Helicopter Maintenance

EA-HF-2

:=JEPPESEN®

Sanderson Training Products

Table of Contents

Preface

Introduction

Chapter I

Helicopters In Use Today

Bell; Hiller; Hughes; Sikorsky; Brantly Hynes; Enstrom;

Vertol; Robinson; Messerschmitt-Boelkow; Aerospatiale

Chapter II

>Principles of Flight

Aerodynamic principles; Effects on lift;

Forces on the rotor;' Thrust; Dissymmetry of lift;

Rotor heads; Aerodynamic characteristics;

Blade tip stall; Autorotation; Ground resonance;

Stability; Flight control

Chapter III

Documentation, Publications,

and Historical Records

FAA p-q.blications; Maintenance records;

Manufacturers publications;

Supplemental Type Certificates

Chapter IV

Helicopter Fundamentals

Basic directions; Ground handling; Bearings; Gears

Chapter V

Main Rotor System

Rotor heads; Semirigid rotor heads;

Fully articulated rotor heads; Rotor blades;

Rotor head maintenance -

Blade alignment;

Static main rotor balance; Vibration; Tracking;

Spanwise dynamic balance; Blade sweeping;

Electronic balancing; Dampener maintenance;

Counterweight adjustment; Autorotation adjustment

Chapter VI

Mast and Flight Controls

Mast; Stabilizer bar; Dampeners;

Swa~hplate;

Flight control

syst~ms

-

Collective; Cyclic;

Push-pull tubes; Torque tubes; Bellcranks;

Mixer box; Gradient unit; Control boosts;

Maintenance,and inspection; Control rigging

iii

Pagev

vii-viii'

1-37

39-55

57-72

73-90

91-158

159-189

Chapter VII Main.Rotor Transmissions

Engine-transmission couplings; Driveshaft;

Clutch; Freewheeling units; Sprag clutch;

Roller unit; Torquemeter; Rotor brake;

Vibrations; Mounting systems; Transmissions

Chapter VIII Powerplants

Fixed wing powerplant modifications; Installation;

Radial and opposed engines; Cooling systems;

Correlation systems; Turboshaft engines;

Powerplants

Chapter IX

Tail Rotors

Operation; Tail rotor system; Bell 47; Hughes 500;

AStar 350; Bell 212; Servicing; Tail rotor track;

System rigging

Chapter X · Airframes and Related Systems

Tubular construction; Sheet metal construction;

. Bonded construction;·Stress and. loads;

Wheel and skid gear; Visibility;

.

Structural components and materials;

Bell 206 fuselage; Hughes 500 fuselage;

Fuselage maintenance; Airframe systems;

Special purpose equipment

Glossary

·Index

191-221

223-275

277-308

309-324

325-331

333-343

PREFACE

This book on Basic Helicopter Maint~nance is part of a course of training and reference publications produced by Jeppesen Sanderson, Inc., one . of the largest suppliers of aviation maintenance training materials in the world. This program is part of a continuing effort to improve the quality of education for aviation mechanics throughout the world.

The purpose of each Jeppesen Sanderson training publication is to provide basic information on the operation and principles of the various aircraft systems and their components.

Specific information on detailed operation procedures should be obtained form the manufacturer through appropriate maintenance manuals, and followed in detail for the best results.

This particular manual on Basic Helicopter Maintenance includes a series of carefully

prepared questions and answers to emphasize key elements of the study. They are contained in the supplemental Jeppesen Sanderson text Helicopter Maintenance Study Guide.

Some of the words may be new to you. They are defined in the Glossary found at the back of the book.

The validity of any manual · such as this is enhanced immeasurably by the cooperation · shown by recognized experts in the field, and by the willingness of the various manufacturers to share their literature and answer countless questions in the preparation of this publication. For product, service, or sales information call

1-800-621-JEPP, 303-799-9090, or FAX 303-784-4153. If you have comments, questions, or need explanations about any component of our Maintenance Trainillg System, we are prepared to offer assistance at any time. If your dealer does not have a Jeppesen catalog, please request one and we· will promptly send it to you. Just-call the above telephone number, or write:

Marketing Manager, Training Products Jeppesen Sanderson, Inc.

55 Inverness Drive East Englewood, CO 80112-5498

Please direct inquiries from Europe, Africa, and the Middle East to:

Jeppesen & Co., GmbH P. 0.-Box 70-05-51 Walter-Kolb-Strasse 13 60594 Frankfurt GERMANY Tel: 011-49-69-961240 Fax: 011-49-69-96124898

Introduction

The concept of the helicopter has been dreamed of for hundreds of years. The first recorded drawings of such a machine were made by Leonardo da Vinci in 1483.

This machine was an aerial screw which he envi-sioned as being able to move vertically into the air with a rotor built with a 96-foot helix. It was from this drawing that the helicopter derived its name - from the two Greek words heliko and pleron meaning helical wing.

It was not until the latter part of the 18th century that any further developments were achieved with helicopters. At that time interest developed in both France and England. Jean Pierre Blanchad flew a model helicopter for the French Acadamie de Sci-ences and Sir George Caley drew several helicopter designs while making contributions to the basic knowledg~ of the principles of flight. ·

Throughout the 19th century, with the invention of the internal combustion engine, men from all na-tions pursued the problem of flight. In spite of the efforts of these inventors, no real significant ad-vances were made in flight. By the latter part of the 19th century and the beginning of the 20th century, all emphasis was placed on powering gliders.

Thomas Edison summed up the situation for ro-tary wing aircraft by stating that an inherent lim-itation in helicopter development at that time was the lack of a lightweight engine.- a handicap which was somewhat less restrictive to the fixed

wing concept. .

By1903 the Wright Brothers had made the first manned powered flight. With this success, the em-phasis shifted from rotary to fixed whig for all bu~

a

few inventors. These few realized the drawbacks of the fixed wing, such as the necessity for long run-ways and forward speed to prevent stalling;

In 1907 Louis Breguet and Professor Richet of France constructed a machine of 45. horsepower with four rotors. This rose to a height of five feet. It

did not, however, receive the distinction of the first free flight because it had to be steadied by four assistants. Instead, this distinction fell to another Frenchman, Paul Cornu, just a few weeks later, who attained a height of five feet with a passenger hanging underneath.

In 1910 a young Russian designer by the name of Igor Sikorsky built a coaxial helicopter powered by a 25-horsepower engine. This helicopter was only capable of lifting its own weight. At that time the

vii

young designer directed his talents to fixed wing aircraft and it was many years before he redirected his talents to helicopters.

During the first quarter of a centruy, after the first flight, designers from all parts of the world became involved in building rotary wing aircraft. None of these passed the experimental stage of development. Although . much was learned that would result in the future development of a suc-cessful helicopter, there were still problems to be encountered by these would-be designers. These fell into three main categories:

1. The engine torque tended to rotate the fuse-, lage in the opposite direction of the rotor. 2. The rotating mass of the rotor was affected by

gyroscopic precession. (Meaning that a tilt of the rotor would result in a movement 90° from the applied force.)

3. The lift forces produced by the advancing blade were greater than the lifting force of the re-treating olade iri horizontal flight, ~suiting in dissymmetry. of lift which would overturn the helicopter.

In spit~ of these overwhelming problems, experi-mentation continued through the 1920's. One of the experimenters was Juan de Ia Cierva, who had designed the first Spanish-built fixed . wing air-craft .. After the crash of one of his designs due tci a stall, he devoted the rest of his life to building a safer, slow-moving aircraft that was not dependent on its forward speed to make safe landings. To in-sure these goals he designed an aircraft which had the wings free to rotate about a vertical axis, giv-ing the wgiv-ings their own velocity.

Cierva's invention employed

a

conventional aircraft to produce forward thrust with freely rotating wings to produce lift. This wind-milling is known as

auto-rotation. Thus the autogyro received its name. The first model built by Cierva had two counter rotating rotors. He had hoped that the gyroscopic effects would be cancelled and the differential of lift would be neutralized. However, the unequal ·flow conditions of the two rotors ~ade this

ar-rangement inefficient.

Cierva next decided to build a single rotor system in spite of the known problems. His first two at-tempts with the ·single rotor system ended in failure. However, the next attempt was an entirely new design which solved the problem of the auto-gyro and paved the way for the helicopter.

