The South African Air Force (SAAF) have reported they are very happy with the performance and capability of the Airwork (NZ) Ltd BK117 Sand Filter. Flight Structures was contracted by Airwork (NZ) Ltd to complete the Design and Certiifcation of the Sand Filter system and gain NZCAA STC Approval for both KHI and MBB models.
Significantly, through a combination of detailed design development, system safety analysis, performance modeling, and flight testing, Flight Structures was able to approve the system for Category A operations and remove the substantial performance penalties applied to the OEM system.
Excerpts from the November 2012 issue of Global Aviator magazine:
"Initial results have proven most favourable with pilots claiming a reduced engine operating temperature. This is significant as this reduces engine stress (fatigue) and therefore extends engine life and increases mean time between overhauls while also increasing mean time between failures of related engine components. These all have positive cost implications, more especially in the long term.
From an aerodynamic perspective, besides the superior aesthetics ('Miss' BK claims to have had more requests for her telephone number than ever before!) a significant reduction in frontal drag has favourable implications in terms of increased maximum and cruise speed, longer range and increased endurance etc.
Unlike the earlier system, the Airwork system is certified to meet full Category A and B transport requirements.
At 32 kg (70.5 lbs) installed weight all told (including all electrical components), the new system is 12.5 kg (27.6 lbs) lighter than the system it replaces."
Read the full pdf article below: