Part 91 operators use of Minimum Descent Altitude as a Decision Altitude

[Dave Piehler]

Did anyone else get the FAASTeam e-mail discussing Notice Number NOTC6369 with the above title?  The upshot is that the FAA is telling us that if we want to use a WAAS GPS to fly a LPV approach or LNAV/VNAV approach to a Decision Altitude lower than the non-precision MDA we need a Letter of Authorization from our FSDO.  No kidding. 

That notice refers to an earlier notice with much more detail: http://fsims.faa.gov/wdocs/notices/n8900_248.htm

The notice refers to FAA Order 8900.1, Volume 3, Chapter 18, Section 5, paragraph C073. That reference can be found at http://fsims.faa.gov/wdocs/8900.1/v03%20tech%20admin/chapter%2018/03_018_005.htm.

I raised the issue with my avionics tech who, in turn, queried his contact at the FSDO, His reply:

Attached is a copy of the LOA requested. The person applying must be willing to accept the conditions in the document. Item 3f is language that is designed for the 121 or 135 world. Our internal guidance states that the "91 operator must be proficient with the VNAV and the IAP to be flown." Discussing this requirement with an operations inspector, we will accept a log book endorsement from an authorized instructor to verify the proficiency. The operator will have to send a letter to the FSDO requesting the LOA . Our office will need to establish a operator file. In the application package please include: 

Aircraft- make, make, model, s/n, and N#

Equipment- make, model and copy of page of flight manual or supplement that states the equipment is capable of the approaches requested.

Company or person- name, phone #, email and address

Proof of proficiency, must be in aircraft training or school like

FlightSafety, not an online coarse.

Airport- where aircraft is based.

Has anyone else looked into this?  The burden is to provide paperwork (the AFMS for your WAAS GPS will have that info -- look for the latest version), get an endrosement (you've flown with your instructor and done LPV approaches to minimums, right?) and get the LOA.

Thoughtful comments requested.

Dave Piehler

[Hank]

This is bureaucracy gone haywire! Since I've not been notified, I'm going to ignore this. The FAA needs to grant individual approval to every operator who has a WAAS GPS installed before said operator can fly an instrument approach using said WAS GPS down to the DA that the FAA has approved when using a WAAS GPS? Or am I misunderstanding you?

[Marauder]

1 hour ago, Dave Piehler said:

Did anyone else get the FAASTeam e-mail discussing Notice Number NOTC6369 with the above title?  The upshot is that the FAA is telling us that if we want to use a WAAS GPS to fly a LPV approach or LNAV/VNAV approach to a Decision Altitude lower than the non-precision MDA we need a Letter of Authorization from our FSDO.  No kidding. 

 

That notice refers to an earlier notice with much more detail: http://fsims.faa.gov/wdocs/notices/n8900_248.htm

The notice refers to FAA Order 8900.1, Volume 3, Chapter 18, Section 5, paragraph C073. That reference can be found at http://fsims.faa.gov/wdocs/8900.1/v03%20tech%20admin/chapter%2018/03_018_005.htm.

I raised the issue with my avionics tech who, in turn, queried his contact at the FSDO, His reply:

Attached is a copy of the LOA requested. The person applying must be willing to accept the conditions in the document. Item 3f is language that is designed for the 121 or 135 world. Our internal guidance states that the "91 operator must be proficient with the VNAV and the IAP to be flown." Discussing this requirement with an operations inspector, we will accept a log book endorsement from an authorized instructor to verify the proficiency. The operator will have to send a letter to the FSDO requesting the LOA . Our office will need to establish a operator file. In the application package please include: 

Aircraft- make, make, model, s/n, and N#

Equipment- make, model and copy of page of flight manual or supplement that states the equipment is capable of the approaches requested.

Company or person- name, phone #, email and address

Proof of proficiency, must be in aircraft training or school like

FlightSafety, not an online coarse.

Airport- where aircraft is based.

Has anyone else looked into this?  The burden is to provide paperwork (the AFMS for your WAAS GPS will have that info -- look for the latest version), get an endrosement (you've flown with your instructor and done LPV approaches to minimums, right?) and get the LOA.

Thoughtful comments requested.

