Category Archives: General

Running Takeoffs in Helicopters

Running takeoffs are easier and more appropriate in wheeled helicopters (think the Augusta/Westland 109) then in skid helicopters (Robinisons, Bells, etc) typically used in training operations. Skids can wear out or damage the surface of the runway over time. Plus, there is the noise factor to consider. The sound of a Robinson R22 making a running takeoff can only be compared to a giant running his fingernails along the world’s largest chalkboard.

The main reason we practice running takeoffs is to show students how to takeoff when power is not available to hover. Generally, if there is not enough power available to hover then it is not safe to complete the flight. Helicopter performance in unpredictable and if there is not enough power to hover, there is no way to be sure that there is enough power to make a running takeoff. Students should be taught to recognize an inability to hover as a warning sign. The appropriate response is to reduce gross weight, not to force the helicopter into a running takeoff.

Running takeoffs increase the operation envelop of the helicopter and allows for takeoffs or landings in low power situations They are most frequently used in high density altitude operations.

TO complete a running takeoff, the pilot will apply about half as much collective power as they would to hover while applying forward cyclic input. This will cause the helicopter to lift weight off the skids and tilt the rotor disc forward to cause forward motion.

As speed increase, the helicopter will transition through translation lift airspeed. AT this point, the pilot should increase collective pitch, apply aft cyclic pressure, and begun to climb to altitude.

For the typical helicopter pilot, running takeoffs are a maneuver the will be practiced often and used seldom. Always remember if you helicopter cannot hover it is tell you you that it is to heavy for atmospheric conditions. Always listen to your helicopter.

Casey Ryan Richards

The Pace Checklist

Helicopter instructors can use the PAVE checklist to teach students how to examine risks before a flight. PACE is broken down into four categories: Pilot in command, Aircraft, enVironment, and External pressures.

Pilot in command refers to the students current experience level, currency, physical/emotional wellness, and mental readiness to complete the flight. Your student should ask themselves if there are any personal issues which could prevent them from safely flying the helicopter. Fatigue, alcohol consumption, stress, sickness, and medication should all be considered.

Aircraft refers to the helicopter. Is the helicopter ready for flight? Has a preflight inspection been completed? Has a weight and balance been completed?

Environment refers to the weather. What are the winds? Are there any storms forecasted in the area? Icing can be a serious complication to helicopter operations, what is the temperature-dew point spread? Is it conductive to icing? Student pilots must learn to ask themselves theses questions and learn to evaluate what conditions are safe for the operations of their helicopter.

External pressures are the most often overlooked, but cause their fair share of accidents. Is a client waiting for you? Or is the airport closing at a certain time? Make sure your students don’t rush and put themselves and others at risk just because they have a case of “get-there-itis.”

Using the PACE checklist, students can easily examine each unique situation and make a successful go/no-go decision.

CASEY Ryan Richards

#caseyryanrichards

Guimbal G2: A Piston-Engine European Helicopter

The Cabri Guimbal G2 has made its foray into the American Light Sport/Training Helicopter market, and has proven to be the only real competition to the R22 Robinson model. Although this Author has not flown the Guimbal, he has flown an R22, and so this is a statement of the differences between the two aircraft.

Both aircraft use a piston engine. The Guimbal makes roughly a hundred horsepower, but it costs almost $175,000 more than the R-22. The explanation for these extra dollars seems to be that the G2 has a fully articulated rotor head and a ducted tail rotor for safety; the R-22 doesn’t have either. The Guimbal also has greatly reduced overhaul costs (approximately $50k cheaper).

The G2 can carry a maximum of 600 lbs, or two very fat pilots, and the R-22’s left capability is roughly the same, making the both of them similar aircraft in that regard. The hourly operating costs including fuel and maintenance are roughly equivalent (with the except of overhaul costs) as well. The main difference between the aircraft is this: Guimbal’s chief designer was also the designer guru at Eurocopter, and the styling and design of the G2 reflect this.

