Welcome to Flightinfo.com
- Register now and join the discussion
- Friendliest aviation Ccmmunity on the web
- Modern site for PC's, Phones, Tablets - no 3rd party apps required
- Ask questions, help others, promote aviation
- Share the passion for aviation
- Invite everyone to Flightinfo.com and let's have fun
LDA/Glide Slope Approach: Precision?
- Thread starter MasterFly
- Start date
- Watchers 8
Welcome to Flightinfo.com
- Register now and join the discussion
- Modern secure site, no 3rd party apps required
- Invite your friends
- Share the passion of aviation
- Friendliest aviation community on the web
No, Pilotyip, this is not correct. You do not have the power or authority to interpret the FAR; neither does your POI, or anybody at the FSDO level.
You are NOT required to demonstrate every approved precision approach in your opspecs. You may not fly an approach you have not demonstrated in the previous 6 months, but nowhere under Part 135 are you required to fly every approach. If you don't demonstrate each precision approach, you may not fly it, but there is NO requirement to demonstrate it, or to later fly it. If you don't demonstrate it, you're simply restricted from flying it.
Do you demonstrate a MLS approach every 6 months?
Part 121 doesn't require even this; only the three approaches as given in my previous post, and quoted from Appendix F.
The CFR, however, is legal evidence of itself, as a codification that stands alone without specific constitutional reference or enpowerment. Being self-evidentiary, the provision of definition set forth in 14 CFR 1.1 is ample description and conclusion as to the nature of an approach that includes vertical guidance.
What does that all boil down to? Your OpSpecs don't define the FAR, or the terms set forth in the FAR. Your POI doesn't have the ability to do so, either. Neither does a soul at your FSDO. The power and authority to do so is not granted at that level.
Any classification in your OpSpecs does not define the FAR, nor does it define TERPS. The OpSpecs do not clarify or represent the FAR, nor may they be used as evidence to interpret the FAR. How should one view an approach if one does not work for a certificate holder, and has no OpSpecs? Would your OpSpecs be applicable to such a person? Of course not. However, 14 CFR 1.1 would be, and is.
You are NOT required to demonstrate every approved precision approach in your opspecs. You may not fly an approach you have not demonstrated in the previous 6 months, but nowhere under Part 135 are you required to fly every approach. If you don't demonstrate each precision approach, you may not fly it, but there is NO requirement to demonstrate it, or to later fly it. If you don't demonstrate it, you're simply restricted from flying it.
Do you demonstrate a MLS approach every 6 months?
Part 121 doesn't require even this; only the three approaches as given in my previous post, and quoted from Appendix F.
The CFR, however, is legal evidence of itself, as a codification that stands alone without specific constitutional reference or enpowerment. Being self-evidentiary, the provision of definition set forth in 14 CFR 1.1 is ample description and conclusion as to the nature of an approach that includes vertical guidance.
What does that all boil down to? Your OpSpecs don't define the FAR, or the terms set forth in the FAR. Your POI doesn't have the ability to do so, either. Neither does a soul at your FSDO. The power and authority to do so is not granted at that level.
Any classification in your OpSpecs does not define the FAR, nor does it define TERPS. The OpSpecs do not clarify or represent the FAR, nor may they be used as evidence to interpret the FAR. How should one view an approach if one does not work for a certificate holder, and has no OpSpecs? Would your OpSpecs be applicable to such a person? Of course not. However, 14 CFR 1.1 would be, and is.
Avbug,
This is a bit off the original subject, but since it came up I have a question. You stated that "Opspecs don't define the FAR" and "do not clarify or represent the FAR" but 121.625 Alternate airport weather minimums states in part that, " weather conditions will be at or above the alternate weather minimums specified in the certificate holder's operations specifications".
Isn't this an example of Opspecs defining an FAR?
Because my Opspecs define LDA w or w/o GS as nonprecision then for me, and everyone at my company, it is nonprecision.
The LDA issue is a matter of semantics. What difference does it make what you call it as long as you know how to fly it and how to make decisions based on your understanding of the approach.