Chapter I

Helicopters In U

_

se Today

Introduction

The helicopters in use today cover a period of time from 194 7 to the present. They have gone from being a novelty to being the work hor~e of the aviation industry, performing tasks of every imaginable de

-scription. In this period, the industry developed a large. commercial fleet which has exceeded the. air carrier and corporate aviation fleets in size. This un-precedented . growth did not occur by accident but because of the versatility of the machine and the ingenuity of the operators seeking new possibilities for their use as a fast and efficient method of complet-ing various tasks, including construction, agricul-ture, forestry, and business. At this time there is probably no area of the economy that is not touched by the helicopter insome manner.

To mee£ the ever-increasing demand to fulfill the needs of the helicopter operators, manufacturers have increased the reliability, decreased the main-tenance requirements, and designed new helicop-ters. They include three generations of machines, from reciprocating two-place helicopters to those that are turbine powered and carry many pas-sengers. Because of the inany different types, it is important to know about those in use today and their capabilities as described in this section.

A. Bell Helicopters

1. Bell47

The Bell 4 7; in 1946, was the first helicopter to receive civilian certification . This helicopter enjoyed

Fig. 1-1 Bell Helicopter Textron's Mode/222 mid-size twin turbine helicopter is representative of today's genera-·

tion of helicopter.

a long production life, until1974, when it became too expensive to manufacture. During this period it was manufactured in a great number of models and its components have been used to build special pur-pose helicopters. It is also presently being con-verted to turbine powerplants. This helicopter once enjoyed such popularity that more Bell4 7's were in use than any other helicopter in the world. Although

Date Fuel

Model Approved Engine H.P. Cap. 47B 11-4-4 7 !Type Franklin 178 24

Cert. H-1 6V4-178·B3

Remarks: 40 pounds maximum baggage- pressure fuel system.

4783 7-2-48 Franklin 6V4-178-B32

178 24

Bell47

this is no longer true, they are still in wide use today, performing numerous tasks such as flight training, agricultural work, traffic control, etc. It will undoubtedly lose its popularity as new and more modern equipment is introduced, but at this time it could certainly be considered the DC-3 of the helicopter industry. Fig. 1-2 showstwo models of the Bell47. Oil Max. Cap. Weight 3 2200 3 2200 Rotor limits 350 Max, 285 Min. 350 Max. 285 Min. Airspeed No. of MPH Seats 92 2 92 2

Remarks: 40 pound maximum baggage- revised cockpit enclosure, furnishing, and cowling.

470 2-25-48 Franklin 178 24 3

6V4-178-B32

Remarks: Similar to 83 except cockpit enclosure, wheel with brakes, 24V electrical.

4701 3-29-49 Franklin 6V4-178-B32 or 6V4-200-C32 178 29 3 2200 2200 350 Max. 285 Min. 350 Max. 285 Min. 92 2 95 3

Remarks: No baggage allowance - cockpit enclosure ventral fin-fixed tab combination, main rotor counterweights, movable battery, gravity fuel system, roller bearing type transmission, elimination of cowling and tailboom covering.

, 47E 4-18-50 Franklin 6V4-200-C32 Remarks: 40 pounds baggage.

47G 6-19-53 Franklin 6V4-200-C32 200 24 200 43 3 2350 3 2350 360 Max. 294 Min. 360 Max. 294 Min. 98 2 100 3

Remarks: No baggage allowance- similar to 01 except saddle tanks, battery location, synchronized elevator, ventral fin and tail rotor gear box.

47G-2 1-20-55 Lycoming V0-435-A1A orA1B, A1D 200 43 3.5 2450 360 Max. 294 Min. 100 3

Remarks: No baggage allowance- similar to G except for engine and relocation of the fore, aft, and lateral cyclinqer hydraulic boost controls and the installation of lock and load valves.

47H-1 3-21-55 Franklin 200 35 6V4-200-C32

2.7 2350 360 Max. 294 Min.

100 3

Remarks: Maximum baggage 200 pounds- similar to 47G except for semi-monocoque tail boom, increased cabin width, contour fuel tanks, revised skid type landing gear, addition to baggage compartment.

47J 8-23-56!Type Lycoming Cert. 2H1 V0-435-A1B Remarks: Maximum baggage 250 pounds.

47G-2A-1 12-28-62 Lycoming V0-435-A1E or A1F 220 35 240 61.6 2.9 2565 3 2850 370 Max. 333 Min. 370 Max. 333 Min. 105 105 4 3

A

-88.65 ₊₂

-I

111.61 (9'3·5/8")

1

1

j

78.00

(6r)

Fig. 1-2 A-Be/147G; B-Be/1 47J.

+ 36.99 288.75(24'- 0.75") 285.815"(23'-9.815") +70.0 142.45 (11'-10.45') 365"(30'- 5") +213.167 + 288.75 + 251.753 388.74 (32'4·314")- - -- - - --- -- - - -·1

1

1

~-::,

113.45.

"T'

"

'

3

Bell47

Date Fuel Oil

Model Approved Engine H.P. Cap. Cap. 47G-3B·1 1-25-63 Lycoming 270 61.6 4.25 lV0-435-81A . or 818 Remarks: 47G-4 1~3-64 Max. Weight 2950 2950 Rotor limits 370 Max. 322 Min. 370 Max. 333 Min. Airspeed No. of MPH Seats 105 3 105 3

Remarks: Similar to 47G-2A-1 except larger engine, and addition of collective boost system.

47G-4A 1-3-66 Lycoming 280 61.6 5 2950 370 Max. 105 3

V0-~818-3 333 Min.

47G-5 1-21-66 Lycoming . 260 28 3 2850 370 Max. 105 3

V0-435-81A 333 Min.

Remarks: Only one saddle tank on right, low instrument panel. Approved: dual saddle tanks, 3 seat capacity.

47K 3~30-59 Lycoming·. 240 35 2.7 2565 370Max. 105 2

V0-435-6A· 333 Min.

V0-435~A1D

Remarks: Similar to 47J except for cabin, open engine compartment, oil system and lights.

47J-2 1-14-60 Lycoming- 240. 48 4:3 370 Max. 105 4

V0-540-818 333 Min.

or 8183

Remarks: Similar to 47J except metal main rotor blades, fixed stabilizer, engine and blue tinted bubble.

47J-2A 3-4-64 Lycoming 260 48 4.3 2850 370 Max. 105 4

V0-540-81 83 333Min.

Remarks: Similar to 47 J except increased weight, addition of collective boost system and main rotor tip weights; change in C.G.Iimits.

4.7G-3 3-17-60/Type Franklin 225 43 Cert. 2H3 6VS-335-A 47G-2A 12-10-60 Lycoming 240 43 V0-435~A1E 47G-382 5-24-61 Lycoming 260 43 TV0-435-A 1 A

Remarks: External supercharger.

Because of the great number of models manufac-tured; each individual model cannot be shown. The following· is a _list of the various models and their major differences. Of course this list cannot point out· an the differences of the various models of this helicopter. Because of the great numbers built for civilian and military use, and the continual updat-ing of the older models, no attempt will be made to give the number of them in existence.

2. Bell204

From its.beginning with the Bell 47, the com-pany grew, building several additional models for civilian and military use. Many of the military

2 2650 370 Max. 105 3 322 Min. 2 2850 370 Max. 105 3 333 Min. 2 2850 370 Max. 105 3 322 Min.

models were modified in design and later became civilian models.

The 204B model was a derivative of the U-Hl series of helicopters built for the military. Although the two helicopters appear very similar in appear-ance, many changes were made between the civilian and the military aircraft, including the length of the tailboom, baggage area, and rotor blades.

The 204B is an 11-place helicopter with turbine power (Fig. 1-3). Although built in small numbers, the 204B paved the way for the turbine-powered helicopter and the use of such helicopters by the petroleum support industry.

l

I.

l

Date Fuel

Model Approved Engine H.P. Cap. 2048 4-4-63!Type lycoming 1100 160

Cert. H1SW T5309A,B,C, orT5311A

Remarks: Transport helicopter- 400 pounds maximum baggage.

\ - - - -48' -0.0" Bell204 Oil Max. Cap. Weight 4 8500 Rotor Limits 324 Max. 310 Min. Airspeed (KIAS) 120 0

...

I

"'

1 - - - ' - - - - , - - - 5 6'-10.84" - - - 1 1 - - - 4 4' -8.02" - - - + 1 Fig. 1-3 Be/12048 No. of Seats 11

3. Bell205

Following the development of the 204B were two improved versions of thi~ aircraft .. These are,the Bell205A and the Bell205.-Al (Fig. 1-4).

'The 205-Al has experienced a long production run s.ince its inception in1968, with new aircraft being manufactured until1978; The major use of this se-ries ha.s be~n in the petroleum support industry.