Dave Piehler

 

Dave -- I think the LOA pertains only to 121 and 135 operators. Part 91 is mentioned, but I don't think we are included in LOAs  

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[Dave Piehler]

Marauder,

That's a common reaction, but wrong according to the documentation,  They specifically indicate it applies to Part 91 (all part 91, not just Part 91K).

Dave Piehler

[Marauder]

Marauder,

That's a common reaction, but wrong according to the documentation,  They specifically indicate it applies to Part 91 (all part 91, not just Part 91K).

Dave Piehler

Dave - when I received the letter a week or so ago, I took it over to a friend who is a CFII and an ATP. He started to explain to me why the 91 part was not a requirement for those operating without a LOA (us). I'm sure other CFIIs on this site will weigh in on the topic.

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[Mooneymite]

Not sure.....seems everyone is confused.

My son flies for a corporate flight department that only operates under part 91.  The flight department is being forced to get LOA's for all sorts of things by the local FAA.  His flight department feels it is "over-reach" by the FAA, but it doesn't want to fight the FAA because the consequences could be worse, so the FAA prevails.

I hope someone fights this!

 

[Marauder]

Dave - I pulled it up and read through the 91 section. If it does pertain to us, it basically says that we are authorized to use the MDA as a DA but warned of the OCS not being guaranteed and requiring a visual to the airport.

I did not read it that you flew an LPV approach to a MDA. Rather that one of the non-precision approaches MDAs they mentioned in the policy may be flown to a DA with certain requirements.

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[Marauder]

Not sure.....seems everyone is confused.

My son flies for a corporate flight department that only operates under part 91.  The flight department is being forced to get LOA's for all sorts of things by the local FAA.  His flight department feels it is "over-reach" by the FAA, but it doesn't want to fight the FAA because the consequences could be worse, so the FAA prevails.

I hope someone fights this!

 

I think your son's part 91 flying is what this policy is all about. It pertains to those who are operating under a LOA. The part 91 flying we do I don't think is covered under an operator's LOA.

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[Dave Piehler]

To quote from Paragraph C073 of FAA Order 8900.1, Volume 3, Chapter 18, Section 5

:A.    Applicability. OpSpec/MSpec/LOA C073 is applicable to all certificate holders/operators/program managers conducting airplane operations under 14 CFR parts 91, 91 subpart K (part 91K), 121, 125 (including part 125 Letter of Deviation Authority (LODA) holders), and 135.

It doesn't say only flight departments.  It says "all certificate holders...conducting airplane operations under 14 CFR part...91."  That includes everyone.  The notice I quoted initially says it in so many words:  "Operators must be authorized with a Letter of Authorization (LOA) C073 in order to use an MDA as a DA with VNAV."

I agree it sure looks like overreach, and I have questions about what authority allows this interpretation (it seems a lot like rulemaking without benefit of the administrative rules process).  However, I'm interested in what the FAA position is, regardless of the question of authority.  Speaking pragmatically, this may only come up in the accident investigation, or possibly in a fly-specking enforcement proceeding, but who wants to risk that?

Dave Piehler

[Danb]

This is a perfect example of a system gone " haywire" as mentioned by Hank.  We have multiple intelligent people attempting to analyze a rule involving our lives. I actually don't think it matters if it would only come up in a potential accident investigation as referred by Dave, what is of serious consequence is the differing results from the same set of facts,regulations procedures etc. as depicted within references. It appears every section of the gov't. has become increasingly difficult to analyze. Where do we go, what do we do to ascertain the rules when regulations seem to have failed in there diligence to resolve a seemingly simple rule? A true reason we need Aopa and other groups to help mold the rule makers is writing understandable guidelines. So much  of the gov'ts rules are just to unrealistic to understand as written the FAA.IRS.ACA , on and on. Where do we go or do?

[Andy95W]

This may not mean what everyone thinks it means, but I'll also not swear to my answer being 100% correct.

Nowhere does it say you cannot continue to fly LPV approaches with your GNS-430W to a Decision Altitude (DA).  Nowhere does it say you cannot continue to fly LNAV/VNAV approaches to a DA.

