steep approach at altitude

[r44]

I experienced an off airport landing at altitude as a passenger. I am left wondering was this the right thing to do?

 

Helicopter: r44 raven II 5/8 fuel 3-200 pound passengers

Altitude: 4500'

Temp: 50degrees F

Wind: Calm/Variable

LZ: log deck on pinnacle w/ trees about 30' tall around it. 120' clear diameter

 

At about 1/8 mile out from the LZ, rate of descent was 500'/min. We were in the ETL shutter the whole way in at 500'/min. until we hit IGE and landed.

 

I know how I would have approached this, but many of you have thousands of hours on me, comments?

[Goldy]

I experienced an off airport landing at altitude as a passenger. I am left wondering was this the right thing to do?

 

Helicopter: r44 raven II 5/8 fuel 3-200 pound passengers

Altitude: 4500'

Temp: 50degrees F

Wind: Calm/Variable

LZ: log deck on pinnacle w/ trees about 30' tall around it. 120' clear diameter

 

At about 1/8 mile out from the LZ, rate of descent was 500'/min. We were in the ETL shutter the whole way in at 500'/min. until we hit IGE and landed.

 

I know how I would have approached this, but many of you have thousands of hours on me, comments?

 

I don't have a few thousand hours in an R44, but based on what you described, its very do-able. Obviously you want to watch that rate of descent closely and come in slow, bring in some power early, but I've done a lot worse. Many times the only way in is vertical that last 100 feet or so. It's not how you would land at an airport, but hey, its a helicopter!

 

You can't help the fact that you are flying with little to no airspeed, you can only do what you can. Just watch that descent rate...sounds like the pilot was in a bit of a hurry. Maybe he was just nervous!

 

Sounds like you were well within the power limits of the aircraft with your load. Other factors like having some plan when to break off, some plan to take off once on the ground,knowledge of ground obstacles, etc...those things would help increase your safety in the situation.

[ADRidge]

At that density altitude, without looking at the charts, it seems like it'd be okay. I'll check the POH later.... I don't check performance charts before 8am.

[SBuzzkill]

Sounds about right to me.

[r44]

From what I saw, we came in way too steep and way too slow. We should have been able to land at less than 300'/min and avoided the whole settling w/ power issue. Riding the ETL shutter all the way down means we were on the edge of ETL, a 5 knot wind change and we could have settled into the side of the mountain or hit the trees on approach.

 

My concern is settling w/ power, not if we had enough performance to land.

[Goldy]

My concern is settling w/ power, not if we had enough performance to land.

If you can do 30/300 then you are golden (usually). Like I said, sounds like he was in a bit of a hurry to get in. If I had to choose going into a confined area, I would prefer less airspeed but keep the rate of descent less than 300. SWP is more likely than losing an engine.

[ADRidge]

Well, I know it's still before 8am, but I'm heading out for the weekend within the hour. At the conditions stated, with a gross wt of around 2300 (2318 is what I got) you're well within the HOGE limits for the raven II. Yes, 300 fpm would have been much better, but it obviously worked out.

 

Don't quote me on this, but I think I read somewhere (cannot remember where at the moment) that the R-44 doesn't REALLY get into SWP until you're approaching more like 800fpm. I could be mis-remembering, or have read someone else's mistake, so don't take my word as gospel.

[Goldy]

Well, I know it's still before 8am, but I'm heading out for the weekend within the hour. At the conditions stated, with a gross wt of around 2300 (2318 is what I got) you're well within the HOGE limits for the raven II. Yes, 300 fpm would have been much better, but it obviously worked out.

 

Don't quote me on this, but I think I read somewhere (cannot remember where at the moment) that the R-44 doesn't REALLY get into SWP until you're approaching more like 800fpm. I could be mis-remembering, or have read someone else's mistake, so don't take my word as gospel.

 

I understand the OP's concern with a light and variable wind. Especially since they had some weight and about 4500 DA. The RavenII definitely takes more work to settle than the R1.

 

My only point is I would rather avoid settling by keeping my descent rate low, rather than by having more airspeed in this situation. Anything to avoid pulling in a bunch of power at the bottom and risk losing main rotor rpm. There was a time I would have advocated more airspeed but I've read many more NTSB reports on SWP type incidents than a sudden engine failure while on a steep approach.

[r44]

My other concern is using the same approach for an LZ at 6,500 feet with 50' trees and only about 60' diameter. His approach seems to be standard operating procedure and I am very concerned about sending him on a flight at high altitude and in the middle of winter. I am afraid I will find a raven II smashed into the LZ...

 

I think the correct approach would be:

 

1. enter an OGE hover with lots of room to escape

2. go to max power and see if I can climb, make sure I have at least 1" between hover and max power

3. slowly crawl the helicopter over the LZ,

4. descend vertically at 100'/min

5. Check for white out conditions

6. Have a tree to reference in case of white out

7. Land w/ tail clear

 

Does that sound right?

[Goldy]

My other concern is using the same approach for an LZ at 6,500 feet with 50' trees and only about 60' diameter. His approach seems to be standard operating procedure and I am very concerned about sending him on a flight at high altitude and in the middle of winter. I am afraid I will find a raven II smashed into the LZ...

 

I think the correct approach would be:

 

1. enter an OGE hover with lots of room to escape

2. go to max power and see if I can climb, make sure I have at least 1" between hover and max power

3. slowly crawl the helicopter over the LZ,

4. descend vertically at 100'/min

5. Check for white out conditions

6. Have a tree to reference in case of white out

7. Land w/ tail clear

 

Does that sound right?

Pointed into the wind the whole time....not many options other than vertical when going into a 60 foot hole.

[C of G]

From what I saw, we came in way too steep and way too slow. We should have been able to land at less than 300'/min and avoided the whole settling w/ power issue. Riding the ETL shutter all the way down means we were on the edge of ETL, a 5 knot wind change and we could have settled into the side of the mountain or hit the trees on approach.

 

My concern is settling w/ power, not if we had enough performance to land.

 

Not being intimately familiar with the R44 performance, but if you're not worried about the hover power available, and the ROD was only 500'/min, SWP would not be an issue. It is difficult to get into, if not impossible at that ROD. Add that there was probably quite a bit of power applied and at that altitude, even higher ROD required for SWP than at sea level.

[Spike]

No matter the aircraft type, by your description, at minimum your rate of descent should be at a crawl once below the tops of the trees. Pretty much hovering or "walking" it in with power and little collective input at the bottom. As stated, always into the wind.

 

Question; was the shutter uncomfortable to you?

 

Personally, I prefer to be on one side of ETL or the other and not surfing the edge. This allows for no peddle surprises and unwary passengers don’t get so freaky.

[r44]

it wasn't the shutter that was uncomfortable, it was the 500'/min and the shutter...

 

 

500'/min and no shutter or 100'/min and OGE hover walking it in...

[JDHelicopterPilot]

R44,

 

As I was reading your description about the choosen approach profile my concern right off the bat was the high ROD at 500'/min. I liked your description of how you thought the approach should be. It is all risk vs reward. In this case my concerns are power settling at the end of that approach with the DA and weight. In other words not vortex ring state but just not having enough power to stop the helicopter at that ROD. in addition to that I would be concerned about hitting an obstruction. Those two situations are going to be more likely in my opinion than having an engine failure.

 

I fly single engine EMS and would be fired if I did approaches that way not to mention the fact that I feel more comfortable coming in with 200' ROD or less. It provides enough time to see something and stop or go around. It keeps me from bringing in a lot of power at the end of the approach. By the time I reach ground effect, it is that which really stops my ROD for the most part.

Edited October 26, 2012 by JDHelicopterPilot