Some words to the starting procedures with a modern turbine helo as BO105, due to my bad english knowledge I will repeat some technical expressions in German, Melchior Franz will understand it:
Modern helos are equipped with a two shaft turbine (Doppelwellenturbine) with air compressing part (Verdichterturbine)(N1) and working part (Arbeitsturbine) (N2). These two parts are only connected by the airflow through the turbine, there is no gear or any mechanical connection between. You use the electrical starter to get the air compressing part up to 10% N1 (Mit dem Anlasser die Kompressorturbine auf 10% Normdrehzahl N1 hochfahren), then you start ignition and carefully set power (10% ..) watching the temperature of the working part (N4). If temperature gets too high you have either to reduce the throttle setting or in the worst case break the start. When the compressor part gets faster (N1 rises) you have to watch the working part (N2) also to turn, otherwise there is a failure and you have to stop turbine-start. (Ein Hochfahren des Kompressorteils bedingt ein Folgen der Arbeitsturbine, andernfalls ist ein Fehler vorhanden. Bereits die Betätigung des Anlassers der Turbine kann in einigen Fällen ein Folgen der Arbeitsturbine verursachen mit leichter Rotordrehung) Normally (modern helos) there is no clutch between working part of turbine and main-gear. So a working turbine will result in a turning rotor disk. The higher N1, the better following of N2. Exception as far as known: Alouette and some other rather older French helos (turbine and clutch). Piston helos do have centrifugal clutches (Fliehkraftkupplung), but I have no experience with this type of copters, just know it from a book. If you lock your rotor brake when starting a turbine you will burn the blades of the working turbine part - good luck! If you have reached ca. 40% N1 you may add the generator to reload the battery for the start of engine 2 (in case you have no extern energy supply). Wait until primary energy flow to the battery (up to 150 Amps) will decrease for the generator hasn't the power to load the battery AND to start engine 2. Rotor RPM should be "in the green". Make the same procedure for engine 2. Before take off you have to go from idle to 100% throttle. Stable turbine RPM will be electronically controlled. Only Piston helos require adjustment of throttle - but ie. Robinson has developed some sort of electronic manager for the R22/44. (Robinson hat für seine Kolben-Hubschrauber ein elektronisches Regelgerät für das Gasnachsteuern entwickelt, welches unter normalen Betriebsbedingungen sehr gut arbeitet). If your Rotor is faster then the turbine (naturally gear between) you have a free wheel (Freilauf), also needed for autorotation. Hope that helped a little. Regards Georg (HeliFLYer, EDDW) --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.756 / Virus Database: 506 - Release Date: 08.09.2004 _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
