Rotor Torque

As foreshadowed in our March ‘Rotor Torque’, Australian Aerospace giant Hawker de Havilland has become a risk partner in the design and production of MDX to the tune of about 20% of the total production value. That represents $60m investment by Hawker de Havilland which – if matters proceed as per plan – Hawkers will recoup by the year 2000.

Hawkers and McDonnell Douglas have identified ·a potential world market of more than 2,500 aircraft of this class over 10 years. If a one third market share can be achieved, the 800 helicopters sold will represent export earnings to Australia over that period (expressed in 1988 dollars) of more than $400m. According to the agreement signed February 21st in Canberra, Hawker de Havilland will be involved in considerable detail in the design phase and will build virtually the entire airframe for shipment to Mesa, Arizona, USA for final assembly.

MDX had its genesis more than 10 years ago when Hughes Helicopter Company began testing a ‘No Tail Rotor’ (NOTAR) design. Hughes was ingested by the aerospace giant McDonnell Douglas just a few years ago and became the McDonnell Douglas Helicopter Company. Development of state-of-the-art variants on the Hughes 500/OH-6 airframe plus the AH-64 Apache were the major projects at that time. In 1987, sensing signs of an upturn in the helicopter industry, McDonnell Douglas began a series of market surveys to identify what the market wanted in a new utility helicopter.

The design process for MDX began with analysis of the responses to a detailed questionnaire from 177 operators, representing about 26% of turbine helicopter operators worldwide. The McDonnell Douglas design team analysed what those operators felt they needed in terms of performance and general layout in a light to medium turbine helicopter. Once the first design concept was established, MDH invited 15 operators to send reps to Mesa for a detailed analysis of that first design. That second round of analysis provided fine-tuning of the initial design but – more importantly – it validated the existence of a market for such an aircraft.

Meanwhile, down in Australia, Hawker de Havilland had been churning out a wide variety of sub-contract components for both F-18 fighters and commercial jet liners. Aside from forging links with McDonnell Douglas, HdH had become well established as Australia’s largest aerospace company. Employing 3,200 people at some 17 locations around Australia, HdH earned over $200m in 1988 with about 55% of sales being for export. The Defence offset programme commitment generated by the 1981 sale of 75 F-18 Hornets to the RAAF provided the stimulus for McDonnell Douglas to find an Australian partner for the MDX venture. Hawkers expect that the MDX project will employ about 500 people when it is up and running – both at HdH and with various sub-contractors to the project.

The MDX is scheduled for first flight in 1992 – with deliveries commencing 1993. Target price for the machine is $1. 7m with direct operating costs of less than $200 per hour. (This compares with a price tag of about $1. 85m for existing helicopters in the same class with DOCs listed at around $500/hour. )

The design that emerged from McDonnell Douglas’ ‘ask before you begin building’ experiment is for a 7 passenger plus single pilot twin turbine utility helicopter with a gross weight of 2,450kg, an empty weight of 1,080kg and a useful load of 1,370kg. Max all up weight with an external load is to be 2,735kg. Standard fuel capacity of 665 litres will allow a maximum range of 350nm with 30 minute reserve. Sea level cruise will be 150kts and VNE will be 173kts. Target HOGE AEO (Hover Out of Ground Effect, All Engines Operating) at ISA + 20 will be 10,000 feet. HIGE OEI (Hover In Ground Effect, One Engine Inoperative) will be 4,000 feet.

The most significant aspect of the MDX design will be the NOTAR anti-torque system. Indeed the NOTAR design team was awarded the 1987 American Helicopter Society Howard R Hughes Award for outstanding improvement in fundamental helicopter technology. Ever since Igor Sikorsky settled on the single main rotor/tail rotor combination for conventional helicopter design, tail rotors have been a mixed blessing to helicoptering. If you mount the anti-torque rotor on the tail -as is necessary to take advantage of weather cock stability – then it gets in the way when you flare to land and people sometimes walk into it. If you try to raise it up high enough to keep people away from it – and it out of the bushes (US Army studies showed tail rotor problems to be the cause of more than 15% of non-combat helicopter losses) – then you introduce rolling moments every time you make a yaw input. Coaxial and tandem contra-rotating main rotors can introduce more technological problems than solutions. And of course tail rotors are the main source of helicopter noise. French manufacturer Aerospatiale developed the fenestron shrouded tail rotor to solve some of the problems. But the fenestron had high power demands at the hover, could still be fouled if one were determined enough and could still shed some airflow disturbances into the main rotor flow during tail wind hovering.

Aside from the obvious safety to both helicopter and persons on the ground that NOTAR offers, plus the opportunity to reduce noise significantly by sound insulation and redirection, those who fly NOTAR say that it offers excellent anti-torque and directional control at greatly reduced pilot workloads. The reason for this is ‘Coanda effect’ – also referred to as ‘circulation control’ or ‘boundary layer control’. By venting a high velocity layer of air across a surface with a relative airflow over it, the entire airflow can be induced to follow the directed flow. This ‘circulation control’ can create lift over that surface.