Bell205

Date Fuel Oil

Model Approved Engine H.P. Cap. Cap.

205A 6-13-68!Type lycoming 1100 215 3.5

Cert. H1SW T5311A orB

Remarks: Transport helicopter- 400 pounds maximum baggage.

205•A1 1 0-25c68 lycoming i250 220 3.15 T5313AorB

Remarks: Transport helicopter category B -400 pounds maximum baggage.

5 Max. Weight 8500 9500 Rotor Limits 324 Max. 314 Min. 324 Max. 314 Min. Airspeed No. of (KIAS) Seats 120 15 120 15

[ ••••.••

~

<> 7' 6.35" APPROX. _l__ GROUND 1- 9'0.2" -.:1 LINE 9' 4.3"

1 - - - -

41'6.32" .__ _ _ _ _ _ _ _ _ 44'10.0" - - - 1 1 - - - -57'7.0" Fig. 1-4 Be/1205

4. Bell206

During the time in which the 204 and 205 series · helicopters were being built to meet the market of a turbine-powered 10 to 15 passenger helicopter,

a

smaller turbine-powered helicopter was placed on the market -the Model 206, better known as the Jet Ranger.

The 206 was first certificated in 1964. Because of its size and versatility it immediately found a sub

-stantial outlet in the civilian market. At the pres-ent timeit enjoys an unprecedpres-ented popularity in many areas which include corporate, agriculture, construction, petroleum support, and ambulance service. This helicopter may be found in almost all areas of the world performing various missions. A profile of a Jet Ranger is shown in Fig. 1 ~5A and B. A list of the various models and abbreviated in-formation about the helicopter follows:

Bell206

Date Fuel Oil Max. Rotor Airspeed No. of

Model Approved Engine H.P. Cap. Cap. Weight Limits (KIAS) Seats 206 4-28-64/Type Allison 250 76 5.5 2750 394 Max. 115 4

Cert. H2SW 250-C10 374 Min.

Remarks: Same as a military model- OH-4A 1200 pounds cargo.

206A 10-20-66 Allison 317 76 5.5 3000 394 Max. 130 5

250-C18, 374 Min.

C18B, or 250-C20 Remarks: 1200 pounds cargo.

206A1 5-6-69 Allison 317 71.5 5.5 3000 354 Max. 115 4

250-C10D 347 Min.

8ell206

Date Fuel Oil Max. Rotor Airspeed No. of

Model Approved Engine H.P. Cap. Cap. Weight Limits (KIAS) Seats

2068 8-19-71 Allison 317 76 5.5 3200 394 Max. 130 5

250-C20 374 Min.

Remarks: 1200 pounds cargo (Jet Ranger II).

2068-1 11-10-71 Allison 317 70.3 5.5 3200 354 Max. 120 5

250-C20 347 Min.

Remarks: 1200 pounds cargo.

206L 9-22-75 Allison 370 98 5.5 4000 394 Max. 130 7 250C-20B 374 Min. 206L-1 5-17-78 Allison 370 98 5.5 4050 394 Max. 130 7 250C-288 374 Min. 206L3 12-10-81 Allison 370 110 5.5 4150 394 Max. 130 7 250-C30P 382 Min.

A

l

r-- - - - -- - -- -- - - - 3 1'2.0"- - - ,- -- - - -- - -- ---1

/1~=-'-.l..=t

1'1.0" t

•Measurement is taken with main rotor blade raised against tt~e dynamic flap restraint. Fig. 1-5 A-Be/1206.

B

~i:=====:zt:=-89.0 (NO LOAD ON GEAR) 92.1 AT GROSS WT OF 4000 LBS. (7'5.0") 13.0 r(1'1.0")

~\__

444.0 (7'8.1") \ _ (37'0.0") 4 4 . 0 - - 1 - 118.9 - - - 1 (3'8.0") (9'10.9") 74.7 (6'2.7")

1

\ _(10'2.4") 122.4 140.3 123.8 (11'8.3") (10'3.8") 120.4 ----:-- (1 0'0.4")

---:-.1

sol-154.2 (12'10.2") 282.2 - - - 1 (23'6.2") 508.7 (42'4.7") 8°30'FLAPPING 62.0 (5'2.0") Fig. 1·5 B-206L. 34.5 (2'10.5")

5. Bell212

In addition to the large single turbine helicopters built by Bell, an additional twin engine was added to

the Bell fleet - Model 212. The 212 added twin en-gine reliability and IFR capability to the helicopters used for petroleum support and construction.

Bell212

Date Fuel 011 Max. Rotor Airspeed No. of

Model Approved Engine H.P. Cap. Cap. Weight Limits {KIAS) Seats 212 10-30-70 United A/C of 645 220 3.76 10,000 324 Max. 115 15

Category B Canada per or 314 Min.

6-30-70 PT6T-3 engine 11,200

Category A Twin Pac TypeCert. Turboshaft

H4SW

1 - - - . - - - -57'3.25" - - - -- - - . 23.38"

l--48

'

DIA

11.5"

f--

9'0.5'"

--l

r=+~~~J?==:=~

12' d:!!==~~:h 6.83" Fig. 1-6 Be/1212

6. Bell222

The latest of the Bell models to go into produc-tion is the Model222. This helicopter is primarilly

aimed at the corporate market because of the twin

turbine reliablity and IFR capability (Fig. 1-7). A

brief summary ofits specifications follows:

Bell222

Date Fuel Oil Max. Rotor

Model Approved Engine H.P. Cap. Cap. Weight Limits 222 10-1-79 Lycoming 615 189 3.7 7200 362 Max.

TypeCert. 2LTS101 each 338 Min.

H9SW

Remarks: 370 NMI with 20 minute reserve at 8000 feet. Flexible seating of 6, 8, and 10 place configurations.

2228 222U 6-30-82 H9SW 4-29-83 TypeCert. H9SW 2each Lycoming LTS 101 750C-1 2each Lycoming LTS 101 750C-1 550 550 187.5 3.7 247 3.7 9 8250 8250 362 Max. 313 Min. 348 Max. 338 Max. Airspeed No. of (KIAS) Seats 150 10 150 9 150 9

r

2'2" .J \ - -40'0\A - 9'3.6 " - - - 12'9.1"- - 1 1'0.1" 1 + - - - 15'10.8"---~ 10'8.7" 6'2.9"

I

2'4;;-r-1---~- 36'0.3" - - -Fig. 1-7 Be/1222

7. Bell412

The Bell Model 412 is a growth version of the 212.

Among the changes made to the aircraft include a four-bladed rotor system and a nodal beam vibration

system. These added features have greatly contrib

-uted to passenger comfort. These helicopters are widely used by the petroleum support industry.

Bell412

Date Fuel 011 Max. Rotor Airspeed No. of Model Approved Engine H.P. Cap. Cap. Weight Limits (KIAS) Seats 412 1-9-81 2each 1600 337 3.2 11900 324 Max. 140 15

Type Cert. PT6-3 314 Min. H4SW

t

46FT. (14M) 9 FT. 4 IN. (2.8 M) ~~=1. !"===-J - - - , 4 5 : - : F : : : T - : . 1:71C:IN.,...--56

(r/j

~It---! (14M) 41 F1.81N. _ _ _ _ _ _ _ 1 12 FT. 10 I N . _ ' _ I (3.9 M) (12. 7 M)

---~::--f---· =========

I

. 6 FT. 8 IN. (2.0 M) Fig. 1-8 Be/1412

8. Bell214ST

L

II FT. 5 IN. (3.5 M)

The newest of the Bell helicopter line is the Model 214ST. This model was developed as a joint venture of Bell and Iran. With the fall of their gov-ernment, the helicopter development was

com-' I I FT. 3 IN. (393 mm) 8FT.71N.~ (2.6 M) 15FT. I IN. (4.6 M)

pleted by Bell. This model may be equipped with either skid gear or wheels and, because of its range and carrying capability, is basically used for off.. shore oil work.

Bell214

Date Fuel Oil Max. Rotor Airspeed No. of

Model Approved Engine H.P. Cap. Cap. Weight Limits (KIAS) Seats

214ST 2-8-85 2each 1625 435 1.9 17500 287 Max. 130 20

H10SW GE T700/2C 284 Min.

