c.  
A propeller, the pitch setting of which may be controlled by a combination of the methods of a. and b.

JAR 1.2  Abbreviations and symbols
‘ACJ’ means Advisory Circular, Joint.
‘APU’ means auxiliary power unit.
‘BTPS’ means body temperature, pressure, saturated, i.e.37°C, ambient pressure and saturated with

water vapour at 47 mmHg partial pressure.

‘BTPD’ means body temperature, pressure, dry, i.e. 37°C, ambient pressure and no water vapour.

*‘CAS’ means calibrated airspeed.

*‘EAS’ means equivalent airspeed.

*‘IAS’ means indicated airspeed.

*‘ICAO’ means International Civil Aviation Organisation.

#*‘IFR’ means instrument flight rules.

*‘ILS’ means instrument landing system. 

‘JAR’ means Joint Aviation Requirements.

‘LDP’ with respect to rotorcraft means the landing decision point.

*‘M’ means mach number. 

‘MIL Spec’ means USA Military Specification.

‘NPA’ means Notice of Proposed Amendment.   

‘NTPD’ means normal temperature, pressure, dry, i.e. 21°C, 760 mmHg and no water vapour. 

*‘OEI’ means one engine inoperative.

‘rpm’ means revolutions per minute.

‘STPD’ means standard temperature, pressure, dry, i.e. 0°C, 760 mmHg and no water vapour. 

‘TAS’ means true airspeed. 

‘TSO’ means Technical Standard Order.

‘TDP’ with respect to rotorcraft means take-off decision point.

*‘VA’ means design manoeuvring speed. 
*‘VB’ means design speed for maximum gust intensity.
*‘VC’ means design cruising speed. 
‘VD/MD’ means design diving speed.