MattL wrote:
The PEC comes from AIPAD section:
What is AIPAD?
Anything that drives the DH up a bit is a good thing for IR training and tests
You are right, add the plus 50 foot tolerance in test standards and the ILS go around could be initiated nearly 100 feet above system minima.
The fact that some AFM actually state a PEC would suggest that the principle is not an IR school artifice.
AIP AD section – sorry typing on phone!
RobertL18C wrote:
I believe the FAA AIM on precision minima calculation states it1.19.2 all DA must be adjusted to determine an AOM which accounts for aircraft pressure error. Operators may apply aircraft Pressure Error Correction (PEC) or, alternatively, add at least 50FT to the published DA. Compensation for aircraft pressure error is not required when determining AOM for non-precision approaches.
Where is this in the current FAA AIM, I can’t locate it and am unfamiliar. There is no section 1.19.2.
@NCYankee you are right that reference did not work for me either, but google brings up position error, as against pressure error (low temperature and high pressure outside the altimeter setting capability), on FAA publications but then it is buried in a 700 page .pdf
It may be in the Instrument Flying Handbook section on instruments.
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’.
I find it amazing that NAA can produce such useless charts. Why the FAA can and we can’t I have no idea. Lets face it lets apply 2 seconds off TEM to this and the answer is obvius the NAA are producing a chart that is less safe than it could be.
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.
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.
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.
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.