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How does one determine DA(H) and MDA(H) using the ICAO charts found in the AIP in Europe?

AeroPlus wrote:

You need to determine the length of the approach lights from the ICAO aerodrome chart to determine if the lights are basic or high-intensity approach lights, thus giving you the BALS etc setting. (…)

I could see if I can find some time after the summer to bring back the FAQ in the app.

Thanks for the approach light explanation, and in advance for the possible return of the FAQ.

AeroPlus wrote:

The app was meant as a contribution at that time to the GA flying community to get rid of the expensive Jeppesen charts.

Yes, that’s how I hoped to use it.

ELLX

RobertL18C wrote:

So if your altimeter over reads by 70 feet on the ramp check (75 feet in FAA renders it unacceptable, UK SOP is lower) you do not feel the need to adjust minima? OCA(H) is unlikely to be 130 feet which is the implication of ignoring a PEC adjustment to minima.

No, the aircraft is unairworthy for IFR use, so before conducting IFR, get it fixed.

RobertL18C wrote:

I am just making the safety case for this, given the relatively unsophisticated nature of a light GA pitot static altimeter system (some altimeters still operating 50 years on). Cracker Jack toy in certain types.

No matter how old the altimeter is, it needs to pass the 91.411 check every two years. Most of the older altimeters can’t pass because of hysteresis and friction or case leaks.

To a US Pilot, what the HEC is PEC :)

KUZA, United States

Bathman wrote:

The bit I’ve never been able to understand is that PEC has already been taken into account with the OCH(A) on a none precision approach. But then hasn’t on a precision approach.

Error just waiting to happen there.

The MOC for a non-precision approach is at least 246 ft, compared to 130 ft for a precision approach, so the margin is greater.

ESKC (Uppsala/Sundbro), Sweden

The bit I’ve never been able to understand is that PEC has already been taken into account with the OCH(A) on a none precision approach. But then hasn’t on a precision approach.

Error just waiting to happen there.

RobertL18C wrote:

So if your altimeter over reads by 70 feet on the ramp check (75 feet in FAA renders it unacceptable, UK SOP is lower) you do not feel the need to adjust minima?

No.

OCA(H) is unlikely to be 130 feet which is the implication of ignoring a PEC adjustment to minima.

My understanding is that the “PEC adjustment” is something different than the altimeter check margin?

Anyway, I assume you mean height of the controlling obstacle, not OCA(H)? If the OCH is 200 ft, then the controlling obstacle is at most 70 ft above threshold. (As Bookworm has already pointed out, the minimum obstacle clearance for an ILS/LPV with normal glideslope is 130 ft for an approach category A aircraft.)

(PS. I am aware that when using the collision risk model for determining the OCA(H), there is no controlling obstacle as such, but the 130 ft MOC still applies.)

Last Edited by Airborne_Again at 09 Jul 19:03
ESKC (Uppsala/Sundbro), Sweden

This altimeter check tolerance is already taken into account when the OCA(H) for an approach is determined.

So if your altimeter over reads by 70 feet on the ramp check (75 feet in FAA renders it unacceptable, UK SOP is lower) you do not feel the need to adjust minima? OCA(H) is unlikely to be 130 feet which is the implication of ignoring a PEC adjustment to minima.

While EASA ATPL papers go into altimetry at length (including the papers required for a PPL/IR), as does the FAA AIP and Instrument Flying Handbook: Should we not apply this learning in the absence of a POH confirmation of PEC adjustment?

I am just making the safety case for this, given the relatively unsophisticated nature of a light GA pitot static altimeter system (some altimeters still operating 50 years on). Cracker Jack toy in certain types.

Minimums are not adjusted because at the high pressure above 31.00 inches,

Correct, but you go around at published DA which is in effect above QNH minima as your altimeter setting is below prevailing pressure. Radar altimeter and CAT 2 allows descent to design minima. Minima for designating alternates is however increased.

Oxford (EGTK), United Kingdom

RobertL18C wrote:

Given that the altimeter check tolerance in the Instrument Flying Handbook is 75 feet, and the duty of care provisions for pilot in command generally, a 50 foot adjustment in the absence of a stated AFM PEC, does not sound like a ‘UK thing’.

This altimeter check tolerance is already taken into account when the OCA(H) for an approach is determined.

ESKC (Uppsala/Sundbro), Sweden

The European and other CAAs threatened the US with some action unless they stop publishing what they regard as copyright material. So the US limited access to their govt and mil users…

The European IFR community is tiny – probably of the order of 1% of the US IFR community – so the pressure to do anything is not really there, and Jeppesen can milk it.

I think a few countries in Europe (Germany?) publish cockpit-usable terminal charts.

Administrator
Shoreham EGKA, United Kingdom

Bathman wrote:

Why the FAA can and we can’t I have no idea.

The FAA charting also produces charts for the globe, but they are only available to Military or Government users. They chart MDA and DA.

KUZA, United States

The 75 feet tolerance is when comparing altimeter at a known altitude on the ground as a check for suitable to use for IFR flight, nothing to do with approaches per say. There are sections of the AIM on altimeter settings, 7-2. The term PEC is not defined or used in any way I am aware of in the US. High pressure correction is for altimeter settings at or above 31.00 inches which is the maximum barometric pressure value on my altimeter (28.10 to 31.00). Minimums are not adjusted because at the high pressure above 31.00 inches, one is higher than the charted MDA/DA and obstacles are not an issue, although distance to the runway may require higher visibility to complete the approach. The US does use cold temperature corrections at certain airports.

KUZA, United States
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