Canadair CT-114 Tutor

Last updated

CT-114/CL-41 Tutor
Canadair CT-114 Tutor (CL-41A), Canada - Air Force AN0223592.jpg
A CT-114 from 2CFFTS, RCAF
Role Trainer, Ground-attack aircraft
National originCanada
Manufacturer Canadair
First flight13 January 1960
Retired2000 as a trainer (Canadian Armed Forces)
StatusSmall numbers currently in flying condition for testing and aerobatic demonstration
Primary users Canadian Armed Forces
Royal Canadian Air Force
Royal Malaysian Air Force
Produced1963–1966
Number built212

The Canadair CT-114 Tutor (company model CL-41) is a jet trainer that was designed and produced by Canadian aircraft manufacturer Canadair. It served as the standard jet trainer of the Royal Canadian Air Force (RCAF), and later Canadian Armed Forces, between the early 1960s and 2000.

Contents

Development commenced as a private venture by the company. On 13 January 1960, the prototype performed its maiden flight; a year and a half later, the Canadian Government placed a major order for the type. The RCAF would be the dominant user of the type, but a limited number were exported as well. Specifically, the CL-41G model, which was supplied to the Royal Malaysian Air Force (RMAF), served as a ground-attack aircraft up until its withdrawal.

The Tutor served as the Canadian Armed Forces primary jet trainer from the 1960s up until 2000, at which point it was finally retired from this role, having been replaced by a combination of the newer British-built CT-155 Hawk and American-built CT-156 Harvard II. While the majority of Tutors have been retired, a small number are still being used by the RCAF’s Snowbirds aerobatics team.

Development

Origins

The beginnings of the CL-41 Tutor can be found in a decision by Canadian aircraft manufacturer Canadair to develop its own indigenous trainer aircraft as a private venture. The design was the product of the company’s in-house Preliminary Design department. [1] [2] By August 1957, the basic configuration of the design had been completed, which was of a turbojet-powered, low-wing aircraft, complete with a tricycle undercarriage and a side-by-side cockpit arrangement. [3] From the onset of development, the aircraft was intended to be a purpose-built trainer for providing elementary jet flight training, as well as additional training up to an advanced level.

Early on, despite a lack of official backing for the endeavour from the Canadian Government, the Royal Canadian Air Force's (RCAF) Directorate of Training’s Jet Trainer Liaison Committee had closely engaged with Canadair; its involvement in the project had reportedly made a significant impact in the final design of the aircraft. [3] Both the Canadian Government and Canadair committed financing towards the production of a pair of flight-capable prototypes, as well as multiple static airframes. This early manufacturing activity was performed in a secretive fashion at the company’s Plant 4 facility, which housed Canadair’s Missiles & Systems division. [3]

Flight testing

On 13 January 1960, the prototype performed its maiden flight, flown by project pilot Ian MacTavish. Originally, the first flight has been scheduled to take place in early 1959, but had been delayed due to issues relating to engine development. [3] While the prototype was powered by a single Pratt & Whitney JT12A-5 turbojet engine, this would be substituted for by a General Electric J85 powerplant for the subsequent production aircraft that followed. [4] This change of engine had required no redesign as the fuselage had been developed to accommodate a wide range of engines without structural modification being necessary; in addition to the JT12A-5 and J85, the Armstrong-Siddeley Viper ASV11, the Continental Gabizo, the Rolls-Royce RB.108, and the Fairchild J83-R-1 had been studied during the early stages of design work. [3]

During March 1960, an RCAF survey team performed a series of preliminary flight evaluations of the CL-41 prototype over the course of one week; prior to this, the team had evaluated various trainers from France, the United States, and the United Kingdom as well. [3] According to aviation historian Bill Upton, those who flew the prototype universally praised the aircraft for its favourable handling and performance. The prototypes were subject to an extensive regime of tests, some of which falling outside the traditional scope of such activities. [3]

Design

The CT-114 Tutor is a single-engine turbojet-powered trainer aircraft. It was purpose-designed for the training role, and possesses numerous favourable qualities, including a high level of reliability and favourable operating economics. [5] It is capable of a wide performance range, possessing a top speed at altitude of 795 kmh (429 kt) and a diving speed of 885 kmh (478 kt) against a relatively low stalling speed of 71kt. [5] The Tutor is furnished with manual flight controls, which incorporate spring tabs. It is intentionally aerodynamically stable in flight, a factor which traditionally has aided in the training of fresh pilots unfamiliar with the demands of flight. [2]