For instance, the G2 has smooth lines, a ducted tail rotor, rounded skids, and a semi-custom interior featuring leather and plastic. The R-22 has none of these things, instead having fully exposed tail rotors, skids that would look at home on a construction site, and a bare-bones interior. But it is also half the price.

And one can indeed customize the R-22 to look a bit better, but that has never been the point of the R-22; it’s a training and light-sport helicopter, not a beauty queen. The G2 on the other hand, although intended as a training bird, reaches just a little high for the US market. Maybe in Europe without the exchange rate the aircraft is comparable in price, but here in the US there is nothing about the Guimbal that justifies the extra price tag.

As always, I encourage you to test-fly both aircrafts before making any purchasing decision. From what I can tell, the Guimbal is a showroom type helicopter that put it’s futuristic design first. Yes, the articulated rotor head and the ducted rotor are nice, but they are unnecessary in the training market- the R-22 has neither and yet is the top sells. I believe the R-22 has nothing to worry about in regards to this newcomer. The Cabri could easily become a serious competitor, but not at this price tag.

Casey Ryan Richards 

Skids versus Landing Gear Systems

Every helicopter shares one characteristic, no matter the make, model, or year, at some point, it has to land. When your helicopter touches down, it has to support it’s weight on something-you wouldn’t park your car on it’s undercarriage, would you? So, modern helicopter designers have settles on two methods to support the qieght of the aircraft when it lands: either skids or wheels.

Skids are metal bars that are permanetly affixed to the frame of the aircraft. They often resemble the rails of a sled. On the bottom of the skids is usually a reinforced metal coating, as when the helicopter touches down, the skid touches the ground (wher it’s name coems from) while the helicopter settles in. Though stroung enough to support the weight of the helicopter indefinitely, and inexpesive enough to be found on most helicopters (including all Robinson models), skids have one major drawback: they are not retractable, and therefore are a big source of aerodynamic drag while in flight.

Landing gear systems, on the other hand, consist of three or more wheels on hydraulic suspension mounts, that can be retracted into the fuselage of the helicopter once the aircraft has taken off, but can be deployed when it is ready to land. Much likethe gear on a fixed-wing airplane, these systems are more expensive, but allow for better aerodynamics while flying, as there is no drag created by skids or wheels hanging out of the aircraft.

The biggest benefit of skids, practically speaking, is that skids distribute the weight of the aircraft over a larger area. This allows for the attachment of floats, or for landing on ice, or for landing on this surfaces in situations where a gear-equipped helicopter might sink or fall through. Landing gear, in contrast, distributes the aircraft’s weight to three (or four) points, rather than spreading it out over a 1-2m long skid, therefore concentrating the weight into those areas. This can lead to a fall-through situation when landing on, say, ice or snow, potentially causing a fatal accident.

The biggest benefit of landing gear is that is can be retracted into the aircraft, reducing the profile and fuel consumption as well as improving the aesthetics. Traditionally, gear systems are found on more expensive helicopters, all of which are typically turbine powered. This is because the systems are expensive, but although it seems counterintuitive, the retractable great is usually fairly lightweight and adds little to the helicopters gross weigh, while improving efficiency by up to 5%, a significant savings in fuel use over the life of the helicopter.

No matter which system your helicopter has, land safe and don’t try to land without one! That’s like doing a belly flop into a pool- you will feel it later.

Bell 505 Jet Ranger X

The Bell 505 Jet Ranger X is Bell Helicopter’s new five-seat aircraft designed for safety, efficiency and reliability through the use of advanced avionics technology. It incorporates proven dynamic components, advanced aerodynamic design, a dual channel FADEC Turbomeca Arrius 2R engine and best-in-class value.

The 505 also features the Garmin G1000H avionics suite. Preliminary data calls for the 505 to have a 61-cu-ft (1.7 cubic meter) flat-floor cabin, a cruising speed of 125 knots, a maximum range of 360 nm (666 km) and a useful load of 1,500 pounds (680 kg). It is a “clean sheet” design, but will use some dynamic components, such as the rotor system of the Bell 206L-4.

