norwegian and UK Civil Aviation Authorities have confirmed that their grounding of the aircraft remains in place until they have considered the final AIBN report. Bristow Helicopter Group also put out an immediate statement that:
“Until the Company is confident that the H225 model aircraft can be operated safely, the Company will continue to suspend all operation of its H225 model aircraft, including for SAR and training.” (SEC Form 8-K, 7th October 2016).
The procedures laid down by EASA for monitoring the aircraft are onerous and could themselves lead to safety concerns with daily interventions into a critical area:
The H225 and AS332L2 will eventually return to service, but there are three key issues outstanding apart from the replacement of the planet gear that will determine when this will occur:
1. An Effective Warning System
Airbus will have to find a solution to the statement by the AIBN in its Preliminary Report that
“…the fracture of the failed second stage planet gear has propagated in a manner which is unlikely to become detected by existing mandatory or supplementary systems for warning of an imminent failure.”
Airbus introduced an interim cockpit alert system and mandatory frequent ultra sonic checks following the first H225 crash. This allowed the aircraft to be returned to service prior to a modified main gear box being produced. These interim processes were cumbersome to apply, particularly in remote locations where qualified NDT personnel had to be sourced. The daily monitoring programme required in the recent EASA Airworthiness Directive does not resolve the lack of an effective early warning system in this area of the MGB. An Airbus spokesperson commented that further work on any advance detection system in this area is premature pending the result of the final investigation. This position will need to change.
2. Operator Confidence
Offshore operators must have confidence in the helicopter and will take steps to receive that assurance from Airbus, a process which has already started with briefings. Individual Accountable Managers will need to be involved as ultimately they take on the responsibility for flying the aircraft. Gretchen Haskins, CEO of HeliOffshore, clearly recognises this and told me at Helitech that she saw it as
“a key function of HeliOffshore to provide Accountable Managers with consistent information to help them make fully informed decisions on safety issues”.
Operators with H225s will eventually want to see them back in service:
However, the timing of any return to service will create uncertainty and some volatility in the market. Vector have a hangar of nearly 40 stored aircraft, many of them H225s with more to come as operators’ H225 leases expire. Although the H225 may be returned to service for SAR duties, there is no economic reason for operators to rush to return the aircraft as it is not needed – indeed its return could further harm their volatile market by increasing the supply of aircraft even further. To support this, John Maloney and the team from Flight Ascend Consultancy at Helitech highlighted the potential further impact on the poor state of offshore helicopter market if the H225 does return to service. In the Northern North Sea there were 34 H225s and 11 332L2s operating before the H225 was grounded. This capacity has been taken up by an increase in the S-92A numbers from 63 to 75 and, according to John Maloney there is still some spare capacity. The H225s can continue to be stored until the market recovers as releasing them onto the market now, given the current surplus of aircraft, will only depress rates further.
CHC have of course declared that they will only fly the H225 on client request and still have considerable fleet reductions of other types to make, although few I spoke to at Helitech think they will reduce the fleet down as low as 75 as they have stated. So far, nearly all of their 41 strong H225 fleet, apart from a few SAR configured aircraft, have been released as part of the Chapter 11 proceedings. CHC are maintaining the S-92A as their preferred heavy type. This decision is as much driven by a prudent business strategy of taking the opportunity to focus their fleet on fewer types, as well as divesting themselves of a current distressed type. Their announced tie up with Milestone Aviation as their lead lessor is a key part of their Chapter 11 restructuring will provide them with further flexibility going forward (CHC Press Release 12th October 2016)
Karl Fessenden, President and Chief Executive Officer of CHC stated: “With the support of the Plan Sponsors, Unsecured Creditors Committee, and The Milestone Aviation Group Limited as our lead aircraft lessor, we look forward to obtaining approval of our restructuring plan, recapitalizing the company, and putting CHC on the path to long-term success. We remain confident that the restructuring we are undertaking will position CHC to capitalize on future growth opportunities as our industry recovers.”
Milestone will serve as the lead lessor for CHC’s future fleet of helicopters, providing CHC with modified lease terms on their existing leases, additional helicopters at market lease rates and a $150 million asset backed debt facility for purchase or refinancing of aircraft.
Fessenden confirms that Milestone as a lessor partner going forward will enables CHC to “…establish a smaller, more productive fleet of aircraft that provides the right aircraft at the right time for our customers’ helicopter service needs, while maintaining our commitment to setting the standard for safety, customer service and value across the industry.”
Milestone are taking a strategic perspective on the current problems in the industry with this partnership the President, Daniel Rosenthal commenting “Milestone Aviation Group has always taken a long-term view of the helicopter industry, and we are committed to the industry’s health and stability during a challenging time. We believe that an agreement that enables CHC to recapitalize and emerge from its restructuring process as a going concern is important for our industry, and we are pleased that Milestone, along with other major creditors, has reached a mutually acceptable agreement with CHC to restructure its obligations.”
3. Oil Company and Passenger Confidence
Andy Evans Director of Aeroassurance, an experienced helicopter safety manager attending Helitech 2016, commented:
“While clearly there will be a challenge to rebuild passenger confidence it’s vitally important for the whole industry (operators, their customers and all OEMs) that rational decisions are made with full understanding of the available information.”
There will be regional differences in passenger confidence and the desire to resume flying the H225, with the North Sea UK and Norwegian sectors taking longer for confidence to be restored. The Asian and Australian markets, where there has been less commentary on the grounding, as well as areas where there are long flight sectors that the S92 struggles with without internal fuel tanks, can be expected to resume flying as soon as the first two criteria above are satisfied.
Ultimately the H225 will return to service, even in the North Sea. Concerns over an effective warning system and confidence in the aircraft could align with economic reasons to push that date out to early to mid-2017. It isn’t a requirement that EASA defer their decisions on airworthiness until a final accident investigation report is published, or that they align their decision making with the principal national aviation authorities involved. However, on this occasion it may have been prudent to do so to assist in rebuilding the confidence that is needed to start flying the H225; clearly there is no market need to rush to take this first step.
Copyright and full responsibility for the content of this article remains with Allan Blake, an independent Aviation Consultant. He was Regional Director (Asia Pacific) with the Bristow Group for seven years. He is also the author of “Dynamic Directors: Aligning Board Structure for Business Success” (Macmillan).