Question about a regulation.

[mjb86]

I was wondering if the area on a height & velocity chart that is shaded & says avoid operation in hatched area, is that a rule that must be followed or more of a guideline. I am not an active student right now or else I would ask my instructor, but the reason I'm asking is because I recently saw a news helicopter hovering about 150 to 250 feet AGL & I'm pretty sure that is within the shaded area on his height & velocity diagram. I looked up the following FAR and it seems to me that it would be a rule, but it would be nice if some of the more experienced pilots could clarify. I also found another section that says a helicopter can operate at any altitude allowing, if a power unit fails, an emergency landing without undue hazard to persons or property on the surface.

 

Sec. 91.9

 

Civil aircraft flight manual, marking, and placard requirements.

 

(a) Except as provided in paragraph (d) of this section, no person may operate a civil aircraft without complying with the operating limitations specified in the approved Airplane or Rotorcraft Flight Manual, markings, and placards, or as otherwise prescribed by the certificating authority of the country of registry.

 

Sec. 91.119

 

Minimum safe altitudes: General.

 

Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes:

(a) Anywhere. An altitude allowing, if a power unit fails, an emergency landing without undue hazard to persons or property on the surface.

( Over congested areas. Over any congested area of a city, town, or settlement, or over any open air assembly of persons, an altitude of 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft.

© Over other than congested areas. An altitude of 500 feet above the surface, except over open water or sparsely populated areas. In those cases, the aircraft may not be operated closer than 500 feet to any person, vessel, vehicle, or structure.

(d) Helicopters. Helicopters may be operated at less than the minimums prescribed in paragraph ( or © of this section if the operation is conducted without hazard to persons or property on the surface. In addition, each person operating a helicopter shall comply with any routes or altitudes specifically prescribed for helicopters by the Administrator.

[rick1128]

The HV graph is not in the limitation section for single engine helicopters. For twin (multi engine) helicopters it is, but according to FAR 27, it applies only to Category A operations. Long lining is not a Category A operation. Experienced Long Line pilots call it the money curve. The deeper you are in it the more money you should be making.

[FauxZ]

I'd like to go on a tangent here and say "Nice question!" Most of my active students couldn't have put together a query that well referenced or researched. I'd expect a question to be formed like that by someone who's maybe working on their commercial or CFI. I'm impressed, you're going to have one lucky instructor.

[ADRidge]

I second FauxZ. Great question. It all boils down to "undue hazard to persons or property on the ground."

 

Photo flights tend to OGE hover quite a bit. As long as you're aware of what the helicopter is doing and steer clear of VRS, you're golden. An auto would be tricky, but I've seen clips of people braver and more experienced than I doing zero speed autos from about that high.

[Goldy]

I don't have a FAR handy (sitting in a mountain cabin at 9000 feet with wireless is pretty cool)

 

but these sections you state are really two different things, none of which are related to HV curve...well maybe one sorta is..

 

OK, lets get rid of operating limitations first. Vne is a stated operating limitation. Its 102 KIAS in the R22, so flying around at 105 KIAS would be a direct violation of that limitation. So while Vne is a publsihed limitation, HV curve is not.

 

The HV curve is generic by nature, every ship has one....but also specific to each aircraft type. The R22 has one curve, an Enstrom or an R44 will be different. Now operating out of that curve is not specifically an operating limitation.....its basically an aerodynamic reality. Now, if you were outside of that curve, lets say hovering at 100 feet....a really bad place to be, and the engine failed, and you crashed and killed someone on the ground, it could easily be argued that you were in violation of the altitude restriction..specifically, you cant endanger persons on the ground...and you did.

 

Now, couple things. Maybe that ENG ship at 300 feet was within the specific HV curve for that ship, in would not be if it was an R22, but might be if it was an Enstrom. Also, maybe that ship was a twin engine, capable of continuing flight on one engine...thats how rescue ships increase safety when they have to hover. Anyway, this post will generate some discussions!

 

PS, of course if you were in court, that HV curve chart would be used against you if at all possible !

Edited August 29, 2008 by Goldy

[Gomer Pylot]

It depends on the helicopter, and where the height-velocity diagram is in the flight manual. In transport category helicopters, it's generally in the limitations section, and thus must be followed at all times - not just during Cat A operations. For light helicopters, it's generally in the performance section, and is thus not regulatory.

