Who screwed up here?

[aterpster]

It was a terrible clearance given by what sounds like a new controller

Quite similar to this one that did not end well because of the lack of EGPWS.

 

[George Chityat]

They both screwed up, but what I don't get is the controller. Why say 7800. Might as well say 0. It's the same thing here. Pilot shouldn't be below 10,000 at that point. Why couldn't the controller just say maintain 10,000 until established inbound, cleared VOR DME-C approach.
The 7800 is absolutely pointless. Even if the controller said at or above 9900. What't the point of it?
He wasn't giving radar vectors, so the MVA doesn't apply here either. Even if he was giving vectors, the MVA is 8700.
Maybe the controller is dyslectic and read 8700 as 7800?

 

[George Chityat]

They both screwed up, but what I don't get is the controller. Why say 7800. Might as well say 0. It's the same thing here. Pilot shouldn't be below 10,000 at that point. Why couldn't the controller just say maintain 10,000 until established inbound, cleared VOR DME-C approach.
The 7800 is absolutely pointless. Even if the controller said at or above 9900. What't the point of it?
He wasn't giving radar vectors, so the MVA doesn't apply here either. Even if he was giving vectors, the MVA is 8700.
Maybe the controller is dyslectic and read 8700 as 7800?

Actually, I just looked at the MVA chart again, and it is 7800 and then goes up to 8700. So even though he wasn't being vectored, why would you give a minimum altitude when that min altitude will need to increase by 900 feet as the pilot flies the approach? The controller's screw up led to the pilot's screw up.

 

[Velocity173]

They both screwed up, but what I don't get is the controller. Why say 7800. Might as well say 0. It's the same thing here. Pilot shouldn't be below 10,000 at that point. Why couldn't the controller just say maintain 10,000 until established inbound, cleared VOR DME-C approach.
The 7800 is absolutely pointless. Even if the controller said at or above 9900. What't the point of it?
He wasn't giving radar vectors, so the MVA doesn't apply here either. Even if he was giving vectors, the MVA is 8700.
Maybe the controller is dyslectic and read 8700 as 7800?

MVA doesn’t only apply when being vectored. Controllers use the MVA for aircraft on unpublished direct routes in approach clearances, such as this case.

 

[rocketflyer84]

Strictly speaking the pilots could have descended below 10k then climbed back up before joining. Obviously that’s very odd and would have been a roller coaster ride but had they done that it would have been within the clearance and at safe altitudes for the area they were in.

Clearly the pilots didn’t properly brief the approach or if they did they weren’t paying attention to what they were doing. Controller shouldn’t have given that clearance as he did, and also should have caught that they were way too low for the approach segment, but at the end of the day the ultimate responsibility for where the plane is at relative to the charted approach sits in the cockpit.

 

[SbestCFII]

Could have ended up very badly.

If you're at an altitude below the MSA and NOT on vectors or a segment of the published procedure, that should be a clue. Seems a TWA flight (514) hit a mountain some years back headed to Dulles because of safe altitude confusion.

 

[SbestCFII]

ATC and the flight crew. If not for GPWS, somebody would be eating dirt instead of crow. ATC, cleared the plane below the MSA to the IAF. Flight crew, failed to stay at or above the published altitudes while on the approach.

 

[SbestCFII]

Strictly speaking the pilots could have descended below 10k then climbed back up before joining. Obviously that’s very odd and would have been a roller coaster ride but had they done that it would have been within the clearance and at safe altitudes for the area they were in.

Clearly the pilots didn’t properly brief the approach or if they did they weren’t paying attention to what they were doing. Controller shouldn’t have given that clearance as he did, and also should have caught that they were way too low for the approach segment, but at the end of the day the ultimate responsibility for where the plane is at relative to the charted approach sits in the cockpit.

From the direction they were approaching the IAF, the MSA was 10,700' The controller was wrong, and they just failed to catch it.

 

[Palmpilot]

From the direction they were approaching the IAF, the MSA was 10,700' The controller was wrong, and they just failed to catch it.

The altitude at which ATC is allowed to vector aircraft is not determined by the MSA, it's determined by the minimum vectoring altitude (MVA).

Still, the controller should not have given them an "at or above" altitude that was below the minimum for the initial segment of the approach, IMO.

 

[PaulS]

The altitude at which ATC is allowed to vector aircraft is not determined by the MSA, it's determined by the minimum vectoring altitude (MVA).

Still, the controller should not have given them an "at or above" altitude that was below the minimum for the initial segment of the approach, IMO.

This, and the MVA is not published on the charts, or so I understand. I thought I understood this stuff, but maybe some CFII's could help me. My understanding is that controllers can assign altitudes below the MEA or MOCA based on their MVAs, is this true? That's enroute stuff, I also thought the info on approach charts is it, you shouldn't go below those altitudes in IMC, is that true?

 

[aterpster]

If you're at an altitude below the MSA and NOT on vectors or a segment of the published procedure, that should be a clue. Seems a TWA flight (514) hit a mountain some years back headed to Dulles because of safe altitude confusion.

Confusion on the flight deck combined with bad training and a chart that didn't have the intermediate segment in the profile view.

 

[aterpster]

This, and the MVA is not published on the charts, or so I understand. I thought I understood this stuff, but maybe some CFII's could help me. My understanding is that controllers can assign altitudes below the MEA or MOCA based on their MVAs, is this true? That's enroute stuff, I also thought the info on approach charts is it, you shouldn't go below those altitudes in IMC, is that true?

You certainly should question it. But, there are ATC procedures in place today that permit vectoring you onto an RNAV or ILS approach below the intermediate segment altitude provided MVA is observed. MVA was not observed by the controller at Medford. It would have been had he assigned "at or above 8,700" although even that would make no sense on a VOR/DME approach over high terrain.

 

[luvflyin]

You certainly should question it. But, there are ATC procedures in place today that permit vectoring you onto an RNAV or ILS approach below the intermediate segment altitude provided MVA is observed. MVA was not observed by the controller at Medford. It would have been had he assigned "at or above 8,700" although even that would make no sense on a VOR/DME approach over high terrain.

Yeah. Even then the clearance would be incomplete. ‘Cross BRKET at or above 8700’ would have to have been included in the clearance. Giving an altitude to maintain until established on a segement of the Approach that requires climbing back up once established is a no no.

 

[aterpster]

Yeah. Even then the clearance would be incomplete. ‘Cross BRKET at or above 8700’ would have to have been included in the clearance. Giving an altitude to maintain until established on a segement of the Approach that requires climbing back up once established is a no no.

Correct.