Control Problems. The Nomad demonstrated certain problems from the first test flights. The writer is not aware of the exact definition of these problems; only aware that aspects of control response were unsatisfactory and believes that the documentation still exists, (or did exist?) just as there are people who do know the full story. (See also the paragraph re RAAF flight testing.) A pointer to these problems is given by the fact that a T-tail version was test flown. Unfortunately, it crashed during it's first flight, apparently due to flutter problems. All aboard were killed. It was subsequently discovered that the engineering orders covering this configuration were unsigned and tragically those who were responsible for their signature had perished in the crash.

In view of the later problems it is a no-brainer to say that a T-tail would have been a better way to go. Putting the elevator on top of the fin gets it into clean air where it has plenty of authority. But the T-tail has it's own problems. T-tails led to another first - the discovery of deep stall. All of that nice clean air across the horizontal stabiliser allows you to get the nose so high that even the T-tail gets blanketed by wing wash, loses all authority and the aircraft just waffles down to earth. (Read about the last test flight of the prototype BAC -111 circa 1963, where the test pilot describes the condition as the aircraft, in a stall, drops some 25,000 feet and slams into the ground with the pilot still calmly narrating the situation and suggesting cures.) Enter stick shakers, to warn the pilot that he is getting outside the envelope.

RAAF Nomads. The RAAF, being responsible for the airworthiness of defence aircraft, decided to test the Nomad. The officer responsible for the testing did an outstanding job of conducting a very thorough program. The author is not quite sure just what this very expensive interlude proved, although the RAAF were able to defer acceptance of any Nomads until testing was completed. Apart from uncovering the fact that with the aircraft CG well forward of the published limit, it showed a gentle yet controllable nose-down tendency when power was applied, nothing else of significance was revealed. Much was made of the nose down tendency around the bar over a beer or two, yet it was somewhat irrelevant.

Many aircraft have unpleasant tendencies when pushed. The mighty P-51D, for example, was prone to pitch-up catastrophically if the pilot attempted to pull more than 4G before emptying the fuselage fuel tank. The recommended technique was to allow the elbow to be braced by the body, preventing excessive back stick. Lockheed's P-38 Lightning developed problems when dived beyong 450kts - the elevator became ineffective. The F-101 Voodoo had similar tendencies to the P-51D. Designed as a fighter, it was quickly relegated to a photo-recon role. The SR-71 Blackbird had the awesome habit of misplacing it's intake centrebodies (also known as spikes), causing an engine to develop sudden indigestion at Mach 2.5 or thereabouts. Known as an "unstart" the resultant yaw was severe enough to bang the pilot's head against the canopy. He then had to identify the "unstarted" engine then manually adjust the engine spike to recover power before things really went pear shaped. These things happened well within the authorised flight envelope and pilots learned to handle these conditions. Aeroplanes are not cars; they do require skill and knowledge to operate successfully.

The Nomad's Horizontal Strabiliser. The Nomad only developed problems with the horizontal stabiliser after it had been in operation quite a long while. There are not that many who appreciate that the aircraft flew for 13 years in the Australian Army, for considerably longer in the Philippine Air Force, before any of the horizontal stabiliser problems manifested themselves. The Horizontal Stab (HS) was built around a single, square section spar. This spar had a large lightening hole in the front face, between the mounting attachments. Any imbalance in lift, be it momentary or longer-lived, would cause torsional loads in this section. In order to prevent cracking from the edges of the hole, the hole was cranked at about 6 mm from its edge by about 15 degrees. Now all of our theoretical designers will say that the vertical faces of this spar took no load. In a perfect world, this is quite true. In point of fact, the atmosphere is not quite that perfect and one does operate asymmetrically at times. And who is to say that the propellers are both identical to the point that their downwash is exactly the same? So it seems that significant torsional stresses were applied to the HS spar.

The long term effect, and I mean maybe 6,000 hours long term, was that the edge crank intended to preserve the lightning hole developed its own radial cracks. These cracks were known in the civil world well before the military ever saw one. The civil approach was to rivet a reinforcing donut around the hole. The military vacillated. An STI was issued. One had to examine the spar at closely specified intervals.

The author has heard that an independent civilian engineer actually simulated the crack on a home computer, using generally available stress programs. The simulation could not be dead accurate as only GAF had the actual spar load data. But, when you have a real live spar to measure you can get quite close, and, in this sort of simulation you can input a range of values, thus bracketing the design. The simulation allowed the crack to propagate into the horizontal surface of the spar and suggested very strongly that spar life under these circumstances was measured in minutes.

This simulation was done primarily as a rough check on the civil method of stopping the cracks from propagating. Now Murphy intervened. The last batch of civil aircraft, hitherto stored, was released to Defence. One such aircraft was assigned to ARDU. An ex-Army pilot was flying it when the crack on an unreinforced front face crept around the corner. The HS spar failed in flight and all onboard were killed.

This particular aircraft had accumulated many hours in engine testing which put an asymmetric load on the HS. You sit there with one engine running at high power and it's propeller wash hits the HS. This causes the spar to accumulate torsional load cycles. There was no legal requirement to document such usage, and it's notable that no other aircraft in the world has had that same problem, as far as the author is aware.

Yet similar problems are legion when one looks at the history of aircraft. The mighty Vickers Vulcan, when brought in for Depot Maintenance, had about 80 % of repair work done in areas where damage was never forecast. Big piston aircraft quite literally shook their engine cowlings apart, despite stainless steel panels and monel riveting.

New materials and techniques have not alleviated this. The first F-16 production run was facing wholesale obsolescence because of unforseen cracking in the composite fuselage. The RAAF's F-18's were heavily reinforced in the fuselage areas where the twin tails are mounted. The F-111 had similar problems in the rear fuselage - the dreaded wing carry-through box will not even be mentioned. As aircraft get older, they develop new problems. The Bell Kiowa had problems with delaminating of the vertical stabiliser. There was a time when Kiowa main rotor blade grips were just unobtainable - Bell were designing new ones and production of the old had ceased.

The Army seemed to regard the Nomad Horizontal Stabiliser spar problem as a major catastrophe. They believed it cast a shadow on the whole aircraft. Not so. It was quite simply, one of the speed bumps along the road of aircraft use. Tragic in some respects certainly, but not uncommon in the history of flight, as they accumulate hours, aircraft display unexpected problems. Army had been through the Pilatus Porter main wing-spar problems when corrosion demanded that the spars be rebuilt, but this episode seemed to be forgotten. Modern design philosophy is not to design unbreakable aeroplanes - instead, one inspects critical areas regularly to detect incipient failure. And the system works - if you don't believe this, you had better never fly again !

The HS spar problem became compounded by the RAAF N-24 problem. The N-24 is a longer fuselage version of the basic N-22 Nomad. The usual way to "stretch" an aircraft is by inserting fuselage plugs. The N-24 had plugs before and aft of the wing - quite a sensible modification - to increase the fuselage capacity. But the flap settings for the N-24 were strange. One could only use the minimum or the maximum settings - the intermediate ones were verboten – and strangely no reason was given for this. Anecdotal evidence suggests that RAAF pilots, condemned to fly admin sorties between the F-18 base at Tindal and Darwin, started to adjust the Nomad’s flap settings using the circuit breaker. One day they experienced uncontrollable longitudinal behavior which left the ailerons bent. The writer has not read the incident report, but the RAAF never flew either of their two N-24's again.

Similar problems with the fleet worldwide caused the then Australian Department of Civil Aviation to require the aircraft to be demonstrated as being safe. One of the problems here is that the flaps and ailerons are structurally identical - a production and maintenance bonus. There are other designs using the same approach (The Pilatus Porter for example) so it’s not rocket science. But, before such a control surface can be actually used as an aileron, it must be balanced on a jig, and anti-flutter weights fitted.

Flutter is a phenomenon discovered in the 1930's. It causes control surfaces to vibrate violently; often in these conditions they self-destruct in seconds. The Lockheed P-38 Lightning is a good example – in the prototypes its elevator developed severe flutter at high speed (usually in a dive) which lead to the entire tail-plane separating. It’s said that in one such flight test, the aircraft (by now tail-less) exceeded Mach 1 – which in turn led to the wartime folk legend that the P-38 was supersonic in a dive. The journalist who wrote this of course conveniently neglected to point out that the P-38 gouged a thirty foot deep crater in the Burbank landscape and Lockheed wasn’t in a hurry to dispel the myth about supersonic speed in a dive. (Editor’s note. We have a US Defence Department wartime documentary on the P-38 where the narrator boldly announces: "Speed in a dive – faster than the speed of sound…")

So flutter can be a problem. The condition is often cured in prop aircraft by adding mass balances - weights made of lead on arms which hang forward of the pivoting axis of the control surface. This lowers the resonant frequency of the entire assembly which then becomes reluctant to vibrate. So, whilst one might have half a dozen Nomad flap-aileron control assembles in the racks, they can’t be fitted as an aileron unless the balancing business is executed. The design wherein flaps and ailerons are structurally similar also meant that they were both actuated from one end. This led to concern about the torsional rigidity of the aileron, which if not strong enough would cause flexing of the structure, so it was stiffened with additional reinforcing material along the trailing edge. More weight.

In the meantime, the Army lost another aircraft at Tenterfield, NSW. This accident is still open; the aircraft was fuel heavy, crashed almost vertically nose in and burned fiercely. Much of the evidence hoped to provide clues to the cause of the crash was destroyed. It seems obvious the aircraft suffered a catastrophic loss of lift at a crucial phase of takeoff, but the underlying cause remains unclear. The crew included an instructor pilot whose experience was encyclopedic, which makes the loss harder to explain. (Editor’s note. One unconfirmed account suggests that a component was recovered showing that full aft trim had been incorrectly applied by the PNG student pilot prior to take-off. This could explain a pitch-up and stall condition)

All of these incidents - the loss of the aircraft at ARDU, the RAAF N-24 problem, the aileron distortion, the Tenterfield accident, led to a crisis of confidence amongst Army aviators. Sadly, this crisis was answered by taking counsel of fears, rather than by bold leadership. The years of almost trouble free Nomad operation was forgotten. The aircraft was withdrawn from Army service.

The result was the Indonesians received maybe $50 million worth of aircraft and equipment for almost nothing as part of an Australian aid package. No-one remembered the Philippine Air Force, our first commercial customers, and they still use their Nomads even today. But the withdrawal from Australian Army service wasn’t executed in a rational manner - one in which the Army exchanged the by then obsolescent aircraft for something newer and more capable.

Traditionally, the armed services exchange old equipment for newer. After all, if one has been operating a fleet of fixed wing aircraft for twenty years, one has very good justification for keeping it updated. You already have the manpower cover, in the way of pilot and maintenance establishments, so one is not fighting that most bloody of all interservice battles, the battle for more personel. Pseudo-experts in the higher level of the Australian Army Office contributed to this withdrawal. In this respect, the American Army instituted Senior Officer programs, designed to allow senior ranks to experience the realities of aviation which helped their understanding of what army aviation was all about, but this wasn't done in Australia. Here insipid administrators failed to see that this was a major selling point. And, let me persist, Aviation in the Australian Army still needs to be sold. The simple fact that it has taken 35 years for infantry-oriented senior Army officers to decide that they need army aviation support needs no further elaboration.

Yet, 35 years ago, the American's first divisional aviation formation, the 1st Cavalry Division, demonstrated that a helicopter-borne division could be handled with tactical success. The Battle of Ia Drang was an American victory, and one which would have been impossible without the helicopter. This action demonstrated a very high level of tactical expertise in many areas, and it is difficult not to conclude that the Australian Army choose to ignore these lessons. It was then fashionable (and to some extent still is) to regard the Americans as wasteful of assets, logistics and life, however Ia Drang showed otherwise.

The Future of Fixed Wing Aircraft in the Australian Army. The demise of the Nomad left the Army without fixed-wing aircraft. The fact that there was already fertile ground waiting to be sown was clearly demonstrated when one very enthusiastic individual almost singlehandedly resurrected fixed wing. Beech King-Airs were leased and have filled some very interesting roles ever since. These are roles which should be part and parcel of the responsibilities of an Army which will never fight on the neat Staff College Division text book frontages, but which instead will be spread haphazardly between Broome and Cape York, with everyone complaining about how far they have to travel to do anything!

A redesigned Nomad? A rework of the aircraft based on the lessons learned would seem to have been a logical step in the aircraft's lifecycle. However GAF vacilated, unable to make a commercial decision. In the end they vacilated too long and with the "privatisation" of GAF on the books, the beancounters were reluctant to embark on any project involving commercial risk which might detract from the prospectus. (Editors note: We know of at least one proposal by an Australian consortium prior to the "privatisation". This group approached GAF with a view to remanufacture the Nomad, with GAF doing some of the work and also receiving royalties. Using the experience gained from 20 years of service, they hoped to build a MK2 version which would overcome the revealed problems. This consortium had access to significant funding, however negotiations made little headway - partly because of the difficulty in finding anyone within the organisation capable of making decisions. The crunch came when it was found that the price expected from GAF for the Nomad drawings and jigs was unrealistic. According to a contact within GAF their value was being kept at their original cost figure as part of the assett value of the new company, and they would be gradually written off at a later stage to minimise the impact on the balance sheet. To accept the consortium's offer would mean having to accept a sudden write down to true market value - which would adversely affect the prospectus prior to the privatisation.)

Would a redesign have worked? When considering a redesign, one is attracted by the Chinese YS 300, an aircraft which seems to be a life-size copy of the Nomad. The problem when considering a redesign is whether one would have changed engines from the puny Allison's to a PT-6. The RAAF trainer, the PC-9, has over 1,000 horses available from the PT-68 version. Two of these and you are in Caribou country - in fact, well beyond it! These engines would have turned the Nomad into a mini-Hercules, and even with the inevitable strengthening, much of which may already have existed in the original drawings, it would have transformed the aircraft into one with outstanding range and payload. Whether or not such an aircraft could have transformed transport patterns in the Australian outback is a good question.

Conclusion 1. As a commercial aircraft, the Nomad was only a partial success. It had it's good points, and it's bad ones. Amongst it's good points was a remarkable freedom from corrosion, and the outstanding lateral control system. The engines were not a good point, and the aircraft was not economical to operate. Maybe a Nomad Mark II would have corrected these problems.

Conclusion 2. The Army decision to withdraw the aircraft was a poor one - primarily because it was based on fear, instead of factual considerations and then the army made no provision for a replacement, which will now have to be argued at considerable lengths and from the ground up.

It is understood that the first formal requirement for the Kiowa replacement was written in 1980. That aircraft might reach service by 2005. It is to be hoped that a new fixed wing aircraft, which might be along the lines of a Cessna Caravan, or maybe a Pilatus PC-12, will not take that long!