My.02
This is a bit off the original subject, but since it came up I have a question. You stated that "Opspecs don't define the FAR" and "do not clarify or represent the FAR" but 121.625 Alternate airport weather minimums states in part that, " weather conditions will be at or above the alternate weather minimums specified in the certificate holder's operations specifications".
Isn't this an example of Opspecs defining an FAR?
Because my Opspecs define LDA w or w/o GS as nonprecision then for me, and everyone at my company, it is nonprecision.
The LDA issue is a matter of semantics. What difference does it make what you call it as long as you know how to fly it and how to make decisions based on your understanding of the approach.
My.02
When the OPSS provides information or direction to an operator, it is binding to that operator, only. Takeoff minimums and alternate minimums may vary, according to the pilot qualifications and experience, as well as the operator limitations. This doesn't redefine the FAR, but only provides on an individual basis the limitations for a given operator or pilot. This is the purpose of OPSS, or OpSpecs.
OpSpecs are approved data, meaning data approved by the administrator for a particular purpose In this case, for a particular operator, and a finite group of pilots. OpSpecs do not define the FAR.
As for inspector opinions and the FSDO...yes, I mean exactly what I said. The FSDO does NOT have the right or authority to interpret regulation or to issue interpretations. The FSDO has the authority to initiate enforcement action (but not to follow through or complete that action).
Does your OPSpec C052 classify an LDA w/gs as nonprecision, or does it classify it under "Instrument Approach Procedures Other Than ILS, MLS, and GLS?" It should include in parenthesis "(eg, nonprecision approaches)." This change was made two years ago, and has been referred to several times here.
According to HBAT 99-17, "C. The general classification of "nonprecision" was replaced in order to recognize current and future authorizations for RNAV and other approaches that may incorporate the use of barometric VNAV to provide a stabilized descent."
Be that as it may, the OPSS doesn't define the FAR. What may be for you, or for your company, is not for everybody. The OpSpec doesn't represent an interpretation, but a set or restrictions and limitations applicable only to the user. Any classifications therein are not evidence of the FAR, and OpSpecs can't b used to define TERPS or Part 97 of 14 CFR.
OpSpecs are approved data, meaning data approved by the administrator for a particular purpose In this case, for a particular operator, and a finite group of pilots. OpSpecs do not define the FAR.
As for inspector opinions and the FSDO...yes, I mean exactly what I said. The FSDO does NOT have the right or authority to interpret regulation or to issue interpretations. The FSDO has the authority to initiate enforcement action (but not to follow through or complete that action).
Does your OPSpec C052 classify an LDA w/gs as nonprecision, or does it classify it under "Instrument Approach Procedures Other Than ILS, MLS, and GLS?" It should include in parenthesis "(eg, nonprecision approaches)." This change was made two years ago, and has been referred to several times here.
According to HBAT 99-17, "C. The general classification of "nonprecision" was replaced in order to recognize current and future authorizations for RNAV and other approaches that may incorporate the use of barometric VNAV to provide a stabilized descent."
Be that as it may, the OPSS doesn't define the FAR. What may be for you, or for your company, is not for everybody. The OpSpec doesn't represent an interpretation, but a set or restrictions and limitations applicable only to the user. Any classifications therein are not evidence of the FAR, and OpSpecs can't b used to define TERPS or Part 97 of 14 CFR.
No, the general classification was changed from nonprecision. Some time ago, too. Regardless, the point is this: what your opspecs classify as approach as for purposes of currency and authorization, do NOT define what the approach is. Your opspecs could say the color blue is red, but that wouldn't change the color blue.
"Precision Like"
LDA Approach (Localizer-type Directional Aid):
[1.1, AIM 1-1-10, AIM 1-1-24, AIM 5-4-5, P/C Glossary, OpSpec C052 & 8400.10, Vol 3, Chap 1, Sec 5, para 83(B)
& FAA-H-8083-15 Instrument Flying Handbook]
1. A navaid used for nonprecision instrument approaches.
2. The LDA is of comparable utility and accuracy to a localizer but is not part of a complete ILS.
3. LDA course width is between 3° and 6° and thus provides a more precise approach course than an SDF installation.
4. The LDA course is not aligned with the runway, but STRAIGHT-IN MINIMUMS may be published where the angle between the runway centerline and the LDA course does not exceed 30°.