Of course large fin surfaces have been used on helicopter tails for a long time to off load tail rotors in forward flight. But they are ineffective at the hover and low speeds. By utilising the ‘Coanda effect’ operating along the tail boom in the rotor downwash, effective anti-torque thrust can now be generated in the hover as well. A directed jet at the end of the boom and the variable pitch fan mounted in the tail boom give sufficient directional control to complement the general anti-torque effect of the tail boom. As power is increased at the hover – and therefore torque effect on the mast – so too is rotorwash increased and therefore antitorque forces. As with conventional tail rotor designs, the addition of fixed surfaces off load the tail rotor as forward speed increases and the ‘Coanda effect’ is reduced. (NOTAR will also be incorporated on the M0-520N and is proposed for the US Army LHX. )

Of course MDX will incorporate other state-of-the-art design features. As previously mentioned, the airframe will make extensive use of composite materials. Cabin design will include a large, flat floor surface with easy access from large sliding doors. A composite flex beam, 5 bladed main rotor system will be used. Skid landing gear is incorporated in the design. The instrumentation will incorporate 2 flat CRT displays with conventional instrument backup. Final powerplant selection has not yet been made however, the Allison 250-C20RX, Turbomeca TM319 and the Pratt & Whitney PW2058 are all candidates for final selection.

So confident is MOH of being able to meet their design objectives – they are offering the MDX with 2 year, 2,000 hour parts and labour warranty. No doubt this confidence has been a significant factor in the operators’ rush to get on the MDX bandwagon.

ASTA to Assemble Ran Seahawks as a Result of Worsening Project Delays at Sikorsky

Aerospace Technologies of Australia (ASTA) have taken over the contract to assemble the second batch of 8 Sikorsky S-708 Seahawk helicopters for the RAN. The contract is believed to be worth in the region of $15m.

This follows the decision by Hawker de Havilland to opt out of the Seahawk project due to recurring delays by Sikorsky in submitting the required test data and parts. When the initial bidding took place between Sikorsky and HdH in 1983, there was no established baseline for the eventual RAN Seahawk configuration. At the time of the October 1984 announcement by the Minister for Defence that Sikorsky had won the RAN FFG helo contract the delivery date of the first Seahawk to the RAN was scheduled for March 1987.

Now more than two years behind, the Seahawk programme never really got off the ground at HdH owing to the Australian company not being supplied with even basic pre-assembly test data. This left HdH in a position where, in addition to still not having Seahawk parts and data, it would be asked to undertake a massive effort on the first Australian batch of Seahawks in late 1988 and early 1989, with potential adverse impact on the Black Hawk programme which would be running concurrently as a result of slippages at Sikorsky. There was also an emerging shortage of skilled airframe and electrical tradesmen throughout the aerospace and airline industry which constrained expansion of HdH’s workforce. However, had Sikorsky completed prototype Seahawk activity on schedule this would have had no impact.

Similar problems plagued the Black Hawk programme also and at the end of 1988, HdH took the decision to opt out of the Seahawk programme (which it had never really commenced in practical terms) to better concentrate its manufacturing assets on completion of the RAAF/Army Black Hawk programme. It is planned that the first US built S-708 will be handed over to the RAN during the course of this issue with aircraft from ASTA being delivered through 1990/91.

Helipads – The Ongoing Saga

It has been said that the greatest single impediment to the development of the helicopter industry in Australia is the lack of adequate landing facilities. Certainly the question of both environmental and operational standards for helipads occupies much of the industry’s total lobbying effort.

Aga-7 Review

Once again, the federal helipad standards are up for review.

The existing AGA-7 standard for helicopter landing areas was the product of a joint industry regulatory authority committee convened in the early ’80s. A similar project is underway again although the Review Committee is a little larger on this occasion. Two representatives each from the Civil Aviation Authority, Australian Federation of Air Pilots and the Helicopter Association of Australia will “review AIP-AGA-7 having due regard to the requirements for helicopter landing sites in other countries and the ICAO Heliops panel report”. The committee has also been directed to “give primacy to safety considerations over commercial ones” and to have regard to the CAA’s corporate objectives. The committee is to report by 1st July 1989.

