Sikorsky H-19 / S-55 Full manual

Introduction

So, this is your H-19 and you don`t know what to do with it. Let`s get started.

This is extremely realistic model, designed using real blueprints and manuals. It simulates amost every aspect of usage of the real helicopter:
- startup procedures
- engine power curve simulation
- engine oil consumption, leaks, wearing and refilling, heat management
- fight with carburetor
- transmission oil consumption, leaks, wearing and refilling
- lights, electics and electric problems
- fuel system simulation, including failures

You`ll need to understand how it works, how to read it and control it. Let`s explore controls and instruments.

Preflight checks

Well, you can just repeat preflight checks from this documentary, so let`s move to short list.

1. Open engine bay doors. Check for ENG LIFE, overall helicopter durability (DR:100% on failure codes display) and malfunctions. If necessary, REPAIR to clear error codes, or keep REPAIR on for 10 seconds to restore engine life. To restore overall durability, do MAINTENANCE.




Engine life: if drops to zero, engine stops. Lower life means less power, lower oil pressure and bigger oil consumption. life decreasing over time, due to engine wearing out. Also, low oil pressure, overheat and overrev lowers life.
Overall durability: lower it is, more likely to have malfunctions. Drops over time.

2. Check for engine oil level and color, using meter glass in the left side of engine bay. Refill if necessary, using oil canister located in baggage compartment in the cabin. Refilling inlet located inside the engine bay. Canister disconnects automaticly when refill is finished. If the canister is empty but you still need more oil, use diesel instead.




Engine uses oil, so level drops over time. Also, oil aging affects oil pressure. How good the oil is can be checked by it`s color, as in real life. Darker is worse.

Check engine visually for leaks. In flight, leak can be detected by significant oil pressure drop (below 60 psi is suspicious) or pressure unstability. In case of oil leak, engine will loose oil quickly, so it`s vital to land as soon as possible, repair the engine and refill it.
High rpm and high oil pressure provokes oil leaking.

3. Check for transmission oil level and color, using meter glass in the right engine bay panel. Refill if necessary. Refilling inlet located behind the transmission service door, on the right side of the engine bay. Use the same oil canister, but it has to be disconnected manually.




Transmission oil is necessary to make hydromechanic clutch work. Losing oil means losing oil pressure, whick means impossibility to lock the clutch and fly.
Oil is leaking because of high pressure (cold start, high rpm) or high temperature. If clutch pump left on after mechanical clutch coupling, oil begins intense heating up, which eventualy causes it to escape transmission, leaving helicopter driveless. Heating above 120 C is not advised.

4. Open electric compartment and check for batteries charge. If main battery charge drops below 9 volts, instruments and controls are unable to function properly. Use external power connector to provide ground power supply.




Main power relay, instruments, lights and deicing system failures considered as electric failures and are to be repaired by REPAIR ELECTRICS in electric compartment. Malfunction probability depends on overall durability.

5. On the left side of the hull, open the OBSERVATION PLATFORM. Grab handle, crouch and get yourself on it.




Examine the hydraulic pressure gauge. Hydraulics powers the servo system, in case of pressure drop it will be hard to control helicopter. If pressure drops below 750 psi (3/4 of the dial), servo control will become unfunctional. Malfunction probability depends on overall durability. To restore hydraulics, do REPAIR and build up engine rpm.




So, preflight checks are over. Next step - cockpit, instruments and switches.

Cockpit and switches: step 1

1. Master battery switch (BAT), powers the main bus and charges service bus.
Failure: floating short circut. Probability depends on overall durability.
Detect: flickering power, voltmeter goes mad, breakers panel.
Engine start: very hard to start.
Flight: allowed if generator is running.
Repair: electric repair.

Electic system is 100% replica of the original layout:



2. Magneto switches. Magnetoes provides ignition, vital for engine running. Malfunction of one magneto leads to 5-10% power loss, two magnetos - immenent engine stop.
Failure: becomes unfunctional. Probability depends on overall durability.
Detect: power loss, alarm sounds, breakers panel.
Engine start: harder to start on 1 magneto. Impossible to start if 2 are broken.
Flight: allowed with speed and load limitations. Landing for repairs is advised.
Repair: engine repair.