If this angle exceeds 30°, only CIRCLING minimums are published.
5. May have Glide Slope if noted. By definition qualifying it as a PRECISION approach. FAR 1.1 and the P/C Glossary define a “precision approach procedure” as ANY standard Instrument Approach Procedure with an electronic glide slope.
6. May incorporate a Decision Altitude(Height). DA(H) by definition is the decision altitude on a PRECISION approach (P/C Glossary).
7. An LDA with a Glide Slope could be considered a “PRECISION” approach due to the fact that it provides an “electronic glide slope” and may also incorporate a Decision Altitude (Height). However the definition of Localizer Type Directional Aid given in the P/C Glossary conflicts with these two statements, calling it “a navaid used for NONPRECISION instrument approaches.”
Of course the P/C Glossary does not define a “Localizer Type Directional Aid w/GS.”
From a Part 91 standpoint at least, I guess you get to choose whatever definition you like!
8. As an additional side note see AIM 1-1-24 — “Precision Approach Systems other than ILS, GLS, and MLS” — “Approval and use of precision approach systems other than ILS, GLS and MLS require the issuance of special instrument approach procedures…”
9. From an air carrier OpSpecs standpoint, an LDA w/GS is classified as a “PRECISION-LIKE” approach that provides vertical guidance but is not as accurate as a true precision approach. FAA policy is that even though a glide slope is available, the accuracy is not the same as an ILS, MLS, GLS, or TLS. OpSpec C052 lists “precision-like” approaches as Instrument Approach Procedures other than ILS, MLS, and GLS (i.e., NONPRECISION approaches), at least for air carriers.
10. From a practical standpoint an LDA with a glide slope normally brings you right down to the end of the runway, that’s pretty darn precise. Who cares if you have to make a slight jog just before touch down… you’ve probably done worse jogs at the end of many of your ILS approaches!
11. For Part 91, the only time the question of precision vs. nonprecision would become an issue is when choosing an alternate.
LDA Approach (Localizer-type Directional Aid):
[1.1, AIM 1-1-10, AIM 1-1-24, AIM 5-4-5, P/C Glossary, OpSpec C052 & 8400.10, Vol 3, Chap 1, Sec 5, para 83(B)
& FAA-H-8083-15 Instrument Flying Handbook]
1. A navaid used for nonprecision instrument approaches.
2. The LDA is of comparable utility and accuracy to a localizer but is not part of a complete ILS.
3. LDA course width is between 3° and 6° and thus provides a more precise approach course than an SDF installation.
4. The LDA course is not aligned with the runway, but STRAIGHT-IN MINIMUMS may be published where the angle between the runway centerline and the LDA course does not exceed 30°.
If this angle exceeds 30°, only CIRCLING minimums are published.
5. May have Glide Slope if noted. By definition qualifying it as a PRECISION approach. FAR 1.1 and the P/C Glossary define a “precision approach procedure” as ANY standard Instrument Approach Procedure with an electronic glide slope.
6. May incorporate a Decision Altitude(Height). DA(H) by definition is the decision altitude on a PRECISION approach (P/C Glossary).
7. An LDA with a Glide Slope could be considered a “PRECISION” approach due to the fact that it provides an “electronic glide slope” and may also incorporate a Decision Altitude (Height). However the definition of Localizer Type Directional Aid given in the P/C Glossary conflicts with these two statements, calling it “a navaid used for NONPRECISION instrument approaches.”
Of course the P/C Glossary does not define a “Localizer Type Directional Aid w/GS.”
From a Part 91 standpoint at least, I guess you get to choose whatever definition you like!