~·

~(

v

Fig. 1-9 Bei/214ST

B. Hiller Helicopters

1. Hiller UH-12

Shortly after the certification of the Bell 4 7, an-other light helicopter went into production, the Hiller 12. The Hiller, like the Bell 47, was man-ufactured in a number of different models and en-joyed popularity as both a civilian and a military helicopter. Although it may not have enjoyed the same popularity as the Bell, a great number of various models of the Hiller 12 are still in use today. In fact, the Hiller 12E (Fig. 1-10) is still being pro-duced in small numbers as both a

reciprocating-powered and as a turbine-reciprocating-powered helicopter. Like the Bell 4 7, the Hiller has been employed in nu-merous tasks which include training, agriculture, construction, and forestry. They are found through-out the world, with one of the highest concentra-tions in the northwestern United States. Many op-erators prefer the Hiller for sling load operations because of its load carrying capabilities.

The following is a brief summary of the specifica-tions, and some of the major differences, of the various models of the Hiller 12: ·

Hiller UH-12 Model UH-12 Date Approved Engine 10-14-48 Franklin Type Cert 6V4-178-B33 6H

Remarks: No baggage allowance.

UH-12A 5·8-50 Franklin 6V4-178-833

UH-128 11-2-51/Type Franklin Cert. 6H2 6V4-200-C33 Remarks: No baggage allowance

H.P. 178 178 200 Fuel Cap. 27 27 28 12 Oil Cap. 2.50 2.50 2.50 Max. Weight 2247 2400 2500 Rotor Limits 350 Max. 294 Min. 350 Max. 294 Min. 360 Max. 300 Min. Airspeed (KIAS) 73 73 73 No. of Seats 3 3 3

Hiller UH-12

Date Fuel Oil Max. Rotor

Model Approved Engine H.P.· Cap. Cap. Weight Limits UH-12C 12-12-54 Franklin 200 28 2-1/2 2500 360 Max.

6V4-200-C33 300 Min.

Remarks: No baggage allowance.

UH-120 12-23-57 Lycoming 250 46 2.3 2750 395 Max. Type Cert. V0-435-A1C 314 Min. Remarks: No baggage allowance.

UH-12E 1-6-59/Type Lycoming 305 46 2.3 2750 395 Max.

Cert. 4H11 V0-540-A 1 A, 314 Min.

B1A-B1E,

C1A-C1B

Remarks: Modification available to 4 seats. Baggage per flight manuaL 12.3 quarts oil with auxiliary fuel tanks.

UH-12E-L 9-18-63/Type Lycoming Cert. 4H11 V0-540-C2A 305 46 2 2750 370 Max. 285 Min. Airspeed No. of (KIAS) Seats 73 3 83 3 83 3 92 3

Remarks: Baggage per flight manuaL Engine and transmission oil systems are separate. Maximum weight 31 00 pounds only with cargo sling used.

UH-12L 2-28-64/Type Lycoming 305 46 2 3100 370 Max. 93 Cert. H1WE V0-540-C2A 285 Min

UH-12L4 2-28-64/Type Lycoming 315 46 2 3100 370 Max. 93 Cert. H1 WE VK0-540-C2A trans 285 Min.

1.12

Remarks: 3 seats in UH-12L and 4 seats in UH-12L4. Maximum weight 3500 pounds, only with cargo sling used.

FRONT Fig. 1-10 Hiller 12

l

r-1

'

-4

"

TOP STA 90 CENTER OF GRAVITY to•ts 1 - - - -- - -- - - --27'-8" -~---+1 SIDE 13 3 4

2. Hiller FH-1100

In addition to the Hiller 12, another model was built and marketed. This model, known as the FH-1100 (Fig. 1-11), was a five-place turbine heli-copter and was marketed by the newly mergered Fairchild Hiller Corporation. This model did not

obtain the popularity of the Hiller 12 and produc-tion was dropped after a few years. However, the 1100 is now back into production. Today there are still a limited number of the older 1100's operating. Listed is a summary of its specifications:

FH·1100

Date Fuel Oil Max. Rotor Airspeed

Model Approved Engine H.P. Cap. Cap. Weight Limits (KIAS) FH-11 00 11-1 0-66 Allison 27 4 68.5 Eng. 2750 390 Max. 110

Type Cert. 250-C18 2.76 295 Min.

H2WE Trans.

2.6 Remarks: 1100 pounds maximum.

/~ 35.33'DIA. 1 10.8 M. DIA. I

i

4.34"

l

1.32 M. 28.375' l " " " i ' i ' - - - -8.65 M. ---.i~ 1 ...

! - - - -

41.334f' - - - , .... 1 12.6 M.

i

9.178' 2.8 M.

_L

I~

7.23'

.1

2.204 M. Fig. 1-11 Hi//erFH-1100

I~

7.75'

_..I

2.36 M. 6.0'DIA. 1.829 M. DIA. No. of Seats 5

C. Hughes Helicopters

1. Hughes HU-269

Hughes began to build helicopters in the 1950's. Their first production was the Model 269, a simple two-place reciprocating powered helicopter. A great number of these aircraft were manufactured for the military. Large numbers have also been

manufac-tured for civilian use and are being used for such tasks as training, agricultural, and police work.

Like most of the smaller helicopters, the Hughes 269 has been built in several different models. One of these is shown in Fig.l-12. A brief summary of their specifications follows:

Hughes HU-269

Date Fuel Oil Max. Rotor Airspeed No. of

Model Approved Engine H.P. Cap. Cap. Weight Limits (KIAS) Seats

269A 4-9-59/Type Lycoming 25 2 1550 530 Max. 75 2

Cert.4H12 H0-360-81A 180 400 Min.

H0-360-828 165 Remarks: Maximum cargo. See flight manual.

269A-1 8-23-63 Lycoming 180 25 2 1670 530 Max. 75 2

HI0-360-B1A 400 Min.

orB1B

2698 12-30-63 Lycoming 180 25 2 1670 530 Max. 76 3

HI0-360-A1A 400 Min.

Remarks: 2698 restricted category. 1 seat left side.

269C 4-15-70 Lycoming 190 30 2 1900 540 Max. 109 3 HI0-360D1A 390 Min. MPH ---12'-6"---~ 7'-11'

j

1--

-

-

-

- - -

-

- - -

22' -3'

-

- -

- -

- - -

- - - -

1

Fig.t-12 Hughes269

2. Hughes 369 (500 series)

In the early 1960's, Hughes started production of a turbine powered helicopter in the same category as the Bell206 and the Fairchild Hiller 1100. These three helicopters were the result of a military com-petitive contract design for a light observation helicopter. The Hughes entry won, resulting in a large contract with the military.

The civilian production of the 369, which is the FAA designation of the 500 series, was limited dur-ing the military contract, but increased when this contract ended. This helicopter series may be

found today in all parts of the world in corporate, agriculture, and construction work.

Like the Bell Jet Ranger,-it has been built in several models. Fig. 1-13A and B shows the 369 (0H-6A) and the 369D (500 D) models.

Hughes helicopters are now part of McDonnell Douglas which has long been known for fixed wing aircraft. The 369 series will continue to be pro-duced by McDonnell Douglas, but the 269C is now being produced by Schweizer Aircraft.

A brief summary of information on the various models in the normal category follows:

Hughes369

Date Fuel Oil Max. Rotor Airspeed No. of Model Approved Engine H.P. Cap. Cap. Weight Limits (KIAS) Seats

369H 11-15-66 Allison 243 416 5.90 2400 514 Max. 130 knots 5 TypeCert. 250-C18A lbs. 400 Min.

H3WE

369HM 4-8-68 Allison 243 402 5.90 2400 514 Max. 130 knots 4 TypeCert. 250-C18A lbs. 400 Min.

H3WE

369HS 1-3-69 Allison 243 416 5.90 2400 514 Max. 130 5 TypeCert. 250-C18A lbs. 400 Min.

H3WE

369HE 5-21-69 Allison 243 416 5.90 2400 514 Max. 130 5

TypeCert. 250-C18A lbs. 400 Min. H3WE

Remarks: Many engines are modified for the Allison 250-C20- rotor limits: C-18 engines 514 RPM to 400 RPM; C-20 engine 523 RPM to 400RPM. Maximum weight SN 101 and up: 2550 pounds. 5 seats (HM 4 seats).

369D 12-8-76 Allison 350 402 11.60 3000 523 Max. 152 5 (500 D) TypeCert. 250-C20B lbs. 410 Min.

H3WE

Remarks: This model uses a five blade rotor system.

369E 12-15-82 Allison 350 416 6 pd 3000 492 Max. 127 5 TypeCert. 250C20B pd 487 Min.

