201er Posted November 11, 2012 Report Posted November 11, 2012 After a hurricane and noreaster in my area I've been wondering if (given the plane is staying tied down outside) it is safer with full fuel or low fuel in the tanks? Mine takes 100 gallons so that's 600lbs difference. I can see an argument both ways. Full tanks: heavy plane is less likely to leave the ground. Empty tanks: if the plane leaves the ground it is lighter, therefore the lift produced by the wing is also 600lbs less and 600lbs less likely to break the tiedown ropes. What do you think?
sleepingsquirrel Posted November 11, 2012 Report Posted November 11, 2012 The airplane is tied down to make it as heavy as the Earth it is connected with. Heavier is better. Once the wind is at cruise speed/ cruise AOA across the wing isn't lift and gravity equal? Increasing airspeed with zero AOA should not really increase lift. Inertia also helps with gusts that could lift a lighter plane and the attendant AOA increase. Makeshift spoilers of simple 1x1 s or sand bags would help as well. Great thought provoking question! My aircraft are tied outside and I have given this some thought. One thing I researched is that chocks under the main gear are more effective because there is more weight on the mains. I believe it is possible to make an airplane heavy enough that It will not take flight but just roll along the ground like a taxi cab. Consider that a tiedown line or chain need not have more breaking strength than the threaded tiedown ring. I have put the second tiedown line to the landing gear for that reason.Float pilots will beach their aircraft and fill the floats with water for security. However in hurricane force winds no matter how well the plane is secured it will be destroyed by the cheapest , longest abandonded, uninsured ramp hog that blows past. Too heavy to fly or roll! http://www.youtube.com/watch?v=nIQqt0t9_qE
Piloto Posted November 11, 2012 Report Posted November 11, 2012 Well tied down planes will withstand hurricane winds. After all they fly in those winds. Most incidents happens when either the tie down anchors or ropes give up. Flying debris or neighboring loose planes can also cause damage. To insure that your plane will not get airborne set the trim tab and elevators for all the way nose down. Also tie the nose wheel to the ground. Avoid tie downs next to trees or signs. José
carusoam Posted November 12, 2012 Report Posted November 12, 2012 Get new tie downs for the Cessna next to you. I have seen several Cessnas and piper Tri-pacers upside down. Most often they get lifted by the tail and get dumped on their noses. I should follow my own advice... Best regards, -a-
jetdriven Posted November 12, 2012 Report Posted November 12, 2012 My shade hangar neighbors tie their airplanes down with those cheap ratcheting straps like you get at Home Depot to tie down motorcycles. They only have a 450 LB breaking strength. They are also 5-6 years old, faded, and would not likely withstand a 60 MPH gust. That bothers me, as I pay the same insurance they do, but my plane it tied down with 5,500 LB rated rope. I would consider that reasonable standard of care. The next windstorm comes through, they both will be on top of my airplane and all 3 would be totalled. You can get 3/8" Amsteel rope that has a 19,600 LB breaking strength for $2.70/ft, it takes 60' to tie down a Mooney. It is so light it floats. I have some for hurricanes. 7/16" Regatta braid: http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&storeId=11151&productId=25269&langId=-1#.UKCMioWNcmU Amsteel: http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?productId=38118&catalogId=10001&langId=-1&storeId=11151&storeNum=50045&subdeptNum=50130&classNum=50132#.UKCM04WNcmU
carusoam Posted November 12, 2012 Report Posted November 12, 2012 I have been out in the pre hurricane time, tying down other peoples airplanes. Try to bring extra rope with you. When the wind gets above 35 kts, dangerous stuff is already blowing around. -a-
N601RX Posted November 12, 2012 Report Posted November 12, 2012 Some of them are probably hoping their plane will get flipped.
rdav Posted November 12, 2012 Report Posted November 12, 2012 ... Also tie the nose wheel to the ground. FAA Advisory Circular AC 20-35C recommends tying down the nose gear as well, although I have never seen an airplane tied down like that. It sounds like a sensible suggestion, particularly if the plane will be sitting for any length of time. In the AC they talk about a nose gear tiedown ring .. do we even have one on our aircraft? I used to work for a company that modified Convair 580's and had a fleet of them on the ramp. Whenever the winds would pick up, the ramp crews would scramble to hang these oil barrels from an attachment point on either side of the cockpit and fill them with what I think was water. It would prevent the nose from picking up when the wind gusted, but I was always concerned that the swinging barrels might knock the side of the fuselage.
Hank Posted November 12, 2012 Report Posted November 12, 2012 I've had the pleasure of experiencing several hurricanes and one typhoon first hand, thankfully all before I became a pilot, much less an aircraft owner. For safety of an aircraft, tied down outside during a hurricane, my suggestion is to fly it at least 200 nm perpendicular to the projected storm track. The biggest threat to your plane will not be "lifting off" due to slack in the ropes, nor even flipping over, unless your tie downs are in poor shape [old; broken down by sunlight, rain or age; frayed; or too lightweight], but rather storm-blown debris. This ranges from broken trees to poorly-tied-down aircraft to trash can lids and shingles, siding or metal roofing from buildings a mile or so upwind. The first hurricane that reaches WV will hopefully find me and my plane in the Carolinas or Georgia, as it will only come here from the Gulf and then up the Mississippi. I figure the Appalachians form a pretty good storm barrier in both directions, they just don't work well on large fronts moving across the continent.
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