Vibration Identification & Minimization (see November Rotor & Wing, page 36) provides a high level overview of helicopter vibration. However, it may be worth adding that helicopter vibration is becoming a smaller issue by the day. I have 10 years of experience at LORD Corp. designing active vibration control systems (AVCS) and active balancing systems (ABS) for helicopters. In the last 10 years I have seen a drop of more than 70 percent in helicopter vibration levels across the industry. Most of the new European helicopters are now equipped with active systems to manage vibration. U.S. companies are also adopting such systems very quickly. I think within five years, most of the helicopters will have a very smooth ride. In addition, once the variable RPM helicopters get the certifications, we will see more active systems on board. At LORD Corp., we have active systems that can be installed on the rotor hub, in the isolation path and on fuselage.
‘Copter Cleaning (November 2010, page 42) is a great article. I’ve been in the truck industry for years and seen the problems due to not keeping the road dirt cleaned off of aluminum truck cabs. Dirt/rust buildup between hardened steel double frame rails can spread them apart and they rust apart from the inside out. I’ve also seen the electrolysis bubble up paint between steel mirror brackets and aluminum doors because of poor grounding for heated mirrors and radio antennas. I had not thought about mold and mildew before, but can see that as a problem too. I do believe that clean, waxed cabin surfaces create less wind drag, giving overall better fuel efficiency.
I must really be getting old! I started UPT-H in Det 1 and was in the first graduating class of the 3588 FTS. I believe Steve “Elroy” Colby was fortunate enough to fly the “Mattel Messerschmit” aka TH-55 like me. If not, I must be one of those stone age pilots! I imagine Lowe AAF has more departures/arrivals in one hour than a comparable civilian airport.
Mr. Bower, touche, and thanks for supporting our CSAR troops (see “USAF Combat Search and Rescue: Dying on the Vine?”, November 2010, page 46). It’s been too many years that CSAR crews have been relegated to second class citizen status at the alter of:
1. Airlift (HH-60D canceled due to C-17 budget in 1986);
2. “Pentagon efficiency” (CSAR-X cancelled due to poor SPO program evaluation execution); and
3. CSAF Prioritization (2010, new CSAF after Moseley relegated CSAR from No. 2 priority to below No. 10.) Your identification of yet another obstacle to their success is timely and welcome. Thanks!
Thanks to everyone at Rotor & Wing for your ongoing commitment to researching and reporting on editorial readership and, especially, advertising effectiveness (October 2010 Signet AdStudy). Advertising can be costly, and with so many new options offering measurable results, advertisers understandably want to know that their investments are worthwhile. Quantifying how much any given ad is seen and read is an important measure and positive step toward better understanding this multi-faceted issue.
BDN Aerospace Marketing
I would like to see continuing development and improvement of tiltrotor aircraft, now that the Bell-Boeing V-22 has baselined tiltrotor technology. But I would also like to see advanced-design troop transport helicopters similar in weight carrying capability to the upcoming CH-53K, but using counter-rotating co-axial main rotors like the Sikorsky X2. The latter has now reached speeds of 250 KTAS in test flights, which is not far below what the V-22 is capable of.
â–¶ R&W’s Question of the Month Should compound helicopters like the Eurocopter X3 be in the same category as helicopters when it comes to speed records?
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