H3WE

369F 7-11-85 Allison 350 402 6 pd 3100 477 Max. 152 5

Type Cert. 250C30 pd 473 Min.

A

(TIP OF UPPER STABILIZER) 8'6" 8'1·112"

I

I

J

4'3"

L

- - - 1 DIAMETER 1- - - -26'4" DIAMETER - - •

3 0 ' 3 · 3 1 4 " (WITH BLADES REMOVED 22'9·112") ;

-B

T

8.2

l

0.76 7.67

D. Sikorsky Helicopters

1. Sikorsky 855

Production of Sikorsky helicopters began in 1942 with the R4 helicopter for the military. This helicop-ter was built prior to the Bell4 7, but early Sikorskies were not certified because they were built for the military. The first civilian certified Sikorsky' was the 851 model. It was certified in April 194 7, shortly after the Bell 4 7. Both the S51 and the S52 were manufactured in small numbers and it is quite doubtful if any ofthese exist today.

The S55 series, however, established Sikorsky as the manufacturer of large helicopters, even if they would not be considered large by today's standards (Fig. 1-14).

At present some of these helicopters are still in use,· mainly in lift work and large agricultural op-erations. A brief summary of the S55 specifications follows:

Sikorsky 555

Date Fuel Oil Max. Rotor Airspeed No. of Model Approved Engine H.P. Cap. Cap. Weight limits (KIAS) Seats

555 3-25-52 Pratt & Max. 104 9.4 7200 245 Max. 95 9 TypeCert. Whitney Cont. 170 Min.

1H4 SIH2 550 15"2.5" 13'4" II

II

J~

...

..

- - ' 1 - - - i

~

~

~--46' Fig. 1-14 Sikorsky S55

2. Sikorsky 858

The 855 soon led the way for the production of the 858 (Fig. 1-15) which was larger and more powerful than the 855. This model enjoyed a long production with the civilian model and it's military countell?art, the H34. This popularity led the helicopter to all parts of the world. It was used in the early helicopter

airline concept and became a standard. A brief summary of the 858's specifications follows:

Today the 858 is used in lift operations and has been converted to a turbine powerplant. This will extend the 858's life even more. A brief summary of the 858 turbine conversions specifications follows:

Sikorsky 558

Date Fuel Oil Max. Rotor Airspeed No. of

Model Approved Engine H.P. Cap. Cap. Weight Limits (KIAS) Seats

S58A 8-2-56 Wright Max. 285 10.5 12700 258 Max. 117 14

TypeCert. Cyclone 1275 170 Min.

1 H11 989C9HE-2

5588 8-2-56 Wright Max. 285 10.5 12700 258 Max. 117 14

TypeCert. Cyclone 1275 170 Min.

1H11 989C9HE-2

S58C 8-2-56 Wright Max. 285 10.5 12700 258 Max. 117 14

TypeCert. Cyclone 1275 107 Min.

1H11 989C9HE-2

S58D 12-15-61 Wright Max. 254 10.5 13000 258 Max. 117 14

TypeCert. Cyclone 1275 170 Min.

1 H11 989C9HE-2

S58E 5-27-71 Wright Max. 254 10.5 13000 258 Max. 117 14

Cyclone 1275 170 Min.

989C9HE-2

S58F 3-15-72 Wright Max. 254 10.5 12500 258 Max. 117 14

Cyclone 1275 170 Min.

989C9HE-2

S58G 3-15-72 Wright Max. 254 10.5 12500 258 Max. 117 14

Cyclone 1275 170 Min.

989C9HE-2

S58H 3-15-72 Wright Max. 254 10.5 12500 258 Max. 117 14

Cyclone 1275 170 Min.

989C9HE~2

5581 3-15-72 Wright Max. 254 10.5 12500 258 Max. 117 14

Cyclone 1275 170 Min

989C9HE-2

S58J 3-15-72 Wright Max. 254 10.5 12500 258 Max. 117 14

Cyclone 1275 170 Min.

Sikorsky S58T

Date Fuel Oil Max. Rotor Airspeed No. of Model Approved Engine H.P. Cap. Cap. Weight Limits (KIAS) Seats S58BT 2-18-72 United AIC of Max. 279 1.6 13000 258 Max. 117 14

TypeCert. Canada PT6-3 Cont. 170 Min.

1H11 Twin Pack 1262

S58DT 2-18-72 United AIC of Max. 244 1.6 13000 258 Max. 117 14

Canada PT6-3 Cont. 107 Min.

Twin Pack 1262

S58ET 2-18-72 United AIC of Max. 279 1.6 13000 258 Max. 117 14

Canada PT6-3 Cont. 107 Min.

Twin Pack 1262

S58FT 3-27-72 United AIC of Max. 279 1.6 12500 258 Max. 117 14

Canada PT6-3 Cont. 107 Min.

Twin Pack 1262

S58HT 3-27-72 United AJC of Max. 244 1.6 12500 258 Max. 117 14

Canada TP6-3 Cont. 107 Min.

Twin Pack 1262

S58JT 3-27-72 United AJC of Max. 279 1.6 12500 258 Max. 117 14

Canada PT6-3 Cont. 107 Min.

Twin Pack 1262 15'10" 14'3.45"

1

65'10" 28'

1

40'

·r

r

-~-~r~ -11'

r

10'6" 5.44~

l

5"

l

a

·

r

·

28'3" 37' 44'7" Fig. 1-15 Sikorsky 558

3. Sikorsky 861

Sikorsky introduced the 861 helicopter in 1961, and it is still being produced. The 861 is much larger than the 858 and was brought into

produc-tion with twin turbine power. It has been used as a commuter transport and is used by the petroleum support industry (Fig.1-16). A brief summary of its specificiations follows: Sikorsky S61 Model S61L S61N Remarks: S61R Date Approved Engine 11-2-61 2 General TypeCert. Electric 1h15 CT58-110-1 9-9-63 2 General Electric CT58-110-1 Same as L except hull fuselage.

12-30-63 2 General Electric CT518-11 0-1 H.P. Max. Cont. 1050 Max. Cont. 1050 Max. Cont. 1050

Fuel Oil Max. Rotor Airspeed No. of Cap. Cap. Weight Limits (KIAS) Seats

410 5 19,000 225 Max. 127 39

184 Min.

654 5 19,000 225 Max. 130 39

683 5.9 19,500 225 Max. 143 39

Remarks: Same as L except modified complete hull, rear loading ramp, airfoil shaped sponsons, retractable gear, and modified tail rotor pylon.

15'4"

1 - - - -

72'8.5" - - - 1

1 - - - -62' DIAMETER (ROTATING) - - - - J

/

4. Sikorsky S64

One of the most interesting helicopters that was manufactured by Sikorsky was the 864 (Fig. 1-17).

It was the first attempt by any manufacturer to

build· a special purpose helicopter. Only a few of these machines were ever manufactured, but it is felt that this was a noteworthy accomplishment. A brief summary of its specifications follows:

Sikorsky S64

Date Fuel Oil Max. Rotor Airspeed No. of

Model Approved Engine H.P. Cap. Cap. Weight Limits (KIAS) Seats S64E 7-30-65 2 Pratt& Max. 1356 2.8 42,000 204 Max. 115 5

TypeCert. Whitney Cont. 671 Min.

H1EA JFTD12A-1 4000

l----~---10&3.313'188'6")---:;---:--;;;~o;:==~--t - - - 2 5 0 " ( 2 1 ' 4 " ) - - - - ,

56'(4'8'1

5. Sikorsky 876

The latest ofthe Sikorsky models is the 876. It is primarily aimed at the corporate industry, but will also be used in the petroleum support industry (Fig. 1-18).

The newest version of the 876 will soon be in production. Among other features, this version will include a new powerplant system.

Sikorsky S76

Date Fuel Oil Max. Rotor Airspeed No. of

Model Approved Engine H.P. Cap. Cap. Weight Limits (KIAS) Seats

S76A 7-26-79 2AIIison 650 286.4 1.27 10,000 336 Max. 156 up to

TypeCert. 250-C3 each per 255 Min. 14

H1NE eng.

Fig. 1-18 Sikorsky 576

E. Brantly Hynes Helicopters

1. Brantly B-2 and 305

In the late 1950's, another helicopter made its appearance on the market. This was the Brantly B-2 (Fig. 1-19). It was a two-place helicopter with a unique three-bladed rotor system having lag

hinges built into the blade. After the original model was produced, two other models followed. Most of these were bought for private use and training. A brief summary of the B-2 models with their specifications follows:

Brantly Hynes B-2

Date Fuel Oil Max. Rotor Airspeed No. of

Model Approved Engine H.P. Cap. Cap. Weight limits (KIAS) Seats B-2 4-27-59/Type Lycoming 180 31 7.3 1600 500 Max. 87 2

Cert. 2H2 V0-360-A1B 400 Min.

or B1A Remarks: 50 pounds maximum baggage.

B·2A 12-21-62 Lycoming 180 31 7.3 1600 472 Max. 87 2

V0-360-A1B 400 Min.

Remarks: Similar to B-2 except bucket seats, bubble doors, and larger instrument panel.

B·2B 7-1-63 Lycoming 180 31 7.3 1670 472 Max. 87 2

IV0-360-A1A 400 Min.

Remarks: Similar to B-2A except addition of two engine cooling fans and fuel injection system.

In 1965, a new five-place reciprocating engine helicopter was brought out by Brantly, the Model 305. Although this helicopter had some unique features, it was too late to capture a portion of the civilian market and very few exist today. Brantly

Helicopters Co. was later sold and has since become Brantly Hynes. They now manufacture the Model 305 and B-2B, as well as factory remanufactured units. Following is a brief description of the 305: Brantly Hynes 305

Date Fuel

Model Approved Engine H.P. Cap. 305 7-29-65/Type Lycoming 305 43.5

Cert. H3SW IV0-540-A 1 A

Remarks: 200 pounds maximum baggage. Similar to B-28 except larger.

Fig. 1-19 Brantly B-28

3'-11" DIA.

Oil Max. Rotor Airspeed No. of Cap. Weight Limits (KIAS) Seats

9 2900 480 Max. 104 5

F. Enstrom Helicopters

1. Enstrom F-28 and 280C

reach their original goals. The F28 series, however, The Enstrom helicopter appeared on the market is still in production, with a newer model on the by the mid-1960's. It was designed with many fea- drawing boards. Fig. 1-20 shows the Enstrom F28 tures that would reduce cost. Although the cost helicopter. A brief description of the various En-was lower than most of its competitors, it did not strom helicopters and their specifications follows:

Enstrom F-28 and 280

Date Fuel Oil Max. Rotor Airspeed No. of

Model Approved Engine H.P. Cap. Cap. Weight Limits MPH Seats

F-28 1965/Type Lycoming 195 HP 30 2 1950 385 Max. 100 3

Cert. H1CE HI0-360-C1A at 2700 315 Min.

or RPM

HI0-360-C1 B

F·28A 1968 Lycoming 205 HP 40 2 2150 385 Max. 100 3

HI0-360-C1A at 2900 313 Min.

or RPM

HI0-360-C1 B

F·28C 1975 Lycoming 205 HP 40 2 2200 385 Max. 112 3

HI0-360 with at 2900 332 Min.

Rajay Super- 36.5 in. charger Hg. 280 1974 Lycoming 205 HP 40 2 2150 385 Max. 112 3 HI0-360·C1A at 2900 313 Min. or RPM HI0-360-C1B 280C 1975 Lycoming 205 HP 40 2 2200 385 Max. 117 3 HI0-36D-E1AD at 2900 332 Min. with Rajay RPM Supercharger 36.5 in Hig. F28F 12-31-80 Lycoming 225 42 10 qt. 2350 385 Max. 112 3 280F HI0-360 332 Min.

I

~.9

I

""'•· 'OJ-4., I I .~1 i!_88(7"-4") _I 331 (27-7")

-========:::1

348(20' - O")O.A.

G. Vertol Helicopters

1. Vertol107

One of the most unusual civilian helicopters was the Vertol107 (Fig. 1-21). For years Vertol and its predecessor, Piasecki, had built military tandem-ro-tored helicopters. The 107 was the first attempt to

enter the civilian market. A small number of these machines were built and all of the remaining aircraft are now owned by one company. However, they do deserve mentioning because of their unique design. A brief summary of its specifications follows:

Vertol107

Date Fuel Oil Max. Rotor Airspeed No. of

Model Approved Engine H.P. Cap. Cap. Weight Limits MPH Seats

107 7-26-62 2General 1250 Max. 350 4.2 Category A 299Max. 168 41 Type Cert. Electric Takeoff 17,9001bs. 233Min.

1H16 CT58-110-1 1050 Max. CategoryB or-2 Continuous 19,0001bs. Remarks: Minimum crew 2-maximum passengers 39.

t - - - s o · o · - - - 1

23.0

Fig. 1-21 Verto/107

2. Boeing Vertol234

Vertol was purchased by Boeing in the mid 1960's. Although they produced military helicop-ters, no civilian helicopters were produced until recent years, with the production of the Boeing

Vertol234. This is a derivative of the CH47 which is widely used by the military in the United States and several foreign nations. The primary use of the 234 is the oil support industry.

Model 234 Date Approved 5-3-82 H9EA

1

10 f111.G ln. (3.35m) Engine 2 Lycoming AL5512 Boeing Vertol 234 Fuel Oil H.P. Cap. Cap. 4015 2100 6gal. gal. 3each engine JSH 10 in. 1 - - - -(11.84m) SIDE VIEW 99 tt 0 in.

1-+---

(30. 18m) 74 tt 9 in. Max. Rotor Weight Limits 48,500 225 Max. 220 Min.

~'---: DIM. WITH 4 BLADES_,...---.----...---l

I

FOLDED

/

\_~ll---l!..-~--:n--60 f1 0 ln. (18.29m) Airspeed (KIAS) 150 K 18 f17.81n. (5.68m)

\

\

/

>(

I 75ft 9 in. I - - - D I M WITH 4 BLADES F O L D E D - - - . . ; PLAN VIEW

Fig. 1-22 Boeing Vertoi234LR- USA

27

No. of Seats

H. Robinson Helicopters

1. Robinson R22

The Robinson R22 series of helicopters have been on the market for the last several years as a light training and observation helicopter.

AI-though this series of helicopter is relatively new, it has been widely used and accepted as a trainer and will probably be around for years to come because of its simplicity and unique design features. Robinson R22

Date

Model ApprQved Engine R22 3-16-79 Lycoming TypeCert. 0320 R22A 10-12-83 Lycoming 0320B2C R22B 8-12-85 Lycoming 0320B2C P22M 9-12-85 Lycoming 0320B2C Remarks: Same as R22B except floats.

I

~I

68/N Fig. 1-23 Robinson R22 H.P. 124 124 124 124

Fuel Oil Max. Rotor Airspeed No. of Cap. Cap. Weight Limits (KIAS) Seats

20 1.5 1300 530 Max. 98 2 495 Min. 20 1.5 1370 530 Max. 98 2 495 Min. 20 1.5 1370 98 2 20 1.5 1370 98 2 t---,ROTOR RAD 151 IN - - - 1 42/N---' 28

I. Imported Helicopters

1. Messerschmitt-Boelkow Helicopters

a. Messerschmitt-Boelkow B0-105

Messerschmitt-Boelkow-Blohm (MBB) have a long history of helicopter research and development in Germany. In recent years they have been active in

importing helicopters to the United States. The first of these to be imported was the B0-105 through Boeing Vertol. Later the MBB Helicopter Corpora-tion was formed in order to market their product in North America. Messerschmitt-Boelkow BQ-105 Model B0105A Remarks: 105C 105S Date Approved Engine H.P. 4·19· 71 ffype 2AIIison 317 Max.

Cert. 250·C18 Takeoff

H3EU 270 Max.

Continuous Minimum crew 1 -passengers 4.

4-20-72 2 each Allison 250 &C20 7-25-77 '2 each Allison 250C&20B 385 400

Fuel Oil Max.

Cap. Cap. Weight

153 2.4 4,629 153 2.4 5291 153 2.4 5291 Rotor Limits 433 Max. 403 Min. 433 Max. 403 Min. 433 Max. 403 Min. Airspeed (KIAS) 135 145 145

tl

..__ _ _ _ _ _ _ _ _ _ _ 38'10.1" - - - , - - - ,

Fig. 1-24 Messerschmitt-Boe/kow B0-105A

29 No. of Seats 5 5 5

b. Messerschmitt-Boelkow BK117

The BK117 helicopter was a joint venture be-tween MBB and Kawasaki. It utilized the technol-ogy of the B0-105 components coupled with a new

transmission and fuselage from Kawasaki. Be-cause of its design it has been popular as a medical and utility helicopter.

