Your item on the first flight of the Block 3 variant of the Boeing/U.S. Army AH-64D Apache stated that "Boeing experimental test pilots performed the first flight" on June 27 at the Boeing’s Mesa, Ariz. facility ("Program Updates," August 2008, page 22). That is incorrect.
That first flight of the first prototype Apache Block 3 was flown by a split crew consisting of a Boeing experimental test pilot and an active-duty U.S. Army experimental test pilot. The test program is being executed as a Combined Test Team, and marks the first time that U.S. Army testers have been integrated on site at the Boeing Mesa facility in these early stages of development. The success of the Block 3 test process and overall program hinges on this execution as a Combined Test Team, and I forward accolades to both Boeing and the Army’s Aviation Technical Test Center for making this historical event successful.
Lt. Col. Dan Bailey Redstone Arsenal, Ala.
If I take a child to the playground, let him climb into a swing, and carefully apply a small push at the proper frequency (the "natural frequency"), large dynamic displacements gratify the child. This is an example of resonance. At any other "forcing frequency," much more force will be required for such a large displacement.
In his letter to the editor, Steven Kersting makes reference to aerodynamic resonance, ground resonance, resonant frequency (a frequency that feeds into itself), etc. ("Feedback" August 2008, page 7). Could he please relate his helicopter flight terms to my simple example?
Wayne Tustin Santa Barbara, Calif.
Col. Clyde Romero’s experience as a Loach driver certainly solidifies his credibility as a combat veteran. The fact that he was shot down nine times certainly is justification for him taking a position on the next combat search and rescue (CSAR) helicopter ("CSAR With a CH-47," August 2008, page 7).
As for me, I was shot down once and forced down by mechanical problems twice during my two tours in South Vietnam. I can tell you from my experience that I didn’t care what type of aircraft rescued my crew and me. For that matter, neither did the OV-10 Bronco crewmembers that I rescued while flying my Boeing CH-47. They didn’t seem to mind the noise, size and downwash; what was important was that they were rescued.
Whether a pilot is flying alone and unafraid, in a hunter-killer team, or as an aircraft in a large combat assault formation, when you are shot down you don’t worry about what type of aircraft will rescue you and your crew, but rather how soon help will arrive.
The rescue aircraft of today and of the future must be capable of conducting operations across a broad spectrum of missions, payloads, and environments. The Chinook is capable of operating in adverse-weather conditions with its terrain-following, terrain-avoidance radar. It can transport greater numbers of personnel, survivors or oversized equipment in its large cargo compartment. Its tandem-rotor system provides the lift to operate at extremely high altitudes or in high-density altitude conditions. The Chinook will outperform the competitors’ aircraft not only in the stated U.S. Air Force CSAR-X requirements, but also the unstated missions the USAF rescue crews and aircraft are routinely asked to do.
That being said, I would like to address Colonel Romero’s comment: "What needs to be done is a simple test." The Air Force did indeed run a flight demonstration similar to what he suggests as part of the first proposal evaluation process and, in the end, the H-47 was deemed the most-capable, lowest-risk solution. Also, the HH-47 now being proposed for the CSAR-X will have 85 percent of the same parts used on the MH-47G.
Finally, the noise issue is a known factor for the H-47 versus a factor that can only be predicted by its competitors. For more than 20 years, the U.S. Army Special Operations Aviation Regiment has been employing the MH-47 very successfully in operations around the world. They, like any helicopter community, have obviously taken into consideration any potential noise issues and developed tactics, techniques, and procedures to mitigate or reduce any problems while operating their aircraft in a combat environment.
I have no doubt that the professional air force CSAR tacticians will undoubtedly do the same for the next CSAR aircraft.
Col. Don Hoover, U.S. Air Force (retired) Leesburg, Va.
A Pat on the Back award for your recent Editor’s Notebook ("The Back Story," August 2008, page 4).
Absolutely well written. I give you an "A" for your writing ability! All of your writings in the Editor’s Notebook are exceptional. Keep up the good work. Also, I’m wondering if your photo is current. You look so young!
CW3 John Brandt, U.S. Army (retired) Etowah, N.C.
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