The Tutor features a side-by-side cockpit. During standard operations, the observing instructor was seated on the right-hand side and the flying student pilot on the left; normally, only the left-hand side normally featured full flight controls. [5] However, following experiences with the Snowbirds display team, a number of aircraft were reconfigured with extra controls so that they would be flyable from either position. [5] The cabin, which is fitted with a rear-hinged canopy over both crew members, can be pressurized to a differential of 3 psi (20 kPa), the equivalent to an altitude of about 2,000 m, for pilot comfort.[ citation needed ]

For aerial display purposes, the Tutor was readily capable of being fitted with a smoke generator, including a pair of under-fuselage pods to house the pressurized diesel fuel used; the use of red dye in the smoke was discontinued fairly quickly as it was found to be highly corrosive. [5] Various other modifications would also be made to display aircraft; these could be routinely installed and uninstalled as airframes would regularly be exchanged between display and training flights. [5]

Operational history

Overview

CT-114 Tutor of 2 Canadian Forces Flying Training School at CFB Moose Jaw in early 1982 CFBMooseJaw01.JPG
CT-114 Tutor of 2 Canadian Forces Flying Training School at CFB Moose Jaw in early 1982
CT-114 Tutors belonging to 2 Canadian Forces Flying Training School parked on the ramp at CFB Moose Jaw, 1982 CFBMooseJaw02.JPG
CT-114 Tutors belonging to 2 Canadian Forces Flying Training School parked on the ramp at CFB Moose Jaw, 1982

During September 1961, the Canadian government, having been impressed by the performance of the prototype and being keen to support local industry, placed a sizeable order for 190 examples of the production variant, referred to as the CL-41A, on behalf of the Royal Canadian Air Force (RCAF). Upon its adoption, the aircraft received the Canadian unified aircraft designation of CT-114 Tutor. The majority of the type was stationed at CFB Moose Jaw, Saskatchewan, in Western Canada; the Central Flying School at CFB Winnipeg, Manitoba, also made heavy use of the Tutor. [2] [6]

Serving as a primary trainer platform, the Tutor was used in this capacity for over thirty years. During 1976, the Canadian Armed Forces decided to have 113 of the remaining aircraft furnished with upgraded avionics and provisions for a pair of belly-mounted 41 US gal (155 L) external fuel tanks.[ citation needed ] By 1998, it was reported that around 120 examples of the type were still in regular service with the Canadian Armed Forces. [2] During 2000, the majority of Tutors were retired, the type having been succeeded as the RCAF's principal training aircraft by a combination of the newer British-built CT-155 Hawk and American-built CT-156 Harvard II. [6] Since then, it has continued to be used in limited numbers by the service for both experimental (by the Aerospace Engineering Test Establishment (AETE) at CFB Cold Lake, Alberta) and aerial display purposes. By 2019, there were 24 examples registered as in service with the RCAF. [6]

Aerobatics

Snowbirds at an airshow Snowbirds aircraft at an airshow.jpg
Snowbirds at an airshow

During 1967, a batch of ten Tutors were modified for use as a formation aerobatic aircraft by the RCAF (and later the unified Canadian Armed Forces) display team, the Golden Centennaires to celebrate Canada's centennial year. At the end of the 1967 season, the display team was disbanded, thus its aircraft returned to routine training duties. In 1971, a new formation team was formed at 2CFFTS (Two Canadian Armed Forces Flying Training School) at CFB Moose Jaw, and once again adopted the type. The following year, the name "Snowbirds" was chosen for the team; during 1978, the team received squadron status as 431 Air Demonstration Squadron. [7]

Since its formation, the Snowbirds display team has regularly performed at air shows and special events, including the annual flypast on Canada Day over the capital city, Ottawa. [8] According to journalist Guy Norris, a defining trait of their aerobatics is the physically-demanding formation flights performed, as well as locally-developed manoeuvres such as the ‘Big Goose’. Unlike most display teams, the Snowbirds do not have a support aircraft; all spares and useful material could be carried by the aircraft themselves in storage areas located in the nose or the wing root. [4]

Those Tutors used by the Snowbirds feature several modifications distinguishing them from standard examples; these include a smoke generating system, a highly-recognisable paint scheme unique to the display team, and a highly-tuned engine for greater responsiveness during low-level flying. [6] Reportedly, display pilots would deliberately fly their aircraft using an above-average level of nose-down trim so that pushing the stick down would become unnecessary. [2] The Snowbirds' aircraft would regularly be cycled with standard training aircraft, allowing the team to operate airframes with comparatively low accumulated flight hours. [5]

Overseas and proposed uses

Canadair also developed an armament training and light attack variant, designated CL-41G. This model was powered by an uprated engine and fitted with underwing hard points, the latter of which allowed for the carriage of various external stores, including up to 4,000 lb (1814 kg) of weapons and drop tanks. During March 1966, the Royal Malaysian Air Force (RMAF) ordered a batch of twenty (serials M-22-01 to M22-11) examples of the CL-41G-5 Tebuan (which means Wasp in the Malay language) aircraft as counterinsurgency (COIN) aircraft. In 1967, the Tebuan entered service in Malaysia. The RMAF operated the type in excess of twenty years, the last Tebuan being withdrawn from service during June 1986, having been replaced by the Italian Aermacchi MB-339A.[ citation needed ] Following their retirement, the majority of the fleet was retained and placed into local storage for over a decade. [2]

CL-41R with an RCAF CF-104 Canadair CF-104 12822 RCAF with CL-41R (mfr H-93 via RJF) (17136018672).jpg
CL-41R with an RCAF CF-104

One other experimental variant was developed, designated CL-41R, which was fitted with the nose of an F-104 Starfighter, as a proposed electronic systems trainer for future RCAF CF-104 pilots. A single airframe (CF-LTX-X) was constructed to demonstrate the concept, however, the R model did not attract any orders and thus never went into production.[ citation needed ]As of August 2019, the airframe was awaiting restoration at the Reynolds-Alberta Museum.[ citation needed ]

Variants

CL-41
Two prototypes, CF-LTW-X and CF-LTX-X used for company engineering and testing program
CL-41A
A total of 190 trainers produced for RCAF and CF use as the CT-114. A number were modified with smoke generating systems and other modifications for the Snowbirds aerobatic team
CL-41G
Unique version for the Royal Malayan Air Force (RMAF). A total of 20 ground-attack variants, known as the "Tebuan" in service with RMAF.
CL-41R
One conversion of CF-LTX-X with a CF-104 nose grafted on to demonstrate the use of CF-104/F-104G radar and avionics; no production examples were built.

Operators

Flag of Canada (Pantone).svg  Canada
Flag of Malaysia.svg  Malaysia

Aircraft on display

Tutor prototype on display at Southport Aerospace, Manitoba, in Golden Centennaires livery Golden Centennaires Tutor.jpg
Tutor prototype on display at Southport Aerospace, Manitoba, in Golden Centennaires livery

Surviving aircraft

Aerospace Engineering Test Establishment Canadair Tutor Canadair Tutor Aerospace Engineering Test Establishment.jpg
Aerospace Engineering Test Establishment Canadair Tutor
CT-114 cockpit CT-114 cockpit CWHM.jpg
CT-114 cockpit

Although the CL-41 Tutor has been retired from active training, 26 Tutors continue to fly with the Canadian Armed Forces Snowbirds and the Aerospace Engineering Test Establishment at CFB Cold Lake or are in short-term storage. [28]

As of August 2011, there were three CL-41Gs and one CT-114 on the U.S. civil registry, while none were so registered in Canada. [29] [30] [31]

During 2001, a CL-41G was given to Embry-Riddle Aeronautical University in Daytona Beach, Florida, by actor John Travolta. [32]

Specifications (CL-41A – CT-114)

Data fromMacdonald Aircraft Handbook, [33] Royal Canadian Air Force [6]

General characteristics

Performance

Armament

See also

Aircraft of comparable role, configuration, and era

Related lists

Related Research Articles

<span class="mw-page-title-main">Canadair</span> Aircraft manufacturer

Canadair Ltd. was a civil and military aircraft manufacturer in Canada. In 1986, its assets were acquired by Bombardier Aerospace, the aviation division of Canadian transport conglomerate Bombardier Inc.

