9 MNPSA

MNPSA 9

•Assess the situation.

•Prepare a proposal to put to the OACC.

•Advise and consult with the OACC.

•Obtain appropriate re-clearance prior to deviation from the previous clearance.

Whilst continuing the flight, the pilot should closely monitor the remaining system and crosscheck heading information with the mag compass and visual indications such as other aircraft tracks and contrail direction. The pilot should also attempt to establish communications with another aircraft that the pilot can see and cross-check heading information with the other aircraft. If the remaining system fails after entering the MNPSA, the pilot should:

•Notify the OACC immediately.

•Make best use of the information obtained from other aircraft.

•Keep a good look out for other aircraft.

•Make maximum use of exterior lights.

•Consider climbing or descending 500 ft.

•Revert to manual navigation if the navigation computer has failed.

Errors Associated with Oceanic Clearances

Navigation errors associated with oceanic clearances fall into several categories of which the most significant are ATC system loop errors and waypoint insertion errors.

ATC System Loop Errors

An ATC system loop error is any error caused by a misunderstanding between the pilot and the controller regarding the assigned flight level, Mach number or route to be followed. Such errors can arise from:- incorrect interpretation of the NAT track message by dispatchers; errors in co-ordination between OACs; or misinterpretation by pilots of oceanic clearances. Errors of this nature, which are detected by ATC from pilot position reports will normally be corrected. However, timely ATC intervention cannot always be guaranteed, especially as it may depend on the use of third-party HF (or even voice communications).

Waypoint Insertion Errors

Experience has shown that many of the track-keeping errors in the NAT MNPS Airspace occur as a result of crews programming the navigation system(s) with incorrect waypoint data. These are referred to as waypoint insertion errors. They frequently originate from:

a.Failure to observe the principles of checking waypoints to be inserted in the navigation systems, against the ATC cleared route.

b.Failure to load waypoint information carefully.

c.Failure to cross-check on-board navigation systems.

Pre-flight and In-flight Procedures

The pre-flight procedures for any NAT MNPS flight must include a UTC time check and resynchronization of the master clock. Operators must ensure that flight crew are familiar with the concept of cross-checking route inputs into the FMS. Ideally the route would be loaded independently, (each pilot loading his own FMS if this is the type of system installed) then cross-checked by the other pilot. This should be done by noting the position in the system, then comparing it to the Master Document, rather than the other way around. Alignment of

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the IRS, or Satellite Availability Prediction Programme, for flights using GNSS, must be ensured, and an altimeter cross-check conducted. Prior to entering the NAT OCA a check of the SELCAL, master clock and altimeter cross-check must be conducted. The altimeters must be within 200 ft of each other, and the standby altimeter difference should be noted, so that the error can be applied should there be a failure of the primary systems. The altimeters are to be compared at each subsequent waypoint, and disagreements in excess of 200 ft must be reported.

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	9			Questions
				Questions
				1.	What is the procedure if unable to continue in accordance with your clearance on
					the NAT OTS?
					a.	Attempt to obtain a re-clearance, but if unable turn to take up a track offset
						by 1 or 2 nautical miles to the right and climb/descend 500 ft
					b.	Immediately climb to above FL410 or descend to below FL290
					c.	Turn to take up a track offset by 500 NM and climb or descend 15 ft
					d.	Turn to take up a track offset by 15 NM and climb/descend 500 ft
				2.	What is the procedure for loss of HF comms on the North Atlantic?
					a.	Return to point of departure
					b.	Continue in accordance with flight plan or, if cleared to do something else
9						immediately return to flight plan route
					c.	Turn to take up a track offset by 15 NM from track, and climb/descend 500 ft
Questions
					d.	Continue in accordance with your last acknowledged clearance
				3.	If travelling west at 72°N how often would you make a position report?
					a.	Every hour
					b.	Every 10° of longitude
					c.	Every 20° of latitude
					d.	Every 20° of longitude
				4.	What does MASPS stand for?
					a.	Minimum Aeroplane Separation Procedures
					b.	Maximum Altitude Separation Parameters
					c.	Minimum Aircraft System Performance Specification
					d.	Maximum Aircraft Seating for Passengers Specification
				5.	What specifically must be checked prior to oceanic flight?
					a.	Altimeters, waypoint insertion, master clock
					b.	Altimeters, FMS, master clock, machmeter
					c.	FMS, FGS, NOTAMS, in-flight catering
					d.	ELTs, TLAs, FMS, FGS
				6.	Over the North Atlantic, outside the times of the OTS which of the following
					aircraft would be on the correct FL?
					a.	Flying 045° at FL340
					b.	Flying 090° at FL340
					c.	Flying 270° at FL340
					d.	Flying 315° at FL430
				7.	What information must a pilot give when calling for oceanic clearance?
					a.	Time of entry, FL and type of aircraft
					b.	Maximum Mach number and FL
					c.	Maximum attainable FL and POB
					d.	FL requested and maximum attainable FL

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