• Bell 212 Flight Manual
• Bell Helicopter 212 Flight Manual Electrical Sectional

PT6T Removal and Installation By Greg Napert February 1999 For the average helicopter technician, an engine change is not a very common event. In the case of the Pratt & Whitney PT6T Twin-Pac® installation, if the engines are operated within acceptable parameters and the number of engine operating hours is average, the technician may go five or more years before having to pull an engine. There are some unscheduled events, such as performance deterioration, that may result in having to pull modules of the engine individually. An individual engine change, for example, can be done easier just by removing that engine and reinstalling it in the airframe. However, removal of the gearbox, for instance, is much easier to accomplish after removing the entire Twin-Pac assembly. Additionally, a dual hot section inspection or gearbox repair, combined with engine inspection, often dictates that you pull the engines from the airframe as an assembly. Dave Mills, instructor at Bell Helicopter Textron's Commercial Customer Training in Fort Worth, TX, says, 'Because it's inevitable that you're going to eventually have to pull the engines, yet infrequent, it's really important that you tap into help from good sources of information.'

First and foremost, he explains, is the helicopter manual. 'The aircraft manual, available from Bell really is a great source of information.

Keep it with you at all times during the installation and removal. Additionally, we have a full time technical support staff.

Never be afraid to call and ask. I'm not too proud, even as an instructor and technician for 21 years — I learn something new during every class. If I can make it easier for someone else, I really enjoy doing so.' Bell's five-day course consists of a day of theory using a computer-based program that shows you how the engine works, along with fluid flows, and operation. Next, the student is led through an actual engine removal and installation.

They then return to the classroom to review the removal and installation, and review any problems or challenges they encountered. Finally, the students return to the engine to perform the full rigging and adjustments of the fuel transducers, ITT, etc.

The rigging is performed twice just to make sure they know what they are doing. Probably the most difficult and time consuming part of removing the Twin-Pac assembly from the helicopter is removal of the firewalls and cowling. The firewall installation is quite extensive on the Bell 412 and 212. Essentially, the firewall surrounds each engine and the gearbox; and the hot section of each engine is separated from the cold section.

'There is a lot of firewall, mounting brackets, and a lot of fasteners. Removal of these items can require some finesse as much of the hardware is difficult to gain access to.

Additionally, organizing and tracking the parts removed can be a chore,' says Mills. The amount of time it takes to perform a quick engine change on average can vary quite considerably. An experienced technician can perform the change in about four hours, but the uninitiated can take two days or more. 'It's something that requires some practice and can be done rather expeditiously when you have done it before. The first time is very slow, however,' says Mills.

He recommends that if possible, all hardware used on the firewall assembly be replaced. 'This will make it much easier for you the next time you remove the hardware.

If this is not possible, at least try to replace any hardware that shows even the slightest sign of rounding over or stripping,' he says. The following are procedures which are listed in Bell's PT6 Quick Engine Change Notebook which outline the procedures for removal and installation of the PT6 Twin-Pack. Although these procedures are very good, they are for training purposes only. Remember that the procedures vary from installation to installation and helicopter model to helicopter model.

Typical Twin-Pac removal from Bell Model 412 Helicopter Preparation 1. Cap all open lines and fittings. Cover both section air inlet and exhaust ducts to prevent foreign objects from entering. Use standard precautions for use of the maintenance hoist; do not stand under powerplant during removal procedure.

Preservation should be accomplished, if applicable before powerplant is removed. Turn off all electrical power and disconnect battery. Open and hinge forward the forward pylon fairing, remove the forward transmission fairing. Disconnect anti-collision light electrical connector at top panel. Remove the upper pylon cowling.

Release and remove left and right engine inlet fairings. Open and remove left and right engine lower cowls. Open engine upper cowls, disconnect starter-generator cooling ducts, fire detection element lead wires, and FM antenna and remove left and right engine top and side cowl assemblies. Remove left and right reduction gearbox inspection doors and side panels. Remove left hand combining gearbox top cowl with side cowl attached. Disconnect oil filler hose and oil vent hose from oil filler adapter.

