Maintain Four Thousand

The clearance on record is 6,000. The readback does not change it, and "Roger" does not approve the error.

• "Roger" means "I received your transmission." It is not a correction and not an amended clearance. The controller very likely heard what he expected to hear, and no one has caught the discrepancy.
• A pilot may not deviate from an ATC clearance. Descending to 4,000 on the strength of your own misread clearance is a deviation - and here it is also a terrain/obstruction problem, since the minimum vectoring altitude in that sector is 5,000.

What you do, immediately:

1. Key the mic yourself if the client will not: "Approach, confirm N123AB is to maintain six thousand until established."
2. If the frequency is congested or you cannot raise them, you fly 6,000. You never resolve an ambiguity by choosing the lower altitude.
3. Then debrief the instructor problem: the readback was incomplete and wrong, and the client accepted a response that was not an approval. From now on he reads back altitude, heading, and clearance verbatim and challenges anything he is not certain of - even when the controller sounds agreeable.

This is a classic link-in-the-chain failure: a bad readback, an unchecked reply, and a crew willing to act on the wrong one.

No - and this is the trap the client is walking into.

• "Maintain 6,000 until established" is an altitude restriction tied to becoming established on a segment of the approach, normally the localizer. It does not authorize a descent to the glideslope the moment you like the picture.
• Being established means a reliable indication on the localizer course within the usable signal distance, with the airplane configured and slowed for the approach - not "the needle is moving."
• Even once established, the geometry is the problem: he is at 6,000 and the glideslope intercept altitude is 4,600. He will cross the final approach fix above the glideslope. "Cleared for the approach" does not mean "descend through the localizer to catch a glideslope you have already passed" - that is an unstabilized, non-standard descent, and at 6,000 he has 1,400 feet to lose before reaching a normal intercept.

The correct move is to talk to ATC early, before the fix:

• Request lower now, while there is still 12 miles to work with: "N123AB requests 4,600."
• If they cannot give it, request vectors off the localizer for a re-intercept rather than diving at the glideslope.
• If neither is available, ask for the localizer approach and brief the localizer-only minimums properly - do not fly the ILS glideslope from above and call it an ILS.

Decision-making happens at the brief, not at the final approach fix.

It depends on what he was actually doing, and this is worth getting right because it is one of the most common currency errors.

• Instrument time may be logged only for flight time when the pilot is operating solely by reference to instruments in actual or simulated instrument conditions. Actual instrument time in cloud counts. Time under a view-limiting device with you aboard as the authorized instructor counts as simulated.
• If he was in actual instrument meteorological conditions for the approach, or wearing a view-limiting device, the approach is creditable. If he was visual with the runway environment for the portion that matters and was not under the hood, the entry is questionable at best - a good approach flown visually is training, not currency.

Practical guidance for his logbook:

• Log actual instrument time for the portion in cloud, hood time for the portion under the device, and do not inflate either.
• Note the approach by type and runway. Vague entries like "2 approaches" are what get flagged at a flight review.
• Remind him that currency also requires holding and intercepting/tracking within the same six months - approaches alone are not the whole requirement.

Your job here is not to police his pencil but to make sure that he knows the difference between an approach he flew and an approach he can count, because in six months he will be the only one checking.