tie-down expertise requested

[N74DV]

I hear that using rope is better than chain but I'm wondering how tight they should be if I'm expecting high winds? for most of the year our weather out here in AZ is nice but summer afternoons can bring on some very nasty winds and microbursts. Until we get a hangar (which may be never out here... 10yr waiting list minimum) I need to know what is the best way to keep the Tcart tied down during storms and high winds.

loose ropes or tight? any other suggestions from those of you in windy areas?

[mhorowit]

Re: tie-down expertise requested

Here's my .02, some of which came from Forrest, some of which did not:
1. rope, so as not to scratch your strut. stress risers.
2. the round thingy is not used as a tie-off point. Run rope thru the ring, around the strut above (toward the wing attach point) the ring 2x, then back thru the ring going the opposite direction. Tautline hitch, followed by another.

3. check for good anchors - Mike

Oh, the tail; almost forgot. Go under any part that would be bent if the tail came up.

[VictorBravo]

Re: tie-down expertise requested

Raise the tail until the wings are level. That is the one single thing that will prevent the plane from getting flipped in high winds. Remember the Taylorcraft can fly safely with 130+ MPH of wind (airspeed) as long as you are in control of how the wind is flowing over the airplane.

Get or make some sort of a four legged table or workbench kind of thing for the tailwheel to sit on. Anchor this table so it can't move anywhere either. Cut a hole or make a tiedown in this table to put your chain through, and tie the tail down as well so it cannot move around on the table. If you are going to tie out all the time, it will be worth the effort to make a ramp so you can roll the tail on and off this table easily. Again, the airplane should sit level so that wind will not make lift on the wings or the stabilizer.

I agree that the tiedown ropes should go over the struts, nut just through the tiedown loop. In fact, I removed my loop clamps and just tie a strap around the upper strut neck when I tie down outdoors. I would use some strong nylon belt strap material, and tie a tight knot around the upper strut so it can't slip down the strut. In the desert you can just run this webbing material down to the tiedown cable or earth anchor. Where it is very wet, you would need to worry about it shrinking and over-tightening when it dries.

Once you have it tied down in a level attitude (zero angle of attack), and you are SURE the tail stand will not fall over or get out of position, then you VERY MUCH should make REAL gust locks for your controls. And I do not mean using the seat belt!!! That is nonsense. With a hand held jigsaw and some cheap plywood you can make a really effective set of gust locks for your tiedown area, about $10 or $15 in materials. These will save you from thousands in damage or flight safety problems.

For the ailerons, cut out four pieces of plywood that are curved like pincers (or old fashioned calipers), about 6 feet long. The inside curve of the pincers should match the upper or lower airfoil shape, leaving half an inch extra for padding. The front and rear of the pincers overlap at the leading and trailing edges. The outside shape of the pincers is the same as the inside, so that the "width" of the pincers is about eight inches or so. Drill holes at the front and rear so that the pincers can be bolted together, and when they are bolted together there is a hole in the middle of this long "collar" the shape of the airfoil plus half an inch. Get some tubular foam pipe insulation, slit the tube so it can cushion the edges of the plywood where it touches the wing.

You can either slide this collar over the wingtips, slide them inboard until they contact the struts, then bungee them to the struts so they can't slide off... OR you can use one of the bolts as a hinge and the other one to open the pincers up and put it over the wing from the front and then put the other bolt in.

The two elevator halves and the rudder get a similar padded collar, but it can be one piece of wood with a slot cut in it and padding on the edges of the holes.

Having the control surfaces padded and immobilized is the best thing you could ever do for gust locks on an airplane tied down outside. This puts NO STRESS on your control system inside or outside the airplane. The Cessna style gust locks on the control yoke just AMPLIFY the forces on the system when the wind blows the controls around. Tying the seat belt does the same thing... it just allows the wind to apply a huge amount of leverage on all the parts of your control system.

As you know, the sun in Arizona can get a little bit intense. A set of covers for the plane would not be a bad investment either. For a couple of hundred bucks in steel tube and greenhouse roofing material you can make up a flat roof shade that will make your covering last for many years, as well as not letting the sun torch the windshield plastic. If you design the shade right, it will not be affected by wind, and it can be removable so the airport doesn't bitch. This shade should be 8 feet tall and T-shaped or triangular shaped to cover the plane. Make it flat on top, so the wind doesn't add any lifting or twisting force. You don't have to worry about snow loads in Mesa The two center front vertical supports can fold up or down to get the plane out. Use the corrugated galvanized metal greenhouse roofing which adds strength. This is a little more than an afternoon project, but I guarantee your airplane will thank you.

