The International Effect of Jeppesen Charting Changes vs. Aerodrome Operating Minima, AOM
Aerodrome Operating Minima are established in order to ensure a desired level of safety for airplane operations at an airport by limiting operations below specified weather conditions. For the most part AOM’s involve the determination of a set of minimum altitude/heights and visibility values.
The State in which the airport is located in is responsible for services such as runways, instrument procedures, visual aids, air traffic control, obstacle identification, MET reporting and publishing AIP, AIC, NOTAMs information and charts. This is usually the source of the minimum altitude or height for a specific approach on the approach plate pilot use in the cockpit.
The State of the Operator/State of Registry is responsible for airborne elements such as: flight crew training, composition and procedures, airworthiness criteria and maintenance operating procedures. Aircraft equipment and operating techniques/procedures are usually the source of the minimum altitude or height for a specific approach on the approach plate pilot use in the cockpit.
Worldwide, states may use any criteria they choose to establish an AOM. Common regulatory procedures for AOM determination are described in FAA’s TERPS, Canada’s TP-308 and the older “EU-Ops”. Since 2012 EU Implementation Regulations, "IR's" are in effect for both commercial, "CAT" operators and private operators of Non Commercial Aircraft, "NCC" (read: Part 91Ops in a transport category jet). In some states the determination criteria is not specified or is unknown. In 2013 ICAO published the latest issue of Document #9365, All-Weather Operations Manual. EASA has adopted this as their standard for determining AOMs’. EASA is working to combine ICAO and national regulations and procedures into one overriding document.
EASA’s adaptation of the ICAO AOM determination created a problem for Jeppesen. Jeppesen had a policy to apply State-defined AOM and if a state-provided AOM was incomplete or not provided… Jeppesen would then apply “Standard” AOM visibility from a widely used TERPS based definition.
This “Standard” method of Jeppesen determining the AOM has changed and is detailed in Jeppesen’s bulletin 15-A (Link here). When a state publishes an AOM it will always be depicted on the Jeppesen chart. Some state AOMs might be supplemented by higher ICAO AOM values and noted (with numbered block notes) in the minima section on the chart. In cases where a state does not provide any AOMs, Jeppesen will use ICAO Document #9365, All-Weather Operations Manual, AWOM.
For now, the label “Standard” on current approach plates indicates the AOM are according to “EU-OPS”. When Jeppesen starts applying ICAO Document #9365…. “Standard” will mean the AOM is predicated on ICAO Document #9365. No implementation date has yet been announced for this change.
This is not the Only Change to Jeppesen Plates
Jeppesen’s is also changing the depiction of the flight track depiction in the Profile View section of Non-Precision Approach, NPA procedure charts. The Profile View graphically represents the approach as the State authority designed it. If a procedure were designed with a continuous descent from the FAF, Jeppesen will publish VDA, VNAV and CDFA information and the flight track would be depicted as such. This vertical track will be based upon:
- State-defined VDA or VNAV angle
- State-defined Distance and Altitude Descent Table
- Jeppesen-defined VNAV angle based on ARINC 424
- If the Non-Precision Approach, NPA does not have a published or derived VDA or VNAV angle the flight track would be depicted using a “stepped” depiction.
This is where what type of flight techniques being used has great effect on the AOM. EASA's Implementation Regulation, CAT.OP.MPA.115 for "Commercial" operators directs that CDFA "SHALL" be used. Reviewing NCC.OP.111 for "Private" operators may opt to not use a CDFA. The new Jeppesen profile depiction is intended to give primary emphasis on the use of Constant Descent Final Approach (CDFA) flight techniques.
A Word on Derived Decision Altitudes
This usually is a discussion of how much altitude should be added to a DH. Some guidance can be found from the OEM's. France has specific guidance based upon the aircraft approach category is directed. Wherever a State has defined a DA(H) for use on a non-precision IAP, (Example: France) Jeppesen will assume the State provided DA(H) includes a height loss adjustment. Jeppesen will not add any “Height Loss Adjustment” to any charted procedure.
US operators may use a MDA w/o adding to the published minimums in specific cases and when utilizing the CDFA technique and VNAV guidance. Under certain conditions of electronic glidepath design (RNAV or ILS) or VASI available to a runway, a US operator does not have to add some factor to the MDA when using a CDFA technique. This is not what PANS-Ops designed procedures "Allows" and runs counter to IR-OPS for private operators not using CDFA. US operators must use the flight procedures of the country they are operating in.
This means that if EASA or ICAO operational criteria are used, they direct a "Derived Decision Altitude/Height" by adding some factor to the MDA so as not to descend below it when using a CDFA technique. Outside the USA, US operators must determine and apply an appropriate Height Loss Adjustment applicable to the aircraft, landing configuration and/or operating requirements.
One last Word on “Approach Ban Policy”
ICAO Annex 6, specifies when weather conditions are reported to be below landing minima, aircraft “Banned” from proceeding beyond a point on an instrument approach procedure 300m/1000ft above the aerodrome elevation or the beginning of the final approach segment. US Part 91 operators are not bound by this domestically in the USA.
“Approach Ban” is generally used worldwide outside the USA and applies to both Commercial and Private operators. The logic here is to prevent a landing/go-around decision at a low altitude and in a vulnerable condition. This procedures also minimizes unnecessary instrument approach operations where a successful landing would be highly unlikely.
- 1. Very little will change for domestic USA operations
- 2. No implementation date has yet been announced for these charting changes
- 3. Jeppesen applies the AOM of the State in which the airport is located, not the State of registry of any aircraft operator
- 4. State AOM will always be charted. State AOM may be supplemented with higher ICAO AWOM values. In some cases, available State AOM lower than ICAO (or vice versa) may be noted.
- 5. If you use CDFA in USA or EU countries, adding some amount to the published mins, and do not go below the published MDA/DA... you might make more missed approaches but will be legal.
- 6. If you do not use CDFA in EU countries and territories, their regs require you to not go below the DA and treat it as you would a MDA.
- 7. Jeppesen will not add any height loss adjustment to any DA(H) or MDA(H) unless specified by the State and will assume the State provided DA(H) includes a height loss adjustment.
- 8. If a ceiling is prescribed by the State as a parameter of their AOM (Straight-in or Circle-to-Land) it will be published.