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R44II edge of WB envelope... Go or no go?


Joe Blow
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After hearing different pilots having different opinions on this discussion. Thought I'd see what VR has to say.

 

A R44II is scheduled to take off from an airport only 130' above Sea level. It'll be landing in a confined area that is also give or take a couple feet 130' above sea level. OAT reading 30C.

 

Pilot: 180

Passenger: 220

Aft left: 140

Aft right: 220

20gal of fuel.

 

Total Flight to and from confined is projected to take no longer than 30 minutes.

 

Take off weight 2300lbs

Max gross is 2500lbs

 

 

wb.jpg

Screen%2520Shot%25202012-11-06%2520at%25207.38.08%2520PM.png

 

CG is in the envelope, we are 200lbs below max gross, do we have enough power for a confined? How would you fly the approach? What is to be considered with such forward CG, while approaching a confined?

Edited by Joe Blow
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There are many other factors that need to be considered here. How 'confined' is the confined area? Height of obstacles? Can you OGE hover at that DA/weight? What are the other weather conditions? An experienced pilot could probably find a way to make it work, or know enough to not try it. The real question is, how far do you want to push it? I probably wouldnt go if I was sitting close to the edge of any envelope, however, that doesnt mean it cant be done. another thing to consider is: Getting into a confined can also be a lot easier than getting back out again. The school I did my commercial/CFI at lost an R44 a few years back. All 4 perished because the pilot couldn't clear the trees coming out of a confined at a high DA near max gross.

Edited by nightsta1ker
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My question.... Is this just a hypothetical or are you doing this for real and putting lives in the hands of a bunch of anonymous people on the internet? If its the latter... I say its impossible and dont even attempt it. If you absolutely positively have to get there.... drive.

Edited by Flying Pig
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Well, let's slow down here and not eviscerate the guy. I think one of the reasons he's posting is because some experienced pilots he knows have already had a disagreement about this.

 

My advice: When you have two experienced pilots arguing about what can/can't or should/should not be done with a helicopter, always follow the lead of the more conservative pilot. You both may outlive the other guy.

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OK, how much power to I have left in that OGE hover? Am I close to max power or do I have quite a bit to play with? Can you post up the performance planning graphics or at least the numbers?

 

Posted OGE hover chart in first post. We'll say you have an inch to play with..

 

 

The senario is fake fellas. I've heard some interesting answers. So I thought I'd post it on VR.

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I would say absolutely not. Why? Because when you run the calculations with zero fuel, the W&B is out of limits, CG being too far forward. Heck it's so close, you probably wouldn't have to burn much fuel before the CG shifts far enough forward to be out of limits. A 30 min flight could push it out of limits. I checked those calculations on 4 of the R44s my school flies, and they are in limits, barely, at 20 gal, but are out of limits at 15 gal. That's really close.

 

Putting both 220lb passengers in the rear seats makes it look a little bit better.

Edited by superstallion6113
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I agree with ApiaGuy, but yes, the bigger guys need to be in back (Largest behind the pilot). Remember it is always easier to get in than to get out. Powerchecks in the hover, and OGE before you take off will let you know what to expect before you commit.

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I would say absolutely not. Why? Because when you run the calculations with zero fuel, the W&B is out of limits, CG being too far forward. Heck it's so close, you probably wouldn't have to burn much fuel before the CG shifts far enough forward to be out of limits. A 30 min flight could push it out of limits. I checked those calculations on 4 of the R44s my school flies, and they are in limits, barely, at 20 gal, but are out of limits at 15 gal. That's really close.

 

Putting both 220lb passengers in the rear seats makes it look a little bit better.

 

 

I'm with this guy. If you're outside the envelope with zero fuel (and especially at just 5 gallons less than takeoff), DON'T GO! What if something unexpected happens and the flight takes longer, and you thusly burn off too much gas and end up over the line?

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The R-44 POH states at the beginning of Chapter 6: "The helicopter must be flown only within the weight and balance limitations specified in Section 2." It also goes on to caution "Fuel is located aft of helicopter CG, causing CG to move forward during flight. Always determine safe loading with empty fuel as well as with takeoff fuel." Operating outside of these limits would be a violation of FAR 91.9 ("no person may operate a civil aircraft without complying with the operating limitations specified in the approved Airplane or Rotorcraft Flight Manual"). If the fuel burn will take the CG out of limits, you can't do the flight as planned. It's not a matter of opinion.

 

It doesn't look like the weight will stop you from conducting the approach but there are aircraft limitations and there are pilot limitations. You need to be aware of both. 100'x100' doesn't sound too difficult for a ~40' aircraft but it might be for some pilots. You said no wind, but that can easily change in flight, and any kind of wind from any direction is going to increase your power requirements for this approach. If this approach was reaching the edge of a pilot's limitation with no wind, it might be exceeded when you consider that.

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The R-44 POH states at the beginning of Chapter 6: "The helicopter must be flown only within the weight and balance limitations specified in Section 2." It also goes on to caution "Fuel is located aft of helicopter CG, causing CG to move forward during flight. Always determine safe loading with empty fuel as well as with takeoff fuel." Operating outside of these limits would be a violation of FAR 91.9 ("no person may operate a civil aircraft without complying with the operating limitations specified in the approved Airplane or Rotorcraft Flight Manual"). If the fuel burn will take the CG out of limits, you can't do the flight as planned. It's not a matter of opinion.

 

It doesn't look like the weight will stop you from conducting the approach but there are aircraft limitations and there are pilot limitations. You need to be aware of both. 100'x100' doesn't sound too difficult for a ~40' aircraft but it might be for some pilots. You said no wind, but that can easily change in flight, and any kind of wind from any direction is going to increase your power requirements for this approach. If this approach was reaching the edge of a pilot's limitation with no wind, it might be exceeded when you consider that.

 

I'm sorry, but how is wind going to increase the power requirements?

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There's no approach path to a 100'x100' LZ surrounded by 100' obstacles that won't put you into downdrafts.

 

So, we're talking about a completely vertical (and really slow) descent from just over 100' in an R44 (followed then by a completely vertical max takeoff to just over 100'),...sounds like fun! :)

Edited by eagle5
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