The Bell 505 Jet Ranger X is designed to customer specifications, combining proven systems with the latest advancements in rotorcraft technology. By putting a strong focus on the MSG-3 working group, the Bell 505 Jet Ranger X will not only provide the best value in the short light single market, but also provide superior performance and reliability for operators.

The Bell 505 Jet Ranger X approximately sells for $1m. There is a mission-critical support package–an hourly maintenance plan–for the 505 to take care of customers’ demand for an affordable aircraft, both in terms of acquisition and full life-cycle costs.

The specifications are:

  • Price (approximate): $1,000,000
  • Engine: Turbomeca Arrius 2R
  • Horsepower: 504 shp
  • Seats: 5
  • Length: 42.4 feet
  • Height: 10 feet
  • Fuselage width: 60 inches
  • Cabin volume: 61 cubic feet
  • Main rotor diameter: 37 feet
  • Tail rotor diameter: 5.4 feet
  • Useful load: 1,500 pounds
  • Max usable fuel: 91 gallons
  • Full fuel payload: 881 pounds
  • Cruise speed: 125 knots
  • Max range: 360 nm

 

The Bell 505 Jet Ranger X is an ideal choice for all business needs.

How a Turbofan Engine Works

In a turbine powered helicopter, the turbine is typically a Turbofan engine. However, unlike Turbofan engines on a jet aircraft, instead of the exhaust gases providing thrust, they are used to spin an auxiliary power shaft, which is what causes the rotor to rotate and provides power to the helicopter. But how, exactly, does a turbine engine work in a modern helicopter?

The majority of turbine engines are high-bypass turbines. This means that immediately past the engine’s intake, the fan assembly (which are effectively a low-pressure compressor) pushes part of the air flow into the main compressor. The rest of the air is pressed into a bypass duct, a separate channel in the engine housing. In high-bypass turbofans, about 40-50% of the air is sent down the bypass duct.

On the surface, this doesn’t make a lot of sense. Don’t you need more air, not less, to make a turbine engine more powerful? In the case of turbofans, however, this is not so. More air is definitely NOT better. Since pressure ratio is the key performance characteristic of a jet engine, and in our case a turbine, designers put a lot of work into increasing this pressure ratio.

If an engine has to compress a lot of air, then the pressure increase is distributed over a large volume. However, by reducing the amount of air that flows into the compressor, more work can be done on a smaller volume, meaning a greater pressure increase. This is very good. Then, the designers increased the rotational speed of the compressor itself. With the compressor stages spinning around quickly, more work is done on the air that IS sent to the compressor, and this again means a greater pressure increase.

And this was where the original turbine designers ground to a halt, because at speed the temperatures that the nickel turbine blades were exposed to were in excess of their melting point. SO, a new process created Single Crystal turbine blades, which had a much higher melting point. On top of this, because they were cast with holes during the forming process, cold air is spread through tiny holes in each blase from the compressor during operation. The bleed holes produce a protective film of air, which keeps the turbine blades from coming into direct contact with the hot exhaust gasses.

Since helicopters don’t use rearward thrust to fly, the gasses are then passed through a second spinning turbine assembly, attached to the auxiliary output shaft, which is itself attached to the gearbox for the main and auxiliary rotors. Even with this added step, these engines produce exponentially-higher power levels than their piston engine counterparts, and are often much smaller and lighter, resulting in high performance aircraft that are light and agile to fly.

Beginning to Fly Helicopters

Learning to fly a helicopter is a fun and rewarding experience, but it can be a frightening one, quite understandably. You’re suddenly in charge of a million and one pieces that are constantly trying to vibrate themselves apart in mid air, and you’re suddenly responsible for pedals and sticks and throttles and temperature gauges and more.