[N74DV]

Re: tie-down expertise requested

thanks Bill. quite an informative post. We have covers from www.aircraftcovers.com on the way. I ordered wings and "over the wing" cockpit cover. A bit spendy at about $800 but worth it until I can get a hangar.

Rumor is a private development company secured a land lease at the airport and will be building hangars for sale. I'm on the list to purchase one which should be built by next summer. Now, to scrounge up $85K that they will sell for.

[N96337]

Re: tie-down expertise requested

I hear that using rope is better than chain but I'm wondering how tight they should be if I'm expecting high winds? loose ropes or tight? any other suggestions from those of you in windy areas?

NEVER loose ropes!!! The shock load when it hits the end of the rope is what will damage the aircraft, and also what will break the rope quickly!
JH

[crispy critter]

Re: tie-down expertise requested

DJ,USE ROPES!!!!!!!!!! Here is what a chain on the tail tie down done to our family T-craft.She has been in the family since the 1950's.She taught my father and grandfather to fly.On May 6,1971 she was setting on her tiedown and was hit by lightning during a thunderstorm .It was said that the chain on the tail tiedown grounded it and turned it into a lightning rod. Now named Crispy Critter I hope to test fly her on or before Thanksgiving weekend . Use the ropes.

[mhorowit]

Re: tie-down expertise requested

Ahh.
Three ropes, four opinions.
Ok.
- Mike

[Richard Boyer]

Re: tie-down expertise requested

The only time I use tie downs is when I am transient. When I'm home, I tuck my T safely in the hangar. I am interested in this thread from the point of view of when I'm traveling. A few years ago on the way to the Alliance fly-in we were one stop from Alliance with a hole in the tailwheel tube. We decided to stay overnight in a hotel and patch it. It was a beautiful day! As I walked out of the FBO I heard one of those NOAA radios go off. I asked the guy behind the counter about it and he said that it was no big deal. (Major warning light went off in my head!!!) I asked if he had hangar space, and as luck would have it he did.

That was one humdinger of a thunderstorm. If she hadn't been in a hangar I would have been sick. nasty nast nasty!

I have since fabricated a set of tiedowns (pdf attached hopefully-have fun mike!!). I don't have the ring on my strut so I wrap the rope around the strut twice where it narrows (no way it is going to slide down) and then tie it off using a knot my uncle taught me. I don't know what it is called but he said they used the same knot to keep a battleship tied up in a hurricane. I snug down the tail as well and always wondered about it.

VB brought up some great ideas, but when I'm transient all that hardware exceeds the gross weight of my plane. That is stuff I would definitely do if I tied down at home, but what about when traveling??

My neighbors liked these tiedowns so much they made a bunch of them at once for our Oshkosh trip 2 years ago.

2 files:
"2003 - 06 - Aircraft Tiedowns.pdf" is the article on them;
"tiedown2.pdf" is a printable to scale drawing of the rings.

[cpirrmann]

Re: tie-down expertise requested

How much tension should we put on the struts? I tie them so they're tight, but I try not to have them so tight, they pull down on the wing (actually compressing the LG tires I suppose). But then, they seem too loose.

[lawheelock]

Re: tie-down expertise requested

Here is my 2 cents worth regarding tying a T-craft in particular and ALL tail draggers.
I owned and flew my first BC12D from 1964 until 1969. The one I have now is being repaired as I bought it as a wreck.
First, especially a T-Craft but applies to all taildraggers: Never leave sight of your airplane even for a few minutes without it being securely tied. No loose ropes. Another airplane running up or a gust of wind can lift it over any chocks in a moment!
Second, I firmly advise against external gust locks. Here is why: I know several people who have been killed by forgetting to remove external gust locks. For instance, the entire basketball team of my college alma mater was killed several years ago at Evansville, IN when someone forgot to remove external gust locks on the DC-3 they were departing in. I have never heard of anyone being killed by an airplane that had been secured with a seat belt on the controls even if it had had the control surfaces damaged because of wind even with the seat belt securing the controls. If damage was sufficient to be a safety problem it would be more likely to be evident before takeoff.
As for the stool under the tail to put it in level attitude, that would help but I worry about the stool getting kicked out and the plane coming down on it and damaging the fuselage and then the tail is loose for the wind to attack. Better to have a secure tiedown on the ground.
I once left my Stinson chocked at Charleston, WVA while I went to resturant. When I came back, it was inches from the Lear parked behind it. Something had started up in front of the Sinson and it jumped the chocks and it is a lot heavier than a T-Craft especially since it had full tanks and luggage inside.
Don't forget: If you leave sight of your plane, make sure it is securely tied...Always.
Larry Wheelock

[VictorBravo]

Re: tie-down expertise requested

VB brought up some great ideas, but when I'm transient all that hardware exceeds the gross weight of my plane. That is stuff I would definitely do if I tied down at home, but what about when traveling??