Remove right hand combining gearbox top cowl with the center panel and side cowl attached. Remove top portion of cooler support cowl. Disconnect ejector drain tubes, vent hoses and remove vent tube and bolts securing ejector to brackets. Remove screws and hardware securing firewall, upper aft, and remove ejector and firewall section. Remove main drive shaft and, using T101588 or 412-20-001-101 holding wrench, remove engine drive shaft adapter. Remove screws to detach center section of aft firewall, and center firewall through, disconnect lines to differential switch and remove centerline firewall. Aft firewall center section will be removed with powerplant.

Remove upper section of induction baffle, disconnect air management valve electrical connector, disconnect engine wash hose at spray ring, disconnect vent line and remove transition duct as an assembly. Remove screws, detach and flex left and right inboard ears of lower middle firewall and induction baffle forward to allow clearance and secure with lockwire. Remove screws to allow removal of panels from lower middle firewall. Remove access doors from aft cabin bulkhead at each side of pylon, in cabin and disconnect bonding strip from each tach generator. Drain engine oil and disconnect engine control tubes, electrical connections, fuel, oil, bleed air and drain lines as required. Loosen clamps and slide oil cooler blower boots aft. Install Engine sling, SWE13833, attach a hoist using the fifth hole from the rear, and take up the slack.

Disconnect right forward engine mount vertical tube at lower end and left forward vertical tube upper end. Remove bolts and disconnect powerplant from bipod and tripod mounts. Lift engine clear of helicopter after checking all lines, electrical wiring and linkages are disconnected. Remove right forward engine mount vertical tube from accessory gearbox.

Position powerplant to engine stand and secure engine mount pads with locking pins. Ensure stand position locks are applied and remove sling. Typical Twin-Pac installation Preparation 1. Transfer from removed powerplant any parts not provided on replacement assembly.

Such parts include exhaust ducts, aft center firewall section, manual fuel control levers and oil filler adapter, and vent hoses. Install engine sling, SWE 13833, attach a hoist, using the fifth hole from the rear, and take up slack. Remove pins and lift powerplant from stand. Install left and right forward engine mount vertical tube upper end to fitting. Bolt heads should be positioned forward for the front engine deck fittings and bolt heads inboard for upper fittings on the accessory gearbox. Installation 1.

Lower powerplant carefully, monitoring all electrical wiring, control tubes, fuel and oil lines, and firewall. Use caution to prevent damage to any of these components. The forward and center fire seals are properly positioned when they are located aft of the lower induction baffle and lower middle firewall. The aft firewall should be forward of the lower aft firewall. Align powerplant to engine mounts as powerplant is lowered.

Install aft mount bolts, then forward mount bolts. Use two washers and a nut for each bolt. Tighten to standard torque and install cotter pin. Remove sling and hoist. Connect engine control tubes, electrical connections, fuel, oil, bleed air, and drain lines. Slide oil cooler blower boot forward, tighten clamps.

Connect bonding strip on each accessory gearbox tachometer generator. Install access doors on aft cabin bulkhead each side of pylon support.

Install left and right inboard ears of lower section of induction baffle to lower center line firewall. Attach panels to lower section of middle firewall. Install upper sections of induction baffle and middle firewall with attached inlet duct, air valve and transition duct, as an assembly, to each side. Connect vent lines as necessary. Connect air management valve electrical connector in front of middle firewall above inlet duct.

Connect each engine wash hose to spray ring connection and install left and right side panes of induction baffle. Install centerline firewall upper web (trough) to lower web and to middle firewall and induction baffle. Connect fuel lines to each differential switch. Install engine driveshaft adapter using T101588 or 412-240-001-101 holding wrench and install main driveshaft.

Install aft firewall center section to aft firewall lower section and to flange of centerline firewall. This section is installed with powerplant. Install both ejectors with upper section to aft firewall, connect ejector links to brackets and install stiffener sections. Connect ejector drain tubes, vent tubes and vent hoses. Install top portion of oil cooler support cowl. Install right hand combining gearbox top cowl with anti-collision light and side cowl attached. Connect oil filler hose and vent hose to oil filler adapter.

Install left hand combining gearbox cowl with side cowl attached. Install left and right combining gearbox side panels with inspection doors. Install left and right engine top side cowl assemblies. Connect starter-generator cooling ducts, fire detection element and lead wires and FM antenna lead. Install left and right engine lower cowls. Install left and right engine air inlet fairings. Install the upper pylon cowling and connect the anti-collision light.

Install forward transmission fairing and hinge forward pylon fairing to closed positions and latch. Rig engine controls to nominal adjustments.

Review of the Engine Control System for Bell 212 February 1999 continued from Main Article. The following is taken from the Pratt & Whitney PT6T Engine/Airframe Interface Rigging and Troubleshooting Training Manual.

It is for review purposes only. For applicable data, refer to the Helicopter manufacturer's maintenance manual. To understand rigging, it is helpful to understand the operation of the Droop Compensator and the Power Turbine Governor. Droop Compensator - Most output shaft Nf governors are of the droop type. A droop governor is used to ensure stability of operation at all power settings.

This means that for each power setting, there is a separate and unique output shaft speed at any fixed setting of the Nf governor. The droop type governors are normally designated in terms of percent of droop (usually 6 to 16 percent). For example, a 10 percent Nf governor droop means that if the rotor speed were set at 100 percent under a no load (flat pitch) condition and full load was demanded, the output shaft speed would droop to 90 percent. In order to achieve 100 percent at full load, the Nf governor would have to be reset. Now, if power demands were reduced, the rotor would overspeed. In order to avoid this problem, a droop compensator is normally used to control the output shaft speed at constant value throughout the power range, regardless of the load applied to the rotor blades. In other words, using a droop compensator, the engine power required will be a function of collective pitch setting, ignoring the effects of tail rotor and cyclic pitch power demands which are combined; these are usually not only less than 10 percent of total power available but also of a transient nature.

The droop compensator mechanism input signal is provided by the collective pitch control system. This input signal, which is a function of the collective control position, is being fed to a compensating cam positioned in the Nf governor control system. The droop compensating cam in the Nf governor control arm will be constantly changed to reset the Nf governor to give the same output shaft speed regardless of the collective pitch setting. This will maintain constant rotor rpm.

Power Turbine Governor - The power turbine governor is mounted on the RGB and is driven at a speed proportional to N2 speed. In order to control the N2 speed, the AFCU supplies a pneumatic signal (Pg) to the power turbine governor. This again, changes the gas generator speed upon sensing an off-speed condition of the power turbine to keep constant N2 speed regardless of loading (collective pitch).

During normal helicopter operation, the throttle lever twist grip is positioned against the maximum speed stop, and N1 is controlled by the Pg pneumatic signal supplied by the AFCU. Rigging procedure Power Turbine Governor Paralleling - Before attempting to adjust the governors, perform the following:. Collective pitch control system rigging. Droop compensator controls rigging.

Torque indicating system check/calibration. In order to prevent interference of the TCU with the adjustment of the P.T.

Governor paralleling, it is recommended to disconnect the torque control unit pneumatic lines. Cap off all connections and lines. Before starting, note the maximum rotor speed limitation given in the Bell 212 Flight Manual. Now you're ready to start the actual rigging procedure: 1. Actuate rpm switch to full Decrease. With collective in down position (flat pitch, turn ENGINE 2 throttle grip to full INCREASE.

Record rotor rpm. This should give the full DECREASE rotor rpm which should be 95 percent.

Slowly actuate rpm switch to full INCR (do not exceed 100 percent). Record rotor RPM. This should give the full INCREASE rotor rpm which should be 99 percent. If range and/or spread is incorrect, adjust as follows. If range is incorrect, adjust actuator rod, lengthen or shorten so range is 95 to 99 percent.

If spread is incorrect, adjust stroke of actuator to give four percent spread (actuator to be in mid travel position when adjustment is made.) 4. Repeat steps 2 and 3 above for recording rotor rpm by using ENGINE 1.

The range again should be 95 to 99 percent. If adjustment is required, adjust control tube (12, Fig. If this does not provide the desired range, move rod end to a new hole in jackshaft arm. Although the initial adjustment is necessary for single power section rotor rpm, the following adjustment is used to finalize by achieving proper twin power section rpm range, and to avoid torque needle split. With rotor at flat pitch, actuate rpm switch to full INCR. Turn both power section throttles to full INCREASE. Record rotor rpm.