Messerschmitt-Boelkow BK117 Model 117A·1 Date Approved 9-10-85 H-3-EU Engine Lycoming LTS101 H.P. 5510 Fuel Cap. 160 Oil Cap. 3 Max. Weight 7055 Rotor Limits 406 Max. 391 Min. - - - 42.65fV13.00m - - - 1 r - - - 3 2 . 5 1 fV9.91 m

---:-::-::1....,---h

Fig. 1-25 Messerschmltt-Boelkow BK117. Airspeed (KIAS) 150 No. of Seats -=E ''"" OM ::M

2. Aerospatiale Helicopters

a. Aerospatiale Alouette and Lama

The French helicopters are manufactured by Aerospatiale and were originally marketed by L.T.V. Corporation. They are now marketed by Aerospatiale in the United States.

Aerospatiale Helicopters have been one of the leading helicopter manufacturers in Europe for many years. They have exported several models to

this country in recent years. These include the

Alouette series, the Lama, Gazelle, Dauphin, Puma, and the AStar. These helicopters cover a wide range of capabilities from 4 to 17 passengers, and are all turbine powered.

The Alouette is the oldest model, with several configurations. The original design dates back to

the late 1950's. A U.S. Type Certificate was first issued in 1962. Two Alouette models are shown in Fig. 1-26. A brief summary of the different models and their specifications follows:

Alouette and Lama

Date Fuel Oil Max. Rotor Airspeed No. of

Model Approved Engine H.P. Cap. Cap. Weight Limits (KIAS) Seats SE160 3-27-62!Type Turbomeca Max. Takeoff 149 2.6 4630 420 Max. 113 7 Alouette Cert. H11N Artouste 5 minutes 270 Min.

Ill 1118 33500 RPM S62HP Max. Cont. 33500RPM

4M..I!e

Remarks: Pilot and 2 front- 4 passengers rear.

SA319B 11-20-72 Turbomeca Max. Takeoff 149 2.6 4960 420 Max. 118 7 Alouette Astazou 43000 RPM 270 Min.

Ill XIV8 592 HP 358 Cont. Max. Cont.

43000RPM 494HP Remarks: Pilot and 2 front- 4 passengers rear.

SA316C 11-20-72 Turbomeca Max. Takeoff 149 2.6 4960 420 Max. 118 7 Alouette Artouste 33500RPM 270 Min.

Ill 1110 592 HP 358 Cont. Max. Cont. RPM 33500RPM

494HP Remarks: Pilot and 2 front- 4 passengers rear.

SA316B 3-25-71 Turbomeca Max. Takeoff 149 2.6 4850 420 Max. 113 7 Alouette TypeCert. Artouste 33500RPM 270 Min.

Ill H11N 1118 542HP 353.2 Cont. Max. Cont.

33500 RPM 444HP

Remarks: Pilot and 2 front- 4 passengers rear. SA3168 may be obtained by conversion of SA 160.

3158 2-25-72 Turbomeca Max. Takeoff 149 2.6 4300 420 Max. 113 5 Lama Artouste 33500RPM Internal 270 Min.

1118 592 HP 5070 353 Cont. Max. Cont. External

33500RPM 494HP Remarks: Pilot and 1 front- 3 passengers rear.

A

- 8 . 5 4 ' - 1 - - - 3 3 . 3 8'- - - 1

31.26'

Blade Tip To Blade Tip

B

33.35 ft. TO BLADE TIPS

1---REAR BLADE ON Cf. TAIL BOOM ---1

10.14'

I--7.80'

---l

1 - - - ' - - - 3 3.58'- - - l

Fig. 1-26 A-Aerospatiale Alouette Ill; 8-Aerospatia/e Lama.

b. Aerospatiale Gazelle

In 1972 Aerospatiale introduced the Gazelle. as a four-place helicopter (Fig. 1-27). A brief sum-mary of its specifications follows:

This helicopter was aimed at the corporate market

Gazelle

Date Fuel Oil Max. Rotor Airspeed No. of Model Approved Engine H.P. Cap. Cap. Weight Limits (KIAS) Seats SA341G 9-18-72/Type Tubomeca Max. Takeoff 120.7 2.4 3970 430 Max. 168 4

Gazelle Cert. H6EU Astazou 43500 RPM 310 Min.

lilA 494HP Power in flight

Max. Cont. 378 ± 12RPM 43500 RPM

494HP Remarks: Pilot and 1 front- 2 passengers rear.

SA342J 1977 Turbomeca Max. Takeoff 120.7 2.4 4190 393 Max. 170 VNE 4 Gazelle Astazou 43500 RPM 320 Min.

XIVH 570HP Power in flight Max. Cont. 349 ± 12RPM

43500 RPM 570 HP Remarks: Pilot and 1 front- 2 passengers rear.

STANDARD 39.26' STRETCHED 39.89'

11.972 m (Rotor rotating) 12.16 m 34.45' dia

DIMENSIONS WITH BLADES FOLDED

STRETCHED 31.90'

9.72m

c. Aerospatiale Dauphin

Aerospatiale introduced the Dauphin in 1976. This model was soon followed by the Dauphin 2, giving twin engine reliability to the helicopter

(Fig. 1-28). It is used mainly for transport by the petroleum support operators. A brief summary of the Dauphin models and their specifications follows: Dauphin 1 _Model Date Approved Engine H.P. Max. Takeoff 43000 RPM 871 HP Max. Cont. 43000 RPM. 804HP Remarks: Minimum crew 1 -maximum passengers 13

SA360C Dauphin 1976/Type Cert.H8EU Turbomeca Astazou XVIII A SA365 1\Nin Dauphin

1 0-11-78 2 Turbomeca Max. Takeoff Arriel 642 HP

Max. Cont. 592 HP Remarks: Maximum passengers 1 pilot and 13 passengers.

DIMENSIONS WITH BLADES FOLDED

-=-

0

~ "\.~.L

N

l' I

~ 13.20m 43.30' Fuel Cap. 169 169 E

..

:. Oil Cap. 2.3 2.8

B

[

Fig. 1-28 A-Aerospatiale Dauphin; B-Aerospatfale Dauphin 11.

Max. Weight 6400 7495 Rotor Limits 393 Max. 320 Min Power in flight 349 ± 12RPM 420 Max. 320 Min. Airspeed (KIAS) 170 170

DIMENSIONS WITH BLADES FOLDED

13.29m 43.59' No. of Seats 14 14

d. Aerospatiale Puma

A few of the Puma helicopters have been ex-ported to this country. These are being used in the

Date

Model Approved Engine H.P.

SA330J 6-9-76 2 Turbomeca Max. Takeoff Puma Type Cert. Turmo 1494 HP

H4EU IVC Max. Cont.

1262 HP Remarks: Crew-2 pilots- maximum passengers 18.

AS332L Super Puma 2-18-82 4.54m 14.90' 2each Turbomeca MAKILA1A 4.05 m 13.29'

Fig. 1-29 Aerospatiale Puma

1515 Puma Fuel Cap. 414 550 18.22 m 59.76' 3.00m 9.84' 14.82 m 48.62' 35

petroleum support industry (Fig. 1-29). A brief summary of its specifications follows:

Oil Max. Cap. Weight 6.34 7055 4 18400 3.04m 9.98' Dia 14.82 m 48.62' Rotor Limits 310 Max. 220 Min. 290 Max. 275 Min. Airspeed (KIAS) 167 167 5.14 m 16.86' 2.10 m 6.89'

f

3.62m 11.87' No. of Seats 20 22

e. Aerospatiale AStar 350

The helicopter which appears to have the most sales is the Aerospatiale AStar 350. A great number of these were sold before production began. Although

the helicopter is new, the technology and desirable characteristics have made a great number of sales in this country (Fig.l-30). A briefsummaryofthe AStar 350 and its specifications follows:

Model

Date

Approved Engine H.P.

AStar 12-21-77fTypeLTS 101-66A2 Max. Takeoff 350C Cert. H9EU 615 HP Remarks: 1 pilot and 5 passengers.

10.69 m AStar350 Fuel Oil Cap. Cap. 140 12.99 m 42.64' 35.07' dia

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Fig. 1-30 Aerospatiale AStar 350

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10.91 m 35.79' 1.80m 5.90' 2.10 m 6.88' ' 10.91 m 35.79 '

Max. Rotor Airspeed No. of Weight Limits (KIAS) Seats

4190 424 Max. 147 6 320 Min. ,... ) If

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t: Aerospatiale Twin Star

Aerospatiale's Twin Star is a derivative of the AStar with twin engine reliability, greater max-imum weight, and comfort for the passengers. Its light twin design is favored for executive transpor-tation and medical evacuation.

