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Nov 25, 2017
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Gliders at Bedwell Bayfront Park

Dear Mayor Keith and Fellow City Council Members, My name is Harry Ackley. I am a retired physician who lives in Menlo Park. I’m one of the pilots who have flown radio-controlled gliders at Bayfront Park and who addressed the Council at the November 14th meeting. I write on behalf of myself and other members of the glider community. During the November 14, 2017 Council meeting, opponents of glider flying made several inaccurate and irrelevant statements. We, the glider community, cannot let those statements go unchallenged. The Ridgeway’s Rail: According to Helen Walter of the Committee for Green Foothills, the Ridgway’s Rails nest in Greco Island, and Ms. Walter argued that they would be disturbed by gliders. Commissioner Ohtaki asked that someone show him on a map where Greco Island is located. No one could come up with a map during the meeting. The map is attached. Note that Greco Island is separated from Bedwell Bayfront Park by Westpoint Slough, and the southern edge of Greco Island is 500 meters (1600feet) from the meadow where we used to fly. Most important, it is not visible from the meadow. If we flew gliders beyond the North ridge of the Park, we would risk losing both visual and radio contact with them, not something that pilots are going to risk. What about the shadow cast by a glider? We fly between 10 am and 2 pm when the weather is good. Menlo Park is located at 37 degrees north latitude, so the sun will be 60 degrees south of directly overhead at noon on the winter solstice. The tangent of 60 degrees is 1.73, so a glider flying at 400 feet over the northern edge of the big meadow would cast a shadow 690 feet north of the big meadow, far short of Greco Island. Accordingly, even on December 21st when the sun is best positioned to cast a glider’s shadow northward a glider flying at the big meadow would pose no threat to any Ridgway’s Rails nesting in Greco Island. Fencing: Chris Macintosh of the Friends of Bayfront Park stated that the glider flying area would have to be cordoned off. Not so. As Mitch Brenner stated in his presentation: “You don’t need to put up any fences. You don’t need to build anything.” Gliders have been flown there since the park opened. Collision between Glider and Hawk: Ms. Macintosh also alleged that a couple of years ago in San Jose a hawk was struck and injured by a glider. We have investigated and can find no support for this allegation. Further, hawks have excellent eyesight (the better with which to spot mice and other food) and are faster and more maneuverable that gliders. It is conceivable that a hawk might have been struck and injured by a propeller-driven model or a quad-copter drone, but not by a glider. Potential for conflict between radio-controlled gliders and full-scale manned aircraft: Alan Bedwell referred to a ceiling being 1,000 feet above the park. There is no 1,000 foot ceiling. There is a 400 foot ceiling for model gliders, and a 1,000 foot floor for full-scale manned aircraft. There is at least 600 feet between the model aircraft ceiling and the full-scale manned aircraft floor. Mr. Bedwell also expressed concern about a new Surf Air flight path. The standard Surf Air Instrument Flight Rules (IFR) approach into San Carlos is well inland from the Bay, much to the chagrin of midpeninsula residents. See the attached approach plate RNAV (GPS) Y RWY 30, and the attached September 29, 2017 Mountain View Voice Article “FAA considering making Surf Air flight path over Bay official.” The experimental Bayside Visual Approach crosses Moffett Field, swings out over the Bay, proceeds northwest over the Bay, then turns west at the Dumbarton Bridge to intercept the straight-in approach to San Carlos. At the point where the Bayside Visual Approach passes north of Bedwell Bayfront it is 5.3 statute miles from San Carlos Airport. The Surf Air airplanes must remain above the 3 degree glide slope. Doing the trigonometry, this means that the Surf Air airplanes must be at or above 1,400 feet as they pass over Greco Island, which is a thousand feet above the 400-foot glider ceiling and approximately a third of a mile north of the park. That is adequate separation right now. Mr. Bedwell also expressed concern about gliders that are “larger and more robust in ability to climb thermals.” But we are talking here about hand-launched gliders weighing between 4 and 16 ounces. That’s about the limit of what can be hand-launched by average people like us. And the Callander report contemplates a weight and size limitation. Mr. Bedwell expressed concern about an airplane getting taken out by a glider going into the jet engine. This was an obvious attempt to conjure up images of US Airways Flight 1549. Flight 1549 ran into a flock of Canada Geese, and ingested several into each of its two engines.That is not a proper analogy. There are no jet aircraft operating into or out of San Carlos or Palo Alto – only propeller-driven airplanes. And the Canada Geese that collided with Flight 1549 weighed between 5.8 and 10.7 pounds each, whereas Flight 1549’s jet engines were designed to cope with only a 4-pound bird. See the attached Fourth Update on Investigation into Ditching of US Airways Jetliner into Hudson River. But a 4-pound bird is still much heavier than a 16-ounce glider. A 16-ounce glider would not stop a jet engine. Propeller-driven aircraft are even less susceptible to bird or glider strikes. The propeller would just chew up a glider without ingesting it. Mr. Bedwell also made reference to his “private plane that’s very fragile.” Full-scale aircraft are not fragile. The Federal Aviation Regulations (FAR) establish standards for aircraft. These are codified in the Code of Federal Regulations (CFR). 14 CFR 25.571(e)(1) requires that “The airplane must be capable of successfully completing a flight during which likely structural damage occurs as a result of impact with a 4-pound bird.” And 14 CFR 23.775(h)(1) requires that windshields “must withstand, without penetration, the impact of a two-pound bird.” A 16-ounce glider weighs considerably less than a 4-pound bird or even a 2-pound bird. In the extremely unlikely event of a collision, a full-scale airplane would fly right through a collision with a hand-launched glider. Accordingly, we respectfully request that the Council reconsider its decision not to include gliders at Bedwell Bayfront. We are available to work with Callander or Park and Rec staff to work out the details. Very truly yours, Harry Ackley Attachments: Map showing location of Greco Island IFR approach plate RNAV (GPS) Y RWY 30 Mountain View Voice article re Surf Air Fourth Update on Investigation into Ditching of US Airways Jetliner in Hudson River 14 CFR 25.572 14 CFR 23.775 Received on Sat Nov 25 2017 - 16:04:38 PST