For traveling, there are several ways to make light weight and light duty control locks.

For ailerons you can use two square pieces of padded aluminum and a long screw with a wing nut on the end. Or a folded piece of aluminum with a bungee.

For the tail, you can use two pieces of carbon fiber tube (expensive but light) lashed together with safety wire and a couple of wood spacer blocks. An additional clip or cord tied around the two tubes and between the elev/rud hinge line makes it very secure.

Yes having control locks requires you to remove them before flight. I am very saddened to hear that the DC-3 crashed with the basketball team, but the pilot overlooked the locks on the preflight, and didn't do his "free and clear" check during runup. That is not really the fault of the control locks. (Again, no disrespect intended but how did the DC-3 manage to taxi out of the parking space with the chocks in front of the tires?)

[Forrest Barber]

Re: tie-down expertise requested

USE control locks on the ailerons, the tieing with seat belt is NO good as there are NO control stops on the ailerons on the Taylorcraft. They can be severly damaged in a wind from aft. I will hunt up photos. IF you have time during a severe storm, nose her into any avaiallbe structure, tightly tie her down. THERE is an old wives tale about tieing manilla "rope" I call it line too tight and it get wet and can damage the aircraft. Never saw it happen, but we used to watch new line when soaked and would release it a bit. Rduce the angle of attack if possible. Raise tail or put gear into a hole; OR use spoilers on the wings., padded boards work...

[Ragwing nut]

Re: tie-down expertise requested

I have watched one of our t-crafts fly by the tie-down ropes about 1-2 feet off the ground in a thunderstorm years ago. Never want to see that sight again. We actually went out and retied it between wind gusts. Ropes got wet and stretched. I tie them tight but not so much I am over extending the bungee cords.

mike

[lawheelock]

Re: tie-down expertise requested

It was a typical accident with a long chain of events leading up to it. Yes, the crew should have removed the control locks, but they didn't! They had departed once but came back because of weather. Then, the second departure was after dark and in heavy rain. The older NTSB reports don't give much detail but here it is. Note, gust locks not removed.

NTSB Identification: DCA78AA004
14 CFR Part 135 Nonscheduled operation of NATIONAL JET S
Event occurred Tuesday, December 13, 1977 in EVANSVILLE, IN
Aircraft: DOUGLAS DC-3, registration: N51071

----------------------------------------------------------------------------------------------------------------------------
FILE DATE LOCATION AIRCRAFT DATA INJURIES FLIGHT PILOT DATA
F S M/N PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-4093 77/12/13 EVANSVILLE,IN DOUGLAS DC-3 CR- 3 0 0 COMMERCIAL AIRLINE TRANSPORT, AGE
TIME - 1922 N51071 PX- 26 0 0 AIR TAXI-PASSG 42, 9100 TOTAL HOURS,
DAMAGE-DESTROYED OT- 0 0 0 4600 IN TYPE, INSTRUMENT
RATED.
NAME OF AIRPORT - EVANSVILLE RGNL
DEPARTURE POINT INTENDED DESTINATION LAST ENROUTE STOP
INDIANAPOLIS,IN NASHVILLE,TN EVANSVILLE,IN
TYPE OF ACCIDENT PHASE OF OPERATION
COLLISION WITH GROUND/WATER: UNCONTROLLED TAKEOFF: INITIAL CLIMB
PROBABLE CAUSE(S)
PILOT IN COMMAND - INADEQUATE PREFLIGHT PREPARATION AND/OR PLANNING
MISCELLANEOUS ACTS,CONDITIONS - GUST LOCKS ENGAGED
FACTOR(S)
MISCELLANEOUS ACTS,CONDITIONS - IMPROPERLY LOADED AIRCRAFT-WEIGHT-AND/OR C.G.
FIRE AFTER IMPACT
REMARKS- RUDDER,R AIL CTL LOCKS INSTALLED.REAR CG AFT OF OPTIMUM RANGE BUT FORWARD OF REARMOST LIMIT.

Index for Dec1977 | Index of months

Quote from a previous message:
"Yes having control locks requires you to remove them before flight. I am very saddened to hear that the DC-3 crashed with the basketball team, but the pilot overlooked the locks on the preflight, and didn't do his "free and clear" check during runup. That is not really the fault of the control locks. (Again, no disrespect intended but how did the DC-3 manage to taxi out of the parking space with the chocks in front of the tires?)"