Washington State aircraft damaged during search and rescue
If you were to use a Bell 212 and have an Engine failure....what kind of performance are you going to have?
Likewise...in the 212...there is a single shaft driving the Rotor System and if it fails....you are right back where you started with the UH-1/205.
Likewise...in the 212...there is a single shaft driving the Rotor System and if it fails....you are right back where you started with the UH-1/205.
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If money grew on trees we would operate a new 412. It doesn't. So we as well as many other public operators use military surplus helicopters. The one in question was recently overhauled to the tune of 2+ million dollars. Not an easy pill to swallow when tax payers are footing the bill.
On the day of the incident a climber had called 911. He had slipped and tumbled on Mt Adams. He was badly injured and unable to describe where he was. The phone coordinates were estimated to be on the south side at about 10,000 feet. It was cold there, just under freezing. We expected no performance issues.
By the time we got a crew together and arrived the ceilings were down to 8,000.
Went back to Yakima and offered to fly some Mountain Rescue folks up as high as we could. Loaded up 2 and headed back up. The Army had provided a UH-60 and they were 10 minutes ahead of us. They tried to climb over the ceiling to insert on the summit but it wasn't happening. They dropped off 4 Mountain Rescue at about 8200. The pilot told us he would loiter in the area until we were done.
First approach didn't feel right so we came back from the other direction. There was a rock outcropping that was big enough to land on. As we were on a low slow approach the tail came around. I was sitting next to the open right door. 3/4 of the way through the second rotation it impacted the snow. Pilot pulled pitch at exactly the right time and it flew away. This was not actually good. I was waiting for the rest of the crash. But the Huey was still running and the ground was getting farther away. The 60 pilot had seen the whole thing. He came up behind us and reported that other than the skid damage torn and torn sheetmetal everything looked good. He climbed high enough to call KYKM and called for ARFF and asked them to "procure" some pallets. Took about 30 minutes to get there. We could hover just fine and had about 800 lbs fuel. All the crew except the pilots and I jumped out. One of the crew stacked the pallets and I guided the pilot onto the stacks.
So all in all a great landing as everyone walked or ran away, and the helicopter still works.
Lessons learned. Still forth coming but basically mountain flying is high risk.
And on a sad note 2 weeks later the fallen climber's body was found.
On the day of the incident a climber had called 911. He had slipped and tumbled on Mt Adams. He was badly injured and unable to describe where he was. The phone coordinates were estimated to be on the south side at about 10,000 feet. It was cold there, just under freezing. We expected no performance issues.
By the time we got a crew together and arrived the ceilings were down to 8,000.
Went back to Yakima and offered to fly some Mountain Rescue folks up as high as we could. Loaded up 2 and headed back up. The Army had provided a UH-60 and they were 10 minutes ahead of us. They tried to climb over the ceiling to insert on the summit but it wasn't happening. They dropped off 4 Mountain Rescue at about 8200. The pilot told us he would loiter in the area until we were done.
First approach didn't feel right so we came back from the other direction. There was a rock outcropping that was big enough to land on. As we were on a low slow approach the tail came around. I was sitting next to the open right door. 3/4 of the way through the second rotation it impacted the snow. Pilot pulled pitch at exactly the right time and it flew away. This was not actually good. I was waiting for the rest of the crash. But the Huey was still running and the ground was getting farther away. The 60 pilot had seen the whole thing. He came up behind us and reported that other than the skid damage torn and torn sheetmetal everything looked good. He climbed high enough to call KYKM and called for ARFF and asked them to "procure" some pallets. Took about 30 minutes to get there. We could hover just fine and had about 800 lbs fuel. All the crew except the pilots and I jumped out. One of the crew stacked the pallets and I guided the pilot onto the stacks.
So all in all a great landing as everyone walked or ran away, and the helicopter still works.
Lessons learned. Still forth coming but basically mountain flying is high risk.
And on a sad note 2 weeks later the fallen climber's body was found.
A 212 is a marginal Cat A aircraft to be sure. I don't think anyone would choose a 212 for a hoist rescue ship if cost were not a factor. Of course a Huey can out perform a 212 if there is any altitude or elevated temperature involved. Yes, the 212 lugs around a C box. The twin pac was designed for a Navy helicopter and as far as I know the only aircraft that use it in the civil world are the 212 and the S58T. Not a popular design for obvious reasons. The answer is , don't think of a 212 as a real Cat A ship.....
The -17 engine is the commercial (type certificated) version of the -703 which is not type certificated. The differences are relatively minor and I believe a 703 can be made a -17 by complying with some service bulletins.
I have to say that in the US where we have public agencies flying restricted catagory or non-certificated Hueys hoisting the public, I am surprised that none of the civil operators have pushed the point that you cannot do any class D loads(non-jettison-able) unless you have a Catagory A Helicopter so why do public use agencies get to do that? The move to twin engine is an expensive one and near as I can tell cost is the ONLY reason to not be using twins for this type of work. An engine failure with people on the hook simply cannot end well unless all are very fortunate.