<span class="mw-page-title-main">Snowbirds (aerobatic team)</span> Canadas military flight demonstration squadron

The Snowbirds, officially known as 431 Air Demonstration Squadron, are the military aerobatics flight demonstration team of the Royal Canadian Air Force. The team is based at 15 Wing Moose Jaw near Moose Jaw, Saskatchewan. The Snowbirds' official purpose is to "demonstrate the skill, professionalism, and teamwork of Canadian Forces personnel". The team also provides a public relations and recruiting role, and serves as an aerial ambassador for the Canadian Armed Forces. The Snowbirds are the first Canadian air demonstration team to be designated as a squadron.

<span class="mw-page-title-main">Royal Canadian Air Force</span> Air warfare and space branch of the Canadian Armed Forces

The Royal Canadian Air Force is the air and space force of Canada. Its role is to "provide the Canadian Forces with relevant, responsive and effective airpower". The RCAF is one of three environmental commands within the unified Canadian Armed Forces. As of 2020, the Royal Canadian Air Force consists of 12,074 Regular Force and 1,969 Primary Reserve personnel, supported by 1,518 civilians, and operates 258 manned aircraft and nine unmanned aerial vehicles. Lieutenant-General Eric Kenny is the current commander of the Royal Canadian Air Force and chief of the Air Force Staff.

<span class="mw-page-title-main">Golden Hawks</span> Canadian military flight demonstration team 1959–1964

The Golden Hawks were a Royal Canadian Air Force (RCAF) aerobatic flying team established in 1959 to celebrate the 35th anniversary of the RCAF and the "Golden" 50th anniversary of Canadian flight, which began with the AEA Silver Dart in 1909.

<span class="mw-page-title-main">417 Combat Support Squadron</span> Canadian military flying unit

417 Combat Support Squadron is an Air Force unit with the Canadian Forces. Based at CFB Cold Lake it provides helicopter support to the base operations. Since 1994, it has also provided search and rescue.

<span class="mw-page-title-main">Canadair CT-133 Silver Star</span> Canadian military training aircraft

The Canadair CT-133 Silver Star is the Canadian license-built version of the Lockheed T-33 jet trainer aircraft, in service from the 1950s to 2005. The Canadian version was powered by the Rolls-Royce Nene 10 turbojet, whereas the Lockheed production used the Allison J33.

<span class="mw-page-title-main">Canadair CF-104 Starfighter</span> Licensed built variant of the F-104 Starfighter

The Canadair CF-104 Starfighter is a modified version of the Lockheed F-104 Starfighter supersonic fighter aircraft built in Canada by Canadair under licence. It was primarily used as a ground attack aircraft, despite being designed as an interceptor. It served with the Royal Canadian Air Force (RCAF) and later the Canadian Armed Forces (CAF) until it was replaced by the McDonnell Douglas CF-18 Hornet.

NATO Flight Training in Canada (NFTC) is a military flight training program for NATO and allied air forces provided by the Canadian Forces.

<span class="mw-page-title-main">CFB Moose Jaw</span> Canadian Forces base in the south of Moose Jaw, Saskatchewan, Canada

Canadian Forces Base Moose Jaw, also known as 15 Wing Moose Jaw, is a Canadian Forces base located 4 nautical miles south of Moose Jaw, Saskatchewan. It is operated as an air force base by the Royal Canadian Air Force (RCAF) and is home to RCAF Pilot training and 431 Squadron, the Snowbirds, which is the RCAF's air demonstration squadron.

<span class="mw-page-title-main">Canadair CF-5</span> Fighter bomber aircraft by Canadair

The Canadair CF-5 is a Canadian licensed-built Northrop F-5 Freedom Fighter. It is a light, supersonic, twin engine, daylight air superiority fighter primarily for the Canadian Forces and the Royal Netherlands Air Force. The CF-5 was upgraded periodically throughout its service life in Canada. While Canadian Forces retired the aircraft in 1995, it continues to be used by other countries.

<span class="mw-page-title-main">CFB Winnipeg</span> Airport in Winnipeg, Manitoba

Canadian Forces Base Winnipeg is a Royal Canadian Air Force base located within the City of Winnipeg, Manitoba. Co-located at the Winnipeg James Armstrong Richardson International Airport, CFB Winnipeg is home to many flight operations support divisions, as well as several training schools. Its primary RCAF lodger unit is 17 Wing, commonly referred to as 17 Wing Winnipeg.

