As350 Blade Tie Downs

[helidoug]

Does anyone out there know of the correct procedure for how secure the blades using the eurocopter tie down kit 350-700414 with rods, ropes, and pulleys.

 

The manual only covers the socks and ropes around skid gear. The chart says to pull the rope about 24" for the B3 which seems extreme. You read down a little further and it says 10mm if droop ring installed, which makes more sense.

 

Eurocopter is telling me to pull tie down rope from snug-24" which on the nose tie down I dont think is physically possible and on the side ones would put one heck of a load on the blades.

 

Just want to advise pilots of correct procedure but cant seem to find one. Tie down STC says to tighten. Doesnt say how much. I know how I do it, but cant put "how engineer does it" in ops manual.

 

Thanks in advance.

[&]

If I remember correctly, take the slack out of the rope and then a further 5 cm.

Hope it helps

[whirlygig]

STC says "Tighten the rope to the desired tension". Classic.

 

There is a strict warning not to use above 40 KTS, and there is even an inspection to be performed if they were used above 40 KTS. These style tie downs DO pull the ends of the blades out, the ECL blade shop HATES this modification.

 

I would use the maintenance manual info for these however (using the sock style procedure). 10-10-00, 3-2, 5. install them and just pull the slack out of the line "tighten without force". Then mark the line, and tighten 100 mm (3.94"). That sounds pretty reasonable to me.

[helidoug]

STC says "Tighten the rope to the desired tension". Classic.

 

There is a strict warning not to use above 40 KTS, and there is even an inspection to be performed if they were used above 40 KTS. These style tie downs DO pull the ends of the blades out, the ECL blade shop HATES this modification.

 

I would use the maintenance manual info for these however (using the sock style procedure). 10-10-00, 3-2, 5. install them and just pull the slack out of the line "tighten without force". Then mark the line, and tighten 100 mm (3.94"). That sounds pretty reasonable to me.

 

This is the reference I was looking for. Thankyou. Had a tech rep send me Open 350 ref 10.00.00.301 which has a table #2 which gives L= 600mm or 23.6" and then paragraph 3.1.1 says L=10cm which matches splitvision ref. It would be nice if the mod instructions were more clear than "tighten to desired tension"

[fan]

hold the metal tie down bar in one hand nicely and evenly wrap the rope on appropriate holders then clip the hook on the bottom ring of the tie down bar....secure the rope at that length..perfect tension....only works for the sides the nose one is always messed up

[skullcap]

Started flying Astars in 1985 and what I heard then was that some initial models came out without the droop ring. Have never heard of one without and is far from ok to pull them down 24 inches unless you want to crack the skin of top of blade. Slack out and 10 cm is fine, do not leave collective lock off in strong winds, put rotor break on. Machines have been on have seen winds of 60 knots and in southern AB day in out 30 kts.

 

What difference would it make with what method of securing the blade be it sock or tie down to the amount pulled down?

 

The blade securing kit from Eurocopter includes the socks, poles which support the blades. Never seen one used.

[whirlygig]

What difference would it make with what method of securing the blade be it sock or tie down to the amount pulled down?

 

The blade securing kit from Eurocopter includes the socks, poles which support the blades. Never seen one used.

 

The difference is that the sock style will never harm your blades (if installed correctly, as per the book), however the ECL tie downs WILL pull the end cap out of the blades. So the question isn't the difference in normal conditions (how tight to make them), it is in "Windy conditions". If you tie the ECL ones too loose (which is OK for the sock style) and in winds above 40 KTS (again OK for the sock style), when the blade 'pops up' after a gust of wind and hammers on the rope damage can be done.

 

The pole (P/N 350A92-1111-00) supplied with new helicopters is for the sock tie down installation (not support), so you can put the socks on without a ladder and without spinning the head. They work great but we rarely use them either.

[ray]

We sometimes get loaner blades without the tiedown hole drilled at the tip, so use the pillow style tiedown for that.