What it says is that you cannot use an MDA as a DA and continue your descent using that FPA (flight path angle) or VDA (vertical descent angle).  But using a standard GA WAAS GPS such as a GNS or GTN unit you can't do that anyway.  You must stop your descent at the MDA.

Some GPS units, in conjunction with a flight management system (FMS), can create a pseudo-glide path to vertically guide you from the FAF (final approach fix) to the runway.  These types of units still use the MDA, but continuing on that angle will put you into an obstacle.

But again, this doesn't apply to LPV or LNAV/VNAV approaches because they have a published DA, not MDA.

Edited January 31, 2016 by N1395W

[Marauder]

To quote from Paragraph C073 of FAA Order 8900.1, Volume 3, Chapter 18, Section 5

:A.    Applicability. OpSpec/MSpec/LOA C073 is applicable to all certificate holders/operators/program managers conducting airplane operations under 14 CFR parts 91, 91 subpart K (part 91K), 121, 125 (including part 125 Letter of Deviation Authority (LODA) holders), and 135.

It doesn't say only flight departments.  It says "all certificate holders...conducting airplane operations under 14 CFR part...91."  That includes everyone.  The notice I quoted initially says it in so many words:  "Operators must be authorized with a Letter of Authorization (LOA) C073 in order to use an MDA as a DA with VNAV."

I agree it sure looks like overreach, and I have questions about what authority allows this interpretation (it seems a lot like rulemaking without benefit of the administrative rules process).  However, I'm interested in what the FAA position is, regardless of the question of authority.  Speaking pragmatically, this may only come up in the accident investigation, or possibly in a fly-specking enforcement proceeding, but who wants to risk that?

Dave Piehler

Exactly. The only LOAs I have ever seen issued for 91 CFR operations are those who fly under regulations like what Gus's son is doing.

Also, the LOA mentioned pertains to operating a non precision MDA as a DA. Not the other way around.

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[Marauder]

This may not mean what everyone thinks it means, but I'll also not swear to my answer being 100% correct.

Nowhere does it say you cannot continue to fly LPV approaches with your GNS-430W to a Decision Altitude (DA).  Nowhere does it say you cannot continue to fly LNAV/VNAV approaches to a DA.

What it says is that you cannot use an MDA as a DA and continue your descent using that FPA (flight path angle) or VDA (vertical descent angle).  But using a standard GA WAAS GPS such as a GNS or GTN unit you can't do that anyway.  You must stop your descent at the MDA.

Some GPS units, in conjunction with a flight management system (FMS), can create a pseudo-glide path to vertically guide you from the FAF (final approach fix) to the runway.  These types of units still use the MDA, but continuing on that angle will put you into an obstacle.

But again, this doesn't apply to LPV or LNAV/VNAV approaches because they have a published DA, not MDA.

I knew a brainiac would come along. That was my read as well, especially when they began giving descent angle ranges that weren't pertinent for our hardware.

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[201er]

A law degree shouldn't be requisite to fly a personal aircraft!

Edited January 31, 2016 by 201er

[Andy95W]

25 minutes ago, Marauder said:

I knew a brainiac would come along. That was my read as well, especially when they began giving descent angle ranges that weren't pertinent for our hardware.

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First time I've been called a brainiac.

I've been called a smart ass lots of times, though.

[Deb]

Article from IFR Magazine on descent angles and VDP: http://www.ifr-magazine.com/issues/1_4/features/Constant-Angle-Descent_32-1.html.

Article from Jeppesen using MDA as DA: http://www.jeppesen.com/download/aopa/dec99aopa.pdf.

Beechtalk has a 5 page thread on the topic: http://www.beechtalk.com/forums/viewtopic.php?f=42&t=117885. (John Collins and Wally Roberts seem to be the go-to guys for TERPS questions on the site).

[tony]

Not that this helps an over zealous regulatory agency, but keep in mind that an order is not regulatory.  It did not go through the public comment and they are not law.  Orders suppose to be written for FAA employees clarifying how to interpret the existing FARs.  A smart lawyer should be able to beat this.