8. As an additional side note see AIM 1-1-24 — “Precision Approach Systems other than ILS, GLS, and MLS” — “Approval and use of precision approach systems other than ILS, GLS and MLS require the issuance of special instrument approach procedures…”
9. From an air carrier OpSpecs standpoint, an LDA w/GS is classified as a “PRECISION-LIKE” approach that provides vertical guidance but is not as accurate as a true precision approach. FAA policy is that even though a glide slope is available, the accuracy is not the same as an ILS, MLS, GLS, or TLS. OpSpec C052 lists “precision-like” approaches as Instrument Approach Procedures other than ILS, MLS, and GLS (i.e., NONPRECISION approaches), at least for air carriers.
10. From a practical standpoint an LDA with a glide slope normally brings you right down to the end of the runway, that’s pretty darn precise. Who cares if you have to make a slight jog just before touch down… you’ve probably done worse jogs at the end of many of your ILS approaches!
11. For Part 91, the only time the question of precision vs. nonprecision would become an issue is when choosing an alternate.
PAIFA-a-joke
New member
- Joined
- Jun 4, 2002
- Posts
- 2
Localizer Type Directional Aid- this is straight from the AIM's Pilot's/Controller Glossary.
A NAVAID used for nonprecision instrument approaches with utility and accuracy comparable to a localizer but which is not a part of the complete ILS and is not alligned with the runway.............. To me the AIM is saying that an LDA is not a precision approach, so I would say "no" and let the interviewer proove it to me, you always have the bible(FAR/AIM) to back ya up.
later...............
A NAVAID used for nonprecision instrument approaches with utility and accuracy comparable to a localizer but which is not a part of the complete ILS and is not alligned with the runway.............. To me the AIM is saying that an LDA is not a precision approach, so I would say "no" and let the interviewer proove it to me, you always have the bible(FAR/AIM) to back ya up.
later...............
flywithruss
Rocky Top!
- Joined
- Nov 26, 2001
- Posts
- 237
NON-precision
As we say down here in the South, "A cat can have kittens in the oven, but that don't make 'em biscuits."
In other words, just because this approach looks like an ILS, that doesn't make it precision! Forgive the non-PC analogy ... but have you ever walked behind a woman who looked really great from behind, but just when you were going to talk to her, she turned around and wound up looking like a troll? Same thing.
LDA approaches NEVER provide alignment with the runway centerline, by definition, whether that non-alignment is an angle of 10 degrees (a la LDA 6 ROA), an angle of 45 degrees (LDA/DME 19 DCA), or a lateral offset (12L and 30L approaches at STL). In most cases, LDA's are installed because a normal ILS or LOC installation does not work. At ROA, it is for terrain ... at DCA, for airspace, and at STL, to allow simultaneous approaches to close-parallel runways.
The fact that you are not aligned with and established on the runway centerline upon reaching DA (H) is the controlling issue here.
An LDA approach, with or without straight-in minimums published, with or without a glide slope, is a NON-PRECISION APPROACH, every day of the week, and twice on Sunday.
Tailwinds, y'all ...
R
As we say down here in the South, "A cat can have kittens in the oven, but that don't make 'em biscuits."
In other words, just because this approach looks like an ILS, that doesn't make it precision! Forgive the non-PC analogy ... but have you ever walked behind a woman who looked really great from behind, but just when you were going to talk to her, she turned around and wound up looking like a troll? Same thing.
LDA approaches NEVER provide alignment with the runway centerline, by definition, whether that non-alignment is an angle of 10 degrees (a la LDA 6 ROA), an angle of 45 degrees (LDA/DME 19 DCA), or a lateral offset (12L and 30L approaches at STL). In most cases, LDA's are installed because a normal ILS or LOC installation does not work. At ROA, it is for terrain ... at DCA, for airspace, and at STL, to allow simultaneous approaches to close-parallel runways.
The fact that you are not aligned with and established on the runway centerline upon reaching DA (H) is the controlling issue here.
An LDA approach, with or without straight-in minimums published, with or without a glide slope, is a NON-PRECISION APPROACH, every day of the week, and twice on Sunday.
Tailwinds, y'all ...
R
Share this page
Latest resources
-
-
-
-
-
AC 90-89C - Amateur-Built Aircraft and Ultralight Flight Testing HandbookAmateur-Built Aircraft and Ultralight Flight Testing Handbook
- Neal
- Updated:
