Robinson R22
The built since 1973 Robinson R22 is a helicopter of the U.S. aircraft manufacturer Robinson Helicopter. The design provided for a simple, light and inexpensive helicopters for training and monitoring purposes and private use. He is currently being manufactured in version R22 Beta II. The Robinson R44 is the slightly larger, but similarly structured sister model of the R22. Since 2010, Robinson also offers a model with turbine drive, the Robinson R66.
Description
The R22 is not as common today driven in helicopter construction with shaft turbines, but over a conventional piston engine manufacturer Lycoming. However, since a piston engine, in contrast to a one-way turbine may not be started with force closure to the rotor system, the use of a releasable coupling has been necessary to disconnect the drive starting process and load. This is accomplished with the R22 through a "stretch " clamping device of the multiple V-belt drive between motor and main gear.
To achieve acceptable performance in spite of the heavier in weight compared to a comparable turbine shaft piston engine, R22 is carried out in absolute lightweight. It has been omitted anything that is not primarily necessary for operation. The reason for opting for a piston engine was the much lower price and cheaper spare parts and maintenance costs compared to a turbine engine. Another benefit that results from this is that the helicopter can be thus maintained and operated from airfields that are not designed for the maintenance and operation of turbine aircraft or on which no fuel is available.
The widespread Lycoming O -360, an air-cooled four-cylinder boxer engine is throttled in his power to occur in spite of the helicopter use high thermal load to achieve the required service life and reliability. Missing travel and Propellerwindanströmung by installing behind the cell to make a forced cooling by a fan necessary, which also takes a portion of the available engine power to complete. The R22 is, however, designed for two people with small hand luggage, or without any payload and has the standard version had no instruments for instrument flight. The dual control is not implemented via two separate control members, but with a central stick to a kind of the bracket is fixed and thus allows control of the two seat positions. On interior trim was also dispensed as a full fairing the hull. Only in this way it was possible, not much over 4 kg to allow the power to weight increase for the fully loaded helicopter / hp.
With a base price of just over 240,000 U.S. dollars it is a cost effective alternative to the classic turbine helicopters, but in terms of acquisition and maintenance (servicing / consumption) affordable for the sport and private flying not only for flight schools. Most R22 are procured by flight schools and media companies. In Australia, many R22 for Cattle Mustering, the modern variant of the cattle drive, used. Above all, under this aspect, the use of R22 play its biggest advantage over its usually larger and heavier competitors: its almost unrivaled maneuverability. For this purpose he makes use of an advantage of the piston engine, which power demand significantly react faster than a turbine. The R22 can be transferred to the shortest distance from full speed in the slow or hovering flight.
However piled up until the mid -1990s, the accidents of the R22 and R44 with the similarly constructed from the same manufacturer, which had an intense observation by the aeronautical authorities of the result. According to the investigation by the AAIB was the low capacity of the helicopter system to intercept effects of a failure or operator error, for the crashes with the cause of many accidents. Especially flight conditions with low load factors ( Low Gravity ) and hustling control inputs resulted in fatal crashes, because the rotor blades smashing into the tail boom and the aircraft is then decomposed in the air. In response to this threat, the training guidelines and establishing the operating limits of the model had to be modified R22 and R44.
Furthermore, it was the change in the altitude performance of a non-supercharged piston engine some pilots undoing. The performance of such an engine decreases with increasing height much greater than that of a shaft from the turbine, because the latter can compensate for the fall in pressure better. Added to this was the wave of turbines (and thus for pilots who have been trained on turbine helicopters ) unknown problem of carburetor icing, and thus the sudden engine stoppage.
Another, very simple design of the R22 owed disadvantage is the low weight-reduced through the rotor blades kinetic momentum energy that can be stored in the rotor in autorotation landings in the unpowered descent. This residual energy in the rotor flywheel must the pilot sufficient to safely and softly put on the helicopter after flaring ( loss of forward motion by raising the nose of the aircraft ) on the skids. Decisive is the level at which the pilot performs the flare maneuver. Therefore landings to be carried out by autorotation to touchdown only by experienced pilots. In the school operation is not generally on autorotations to touchdown and the maneuver ended a few feet above the ground immediately after the flaring by raising the engine performance, including the descent, the engine must run along on idle.
Fatal accidents in the cattle drive in Australia, where the machines are flown without security level, speed and safety of inexperienced pilots with breakneck flight maneuvers, contributed to the overall crash statistics R22 serious negative.
A well-trained R22 pilot can feel very safe in his machine, especially in Germany, Austria and Switzerland, the fewest crashes are recorded per flight hour worldwide ( source: Federal Aviation Authority 2007). This fact can not be attributed with domestic flight training provisions ( a helicopter license for the R22 costs about 25,000 euros ), but also the fact that the prescribed maintenance schedules in the three countries are complied meticulously.
Specifications
Similar types of helicopters
- Bell 47 ( no longer in production)
- Brantly B -2B
- Enstrom F-28
- RotorWay Exec (kit helicopters of similar size )
- Schweizer 300C
- Cabri G2