3. Fuel pumps. There are 3 fuel pumps in the system - two electric boost pumps and one main engine driven pump. Engine driven pump is powered by engine (surprise) and it`s pressure depends on engine rpm. Boost pumps are used to prevent power loss from low fuel pressure and to provide pressure for the priming and oil dilution, and in . It is possible to fly using only main pump, but there can be power issues if rpm too low.
If fuel pressure became unstable - highly likely that you have main pump failure coming.
In case of main pump failure fuel will flow around the pump through bypass.

Main pump
Failure: becomes unfunctional. Probability depends on engine life.
Detect: fuel pressure loss if boost pumps are off, indicator in engine bay.
Engine start: not affected if boost pumps are functional.
Flight: allowed.
Repair: engine repair.

Boost pumps
Failure: becomes unfunctional. Probability depends on overall durability.
Detect: fuel pressure loss if boost pump are on, breaker panel.
Engine start: priming and oil diluting affected, hard to start in cold weather.
Flight: allowed, but significant power loss can occur. Repair advised.
Repair: engine repair.

Fuel system is 100% replica of the original layout:



4. Oil dilute. This is necessary feature to handle cold start. Engine oil is being diluted with fuel, to lower viscosity and make it easier to crank the engine. Also, the colder it is, faster battery drains because of slower and harder cranking.
If temperature outside is lower then about -7C, you need to use this system, otherwise engine will fail to reach 300 rpm needet to start.
First, build up fuel pressure. As long as diluting system uses fuel, it needs pressure to operate, 10 psi is desired. Could be less, but effect will be smaller. After pressure built, press and hold DILUTE OIL button for at least 5 seconds. Then, push starter button and keep two buttons pushed until engine starts. Oil pressure will be way lower than normal because of the lower viscosity, but it will raise as fuel evaporates away from oil.
Do not use dilute on hot engine - it can be damaged by too low oil pressure!

5. Engine prime. This also is necessary feature to handle cold start. Priming injects fuel into engine to make it easier to start. System needs fuel pressure to operate, 15 psi is desired. Use if outside temperature below -5C or so.
To use, press and hold ENG PRIME button for 3-5 seconds, then push starter button. Fuel evaporates slowly from cylinders, so you will have 20-30 seconds to start.

6. Warning lights.
Low fuel warning. Comes on if total fuel quantity is less than 200 lb, which is enough for about 30 km of flight distance in economy cruise.
Transmission oil pressure. Comes on if pressure drops below 12 psi. Under this pressure clutch can not be operated, but until it`s mechanicaly coupled, you can continue flight.
Servo off. Comes on if servo is off, or failed because of malfunction or hydraulic system pressure loss.
Generator off. Comes on if generator switch is of, or there is no charge. Reasons of charge absense: generator off, generator failed, rpm too low.

For step one startup procedure:
- Bat: on
- Magnetos: on
- Boost pumps: if necessary
- Oil dilute and engine prime: if necessary

Cockpit and switches: step 2

Now, the power is on and you can do more things in the cockpit. But let`s turn lights on first.
This is the lights control panel:


Seems to be pretty obvious, so here is short manual for malfunctions handling.
In case of light failure, it will flicker for a few seconds, before complete fail, or remain flickering to make pilot nervous. To fix it, you`ll need to land and access electric compartment, and make repairs there. This is random failure, doesn`t depends on overall condition of the helicopter.

Now, when we handled the lights, let`s move on to further investigation of switches.




1. Generator switch. Connects and disconnects generator from the main bus. Functions obvious.
Failure: becomes unfunctional. Probability depends on overall durability.
Detect: warning light, alarm sounds, breakers panel, battery discharging, ammeters renders zero.
Flight: landing for repairs is advised. If voltage drops below 9 volts, instruments and systems becomes unfunctional, but main fuel pump, oil pump ignition and controls stays intact, because it`s driven directly by engine, so technically you can continue flight without electicity at all.
Repair: engine repair.

2. Main and misc invertors. There is instruments in board, requiers 115 volts AC to function. So there is two separate invertors to make 28 volts DC become 115 AC. Main invertor powers gyro attitude and gyro compass. Misc invertor powers fuel quantity gages and all pressure gages.
Failure: becomes unfunctional. Probability depends on overall durability.
Detect: warning light and alarm sounds if failed or turned off both invertors, breakers panel, instruments powered by invertors becomes unfunctional.
Flight: landing for repairs is advised but not obligatory.
Repair: electrics repair.

2.1 Both invertors fail warning light. Lights in case of both invertors failure. Not in case one invertor fails, only two invertors should fail, to set both invertors failure warning light on. Both.

3. Master alarm off. In case of malfunction that considered as not important or not fixable at the present moment, sounding alarm bell can be shut off.
Can`t fail.

4. Cabin heater. Function obvious, but keep in mind - it`s not going to heat you if cockpit sliding windows are opened, because of, you know, wind in the cockpit.
Failure: becomes unfunctional.
Detect: getting cold.
Flight: becomes uncomfortable.
Repair: engine repair.

5. Pitot heater. In case of heavy for or rain, if temperature drops below zero, pitot tube icing process begins. This affects airspeed, altitude and climb readings, up to total uslesness. To prevent this happening, in bad weather conditions, or when that instruments becomes weird, turn pitot heating on. This system can fail.
Failure: becomes unfunctional.
Detect: airspeed, altimeter and climb indicators becomes unusable.
Flight: becomes uncomfortable.
Repair: electrics repair.

6. Outside temperature gage. As long as it`s simple mechanical device - it can`t fail.

For step two startup procedure:
- Main invertor: off
- Misc invertor: on
- Heaters: off

Cockpit and switches: step 3

1. Rotor brake. Should be disengaged before startup procedures. Rotor brake can`t brake.

2. Fuel tank selector. Can`t break either.

3. Mixture lever. In this model this is combination of throttle and mixture levers, because of Strmwrks seats controls limitations. Whatever, it works more or less like throttle.
Too much throttle on cold engine (below 120 C), and you`ll get misfire. Don`t throttle too much without load. Warm up your engine before attempting to fly.

4. Starter button. Function obvios. Can`t fail.

5. Clutch pump switch and indication light. This helicopter is equipped with hydromechanic clutch, driven, which needs oil to match speeds of engine and rotor. When speeds are matched, mechanical lock engages and oil is drainig from the clutch.
Warning - do not leave clutch pump engaged after mechanical coupling engaged! This will overheat the oil and make it escape from transmission, leaving clutch dry and unabled to do coupling. Overheating transmission over 180 C makes it disintegrate.

6. Servo switch. The switch activates hydraulic servo system to reduce pressure applied to controls. Without servo, it will be hard to control helicopter, it will become "heavy", but still remain controllable. Servo system hydraulic pump is driven by engine, the pressure meter located in the transmission compartment behind the cockpit, on the left side. There is foldable observation platform to access the meter; refer to preflight checks for more information.
Nominal pressure is 1050 psi, lower pressure means less help from servo, and if pressure drops below 750 psi, servo becomes unfunctional. Servo system pump can fail, resulting pressure loss over time. Repair by engine repair.

Note: H-19 haven`t been equipped with autopilot, but it woul be cruel to force user to do all the job. It`s a game, not reality. So I`ve made it to stabilize itself, something like literally "auto-pilot" - so it imitates the pilot job, not the system.With servo off, this "auto-pilot" greatly reduces it`s help to user, helicopter will start drifting around and won`t be able to automatically hold altitude.

7. Carburetor heating and engine cooling vents shutter. These controls do not have indication, just keep an eye on corresponding instruments (CYL HEAD TEMP and CARB AIR TEMP). It takes about 2 seconds to set it from full open to full shut position. Refer to instruments section for further information.
Can`t break.

8. Breakers panel. Let`s have closer look:



This is electric breakers panel, and it`s an easy way to control systems are intact.
In case of system enabled, corresponding breaker glows green. In case the system is not enabled - grey. In case of malfunction - red. Panel is not interactive, it`s just displays status.

For step three startup procedure:
- Rotor brake: off
- Tank selector: as necessary
- Mixture: 0.1
- Breakers panel: all green exept "Instruments" and disabled systems
- Clutch pump: off
- Vents shutter: full open
- Carburetor heating: full cold
- Servo: off
- Starter: on

Reading instruments

Now, if you did everything right, the engine is running. So it`s time to check all the gages and explain them, before you broke something.


This is critical systems vitals - engine and transmission gages. Keep in mind that any of it can fail separately, or it can fail by groups. All instruments repairs are considered as electrical problems and to be fixed by electric repair.
Let`s have closer look.

1. Engine oil pressure. Desired pressure range is 60 to 90 psi.
Oil pressure depends on oil temperature, oil life, engine life and dilution status. Colder oil leads to higher pressure; used oil, worn out engine and dilution system leads to lower pressure.
If pressure drops too low, engine begins to damage itself. For nominal 2200 rpm the limit is about 38 psi, for lower rpm and load limit is lower. If pressure drops below 40 psi, alarm sounds and warning light comes on.