Acoustic Standard

Last issue we reported that the Standards Association of Australia was considering· the content of its draft “Acoustics – Assessment of Noise from Helicopter Landing Sites”. It is understood that the Helicopter Association’s submission – prepared in consultation with James Madden Cooper Atkins – has been well received by the Committee. Final figures are not available at presstime, however it is understood the recommended levels will be higher than those requested by the New South Wales State Pollution Control Commission. It is also understood that the standard will contain the Standardised Methodology for Noise Assessment in the body with the recommended levels set out in an appendix. It will then be open to each state’s environmental protection body to set it’s own ‘maximum levels’ by legislation if the Standards Association recommendations are considered inappropriate – whilst leaving intact the methodology for measurement. In light of the increased permissible noise levels (which will be measured using the ‘fast response’ setting), a new ‘Noise Footprint Overlay’ will be developed so that individual site testing will no longer be necessary in every case.

Australian on International Helicopter Noise Panel

Steven Cooper, who advised the HAA in preparation of their submission, looks set to become a member of the ‘Helicopter Association lnternational’s Environmental Panel’. The Australian Helicopter Association has endorsed his membership submission and it is anticipated that having representation on the body that advises the major airworthiness authorities of the world on the subject of Helicopter Noise will be invaluable to the Australian industry.

Floating Helideck Sinks

Despite having a ‘win’ in respect of the Acoustic Standard, there have been two notable ‘losses’ for the helicopter industry recently. Sydney Helicopter Service’s Floating Helideck proposal for the Sydney CBD/Harbour has been officially given the ‘thumbs down’. According to David Gemmell, the MSB considered his novel application after it was referred to them by the State Pollution Control Commission. The Maritime Services Board, in refusing to permit the operation, noted that they had received 115 submissions from the public in respect of the proposal – 24 in support and 87 against. According to Gemmell, one of the ‘pro’ submissions contained a with 843 signatures favouring the proposal. Of the 87 ‘anti’ submissions, 9 came from one person. One ‘anti’ submission contained a petition with 383 signatures. The MSB, in citing their reasons for rejection noted that 20 of the ‘anti’ submissions represented sizeable groups of people. One of the objectors was the NSW State Pollution Control Commission who argued that the ‘Noise Footprint Overlay’, which they themselves had prepared, should not be used in lieu of actual noise testing at each of the locations proposed for helicopter movements. Gemmell’s proposal had been to move the floating helideck around the harbour so that no single location bore the brunt of all the helicopter movements.

Phillip Island Helicopter Landings Out

The other helipad proposal that failed to ‘get up’ was put forward by the organisers of the Phillip Island International Motorcycle Grand Prix which was held in April. Moorabbin based Jayrow Helicopters had secured an arrangement with race organisers to carry passengers from the mainland to the Bass Strait Island for the event. A helipad located within the racing circuit was surveyed and flight paths established in consultation with the CAA. Jayrow had brought on line a large (10-passenger) Sikorsky S-62 and had also arranged for a fleet of commercial helicopters from other regional operators to undertake the airlift. However, the Shire of Phillip Island declined to permit the change of use necessary to conduct commercial helicopter operations on land zoned for rural use. Apparently, corporate, media and ambulance helicopters will be permitted to use the site.

Yarra River Terminal Rebuilt

The Melbourne Heliport Terminal Building, which was destroyed by a fire set by vandals a year ago, is being rebuilt by Jayrow. The Heliport is situated on a pontoon moored in the Yarra River and services the Melbourne CBD.

Ato Develops Jetranger Particle Separator

Another item of interest from Moorabbin is the development by Aviation Turbine Overhaul of a new particle separator system for Jetranger series helicopters. The 2 stage system is being designed to cope with the particularly damaging Aussie outback ‘bull dust’. According to ATO Managing Director Lindsay Rose, field trials have been completed and test flying for icing conditions will be conducted in June and July. An Australian Supplemental Type Certificate for the installation is being sought.

The Value of a Civil Helicopter Fleet to The Community

In 1989, rescue by helicopter has become so commonplace that it hardly rates a mention. Stories of derring-do by helicopter heroes that might have covered the front pages of city daily’s once – now barely merit more than a short para on about page 7. Little wonder that the public has become so accustomed to the idea of an ‘Angel of Mercy’ swooping from the heavens to save their souls when they’re in strife. Indeed, the first known helicopter rescue occurred way back in April, 1944 when one Carter Harman landed his helicopter behind enemy lines in Burma to extract his comrades in distress.

Perhaps the first civil helicopter mercy mission occurred in January, 1945 when Bell pilot Floyd Carlson flew a doctor to the aid of an injured pilot who had bailed out near a snowbound New York farmhouse. Later that same year, he manoeuvred his Model 30 to pluck four fishermen from the ice on Lake Erie – a spectacular demonstration of the helicopter’s unique rescue capabilities – considering the state of the art at the time.

Father of the modern helicopter, Igor Sikorsky, was reported to have said on the day before he died in 1972, “I always believed that the helicopter would be extremely useful for the greatest variety of lifesaving missions. And now, near the end of my life, I have great satisfaction knowing this to have been true. ”

In 1980, when NASA commissioned Systems Control Inc to research the matter, it was revealed that an estimated 800,000 people had been rescued from life-threatening situations by helicopters worldwide since the end of the Second World War. This figure is actually grossly conservative as it does not include those many beneficiaries of the virtual explosion of Emergency Medical Service (EMS) helicopter programmes that has occurred since that study was conducted.

Australia, in particular, is well served by dedicated rescue and medical helicopters.

The National Safety Council offered what some might argue was the most sophisticated helicopter SAR capability in the world. Nine surf life-saving rescue helicopters patrol the coastlines of this beach loving nation. Police Air Wings in Victoria and NSW carry out rescues as an adjunct to police work – whilst in Queensland and Tasmania, SES helicopters perform the occasional law enforcement task as an adjunct to their rescue roles. Westmead Hospital based HCF-Careflight conveys specialist doctors and the most advanced airborne life support gear across the Sydney region at 120 knots plus – whilst in Victoria, the Southern Peninsula Rescue Squad looks after its corner of Port Phillip with a rescue equipped Jetranger.

In general, these dedicated services receive – not just the recognition which is their due – but also the support from the community and government to enable them to do their job. For example, the same resident action group which might bitterly (and all too often successfully) oppose a private or commercial helipad – would not be so small-minded or impolitic as to oppose emergency service helicopters carrying out life-saving flights. And the CAA would be unlikely to prosecute a breach of rules committed during a genuine mercy flight.

What is seldom recognised by the community, is that lifesaving flights are often carried out by ordinary civil helicopters which just happen to be in the area when the need arises. An example of this occurred on 19th January 1989, when the NSW National Parks and Wildlife Helicopter responded to a mayday

call from a yacht with a man overboard several kilometres away. Of course that was hardly the first time such a non-rescue dedicated helicopter had helped save lives. In late 1979, for example, helicopters from the three Sydney commercial TV stations were despatched to Royal National Park south of Sydney where it was reported a bushfire was out of control. Arriving south of Heathcote, the helicopter news crews found themselves about to witness a catastrophe as flames closed in on a group of 160 schoolgirls huddled around Karloo Pool. Newsgathering became secondary as camera crews -‘- so often criticised as being ‘ghouls’ at disaster scenes – were dropped to assist loading and unloading the schoolgirls. Led by one police machine, a shuttle began in which the four helicopters lifted all 160 schoolgirls to safety in just under an hour. Another group of 120 boys and girls had fled as a trail of flames closed in on them and they had become disoriented in the smoke, bush and confusion. A TV chopper spotted them, picked up a police constable, dropped him in with the children and then hovered overhead, directing the group to safety. In the drama, several children collapsed from heat exhaustion and hysteria – but there were no burns or serious injuries. Without the speedy presence of the helicopters the situation might well have had a tragic end.

In late 1980, when the Las Vegas MGM-Grand Hotel became a “Towering Inferno” killing 85 people, several privately owned helicopters were amongst the first on the scene – airlifting scores to safety. Three months :ater, history virtually repeated itself as the 30 storey Las Vegas Hilton burned. Once again, dozens were lifted from the rooftop by civil helicopters working alongside government and military machines. Hotel guests were lucky that – whatever the shortcomings of the Las Vegas· ‘fire code’ – the city supported a healthy, viable, civil helicopter community.

How many people today owe their lives to the availability- not only of dedicated rescue and EMS helicopters – but of civil helicopters ever ready to augment the capacity of the emergency service fleet. Conversely, how many lives might have been saved, had it not been for the short sightedness of so-called ‘progress associations’ and other resident action groups whose lobbying has deprived the metropolitan helicopter community of the helipads essential to its viability?

What has the metropolitan based sector of the helicopter industry done to draw public attention to either its plight or its virtues? When has a public education campaign been mounted, pointing out that the relatively minor and short-lived irritation of helicopter noise is indeed a small price to pay for the security that a healthy civil helicopter fleet provides in civil emergencies? Unless the industry itself tells them, how can we expect the public to understand that the same media helicopter which today hovers over the harbour filming yacht races, was yesterday helping to rescue lost bushwalkers in the Blue Mountains; that the same charter machine which today lifts air conditioners onto a suburban factory rooftop, was last month lifting food and supplies to flood isolated properties in northwestern NSW; or that the very same corporate helicopter which today transits the helicopter lane into Sydney Airport on a VIP flight, was last week water bombing a bushfire on the suburban outskirts?

The problem is, if the metropolitan sector of the helicopter community in Australia cannot find a way to get its message across to the public and the politicians that there are ‘pluses· for them in having helicopters busily buzzing about the skies on routine jobs-but ever ready to don their ‘haloes· when an emergency strikes – then the helicopter industry will find itself well and truly banished to the bush for a long time to come. And we will all be the losers for it.