That being said, the best place to start is to purchase a copy of a good flight simulator application. Microsoft Flight Simulator is a good example. Try flying a virtual helicopter for a while to see if you can stomach the idea of being in the cockpit.

The next step would be contacting your local flight school that offers Helicopter Pilot Training. The FAA certifies flight schools to offer rotor craft (the technical term for a helicopter pilots’ license) license instruction.

The next step would be to contemplate if you’re going to purchase your own helicopter (most commonly, a Robinson model). R22 Helicopters cost just over $250,000 brand new or they can be rented from many flight schools for $250 per hour.

Finally, you’ll have to take and pass a test administered by a designated examiner. Your flight school will help with this.

Tilt rotor Aircraft

Tilt-rotor aircraft have only recently entered the civilian market with the Agusta-Westland AW169. Yet, these aircraft, which theoretically combine the best capabilities of a helicopter and a fixed wing propeller-driven airplane, have existed for some time in the military aviation community, most notable in the form of the US Marine Corps’ VH-22 Osprey transporter. But what, exactly, sets a tilt-rotor apart from its cousin, the helicopter, or its other cousin, a turboprop?

The civilian entry into the market is in the form of the AW-169, which is a civilian version of the VH-22. This aircraft has two counter-rotating rotors mounted on engine nacelles, driven by a single turbofan engine for each nacelle. What makes this aircraft unique is that these nacelles, or pods, can rotate. And in doing so, they take the AW169 from flight characteristic of a helicopter, in terms of ability to hover and maneuver, and turn it into a fixed wing turboprop.

The nacelles of the AW169 are mounted on the aircraft’s wings. Wings on a helicopter may seem sacrosanct, but in this instance, its what allows the aircraft its impressive maneuverability. The wings contain hydraulically operated control surfaces to aid in fixed wing flight, and the nacelle gears-those that allow the massive rotors to rotate from a upward position to a forward facing position- and motors are hydraulic as well. By placing the aircrafts engines at the end of the hollow wings, which store fuel, this allows the aircraft to contain much more within itself.

Further, the configuration of the tilt-rotor allows for an impressive amount of lifting ability. In testing, the AW169 had been able to lift almost 10,000 lbs. Although this has not been certified, nonetheless it remains a spectacular feat for any helicopter, and opens the door to the possibility that the AW169 may, one day, replace the Sikorsky Skycrane as the heavy lift helicopter of choice on the civilian market.

Although the AW169 is new to the market and is, at the time of this writing, pending FAA certification, Agusta-Westland has stated that it is no more difficult to fly than a standard configuration helicopter. Further, Augusta Westland will offer AW169-specific training for the aircraft. The FAA< meanwhile, is deciding whether or not additional licensure, type-rating, or endorsements will be needed for the tiltrotor, which has not been priced as of yet.

Still, the AW169 represents an exciting new dimension to the helicopter world, and one this author hopes to experience in the near future. So if you happen to buy one, give me a call-I’d love to ride in the right seat with you!

What Does a Cyclic Stick Do?

The cyclic stick in a helicopter is, by far, the most important of all the controls in a modern helicopter, and yet, it is often the least glamorous. Located between the pilots legs in all but a few helicopter, this stick is the pilots link to telling the aircraft what he wants it to do. But how, exactly, does the funky stick work?

Well, the cyclic controls the direction of flight by changing the angle of attack of the rotor blades. The servo motors that control the angle at which the blades meet air are control-led by the cyclic. In most helicopters, there is also a twist throttle that controls the amount of power the engine produces. This throttle is what I like to refer to as ‘the potential’. As you give the aircraft ‘potential’, now you have to learn what to tell it to do with the power.

For instance, if I have my cyclic perfectly centered, and twist the throttle, with my anti-torque pedals controlled, my aircraft will simply make a lot of noise and act as a big fan. But with a little action for the cyclic, now I can gain altitude and climb while not moving laterally. If I push the cyclic forward, the nose of the aircraft will dip as it attempts to move forward. If I pull the cyclic back, the nose will raise, and the aircraft will being to climb.