<span class="mw-page-title-main">Beechcraft CT-134 Musketeer</span> Canadian military aircraft

The Beechcraft CT-134 Musketeer is a military training derivative of the Musketeer built by Beechcraft for the Canadian Armed Forces. The CT-134 was a single engine, low-wing, four-seat light aircraft with fixed landing gear and a limited aerobatic capability.

<span class="mw-page-title-main">2 Canadian Forces Flying Training School</span> Military flying school

2 Canadian Forces Flying Training School is one of the Royal Canadian Air Force's training centres for pilots and also one of the facilities of the NATO Flying Training in Canada (NFTC) program.

<span class="mw-page-title-main">Cold Lake Air Force Museum</span> Military aviation museum in Alberta, Canada

The Cold Lake Air Force Museum is a military aviation museum located in Cold Lake, Alberta. The museum preserves and exhibits the heritage and history of 4 Wing Cold Lake and 42 Radar Squadron. The Air Force Museum is actually one of four museums based on the old site of 42 Radar Squadron, who re-located to CFB Cold Lake in 1992. The Cold Lake Museums are connected to the Air Force Museum through a covered hallway affectionately dubbed 'The Tunnel'. All together, the museums are referred to as the Cold Lake Museums or the Tri-City Museums. The old facility of 42 Radar Squadron was decommissioned in 1992, and the museum opened its doors for the first time on July 1, 1998.

<span class="mw-page-title-main">National Air Force Museum of Canada</span> Aviation museum in CFB Trenton in Trenton, Ontario

The National Air Force Museum of Canada is an aviation museum dedicated to preserving the history of the Royal Canadian Air Force (RCAF) and is located on the west side of CFB Trenton in Trenton, Ontario.

<span class="mw-page-title-main">Shearwater Aviation Museum</span> Aviation museum in Canada, at CFB Shearwater

The Shearwater Aviation Museum is an aviation museum located at CFB Shearwater in Shearwater, Nova Scotia. The museum acquires, conserves, organizes, researches and interprets to Canadian Forces personnel and the public at large for their study, education and enjoyment, artifacts and documents which exemplify the history of Canadian maritime military aviation.

Lt. Col (Ret.) Joseph Armand Gerard Fernand Villeneuve was a Canadian aviator who joined the Royal Canadian Air Force (RCAF) in 1950 and was the first leader of the RCAF's Golden Hawks aerobatic team. He flew for 32 years as a military jet fighter pilot Villeneuve was inducted into the Canadian Aviation Hall of Fame in 2006.

<span class="mw-page-title-main">Jim McCombe</span>

James David McCombe was a Royal Canadian Air Force (RCAF) pilot who was a commander of the Golden Hawks aerobatics team. His career with the RCAF spanned 23 years.

<span class="mw-page-title-main">Trans-Canada Air Lines Flight 9</span> 1954 mid-air collision

On April 8, 1954 Trans-Canada Air Lines Flight 9, a Canadair C-4 North Star four-engine commercial propliner on a domestic regular scheduled flight, collided in mid air with a Royal Canadian Air Force (RCAF) Harvard Mark II single engine military trainer on a cross-country navigation exercise over Moose Jaw, Saskatchewan.

This is the structure of the Royal Canadian Air Force, as of November 2020.