Actuate rpm switch to full DECR. Adjust length of actuator rod end to obtain 97 to 101.5 percent. Shorten rod to raise rpm or lengthen to lower rpm. When performing checks of the next step, the helicopter will become airborne. Reconnect pneumatic lines to TCU. With rotor at flat pitch, turn ENGINE 1 and 2 throttle grips to full increase.

Beep to obtain 100 percent rotor rpm. Increase collective pitch slowly in a series of equal steps from flat pitch to full power (either engine temperature/rpm limit or transmission torque limit). Rotor rpm should remain at 100, ±1 percent throughout the power sweep. In the meantime engine torque should be matched within 4 percent during steady state operation. Ensure that the torque pressure transmitters are properly indexed to the numbers stamped on the RGB dataplate. If torque does not match within four percent, perform the torque matching procedure given in the next paragraph. Where torque matching requirement conflicts with the beep range, or the relationship of N1, ITT, or fuel flow between the two engines, torque matching shall be favored.

If rotor rpm droops (decays below tolerance) or overspeeds above 100 percent during power sweep, the compensation cam rate should be changed. After each cam adjustment, an adjustment of control tube (6) may be required to ensure that cam slot does not bottom out during full down collective. Check for any interference and for security of parts. With collective full up and rpm beep switch at INCR, adjust max. Power stop screw on governor to within 0.010 inch of stop arm. Finally, perform Torque Matching - Before attempting to obtain correct torque matching, ensure that the torque pressure transmitters are properly indexed to the numbers stamped on the RGB data plate; also, check the integrity of the airframe indicating system before attempting to alter the rigging of any components.

Bell 212 Flight Manual

The engine controls rigging shall allow steady state single engine flight at 97 percent Nf or higher with either engine. If torque split exceeds 4 percent during steady state operation, adjust control tube (12) to match both power sections.

Bell Helicopter 212 Flight Manual Electrical Sectional

Lengthen control tube if ENGINE 1 torque is too high and shorten if it is too low. Don't forget to check the governors to ensure some clearance exists between stop arm and minimum stop screw.

Bell 222/230 A Bell 222 Role Executive/utility helicopter National origin United States Manufacturer First flight 13 August 1976 Introduction Bell 222: 1979 Bell 230: 1991 Produced Bell 222: 1980–1991 Bell 230: 1992–1995 Number built Bell 222: 199 Bell 230: 38 Variants Developed into The Bell 222 is an American twin-engine light built. The Bell 230 is an improved development with different engines and other minor changes.

A cosmetically modified version of the 222 was used as the titular aircraft in the American television series. Contents. Development Origins In the late 1960s, Bell began designing a new twin-turbine engine light helicopter.

A mockup of the new helicopter was displayed in January 1974 at a helicopter convention. Following interest at the convention the company announced the new Bell 222. It was the first light commercial twin-turbine helicopter developed in the United States. The Bell 222 incorporated a number of advanced features including dual hydraulic and electrical systems, sponsons housing the retractable landing gear, and the Noda Matic vibration reduction system developed for the Bell 214ST. Manufacturing began in 1975. The Model 222 first flew on August 13, 1976.

It received certification from the (FAA) on August 16, 1979 and was approved for (VFR) use on December 20, 1979. Helicopter deliveries began on January 16, 1980. The FAA approved the 222 for single-pilot (IFR) operation on May 15, 1980. A Bell 222U Improved versions The more powerful Bell 222B was introduced in 1982 with a larger diameter main rotor.

The 222B-based Bell 222UT Utility Twin, with skid landing gear, was introduced in 1983. A development of the 222 is the Bell 230, with the 222's LTS 101 engines replaced by two Allison 250 turboshafts, plus other refinements. A converted 222 first flew as the prototype 230 on August 12, 1991. Transport Canada awarded certification in March 1992, and the first production 230 was delivered that November. The 230 had optional skid or wheel undercarriage. Production ended in 1995 with 38 having been built, being replaced in Bell's lineup by the stretched, more powerful.

LTS 101-750 engine installation (left engine) in a 222U The design includes two main rotor blades of stainless-steel-fiberglass construction and rotor hub with elastomeric bearings, which are lubricant free. Its cabin holds a maximum of ten persons with one-two pilots and eight-nine passengers. Seating configurations include standard seating for a pilot and seven passengers; or executive seating with one-two pilots and seating for five-six. The Bell 222 and 230 are usually flown single-pilot (optional dual controls are available), and can be configured for corporate/executive, EMS or utility transport missions. Transmission installation in a 222U The Bell 222 is powered by twin turboshaft engines, rated at 592 shp each.