 

Short answer: if the diagram is in the limitations section of the RFM, then you have to stay out of the avoid area, because it's a limitation. If it's in the performance section, it's just advisory and you don't have to legally follow it, but it's still a good idea, because gravity is a law and must be obeyed.

[mjb86]

I apperciate the responses, I thought I may have been wrong about that and it's been a year since I have been to flight school, so I didn't want to call my instructor up just to ask him. I am trying to get ready to start training again and I was brushing up on some of the flight regulations, when I thought about the news helicopter flying low like that. I know it was a single engine helicopter, it looked like a bell but I definently couldn't tell you what model. I'm sure he was well experienced and knew what he was doing, but I just thought it was strange.

[rick1128]

It depends on the helicopter, and where the height-velocity diagram is in the flight manual. In transport category helicopters, it's generally in the limitations section, and thus must be followed at all times - not just during Cat A operations. For light helicopters, it's generally in the performance section, and is thus not regulatory.

 

Short answer: if the diagram is in the limitations section of the RFM, then you have to stay out of the avoid area, because it's a limitation. If it's in the performance section, it's just advisory and you don't have to legally follow it, but it's still a good idea, because gravity is a law and must be obeyed.

 

That's interesting, but guess where all the long line guys in 212's, etc sit just about all day long. The FAA issues 133 certificates to 212 operators all the time. Maybe it is because they are running in restricted category.

[Gomer Pylot]

If you're flying public use aircraft, the FAA doesn't regulate you, regardless of what type you fly. You don't need a pilot's license, nor does the aircraft have to be certificated, at least from the FAA perspective. You also have different rules in the restricted category. It all depends on what CFRs you're operating under, and how the RFM is organized. That's why I used 'generally' and other hedging terms. There are always exceptions to everything.

[Fidelis]

Exactly right Gomer...... If it's in the limitations or placarded in the aircraft, it's a rule. If it is in the performance section of the POH as is most often the case, it is a guideline.

 

Let's point out that you most likely operate within the shaded areas of the height velocity diagram on every single flight. Taking the R-22 as an example (considering it's frequency of use in training), consider how you make a normal approach to land. When you are at an approximate airspeed of 60 knots and a 10 degree angle to your landing spot, having rolled out on final approach at 300 feet agl, you begin to bleed off airspeed and maintain your constant rate of descent at an apparent walking pace. This takes you directly through the shaded area of the HV diagram. You would have to make a very shallow approach at above 45-50 knots until you were within 10 feet agl in order to stay out of the HV diagram on approach. This is not realistic in ordinary flight.

 

Secondly, a max-performance take-off would be quite impossible to perform without entering into the HV diagram, as well as some other maneuvers/procedures.

 

The Height Velocity diagram is based on the principle that it would be difficult for the average pilot to safely perform an autorotation in the event of an engine failure. "Average" being the key term. It is not impossible to safely put the aircraft on the ground, just difficult.

 

As with many helicopter principles it is paramount that you know your own limitations. While I would be comfortable demonstrating some maneuvers inside the HV diagram (within reason) I would not allow my students to perform those same maneuvers solo.... the exception being the normal approaches of course.

[rmiller4292]

I have read that the FAA has used the HV diagram to go after pilots under the Careless and Reckless section...Unfortunately, I can't tell ya where I read it...but as we all know that is the catch all for the FAA.

 

Ryan

[Gomer Pylot]

You should have to worry about the careless and reckless only if you endanger other persons on the ground. Most pilots will operate inside the HV diagram at some point, and some of us do it routinely. You can't fly EMS in a single-engine helicopter without being in it for takeoff and landing, nor can you do any slingload operation, nor most other commercial operations. If you're doing powerline repair, you need to be aware of bystanders, houses, etc. It's not usually a problem, though, as long as you act prudently.

[bqmassey]

I'm not a pilot (or even training) yet, so I could be wrong, but I would think that the restricted area on the H/V (at least the one on the left side) is AIRspeed, not groundspeed. Maybe there was a head wind that, combined with a slow ground speed that looked like a hover from 200ft away, put him outside of the restricted area.

[TimW68]

Not for us low-timers !!

[IFLY]

For a R-22 - If you are taking off you are normally using max continous power (around 22") and have a high blade angle, if the engine quits it doesn't take long to stop the blades. If you are landing your power is down around 15", the blades are flatter and you lose much less RRPM entering an auto, you have a much better chance of successfully completing an auto from low altitudes. It all depends on if you are in low or high power modes for how critical the HV diagram is.

 

Jerry