[Bob - S50]

I agree with N1395W.  Here is a quote from the first reference made:

"1.    Purpose of This Notice. This notice provides changes to operations specification (OpSpec)/management specification (MSpec)/letter of authorization (LOA) C073, Vertical Navigation (VNAV) Instrument Approach Procedures (IAP) Using Minimum Descent Altitude (MDA) as a Decision Altitude (DA)/Decision Height (DH),..."

To me that says that it applies to approaches that use an MDA, for example an LNAV, ADF, LOC, LDA or VOR approach.  It does not apply to LPV or LNAV/VNAV approaches.  Since it references Opsecs, I suspect it pertains only to commercial operators, not us.  It is just warning operators that an advisory glideslope (as opposed to a published approach that contains a glideslope) does not guarantee obstacle clearance if that advisory glideslope is followed below the MDA.  Once you get to the MDA you MUST be visual to the runway.

[Marauder]

Article from IFR Magazine on descent angles and VDP: http://www.ifr-magazine.com/issues/1_4/features/Constant-Angle-Descent_32-1.html.

Article from Jeppesen using MDA as DA: http://www.jeppesen.com/download/aopa/dec99aopa.pdf.

Beechtalk has a 5 page thread on the topic: http://www.beechtalk.com/forums/viewtopic.php?f=42&t=117885. (John Collins and Wally Roberts seem to be the go-to guys for TERPS questions on the site).

Thanks Deb (or David). Pretty clear in both the IFR mag and Jepp article.

IFR mag; "Don’t be confused by Jeppesen’s note about using a DA. Some certificated operators are authorized to treat the MDA as a DA, making a land/miss decision at MDA and consequently going a bit below on the miss. General aviation isn’t one of those authorized operators. Don’t do it."

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[1964-M20E]

I saw something and didn't think about it or bother to investigate any further.  I have no plans to worry or do anything regarding this.  I have enough things to concern my limited brain capacity and time resources with to be bothered with something like this.  I will fly as needed to maintain a safe and reliable transportation.

 

 

[gsxrpilot]

Maybe I'm missing something... but unless the FSDO is sitting next to me, how does anyone know what I used as my DH?

I shot an approach into JLN a couple of years ago and broke out above the minimums, and as I touched down, the tower said they still couldn't see me.

[Cruiser]

maybe the tower couldn't see you but the radar can........ 

[gsxrpilot]

10 minutes ago, Cruiser said:

maybe the tower couldn't see you but the radar can........ 

But radar doesn't know if I saw the ground or not. I'm not trying to break any regs here, and my personal minimums probably wouldn't let me get to the MDA anyway. But just like we often go around when the reported weather is above minimums but the runway's not in sight at the MDA, there's no one able to say I didn't see the ground at whatever height.

[Marauder]

23 minutes ago, gsxrpilot said:

But radar doesn't know if I saw the ground or not. I'm not trying to break any regs here, and my personal minimums probably wouldn't let me get to the MDA anyway. But just like we often go around when the reported weather is above minimums but the runway's not in sight at the MDA, there's no one able to say I didn't see the ground at whatever height.

Unfortunately there have been a few incidents where the FAA went after pilots for what they considered reckless behavior. A number of years ago I remember the suspensions that were issued to some pilots who cancelled IFR in flight at uncontrolled airports when weather conditions were considered IMC. 

 

[ArtVandelay]

23 minutes ago, gsxrpilot said: But radar doesn't know if I saw the ground or not. I'm not trying to break any regs here, and my personal minimums probably wouldn't let me get to the MDA anyway. But just like we often go around when the reported weather is above minimums but the runway's not in sight at the MDA, there's no one able to say I didn't see the ground at whatever height.

Unfortunately there have been a few incidents where the FAA went after pilots for what they considered reckless behavior. A number of years ago I remember the suspensions that were issued to some pilots who cancelled IFR in flight at uncontrolled airports when weather conditions were considered IMC. 

 

With automated weather that's easy to check, but around here, they lose you on radar once you get down pattern altitude give or take, at an uncontrolled airport, it's the honor system.

Also, they give you a GPS approach, but they don't ask if you have WAAS or not and what your limit will be.

Unless there is an accident, you can do a 0/0 approach just using your iPad with synthetic vision and nobody will know.