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US Part 133 class D

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US Part 133 class D

Old 13th Jun 2013, 10:44
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US Part 133 class D

Anyone know of a US operator who holds a class D for a Bell 412? There are several non-civil using 412's but am curious if any Part 133 certs have been issued for Class D loads.

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Old 13th Jun 2013, 11:26
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class D as in Human External Cargo for rescue purposes? i am under the impression that there is no such thing in the US; it is just known as longline rescue.
on a 412, i am sure its more common to have a hoist (?). i could be wrong and i am prepared to sit corrected.
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Old 13th Jun 2013, 14:43
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Fun Police,

HEC Class D is nothing to do with rescue, it is described in (d) below:

Sec. 133.1


This part prescribes--

(a) Airworthiness certification rules for rotorcraft used in; and

(b) Operating and certification rules governing the conduct of rotorcraft external-load operations in the United States by any person.

(c) The certification rules of this part do not apply to--
(1) Rotorcraft manufacturers when developing external-load attaching means;

(2) Rotorcraft manufacturers demonstrating compliance of equipment utilized under this part or appropriate portions of Part 27 or 29 of this chapter;

(3) Operations conducted by a person demonstrating compliance for the issuance of a certificate or authorization under this part;

(4) Training flights conducted in preparation for the demonstration of compliance with this part; or

(5) A Federal, State, or local government conducting operations with public aircraft.
(d) For the purpose of this part, a person other than a crewmember or a person who is essential and directly connected with the external-load operation may be carried only in approved Class D rotorcraft-load combinations.
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Old 13th Jun 2013, 18:28
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alright then, apologies accepted i presume?
class D in canada is HEC for the purposes of LL rescue.
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Old 15th Jun 2013, 13:50
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US Part 133 Class D HEC in 412

As far as the non-civil 412 operations. I don't know about their "certificate" or Ops Specs but Evergreen uses hoist equipped 412s in Hawaii and Alaska for US government SAR support contracts (Army. I thought the gov't wanted them to comply with the civil regs but......it is a gov't or public service gig so they don't have to. I don't see a 412 meeting the power requirements for a commercial operation.

Last edited by Redhawk 83; 15th Jun 2013 at 13:55.
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Old 17th Jun 2013, 10:25
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I finally spoke to them and they do not meet the reqirements for Class D loads. It appears that they are just "training" and not actually moving class D loads.
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Old 20th Jun 2013, 03:01
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Thumbs up If I recall correctly...........

About 5 years ago I was tasked with securing a replacement aircraft for our FAR Part 133 D operation. While researching the Bell 412 I believe that the only variant that met the FAR requirement was the 412EP.

Between FAR 133, 27 and 29 you will find that the number of aircraft manufactured that truly meet the requirement are very few.

At that time there was one operator in Texas that had a 412 listed on their 133 certificate. After a short conversation with them it was said that they did not actually meet the requirement even though the local FSDO had approved the FAR Part 133 D operation.

I have found that Part 133 D operations are extremely misunderstood. Much of the confusion comes from the hoist manufactures that make hoists for just about every helicopter made. If you look around you will see hoists mounted on anything that can hover!!

As the regulations don't apply to Public Use aircraft they are free to mount a hoist on a light single and hoist all day with it!

Sorry I didn't answer your question, It's a great topic!!
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Old 20th Jun 2013, 18:41
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FB....I'm back!

I wanted to mention the level of confusion covering this topic. This thread is a perfect example of the confusion.

I've spent hours with FAA types educating them on "their" rules and reg's!

When someone says FAR Part 133 D. Most folks follow the same path as JimL.

When actually it's the load classification that is being referenced A, B, C, D. Not FAR Part 133.1 para (d).

Most FSDO's view clas A, B & C as bothersome in my view. I've spent many, many hours getting approvals from local Inspectors, racking up many $$ in man hours for lift jobs that take minutes accomplish. Most inspectors are clueless as to their responsibilities regarding lift op's.

Not the case with Class D operations. Lifting live human loads is serious business. At the present time my sources in the FAA tell me that there are less then a handful of approved FAR Part 133 operators with a Class D approval in the USA.

Additionally, the operators insurance company will charge large for FAR Part 133 D operations. Unless the operator is actively engaged in the lifting of live human loads it is often cost prohibited to have the FAA approval.

Good day!
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Old 21st Jun 2013, 07:39
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It is not clear why you have referred to my post above; it pointed specifically at HEC Class D loads and not paragraph (d) (that was coincidental).

For information about all load classes and the conditions under which they might be carried, one should look to the definitions in 14 FAR Part 1; the operational requirements in Part 133; and the airworthiness guidance contained in AC 29-2C (specifically AC 29.865B) - they are closely integrated. The following extract from AC 29.865B provides some background and explanation:
a. Background. The standards for external load attaching means, transport and normal category rotorcraft were originally contained in Subpart D, "Airworthiness Requirements of 14 CFR Part 133, Rotorcraft External-Load Operations." Amendment 29-12, issued in 1977, added a new § 29.865, which moved these standards from Part 133 to Part 29. An identical transfer occurred in 1977 for Part 27. Amendment 29-26, issued in 1990, clarified the intent of Amendment 29-12 but did not change it substantively. Transport Categories A and B and Normal Category rotorcraft were initially used under Part 133 operations, and after Amendment 133-6, restricted category rotorcraft were also included under Part 133 operations. The carriage of persons external to the rotorcraft for hire first came about when a Part 29 operator, exempt from Part 133, transferred harbor pilots to and from ships by a hoist and sling. The exemption was granted to study the feasibility of passenger transfer outside of the cabin. Grant of the exemption was based, in part, on similar, prior operations that had been conducted in Europe and Africa, for hire, with helicopters approved by the appropriate authorities and, in part, on similar military and public helicopter operations, not for hire, in the U.S. Subsequently, Amendment 133-9,adopted in January 1987, established a new Class D rotorcraft load combination (RLC) for transporting loads other than Class A, B, or C that are specifically approved by the Administrator external to the rotorcraft. Amendment 133-9 also provided for the limitations and conditions for transport of external loads other than Class A, B, or C and the necessary, associated safety requirements. Part 29 has recently been changed to reflect RLC Class D requirements. Also, the scope and thus the title of the standard have changed from "External load attaching means" to "External loads" to reflect the more comprehensive approach for external loads required to assure the proper level-of safety.

b. Explanation.

(1) This advisory material contains guidance for the certification of helicopter external load attaching means and load carrying systems to be used in conjunction with operating rules such as Part 133, "Rotorcraft External Load Operations." Subpart D of Part 133 contains supplemental airworthiness requirements. 14 CFR Part 1 defines the four RLC classes that are approvable under Part 133 operating rules and that are eligible for certification under § 29.865. The four RLC classes are summarized in figure AC 29.865-1 and discussed in paragraph d. Under the operating rules RLC Classes A, B, and C are eligible, under specific restrictions, for both human external cargo (HEC) and nonhuman external cargo (NHEC) operations. However, under U.S. operating rules, only RLC Class D is eligible for transporting HEC for compensation. Paragraph AC 29.25 (reference § 29.25) also concerns, in part, jettisonable external cargo.

(2) Section 29.865 provides a minimum level of safety for transport category rotorcraft designs to be used with operating rules such as Part 133. Certain aspects of operations such as microwave tower and high-line wirework may also be regulated separately by other Federal agencies such as DOE, EPA, and OSHA or by other international entities. For applications that could come under multiple agency regulation (or regulation by other entities), special certification emphasis will be required by both the applicant and the approving authority to assure all relevant safety requirements are identified and met. Potential additional requirements, where thought to exist, are noted herein.

Last edited by JimL; 21st Jun 2013 at 07:46.
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Old 21st Jun 2013, 08:03
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Further, because I know that most will not take the time to find and read AC 29.865B, the required performance standard is reproduced:
(12) § 29.865(c)(6) Limitations for HEC Operations: For jettisonable HEC operations, it may be required by Operations Requirements, that the rotorcraft meet the Category A engine isolation requirements of Part 29 and that the rotorcraft have One Engine Inoperative/Out of Ground Effect (OEI/OGE) hover performance capability in its approved, jettisonable HEC weight, altitude, and temperature envelope.

(i) In determining OEI hover performance, dynamic engine failures should be considered. Each hover verification test should begin from a stabilized hover at the maximum OEI hover weight, at the requested in-ground-effect (IGE) or OGE skid or wheel height, and with all engines operating. At this point the critical engine should be failed and the aircraft should remain in a stabilized hover condition without exceeding any rotor limits or engine limits for the operating engine(s). As with all performance testing, engine power should be limited to minimum specification power. Engine failures may be simulated by rapidly moving the throttle to idle provided a ‘needle split’ is obtained between the rotor and engine RPM.

(ii) Normal pilot reaction time should be used following the engine failure to maintain the stabilized hover flight condition. When hovering OGE or IGE at maximum OEI hover weight, an engine failure should not result in an altitude loss of more than 10 percent or four (4) feet, whichever is greater, of the altitude established at the time of engine failure. In either case, sufficient power margin should be available from the operating engine(s) to regain the altitude lost during the dynamic engine failure and to transition to forward flight.

(iii) Consideration should also be given to the time required to recover (winch up and bring aboard) the Class D external load and to transition to forward flight. This time increment may limit the use of short duration OEI power ratings. For example, for a helicopter that sustains an engine failure at a height of 40 feet, the time required to restabilize in a hover, recover the external load (given the hoist speed limitations), and then transition to forward flight (with minimal altitude loss) would likely preclude the use of 30-second engine ratings and may encroach upon the 2 ˝ -minute ratings. Such encroachment into the 2 ˝ - ratings is not acceptable.

(iv) For helicopters that incorporate engine driven generators, the hoist should remain operational following an engine or generator failure. A hoist should not be powered from a bus that is automatically shed following the loss of an engine or generator. Maximum two-engine generator loads should be established so that when one engine or generator fails, the remaining generator can assume the entire rotorcraft electrical load (including the maximum hoist electrical load) without exceeding approved limitations.

(v) The Rotorcraft Flight Manual (RFM) should contain information that describes the expected altitude loss, any special recovery techniques, and the time increment used for recovery of the external load when establishing maximum weights and wheel or skid heights. The OEI hover chart should be placed in the performance section of the RFM or RFM supplement. Allowable altitude extrapolation for the hover data should not exceed 2000 feet.
As has been pointed out to the Airworthiness Authorities, the highlighted section should have referred either to the 'length of the line' or the ' hover height', not the altitude. (I'm sure that hoisting at 10,000 ft would not permit a drop of 1,000 ft from the hover altitude.)

A number of helicopters have been certificated to meet this standard!

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Old 21st Jun 2013, 22:25
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Thank you thank you thank you !

It makes me smile to see that there are folks out there like yourself that know stuff!

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Old 22nd Jun 2013, 14:25
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This does not exactly answer your question, though you may find helpful. There are only a couple of locations in the US that human class D rescues are carried out by civilian operators. One is in Denali national park in AK, the current company with the contract is TEMSCO based in Ketchikan, AK. They are using a AS350 B3. Although TEMSCO also has some bell mediums, not sure if they are Class D certified. The other place that I am aware of where these recuses are done on a regular basis, is in the Tetons, out of Jackson Hole, WY. Last I knew Helicopter Express, out of George had this contract. They had a Bell 407 based there. Some of this info, may be out dated or incorrect. Although you may want to contact these companies if you want more accurate information. AGO
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Old 24th Jun 2013, 07:01
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This is beginning to appear like a schizophrenic thread. Whilst the operations described by 'agodesign' are informative, the description is technically incorrect. So, for further illustration, here is another extract - this time from FAR 133.45 - to clarify the situation:

§ 133.45 Operating limitations.
In addition to the operating limitations set forth in the approved Rotorcraft Flight Manual, and to any other limitations the Administrator may prescribe, the operator shall establish at least the following limitations and set them forth in the Rotorcraft-Load Combination Flight Manual for rotorcraft-load combination operations:


(e) The rotorcraft-load combination of Class D may be conducted only in accordance with the following:
(1) The rotorcraft to be used must have been type certificated under transport Category A for the operating weight and provide hover capability with one engine inoperative at that operating weight and altitude.

(2) The rotorcraft must be equipped to allow direct radio intercommunication among required crewmembers.

(3) The personnel lifting device must be FAA approved.

(4) The lifting device must have an emergency release requiring two distinct actions.
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Old 24th Jun 2013, 15:59
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Not Part 133

Those mentioned are not Part 133.

They are civilian operators operating in Public Use status. They are contracted to US Department of Interior/National Park Service. The contract allows them to operate in Public Use status because the mission cannot be performed Part 135/Part 133.

Most helicopter rescue missions in the US are performed by government agencies in Public Use status.

The aircraft performance requirements posted by JimL for Part 133 are very difficult to meet in any aircraft in a real mission configuration (depending on weather the day of the test). Several have a testing configuration and real mission configuration.
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Old 24th Jun 2013, 19:17
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I'm not sure anyone is arguing for HEC Class D in rescue - to my knowledge, there are no such operations anywhere in the world. What is being pointed out is the liberal use of the term HEC Class D under circumstances where, although persons are being hoisted (or, in fact lifted for short haul), it is not to Class D standards.

The initial question was about the qualification of the Bell 412 for HEC Class D; what was pointed out subsequently is that HEC Class D is tightly defined concept which is used in specific circumstances - mostly 'sea pilot transfer' or 'passenger transfer' under conditions of Commercial Air Transport.

What makes this an interesting discussion is the use of the regulatory language used in Parts 1, 29 and 133. As an example, below are the notes to the table describing the elements of RLC A, B, C and D in AC 29-2C:


1. A person(s), being carried or transported for compensation outside the rotorcraft can only be carried as a Class D RLC.

2. A person who is not being carried or transported for compensation, is knowledgeable of the risks involved, and at some point is required to be outside of the rotorcraft in order to fulfill the mission. These persons are considered as RLC Class A, B, or C HEC as appropriate to the operation.

3. The rotorcraft is approved to the Category A engine isolation requirements of Part 29 and have One Engine Inoperative/Out of Ground Effect (OEI/OGE) hover performance capability, for the requested operating and weight envelopes, to be eligible for certification to the Class D RLC. Reference Paragraph d(12))

4. A Class D RLC operation may be conducted with an external cargo design having a physical configuration that meets the definitions of § 1.1 for RLC Class A, B, or C.
Although these notes are better read along with the table in AC 29-2C, note 4 appears to say that not only in hoisting does HEC Class D apply; if a person is carried for compensation in configurations A, B or C then the condition of HEC Class D should also apply. In fact because almost all conditions of HEC apply equally whether Class D or not, the only additional condition called for would the the performance requirements.

However, my interpretation appears to show a conflict between notes 1 and 4 and also a conflict with the definition of HEC Class D:
(iv) Class D rotorcraft-load combination means one in which the external load is other than a Class A, B, or C and has been specifically approved by the Administrator for that operation (i.e., HEC operations for which the operator is receiving compensation from the person being transported).
or does it?

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Old 24th Jun 2013, 22:39
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Part 133

It is my understand that those commercial entities providing contracted SAR services (ERA, Cougar etc.) in the US are doing so under a Part 133 certificate.

From ERA Brochure


• CFR 133 Class D Qualified

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Old 25th Jun 2013, 04:26
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Yes, an interesting use of language.

As has been teased out in the discussions above, the application of AC 29.865B provides a qualification for HEC Class D as prescribed in FAR 133 - i.e. the aircraft is suitably equipped and qualified, and substantiation of performance has been provided in the form of graphs. The final sequence is the application of Part 133 to ensure that hoisting operations are conducted at the correct mass.

One of the more interesting issues has always been the interpretation of 'transported for compensation'; although a civilian operator is receiving compensation for operations when conducting hoisting under contract, we are reliant upon a (secondary) interpretation of the type of operation to establish whether that would constitute CAT or not. It is helpful in the case of SAR that ICAO makes an absolute statement that SAR is not CAT. In that sense, the use of 'transported for compensation' is probably too blunt a term to be immediately intuitive.


Last edited by JimL; 25th Jun 2013 at 04:36.
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Old 25th Jun 2013, 10:14
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In that sense, the use of 'transported for compensation' is probably too blunt a term to be immediately intuitive.
But presumably does apply for training flights?
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Old 25th Jun 2013, 12:25
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From 133.11

(c) The certification rules of this part do not apply to—

(4) Training flights conducted in preparation for the demonstration of compliance with this part;

So just say your training in preparation for demonstration of compliance...
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Old 26th Jun 2013, 00:15
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There is a operator in Oregon that transports the Columbia River Bar Pilots on and off the cargo ships entering and departing the Columbia River.

They operate day/night, VFR/IFR.

I can't speak for the present operator, but a prior operator held a waiver that allowed for FAR Part 133 part D / FAR Part 135 operations simultaneously. This allowed for the pick up of one Bar Pilot then the hoist lowering of another without making the hop back to the airport.

The contract utilizes a Agusta 109 Grand now, a 109 Power was used in the past.

There was a time when this operation was conducting over 1200 live hoists a year.

There was (is) a very knowledgeable Lead Pilot there, he knows the in's and out's of live load hoisting.
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