I have to say that in the US where we have public agencies flying restricted catagory or non-certificated Hueys hoisting the public, I am surprised that none of the civil operators have pushed the point that you cannot do any class D loads(non-jettison-able) unless you have a Catagory A Helicopter so why do public use agencies get to do that? The move to twin engine is an expensive one and near as I can tell cost is the ONLY reason to not be using twins for this type of work. An engine failure with people on the hook simply cannot end well unless all are very fortunate.
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The BH-212 blade airfoil is designed for high speed forward flight. The UH-1 (BH-205) airfoil is much better for lift. We flew both models, and always tried to use the 205 for sling loads and long line work. Unlike the UH-1, the FAA approved the 205 for 91% minimum rotor RPM during takeoff, below 30 knots. Many times I would pull max torque at 100% Nr with the load still firmly on the ground, then beep the Nr down, keep the torque at max, and watch it climb right up at several hundred feet per minute. Wonder why the military never put this in the -10 manual for the Huey?
212,,,high speed....errrrr....mutually exclusive concepts I am afraid!
Apply that same concept to 212's verse 412's and you have it figured out.
212's like lifting as compared to the 412.
Apply that same concept to 212's verse 412's and you have it figured out.
212's like lifting as compared to the 412.
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Three Lima Charlie,
the reason why you get a bit more lift in the hover at low rpm is tied into the basic trade-off we face when we select the rotor characteristics. To prevent retreating blade stall at cruise speed (I would say "high" speed, but that is ridiculous for a 212), we size the blade chord much bigger than that needed to hover, so there is enough blade area at the retreating tip to support the whole helicopter as the root has stalled.
In a hover, the skinnier the blades the better, since extra blade area adds drag.
One way to make fat blades seem skinnier (like all these aerodynamic words?) is to slow the rotor down and make the blades go to a higher angle of attack, closer to the best lift/drag point for the airfoil.
As you slowed the rotor down, the blades became a better match fo a hover, and you got more lift for each horsepower.
This is also true of most helicopters, if the rotor can stand the lower rpm.
Why not do it for all rotors? Because you risk lots of other problems, such as loss of tail rotor thrust (this is a big issue with many of the older Bells), and also making a drive shaft jump into your lap (since no real testing was done outside of the green rotor rpm arc).
For many helos, dropping the rotor rpm 5% below the normal/max in a hover will create about 5% more lift so for a 10000 lb helo, 500 more lbs of payload could be had. In Vietnam, we drooped from 6600 to 6200 regularly in takeoff and it helped.
the reason why you get a bit more lift in the hover at low rpm is tied into the basic trade-off we face when we select the rotor characteristics. To prevent retreating blade stall at cruise speed (I would say "high" speed, but that is ridiculous for a 212), we size the blade chord much bigger than that needed to hover, so there is enough blade area at the retreating tip to support the whole helicopter as the root has stalled.
In a hover, the skinnier the blades the better, since extra blade area adds drag.
One way to make fat blades seem skinnier (like all these aerodynamic words?) is to slow the rotor down and make the blades go to a higher angle of attack, closer to the best lift/drag point for the airfoil.
As you slowed the rotor down, the blades became a better match fo a hover, and you got more lift for each horsepower.
This is also true of most helicopters, if the rotor can stand the lower rpm.
Why not do it for all rotors? Because you risk lots of other problems, such as loss of tail rotor thrust (this is a big issue with many of the older Bells), and also making a drive shaft jump into your lap (since no real testing was done outside of the green rotor rpm arc).
For many helos, dropping the rotor rpm 5% below the normal/max in a hover will create about 5% more lift so for a 10000 lb helo, 500 more lbs of payload could be had. In Vietnam, we drooped from 6600 to 6200 regularly in takeoff and it helped.
I have seen 5800 RPM in a UH-1 and still flying....so long as you wanted to turn Right in the process because the Tail Rotor was not very effective at that RPM.
Some Bristow Pilots with a bit of brain power left can tell us what MR RPM we used to droop the 212 to while practicing Single Engine Failures on Take Off....it seems like it was 91% but then I had a few too many bottles of Gulder Beer which was 212Man's Beer of Choice as I recall.
Some Bristow Pilots with a bit of brain power left can tell us what MR RPM we used to droop the 212 to while practicing Single Engine Failures on Take Off....it seems like it was 91% but then I had a few too many bottles of Gulder Beer which was 212Man's Beer of Choice as I recall.
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Yes SAS, it was droop to 91% Nr for a single engine take off. When I had my SE fire/failure off Port Said, the Nr went down to below 85% but somehow I managed to recover them and the old girl recovered and got me the 60 miles back to the beach (with a chip warning on the other engine and the floats half inflated (but that's another story!). 
Nick.....tis all of Soggy's flying abilities jointly and severally that gave him that nick name! That Trail of Tears began clear back when he was arm wrestling S-58T's on the North Sea.