You can move the cyclic side to side to cause the aircraft to bank, and of course the anti-torque pedals, which control the tail-rotor, can be used to ‘spin’ the aircraft to point in the direction you want it to go. Once the nose is in the direction you want it to be facing, you can again use the cyclic to control altitude, speed, and direction. However, in a helicopter, the aircraft doesn’t have to be pointing in the direction you want it to go- you can ‘bank’ the aircraft, or have it move sideways without any forward movement or cornering, by simply moving the cyclic sideways.

The majority of newer helicopter also have a radio and, if so equipped, autopilot controls on the cyclic’s handle. Military and law enforcement helicopters, and well as rescue helicopters, may have the controls for a camera system or thermal imager, or a spotlight, one the cyclic handle as well. In a military attack helicopter, the controls for the aircraft weapons are typically mounted on this handle, making the cyclic by far the most important control in the helicopter.

In conclusion, all pilots should be intimately familiar with their cyclic stick control in the aircraft they intend to fly. By simply taking 10 minutes to become comfortable with the different layout of the cyclic, and of course performing a pre-flight by moving the actuating the cyclic to engage the servos up in the rotor assembly, you can be assured that you’ll avea great and safe flight.

Controlled Flight into Terrain Avoidance

Controlled flight into terrain is the technical term for crashing your helicopter into the earth. This is not just into the ground-it can also man into a hill or mountain. And it happens quite often to both fixed and rotor-wing aircraft, although we’ll be focusing on the helicopter aspect of things, obviously. CFIT accidents are a major safety concern for helicopter pilots, and yet these accidents are often quite difficult to explain because they involve a pilot being aware of the impending disaster.

The most common factor in CFIT accidents is that the outside visibility is limited, or the accident occurs at night, and you can’t see the terrain features due to darkness until you’re moments away from impacting it. Another common factor with CFIT accidents is a lack of situational awareness, but vertical awareness as well. Knowing not only where your helicopter is in relation to the ground, but the terrain features around your flight areas, is the best way to prevent a CFIT accident.

The best defenses a pilot can have to avoid a CFIT accident is Training, Planning, and Preparation. Taking a few minutes before takeoff to become familiar with the proposed flight and any terrain obstacles in the flight path can go a long way towards preventing a CFIT accident. Pilots must also ensure they have adequate visibility to fly their aircraft safely. Whether this means that they can see with the naked eye, or have suitable instruments on board, or even night vision equipments, if you can’t see the terrain and obstacles around you, you’re flying into a CFTI-conducive condition.

Practicing flying with instruments while you can see with the naked eye is the best way to get comfortable with potentially needing to rely on instruments alone to guide you safely. Pilots should practice immediate CFIT avoidance procedures, such a rapid altitude increases and aerial avoidance maneuvers, in an area free of actual hazards. Pilots should also ensure that their altimeter works properly before takeoff.

Today’s modern aircraft have sophisticated electronic safety and autopilot, auto throttle, flight director, and flight management systems. No matter how face your helicopter is, however, ultimately, the pilot is responsible for CFIT avoidance. If you rely on an autopilot, crosscheck it with your instruments and your eyeball frequently failure to do so is practically begging for a CFIT accident). Caution should also be used while using illumination inside the aircraft, for certain colored lenses and lights could bleach out symbols on a map, or blind the pilot from seeing outside obstacles.

The FAA has a CFIT avoidance checklist, published by the NTSB, available on its website. I highly encourage you to download it and keep it handy. Remember, there’s no cute bear that says “only you can prevent CFIT accidents!” However, if you enjoy the controlled landing part of a helicopter flight, be responsible and know your surroundings. Fly only in conditions you’re comfortable with, and ensure your instruments work properly before flight. Safe flying is in your hands. I might not be a bear, but I’ll remind you anyways!