References

Citations

  1. Dishlevoy 2005, pp. 8–10.
  2. 1 2 3 4 5 6 Norris 1998, p. 22.
  3. 1 2 3 4 5 6 7 Upton, Bill. "CL-41 Prototype." Canadian Aviation Historical Society, Retrieved: 31 May 2019.
  4. 1 2 Norris 1998, pp. 22–23.
  5. 1 2 3 4 5 6 7 Norris 1998, p. 23.
  6. 1 2 3 4 5 "CT-114 Tutor." airforce.forces.gc.ca, Retrieved: 31 May 2019.
  7. "431 Air Demonstration Squadron". Government of Canada. Retrieved 18 May 2020.
  8. Bradshaw, Stacey. "Snowbirds to fly over the Canada Aviation Museum". Wings. Retrieved 18 May 2020.
  9. https://static1.squarespace.com/static/5ce2eac378733900016331b2/t/5ecc62f6ab61810adc2259c0/1590452987995/CT-114+Tutor+Serials_Complete_2020.pdf
  10. "Canadair CT-114 Tutor". www.canadianflight.org.
  11. "Canadair CL-114 Tutor RCAF #114004 - Royal Aviation Museum of Western Canada". royalaviationmuseum.com. 24 June 2022. Retrieved 26 January 2024.
  12. Rousseau, Jean-Philip (1 August 2009). "Un nouvel avion pour les cadets". Le Journal de Québec (in French). Québécor. Retrieved 24 March 2024.
  13. "Bagotville, Quebec, Canada". EuroDemobbed. Retrieved 24 March 2024.
  14. "Tutor – National Air Force Museum of Canada" . Retrieved 26 January 2024.
  15. "Canadian Warplanes 6: Canadair CT-114 Tutor". www.silverhawkauthor.com. Retrieved 26 January 2024.
  16. "Canadian Warplanes (3) Saskatchewan, CFB Moose Jaw". www.silverhawkauthor.com. Retrieved 26 January 2024.
  17. "Aircraft Details". Canadian Warplane Heritage Museum. Retrieved 26 January 2024.
  18. "Shearwater Aviation Museum - Ruud Leeuw". www.ruudleeuw.com. Retrieved 26 January 2024.
  19. Welch, Dave. "Canadair CT-114 Tutor, 114076 / 1076, Reynolds Alberta Museum". abpic.co.uk. Retrieved 26 January 2024.
  20. "The Tutor Jet". Tourism Moose Jaw. Retrieved 26 January 2024.
  21. "Canadian Warplanes 6: Canadair CT-114 Tutor". www.silverhawkauthor.com. Retrieved 26 January 2024.
  22. "Canadair CT-114 Tutor - Canada Aviation and Space Museum". 3 July 2016. Archived from the original on 3 July 2016. Retrieved 26 January 2024.
  23. "Air Force Museum - Cold Lake Museums". www.coldlakemuseums.org. 2 August 2020. Retrieved 26 January 2024.
  24. "Canadair CT-114 Tutor – Comox Visitor Information Centre". experiencecomoxvalley.ca. Retrieved 23 September 2022.
  25. https://static1.squarespace.com/static/5ce2eac378733900016331b2/t/5ecc62f6ab61810adc2259c0/1590452987995/CT-114+Tutor+Serials_Complete_2020.pdf
  26. "Canadair CT-114 Tutor". Bomber Command Museum of Canada. 5 April 2019. Retrieved 26 January 2024.
  27. Yates, Kelsey (27 July 2022). "Snowbirds fly over Creston to honour Golden Centennaires squadron leader". Creston Valley Advance. Archived from the original on 29 July 2022. Retrieved 29 July 2022.
  28. Canadian Armed Forces (29 July 2019). "CT-114 Tutor". rcaf-arc.forces.gc.ca. Retrieved 23 May 2020.
  29. "Make / Model Inquiry Results CL41." Federal Aviation Administration, August 2011. Retrieved: 15 August 2011.
  30. "Make / Model Inquiry Results CT-114." Federal Aviation Administration, August 2011. Retrieved: 15 August 2011.
  31. "Canadian Civil Aircraft Register: Canadair CT-114." Transport Canada, August 2011. Retrieved: 15 August 2011.
  32. Ross, Bob. "John Travolta Donates Jet to Embry-Riddle." Archived January 5, 2008, at the Wayback Machine Embry-Riddle Aeronautical University, November 2001. Retrieved: 6 September 2009.
  33. Green 1964, p. 470.

Bibliography

  • Dishlevoy, Roy W. "Hatching the Snowbirds: The Canadair CL-41/CT-114 Tutor, Its Early History Remembered." CAHS Journal, Vol, 45, No. 1, Spring 2007.
  • Green, William. Macdonald Aircraft Handbook. London: Macdonald & Co. (Publishers) Ltd., 1964.
  • Molson, Ken M. and Harold A. Taylor. Canadian Aircraft Since 1909. Stittsville, Ontario: Canada's Wings, Inc., 1982. ISBN   0-920002-11-0.
  • Norris, Guy. “Rocky Mountain High.” ‘’Flight International’’, 6 January 1998. pp. 22–23.
  • Pickler, Ron and Larry Milberry. Canadair: The First 50 Years. Toronto: Canav Books, 1995. ISBN   0-921022-07-7.