The helicopter has gone from its infancy to a multi-billion dollar business. The helicopter

indus-try approached thirty-seven billion dollars in sales in 1978 and employs 25,000 people in the production of helicopters. This figure does not include the number of people employed in the operation of these heli-copters nor does it reflect their salaries.

Twin Star

Date Fuel Oil Max. Rotor Alrspef:)d No. of Model Approved Engine H.P. Cap. Cap. Weight Limits (KIAS) Seats AS355E 4-11-84 2each 420 90 3 5070 390 Max. 150 6

and F H11EU Allison (Each) 375 Min. 250 C20F 12 9·1 rn 42.45 It 1!10.69 m

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Chapter II

Principles of Flight

Introduction

-The helicopter as we know it today is a complex aircraft capable of flight maneuvers of hover, verti-cal, forward, backward, and sideward flight. In spite of the fact that the helicopter is capable of maneu-vers that are not possible for fixed wing aircraft, it still operates on of the same basic principles.

The need for maintenance personnel to study these principles 'may not be apparent at first. How-ever, it is very necessary because a thorough know-ledge will be required to understand the mainte-nance and troubleshooting practices of the various systems.

Like fixed wing aircraft, the helicopter flies be-cause of its airfoils. The airfoils of the fixed wings are primarily their wings. However, the tail sur-faces and sometimes the fuselage, as well as the propeller may also be airfoils. The primacy airfoil of the helicopter is the main rotor. For this reason the helicopter is often referred to as a rotary wing aircraft. An airfoil, by definition, is any surface which gets a useful dynamic reaction from the air. For our purposes, this reaction is the lift and thrust which will be necessary for flight and ma-neuvering.

A. Aerodynamic Principles

The blades of the main rotor are the airfoils. With these airfoils certain nomenclature is used.

SPAN

-

~

t?

TIP

ROOT

Fig. 2-1 Nomenclature of the blade.

The span of the blade is the distance from the root of the blade to the tip of the blade, measured along the center line (Fig. 2-1).

If a cross section of the blade is shown, it may have an imaginary line drawn from the leading

39

edge to the trailing edge. This line is referred to as the chord of the blade as shown in Fig. 2-2.

CHORD

LEADING EDGE

TRAILING EDGE

Fig. 2-2 Nomenclature of the cross section of an air-foil.

The shape of the airfoil section may take many different forms. This shape actually affects the flight characteristics of the aircraft. Certain air-foils are noted for high speed, while others are known for low speed, high lift, and supersonic char-acteristics. See Fig. 2-3 for the general characteris-tics of various airfoils.

c

~

GENERAL PURPOSE

HIGH SPEED

c

_---~

~

HIGH LIFT

Fig. 2-3 Various airfoil cross sections.

The airfoils which are used for helicopters are usually referred to as symmetrical airfoils, mean-ing that the airfoil section has the same shape above and below the chord line. This curvature of the airfoil is referred to as the camber. Some suc-cessful designs have been built with an unsym-metrical airfoil, meaning that the top and bottom camber are not the same shape.

Some efforts are being made to change the airfoil shape along the span to achieve better flight char-acteristics in the blade (Fig. 2-4).

Fig. 2-4 A modern rotor blade.

1. Relative wind

As the rotor blade moves, it is subjected to rela-tive wind. The relative wind is the direction of the airflow with respect to the blade. This is always opposite the flight path of the blade. For example, if the blade moves forward horizontally, the relative wind moves backward horizontally. If the blade moves backward horizontally, the relative wind moves forward horizontally. If the blade moves for-ward and upfor-ward, the relative wind moves back-ward and downback-ward. If the blade moves backback-ward and downward, the relative wind moves forward and up~rd (Fig. 2-5).

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~FLIGHTPATH

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..._!-;;_r,ve!;

Fig. 2-5 The relationship of the rotor blades and the relative wind.

At first, one might wonder how the blade can move backwards. It must be remembered that this is in relation to the nose of the helicopter. For this reason the forward moving blade is referred to as the advancing blade, while the backward blade is called the retreating blade. The relative wind may be affected by several factors such as movement of the rotor blades, horizontal movement of the heli-copter, flapping of the rotor blade, wind speed, and direction. The relative wind of the helicopter is the flow of air with respect to the rotor blade. For exam-ple: :when the rotor is stopped, the wind blowing over the rotor blades creates a relative wind. When the helicopter is hovering in a no-wind condition,

the relative wind is created by the motion of the rotor blades. If the helicopter is hovering in a wind, the relative wind is a combination of the wind and the rotor blade movement. When the helicopter is in forward flight, the relative wind is created by the rotor blades, the movement of the helicopter, and possibly a wind factor.

PITCH ANGLE

REFERENCE PLANE

Fig. 2-6 The relationship of the pitch angle to the plane of rotation.

2. Pitch angle

Pitch angle is the acute angle between the rotor blade chord and a reference plane. The reference plane of the helicopter will be determined by the main rotor hub. The pitch angle is varied by move-ment of the collective control which will rotate the blade about the hub axis, increasing or decreasing the pitch (Fig. 2-6). The pitch angle may also be varied by movement of the cyclic control, which will be discussed in detail later in this section. Often the pitch angle is confused with the angle of attack.

ANGLE OF ATTACK

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DIRECTION OF RELATIVE WIND

Fig. 2-7 The angle of attack in relation to the relative wind.

3. Angle of attack

The angle of attack is the acute angle between the chord line of the airfoil and the relative wind. The angle of attack may be equal to the pitch angle. How-ever, it may also be greater or less than the angle of attack (Fig. 2-7). The pilot can increase or decrease the angle of attack by moving the pitch angle of the rot6r. When the pitch angle is increased, the angle of attack is increased and when the pitch angle is

decreased, the angle of attack is also decreased. Since the angle of attack is dependent upon the relative wind, the same factors that affect the rela-tive wind also affect the angle of attack.

4. Lift

Lift is the force produced by the airfoil that is per-pendicular to the relative wind and opposes gravity. The lift is developed by the rotor blade according to Bernoulli's Principle, which simply states that as ve-locity is increased, the pressure is decreased. This principle creates a low pressure at the top of the rotor blade, while the bottom of the blade has an increased pressure. This applies to both symmetrical and un-symmetrical airfoils (Fig. 2-8). Whenever lift is produced, drag is also produced.

LIFT

'fr

~¢DRAG

LIFT

1J

.

~~DRAG

Fig. 2-8 Lift versus drag.

5. Drag

Drag is the force which tends to resist the air-foil's passage through the air. Drag is always paral-lel to the relative wind and perpendicular to lift. It is this force that tends to slow down the rotor when the angle of attack isincreased in order to produce more lift. In fact, drag varies as a square of velocity.

6. Center of pressure

The center of pressure is an imaginary point . where the result of all the aerodynamic forces of

the airfoil are considered to be concentrated. This center of pressure can move as forces change.

On some unsymmetrical airfoils, this movement can cover a great distance of the chord of the airfoil.

41

As the angle of attack is increased the center of pressure moves forward along the airfoil surface and as the angle of attack is decreased the center of pressure moves aft along the airfoil surface. This is oflittle consequence in fixed wing aircraft because longitudinal stability may be achieved in several other ways. On helicopters, because the rotor blades are moved from a fixed axis (the hub), this situation could lead to instability in the rotor, with the rotor blades constantly changing pitch. For this reason, the preferred airfoil is symmetrical where the center of pressure has very little movement (Fig. 2-9). Ac-companying lift and drag is stall.

UNSYMMETRICAL

SYMMETRICAL

Fig. 2-9 Symmetrical and unsymmetrical airfoils.

7. Blade stalls

Stall is the condition under which the stream-line flow of air separates from the camber of the blade and reverse flow occurs, resulting in.an al-most complete loss of lift. As the angle of attack increases, lift increases until the stall angle is reached, provided the velocity remains the same. However, as the angle of attack is increased the lift increases, and so does drag. Because of this in-crease in drag, the rotor blades have a tendency to slow down. If this should occur the stall angle will be reached prematurely (Fig. 2-10).

. LIFT

DRAG

¢== R.W.

Fig. 2-10 The stall angle of the airfoil.

This is the reason that power must also be added in order to maintain the velocity of the rotor when the pitch is added to the rotor system. This also means that the lift of the rotor could be controlled by varying speed, increasing or decreasing the relative wind. However, this situation is avoided because of the slow reaction time, in favor of keeping the ve-locity constant and changing the angle of attack.