- Why my pressure dropped?
- You ran out of oil because of the mailfunction or normal oil consumption. Go check oil level in the left side of the helicopter, refill if too low.
- How do I know about malfunction?
- Noticable pressure drop in normal conditions, pressure unstable. In case of that, land and go check engine for the leaks.

If pressure is more than 90 psi, engine starts to burn oil, which leads to exessive oil consumption. Also, higher pressure provokes oil system failure.

- Why my pressure is too high?
- Oil is too cold, and rpm is too high. Lower rpm and wait for oil to warm up.

2. Engine oil temperature. Desired range is 60 to 75 C.
Oil system equipped with thermostat unit, which struggles to keep temperature in desired range, but under heavy load, high rpm or cylinder heads overheat, temperature still can go higher than desired range. Oil overheat provokes oil system failure.

3. Fuel pressure. Desired range is 18 to 25 psi.
Fuel pressure affects engine power. If you`re not using boost pumps (or it failed) but only main pump, at nominal 2200 rpm you will get around 8.5 psi and 90% of engine power. To get 100% you need to have at least 11.5 psi. With booster pumps you will have more than 20 psi, which fits perfectly to the desired range. Also, 15 psi desired to operate dilute and priming systems.

4. Fuel quantity. Simple gages, nothing to say.

5. Carburetor intake air temperature. Desired range 30 to 40 C.
Because this engine is supercharged, under load (if manifold pressure higher than atmospheric) intake temperature will be significantly higher than outside temperature.
This gage is measuring air temperature after supercharger compression, but before throttle body. Due to fuel evaporating and air pressure drop after the throttle, air temperature inside the carburetor may drop up to 30 C from the measured. If it drops below zero, and weather is humid, carburetor icing may occur, whish causes power loss and engine cutoff as the final stage of icing. So, it`s important to keep air temperature before the throttle at least 30 degrees above zero, to prevent icing.
If you encounter power loss and intake air is colder 30 C, heat up carburetor ASAP.
Higher intake temperature means lower power, and on the other hand, lower temperature means more power. So control it on your own risk, if you need to squeeze some extra power from the engine.
Also, there`s no consequences for too high intake air temperature, exept lower power. So for warm weather it`s okay to have it more than 40 C.

6. Cylinder head temperature. Desired range 150 to 232 C.
If it`s colder than 120 C, there`s going to be misfiring and stall if load is applied and throttle/mixture is too high. If hotter 240, engine will loose power, oil and in case of further temperature increase (over 260) - durability. Overheat is an easy way to kill the engine.
To prevent it from overheating:
- keep shutter open
- avoid steady hovering for too long
- avoid too high engine rpm (more than 2350) in any cases
- avoid overload
- speed helps to cool, faster flight = better cooling
To prevent engine from underheating:
- close cooling vents
- increase rpm

7. Transmission oil temperature. Desired range 20 to 100 C.
Depends on rpm and engine oil temperature (because it`s mounted right next to the engine).
Temperature grows rapidly when clutch pump is enabled, and even more rapidly if clutch pump remains enabled after mechanic coupling occures. If oil is hotter than 120 C, it starts to leak from the clutch, and at about 180 C transmission disintegrates.

8. Transmission oil pressure. Desired range 15 to 60 psi.
Depends on rpm, transmission oil temperature, oil level. If pressure exceeds 100 psi, oil starts to leak from the clutch.
If pressure is lower than 20 psi, clutch renders unable to couple, but if it`s already mechanically coupled, it will hold coupled. In case of further pressure loss, mechanical coupling becomes unstable and at 10 psi or lower it breaks, making helicopter stationary.

9. Battery voltage and ammeter.
It`s all pretty simple - keep battery charged and amps flowing smooth. Fully charged battery rates at 24 volts, with generator running - 28 volts. Desired ammeter readings - about 300 amps at nominal engine speed.

10. Clutch locked light.
Hydromechanical clutch in this helicopter contains two parts - hydraulic coupling mechanism and mechanical lock mechanism. First one driven by clutch pump, and intended to smoothly couple engine driveshaft with transmission driveshaft. Second one automatically enebles when shafts rpm`s matches. So, this light lets you know that mechanical lock is enabled. Automatic decoupling occurs if engine rpm is lower 1100. Keep an eye on clutch pump, never run it after mechanical coupling occurred!

