Jeppesen Approach Charts Non Precision DA

[westhawk]

The LNAV/VNAV approach is temperature compensated for -15°C, the LNAV approach isn't.

Thanks Denti, that makes sense.

[stevestpierre]

height loss after go-around initiated

Thank you 'FlightPathOBN' for the detail. I will add to my sim sessions when this topic comes up.

The link below to Transport Canada shows how it is handled in Canada.
A specific exemption is given ... 'R745,47 - Exemption from respecting MDA.'

R745.47 - Exemption from respecting MDA:

(a) this guidance applies to non-precision approach operations using FMS approach slope or other stabilized approach angle techniques;

(b) CAR 602.128 (2)(b) forbids descent below minimum descent altitude (MDA) during a non-precision approach unless the required visual reference has been established;

(c) an exemption to this regulation is available to turbo-jet aircraft with over 100,000 lbs. take-off gross weight if the air operator is using stabilized approach angle techniques, provided that certain conditions are met. This exemption permits pilots to treat MDA as a DH;

(d) all air operators who are not exempted from the requirements of CAR 602.128 (2)(b) must conduct non-precision approaches in such a way that the aircraft does not descend below the published MDA unless the required visual reference has been established (with due allowance for momentary variations during turbulent conditions). These air operators would be considered to be "respecting MDA" only if their operational procedures, training and checking programs required pilots to maintain an altitude at or above the published MDA prior to establishing visual reference;


There are several conditions for exemption. One of the conditions...

"(ii) the air operator must have procedures in place to ensure that pilots will add a specified amount to MDA that will compensate for the additional height loss during the go-around initiation during approaches where:

(A) there is a failure of an aircraft system that would affect the aircraft height loss during the initiation of a missed approach;
(B) the aircraft is above normal maximum landing weight;
(C) the aircraft landing weight is limited by aborted landing climb performance; or
(D) any other situation where a larger than normal height loss during the initiation of a missed approach could be expected;..."

Division III - Flight Operations - Transport Canada
(scroll link to the bottom for full text of 'R745.47')

In my experience, depending on the operator, a standard addition of 'a specified amount to MDA' used on the A330/A340 has been 50'

Cheers

[FlightPathOBN]

Denti has it....the VNAV is uncompensated baro, so the effective GPA may be down as far as 2.5 degrees, plus the ROC, this will push the min up...
Looks like there are quite a few obstacles in the final...

(BTW...this procedure is a horrible design...)

Steve..you are welcome...

50 foot height loss is a criteria supported standard....

[172_driver]

The temp consideration certainly makes sense, thanks! Flying the approach regularly I concur you don't want to be too low, it takes you pretty close to hills just left of the final.

Another interesting point for KCRQ, the straight-in LLZ MDA is 1000 ft. For several weeks there was an FDC NOTAM out lowering the circling MDA to 940 ft. Unfortunately the NOTAM is no longer around to prove my point, probably since they just updated the approach to include a DME. Is that something that could theoretically occur or was it a mis-print?

KCRQ ILS/DME: http://204.108.4.16/d-tpp/1109/05310ILD24.PDF

[FlightPathOBN]

my head hurts looking at that chart! At least you have something close to a 5nm FAF...and descent mins..

(the NOTAM may have noted the controlling obstacle was removed and replaced)

Not sure what you are flying, but I would use the GPS to an ILS intercept

these procedures really are an irritation, as they illustrate the 'criteria' issues, and many people wonder what is the benefit of GPS or RNP, when the mins are frequently higher...

the 250 HAT just kills me..

[172_driver]

The JLI transition is a pain in the butt, especially considering the accuracy of the VOR's in that area. They seem to be very affected by the mountainous terrain around and the needles are swinging like having a rock party! Flying a little twin so the approach is doable. ATC normally vectors you (albeit quite crappy at times, normally G/S from above..).
Regarding the NOTAM, I can see the controlling obstacle has been removed, just don't understand why it affected only the circling MDA and not the straight in. On the previous chart there was a MKR (DEASY) about where CIDRU is on the new chart, and after that you could drop to 1000 ft MDA, but for circling NOTAMed to 940 ft.

[thermostat]

VOR/DME 27

A constant descent seems possible from the VOR. Maintain 3000 ft inbound to the VOR then on crossing, set -2 degrees (actually 1.96422 degrees) on the FPA all the way to the VDP/ MDA. Works great. I thought these step-down approaches were history. What gives??

[aterpster]

172 Driver:

Affirm, here is one example. KCRQ GPS RWY 24. And it's a significant difference, 287 ft in MDA. What is the reason for that? aterpster? FlightOBN?

Non-RNP AR VNAV criteria has ILS like vertical clearance from the P-FAF inbound, but with larger margins to account for the lowest common denominator of IFR BARO VNAV equipment, and the DA forces the visibility to be higher than LNAV. LNAV is simply 250 feet of obstacle clearance from the FAF to the runway.

The "name of the game" for this IAP is LPV, which uses the exact lateral and vertical surfaces of ILS and is temperature independent. There is a revision pending, which is on hold at the present time.

[aterpster]

FlightPathOBN:

my head hurts looking at that chart! At least you have something close to a 5nm FAF...and descent mins..

The Jeppesen chart is much, much clearer. The real purpose of this approach is LPV.

[Capn Bloggs]

I've got my doubts about that KCRQ LOC/DME approach. The 4.2 DME step looks really limiting: 3.6° -ish to get down to the runway from there?

Where's the DME/ALT scale for the LOC/DME approach?

[aterpster]

Capn Bloggs:

I've got my doubts about that KCRQ LOC/DME approach. The 4.2 DME step looks really limiting: 3.6° -ish to get down to the runway from there?

What are your doubts? The FAA doesn't assure the same path on the LOC procedure as they do on the ILS procedure.

Where's the DME/ALT scale for the LOC/DME approach?

FAA has never done that.

[Capn Bloggs]

The FAA doesn't assure the same path on the LOC procedure as they do on the ILS procedure.

No wonder the world is still trying to get over Dive and Drive. Approach charts like that, in 2011, with no help at all in flying past that limiting step with some semblance of a stable sink rate/approach are not doing anybody any favours.

Out of interest, Aterpster, how would you suggest someone fly that LOC approach without VNAV?

[aterpster]

Capn Blogg:

No wonder the world is still trying to get over Dive and Drive. Approach charts like that, in 2011, with no help at all in flying past that limiting step with some semblance of a stable sink rate/approach are not doing anybody any favours.

The FAA is not in the "favors" business. It is an ILS approach, so the odds of anyone having to fly the LOC/DME IAP are quite small.

Out of interest, Aterpster, how would you suggest someone fly that LOC approach without VNAV?

I wouldn't. My suggestion would be to join the 21st Century with a WAAS navigator so they could select the LPV IAP to the same runway in the event of an outage of the ILS GS.

[Denti]

Well, sadly the oh so american company Boeing does not believe in LPV and does not offer it on its models...

But GLS is standard equipment

[aterpster]

Denti:

Well, sadly the oh so american company Boeing does not believe in LPV and does not offer it on its models...

But GLS is standard equipment

Bad decision on their part. Then again, it's not the first time they've been wrong.

More and more business aircraft are equiping with SBAS. The mix of users at KCRQ is such that probably 80% of them can fly either LPV or LNAV/VNAV.

But, the LNAV/VNAV minimums at KCRQ are way higher than the LPV and higher than LNAV only. Boeing is painfully aware of how lousy LNAV/VNAV is except for RNP AR.

[172_driver]

I've got my doubts about that KCRQ LOC/DME approach. The 4.2 DME step looks really limiting: 3.6° -ish to get down to the runway from there?

Maybe... but on the old chart there was a drop from 2300 ft around CIDRU right down to a 1000 ft MDA and only timing to define MAPt... so at least something has improved. Usually good weather at KCRQ, but in evening/night/morning marine layer can drift in and occasionally give weather close to CATI minima, and often lower than LLZ minima. LPV isn't a bad back up.

[FlightPathOBN]

It is not Boeing nor Airbus fault that GLS in standard, the FAA promised NextGen and outlined the future, which has most, if not all, VOR out of operation by 2015....WAAS is a waste of money to equip for given GBAS,(and lack of procedure guidance) and ILS does not give the capacity needed by 2015...
RNP is virtually unsupported by the FAA as far as viable procedures...while airlines such as Alaska Airlines and FedEx, use RNP exclusively for access and performance gains...

[chimichanga]

Can somebody help clear this up for me?

I am looking at an approach chart in Europe and it is confusing. Say I am doing the LOC only (GS out) approach. I am used to seeing an associated MDA and then flying down to that MDA and holding it 'till the Missed approach point. According to the new Jepps in Europe it apparently doesn't work like this any longer? All I see is a DA listed. So here is my question: Do I simply descend as if I had a glideslope and now go missed at the LOC (GS out) DA?? I ask because there is still a M or missed approach point listed on the damn chart...why would they publish a Missed approach point if I am now to simply obey a higher DA? Or do I get to this new/higher DA for the LOC approach and then hold the altitude and continue to the missed approach point.....this is really confusing!

Thanks

[bluk]

Hi,
You should stop approach at DH or MAP whatever you meet first.
If you descent correctly, you will achieve DH first, but if you descent too slow, there is a possibility that you achieve MAP first,
It's better to understand at NDB approaches w/o DME, where you descent and simply waiting what is first.

edit/ look at post #21 in this topic, there you'll find full answer

[chimichanga]

Bluk: Thanks for the info.