Discovering Tutor Jet, the pride of Canada's Snowbirds, one of the most famous aerobatic demonstration squadrons in the world.

1. EVERYTHING YOU SHOULD KNOW ABOUT THE

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3. What started as a compulsory assignment for the Aircraft Design (AE 332)
course taken up in my pre-final semester at IIT Bombay, has become a
fascinating journey through the design and development of one of the Royal
Canadian Air Force’s finest trainer aircrafts of all time. Over the course of the
past fortnight, I have uncovered a lot of interesting information regarding the
Canadair CL-41 Tutor and wish to share it to the best of my ability with the
prospective reader.
All the information contained in this document is available on the internet and
has been derived from various sources listed at the end of the report. I have
merely performed the task of curating the available information to give a
holistic overview of the aircraft.
Feedback and constructive criticism regarding the report are much appreciated
and can be shared across with an email to neal.iyer94@gmail.com
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4. I would like to acknowledge the contributions of the following people towards
creating the report:
Prof. Pant from the department of Aerospace Engineering at IIT Bombay who
is also the instructor for the course which prompted me to embark on this
adventure via an innovative course assignment. The Teaching Assistants of the
course Hemant and Diganta who helped us structure the report into a
meaningful outcome. Lastly, I would like to acknowledge the contributions of
my batchmates who had taken up the course in the Autumn semester of 2015-
16, discussions with whom have been extremely valuable in understanding the
expected results and approaches to the problem.
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6. Flying the Tutor Jet
Although these specifications can be found in the slides to follow there
is nothing quite like the video in the description below to sum up the
Canadair CL 41A Tutor
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7. The Canadair CL-41 Tutor was manufactured by Canadair, a civil and military
aircraft manufacturer in Canada, as a trainer aircraft for the Royal Canadian Air
Force(RCAF).
Canadair was initially a private subsidiary of many companies before being
bought and owned by the Canadian Government for a span of 10 years from
1976 to 1986 until it made record losses on making a business jet(Challenger)
and had to be sold to Bombardier Inc., which today stakes claim to being the
third largest aircraft manufacturer after Airbus and Boeing.
Canadair has a rich legacy of several aviation firsts. The CL-44D, was the first
design that allowed access by swinging the entire rear fuselage. The CL-89 and
CL-289 were the first surveillance drones to be put into service in several
countries' armed forces. The CL-84 was the first VTOL aircraft that rotated the
wings to achieve vertical lift-off (tiltwing). The CL-215 was the first purposed-
designed water bomber.
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8. In September 1961 the Canadian government ordered 190 examples of the
production variant, CL-41A for the RCAF. The Tutor served for over thirty years
as a primary trainer.
In 1967, ten Tutors were modified for use as a formation aerobatic aircraft by
the RCAF display team, the Golden Centennaires to celebrate Canada's
centennial year. The display team was disbanded after the 1967 season. In
1971 the CL-41A found its biggest claim to fame as a formation team was
formed and in 1972 the name "Snowbirds," was chosen following which the
team gained squadron status as 431 Air Demonstration Squadron, who
continue to perform at air shows and special events including the
annual flypast on Canada Day over the capital city, Ottawa.
RCAF LOGOS
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9. The Snowbirds are Canada's military aerobatics or air show flight demonstration team whose purpose is to
"demonstrate the skill, professionalism, and teamwork of Canadian Forces personnel". The show team
flies 11 CT-114 Tutors—nine for aerobatic performances, including two solo aircraft, and two as spares,
flown by the team coordinators. The Snowbirds are the only major military aerobatics team that operates
without a support aircraft.

10. It turns out that Canadians took to flying aircrafts very early and did it very
well from the beginning thus it comes as no surprise that Canada has the
richest legacy of Aerobatic squads and shows in the world. The fascination
with flying in the country has made becoming a Snowbird a dream to pursue
for even the best airline pilots in Canada and central to the image of the
snowbirds are their characteristic red and white CL-41 Tutors.
Snowbirds Video
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12. Specification Detail
Manufacturer Canadair
Model Name CL-41A
Air Force Designation CT-114
Role Trainer
Manufacturing Period 1963-1966
Number Built 212
Seating Capacity 2
Retirement 2000(as Trainer)
The CL-41 took its first flight on 13 January 1960. It also has 3 other variants
which have slightly different specifications but we will primarily be looking
at the CL-41A which was used by the RCAF.
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13. Specification Detail
Manufacturer General Electronics
Number of Engines 1
Model Number Orenda J85-CAN-40
Engine Type Turbojet
Maximum Thrust 11.8 kN
Length 115–130 cm
Engine Intake Diameter 45 cm
Total Number of Stages 8 compressor, 2 turbine
Mass flow rate 20 kg/s
The CL-41 has a single fuselage mounted engine but it is much more
powerful than the ones used in other jet trainers which have come up after
its time
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14. Specification Detail
Wingspan 11.07
Wing Ref. Area 20.4 m2
Wing Dihedral Angle 2 degrees
Wing Aspect Ratio 6
Wing Taper Ratio 0.5
The CL-41 has low, fixed-sweep, short wings with low aspect ratio and also
has a pitot static tube mounted below one of the wings.
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15. Specification Detail
Tail Type T-Tail
Horizontal Tail span 4.16 m
Horizontal Tail Ref. Area 4.92
Horizontal Tail Dihedral Angle 0 Degrees
Quarter Chord Sweep 2 Degrees
Taper Ratio of Horizontal Tail 0.5
Vertical Tail Span 2.34 m
Vertical Tail Ref. Area 5.5 m2
Vertical Tail Quarter Chord Sweep 4 Degrees
Vertical Tail Taper Ratio 0.5
Number of Vertical Tails 1
Angle b/w Vertical tail and axis 0
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16. Specification Detail
Length 9.75 m
Height 2.86 m
Wheel Track 4.02 m
Wheel Base 3.38 m
Max Takeoff Weight 5000 kg
Max Landing Weight 3175 kg
Max Zero Fuel Weight 2195 kg
Max Operating Empty Weight 3333 kg
Standard Internal Fuel Capacity 1170 litres
Extra Fuel Capacity 1086 litres
The aircraft is relatively small in size and the steering capabilities
of the aircraft lie in the nosewheel.
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17. Specification Detail
Take-off Distance at SL ISA Conditions 532 m
Landing Distance at SL ISA Conditions 710 m
Max Operating Speed 217 m/s
Normal Operating Speed 144 m/s
Max Cruise Speed 210 m/s
Altitude for Max Cruise Speed 8700 m
Max Range with no payload 1520 km
Altitude of Operation for Max Range 8000 m
Maximum Payload 1590 kg
Maximum Sustained Turn Rate 4 degrees/sec
The aircraft can reach a speed of 400 knots and has ejection
seats for both pilots which can help in recovery of pilots.
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19. The CL-41A was primarily used in aerobatic shows by the Snowbirds. The
aircraft would take-off from a base close to the airshow hence it would
have to cruise for a minimum time. The vast majority of the mission would
involve loitering around the air-show area, we will be neglecting the ascent
and descent in the mid-air maneuvers during the air-show for our weight
estimation purposes.
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21. We is the empty weight fraction and W0 is the maximum take
off weight which includes Wcrew+ Wpayload+ Wempty+ WFuel
‘A’ for a Jet Trainer is given to be 1.47
‘c’ is given to be -0.1
We=1.47*(W0)-0.1
We = A* (W0)c 21

22. The Tutor has a total of 2 pilots with 2 parachutes. Let us assume an
average weight of approximately 100 kg for each pilot and parachute
So the total payload weight becomes 200 kg
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23. We will be using the standard fuel weight fraction(Wi/Wi-1) for Take off,
climb and landing which are 0.970, 0.985 and 0.995 respectively and
that during descent as 1 as given by Raymer.
Also cruise is negligible in our case as the aircraft takes flight from a
very close by airfield. Hence even that coefficient is treated as nearly
equal to 1
(W6/W0) = (W6/W5)*(W5/W4)*(W4/W3)*(W3/W2)*(W2/W1)*(W1/W0)
= (0.95067)*(W5/W4)
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24. Tsfc= 27 g/kN*s
From the graph we can see that (L/D)max for an aircraft with aspect
ratio 6 is close to 16
The approximate duration of an airshow as quoted in the Snowbirds’
video is 2 hours or 7200 seconds
This gives us W5/W4 = 0.988 so W6/W0=0.988*0.95067=0.939
Reserve Fuel Fraction=0.05
Wf=(1.05)*(1-0.939)=0.06377
E=(1/tsfc)*(L/D)max*(ln(W4/W5)) 24

25. W0=(200)/(1-0.06377-1.47(W0)-0.1 )
0.936*W0 – 0.1*(W0)0.9=200
The following equation needs to be solved in MATLAB to obtain the
result which comes out to be approximately 3,471.64 kg which is very
far off from the actual value of 5000 kg.
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27. The answer that we got from our analysis is very different from
the actual value. This leads us to the conclusion that ignoring
maneuvers during loiter may be a good assumption for general
aircrafts but for an aircraft in an airshow, the assumption is
fatal as it needs to perform multiple climb sequences. Also
apart from the engine fuel, these aircrafts also carry diesel
tanks to generate smoke and add visual elements to their
performance. These tanks would also contribute to the fuel
fraction but we have not been able to account for them in the
analysis
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28. The whole exercise has been hugely informative for me and I
hope it was the same for any potential readers. The videos that
I viewed in order to compile the following presentation give a
great sense of perspective about timelines in the evolution of
the aviation industry.
I was entirely new to the concept of professional airshows
being an occupation of pilots but knowing more about the CL-
41 Tutor and especially the Snowbirds should give everyone an
understanding of why air superiority is considered the pride of
so many nations.
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29. All the information contained in the following presentation has been
referenced from the following sources:
http://www.sooeys.com/viewtopic.php?p=113687&sid=a59322d990
86a5a4817c3c2bc965e6bd (The answer has been sourced from
Jane’s all the World’s Aircraft)
https://en.wikipedia.org/wiki/Canadair_CT-114_Tutor
https://en.wikipedia.org/wiki/General_Electric_J85
http://learntofly.ca/snowbirds-learn-to-fly-a-snowbird-tutor-jet/
http://www.combataircraft.com/en/Military-Aircraft/Canadair/CL-
41-Tutor/
Aircraft Design by Daniel Raymer
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30. AE-332 class notes and presentations compiled by Prof. Pant
Image Sources:
http://www.orilliapacket.com/2012/06/27/snowbirds-take-
flight-in-orillia-on-saturday
http://www.greatnewenglandairshow.com/
http://www.combataircraft.com/aircraft/TCL41_vl.jpg
http://images.google.com
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31. THANK YOU
Comments & Feedback Appreciated
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