Just one step away from the sky

So, we have engine running and all the parameters in desired ranges. It`s time for flight instruments.



1. Attitude gyro and gyro compass. Powered by main invertor, can fail separately.

2. Manifold pressure. Desired range from 20 to 38 mmHg.
Basically, indicates how much engine power is used. Higher means more power used.
If engine is cutoff, indicates atmosferic pressure (29.92). Can fail, repair by electric repair.

3. Engine and rotor rpm. Desired range (helicopter fully fueled, no cargo) for engine is from 800 to 1900 idling, 2000 for hovering, 2120 for economy cruise (78-80 knots). Rotor rpm is irrelevant due to impossibility to implement proper autorotation procedure in Strmwrks. Can fail, repair by electric repair.

4. Altitude and climb rate. Pretty obvious instruments. Can fail in case of icing only.

5. Indicated airspeed. Shows speed relatively to the air, not the ground! Also can fail only because of icing.

6. Magnetic compass and parking brakes doesn`t needs an introduction.

Now you`re ready to go.
Final step to the sky:
- Mixture: 0.1-0.7 for warm up, >0.7 for taxi, >0.8 for flight.
- Breakers panel: all green
- Clutch pump: off
- Vents shutter: as necessary
- Carburetor heating: as necessary
- Servo: on
- Parking brake: off

Final word about procedures

Just few more words about not-so-obvious things.

- Does it have autopilot?
- As I was saying before, this helicopter was never equipped with autopilot, but there is hidden system it to stabilize it automatically, literally "auto-pilot" - it imitates the pilot job. Helicopter will autmatically hold heading (a/d to adjust), altitude(up/down to adjust), roll and pitch, and also will resist drifting if hovering.
Also, it can maintain forward flight. By pressing "1" or "2" you can change target pitch to hold, resulting to fly forward with desired speed. There is no indication for that, so just keep in mind there is 5 pitch positions: 1-4 is for normal flight, and 4 means most economical cruise mode, with speed aprox. 78 knots. 5 - for maximum speed, which is unreachable with fully fueled helicopter. You need to lose some weight and throttle engine to maximum to reach top speed, and better set your records in arctic, where there`s more power because of the cold air.

- I went to the arctic and can`t start it.
- It won`t start if it`s colder than about -26 C. You need ground power for that.

- Heater doesn`t work but the breakers is fine!
- Close cabin doors. How do you suppose heater to heat you if there`s blizzard in the cockpit?

- It`s flying and roll is uneven.
- It`s compensating slide and wind.

- I don`l like controls, I want it to be traditional.
- This is made to be able to control helicopter with one hand, and use another for camera control. But if you want go traditional - open electric compartment, find key switch, turn it on. Now you have A/D for roll, W/S for pitch, Left/Right for yaw and Up/Down for collective.

- What if I ran out of the electicity?
- In the electric conpartment there is connector for ground power.

- What if I ran out of the fuel?
- Refueling inlets are marked orange and are located on the right side of the helicopter.

- What if I ran out of the oil?
- Refill canister with diesel and use it instead of oil.

- Can`t find canister.
- It`s in baggage compartment in the back of the cabin.

- How does winch works?
- It have buttons in cabin and hints.

- Autopilot works bad!
- There is no autopilot on this helicopter!

If you still do have any questions left, feel free to ask.

[kknd_3apa3a]

checked. works perfectly fine. you`re doing something wrong.

[Frosted Flake]

Is there a way to hook up an APU? I keep having the batteries die on startup.

[Frosted Flake]

I'm having some issues getting it started, or at least getting the pressures up.

[squeaker0704]

it constently spins as if the tail roter is faling

[squeaker0704]

i seem to have found another problem

[squeaker0704]

thanks for the help

[kknd_3apa3a]

well anyway I`m glad you`re fell into one of my traps

[kknd_3apa3a]

even throttle lever telling you - "do not exceed 0.7 without load". with letters THIS BIG.

[kknd_3apa3a]

I`m quoting here:
If it`s colder than 120 C, there`s going to be misfiring and stall if load is applied and throttle/mixture is too high.

that`s exactly what`s happening - you`re trying to start cold engine with throttle full open. of course it`s not going to work.

[kknd_3apa3a]

wait... what was throttle position? 1.3+, right? and what should be position for starting up?