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L4 Vs B2


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I don't know anthing about the L Series...but if you are considering the B2, while a great machine, it is very temp sensitive. Mine was 2798 empty, and I had issues with anything nearing 1800 lbs, NG out in no time if your DA is too high, ie if you are anywhere near 20 C TQ doesn't matter. The FX/D2 on the other hand, no problem. Providing it's a stripped bush machine you should be able to legally lift 2000 lbs for 10 miles at 3000 ft at standard...just TQ limited...don't forget to get yourself a tattle tale B)

 

This is all by aging memory so I'm playing on the safe side.

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We operate a number of B2's and as stated they are limited as soon as OAT goes up or altitude goes up. I normally fly the B2 at 4000+ feet and in the summer, you can't lift max external at this altitude. For an idea here are a few numbers for OGE at alt for the B2.

 

4000' @ 20 oat approx. 5200 (max external is upto 5500 lbs)

5000' @ 20 oat approx. 5050

6000' @ 20 oat approx. 4850 (max internal is 4960 lbs)

 

4000' @ 30 oat approx. 4950

5000' @ 30 oat approx. 4700

6000' @ 30 oat approx. 4550

 

our B2's average around 2950lbs without a basket on them. In the summer we offten get 30 deg. C at 6000' while fighting fires. So in the summer at 6000' and 30 oat a realistic load with 50 % fuel (500lbs) would be around 900lbs max. We normally carry between 900-1000lbs of forestry loads with no more than 60% fuel. This gives me a hour or so of fuel and okay IGE as long as I don't have to vertical into a hole. I have found that a 120 gal Bambi bucket works well for most conditions left wide open. If I am heavier on fuel I just don't take as much fuel.

 

Haven't flown a L4 at altitude so I can't help you there.

 

Koala

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CSX,

 

We operate 2 L-4's and have had great success. (both have load cell)

 

These are loads that we have done:

 

Drill move: at 7000 feet- +4C. 1500 lbs with 20 minutes or so fuel, 150 foot longline no wind.

 

Ice drill move: 10,000 feet- +2C. 1100 lbs 45 minutes fuel, no wind, 50 foot line

 

1250 bucket (1300 lbs with gear) 2 hours fuel- any temp in B.C., works fine- regular tailrotor you can only turn to the right, high alt tailrotor turn any direction (also H.A. tailrotor uses less torque)

 

30C- 3000 ft- internal is around 900 lbs with full fuel- 2+45 minutes.

 

Regular tailrotor gross (4450 and 4550) is to 10,000, H.A. tailrotor gross is to 12,000 DA.

 

Machines empty weight is around 2500 lbs.

 

B.M.

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CSX,

 

We operate 2 L-4's and have had great success. (both have load cell)

 

These are loads that we have done:

 

Drill move: at 7000 feet- +4C. 1500 lbs with 20 minutes or so fuel, 150 foot longline no wind.

 

Ice drill move: 10,000 feet- +2C. 1100 lbs 45 minutes fuel, no wind, 50 foot line

 

1250 bucket (1300 lbs with gear) 2 hours fuel- any temp in B.C., works fine- regular tailrotor you can only turn to the right, high alt tailrotor turn any direction (also H.A. tailrotor uses less torque)

 

30C- 3000 ft- internal is around 900 lbs with full fuel- 2+45 minutes.

 

Regular tailrotor gross (4450 and 4550) is to 10,000, H.A. tailrotor gross is to 12,000 DA.

 

Machines empty weight is around 2500 lbs.

 

B.M.

 

If by stating that only right pedal turns can be made, the poster means that insufficient tail rotor authority is available to make left pedal turns, then how is sufficient tail rotor authority available to stop a right pedal turn once it has begun? It should take more tail rotor authority to stop right pedal turn than it does to initiate a left pedal turn. It sounds a little dicey to me.

 

The only way a tail rotor can turn the helicopter is by producing force. If the helicopter cannot make pedal turns at altitude, more force must be produced. More force requires more torque, not less. More force generated by a tail rotor is usually done by making it larger.

 

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For comparrison

 

Longbuggy 4

 

basic inlet, regular tail rotor

 

OGE

 

4000'@20 4450-4500 max internal 4450 external 4550

5000'@20 4450

6000'@20 4350

 

4000'@30 4450

5000'@30 4400

6000'@30 4300

 

 

All above number fall into area C of the chart. Area C is an area from 315-045 degrees up to 26kn all other areas winds calm. basically any where other than straight on the nose, hasn't been demonstrated safetly.

 

moving the numbers to area A of the chart. 210-050 up to 26kn all other areas calm. Basically no wind from the right side.

 

4000@20 4450-4500

5000@20 4300

6000@20 4150

 

4000@30 4300

5000@30 4150

6000@30 4150

 

2500lbs empty seems on the lean side. more realistic add a 100 or so pounds.

 

 

A BC I.A. crew is 850lbs. plus a bucket, net, longline, Foam (on the coast) 200lbs

 

 

2600+

850+ ia crew

200+ bucket other gear

200 pilot

= 3850

-4150

= 300lbs for fuel 250lbs/hr fuel burn

 

to carry all this gear your probably going to need a basket add 50lbs

 

 

Performance charts are just a suggestion. and not a limit. Except when your in court defending yourself.

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For comparrison

 

Longbuggy 4

 

basic inlet, regular tail rotor

 

OGE

 

4000'@30 4450

5000'@30 4400

6000'@30 4300

 

 

Interesting: At 4000' @30 deg. L4 useful OGE is 1850 while B2 is 2000lbs. But at 6000'@30 degs, the L4 pulls ahead with a useful load of 1700lbs verus the B2 at only 1600. I know the B2 charts are pretty accurate and use them up to 8000' regularily, how accurate are these figures for the L4?

 

Koala

 

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Interesting: At 4000' @30 deg. L4 useful OGE is 1850 while B2 is 2000lbs. But at 6000'@30 degs, the L4 pulls ahead with a useful load of 1700lbs verus the B2 at only 1600. I know the B2 charts are pretty accurate and use them up to 8000' regularily, how accurate are these figures for the L4?

 

Koala

 

The long buggy performs as advertised, if your performance expectation are low.

 

 

 

 

 

 

 

 

 

 

 

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