Later 222 versions feature more powerful engines. Engine output is at 100% of rating at 9598 RPM. Two independent driveshafts deliver power from the engines to the transmission. The Bell 222's LTS engine exhaust stacks are located at the rear of the engines, while the 230's Allison engine exhaust stacks are located high on the cowling. Fuel is stored in three tanks, one in the fuselage and one in each. The main rear landing gear retracts into the sponsons.

The Bell 222's rotor systems include:. Two-blade, semi-rigid high-kinetic energy main rotor with preconing and underslinging. The rotor head incorporates elastomeric bearings for hub springs, and flapping and pitch change bearings. The system is similar in design to that used by the AH-1 Cobra. Rotor speed at 100% engine speed is 348 RPM. All series models incorporate a -type two-bladed tail rotor mounted on the left side of the tailboom, turning at 3396 RPM. Variants Bell 222 The original Model 222, sometimes unofficially called a Bell 222A to distinguish it from the Bell 222B.

It was powered by two (618 hp takeoff rated, 591 hp max continuous rated) (formerly Lycoming). Bell 222B In 1982 the 222 was given a power upgrade (two Honeywell (formerly Lycoming) LTS-101-750Cs with takeoff rating of 680 hp each), a larger main rotor, and was renamed the Bell 222B. Bell 222B Executive This model had improved systems and a luxury interior. Bell 222U rotor head and flight controls Bell 222UT A 222B variant with skids, introduced in 1983. The lack of retractable landing gear allowed for larger auxiliary fuel tanks.

The Advanced Composite Airframe Program (ACAP) was a 1985 all-composite LHX proof-of-concept project. The Bell D-292 used the Avco Lycoming engines, transmission, two-bladed main and tail rotors, tailboom, vertical fin, and rotor pylon of the 222. The D-292 had a new composite airframe. Bell 230 In 1991 the 222B design was updated, given more powerful engine versions, and renamed the Bell 230. Production ended in 1995.

Bell 230 Executive Executive transport version. Bell 230 Utility Utility transport version. Bell 230 EMS Air ambulance version, equipped with one or two stretchers. Bell 222SP During the 1990s, some Bell 222s were modified with the 222B's engines and 230's Allison 250-C30G engines for improved single engine (engine-out) performance, and redesignated as 222SPs. In 1995 the Bell 430, a stretched 230 (adding another seating row), was launched, with more powerful engines and a four-blade main rotor. Operators.

A London Bell 222 fitted with a Marconi Heli-Tele in 1982 Model 222 222B 222U 230 Announced 1974 1982 1982 1990 First Flight August 13, 1976 1982 1983 August 12, 1991 Certified December 1979 August 1982 April 1983 March 1992 Delivered 1980 1982 1983 November 1992 Seats Front: pilot + one. ^ Frawley, Gerard, The International Directory of Civil Aircraft, 2003-2004, Aerospace Publications Pty Ltd, 2003,. ^ Apostolo, Giorgio. 'Bell Model 222'.

The Illustrated Encyclopedia of Helicopters. New York: Bonanza Books. Frawley, Gerard, 'Bell 222 & 230', The International Directory of Civil Aircraft, 2003-2004, p. 46, Aerospace Publications Pty Ltd, 2003,. ^ Donald, David, ed. 'Bell Model 222'.

The Complete Encyclopedia of World Aircraft. Barnes & Nobel Books, 1997.

^ Pelletier, Alain J. Bell Aircraft Since 1935. US Naval Institute Press, 1992. 'Bell 222'. Jane's Helicopter Markets and Systems. Jane's Information Group, 2009.

Retrieved 15 January 2013. Demand media.

Retrieved 15 January 2013. 2007-12-27 at the. Archived from on 20 June 2016. Retrieved 22 June 2016.

Bell 222/230 Field Maintenance Training Manual. Bell 222U Rotorcraft Flight Manual External links Wikimedia Commons has media related to. (in English and German).