Drift Down Routes

[Nevets]

Any controller ever have a pilot unable to accept a reroute due to being on a drift down or terrain clearance route? And what did and or the pilot do about it?

 

[ERJFO]

Not a controller, but last week I had to turn down 2 offers for direct because out enroute net ceiling was lower than the grid MORA. I use the ISA # and A/I factor that's on the release and go from there.

As far as terrain clearance and drift down go, as soon as you're "light" enough to drift down above the grid MORA for the conditions you can go off route.

The place I work also has generic TC/DD charts for certian areas of the country that can pretty much let you take any reroute as long as your an an airway.

I know this wasn't what you were looking for but I'm currious if you've seen stuff you couldn't take after looking at the MORA's and generic pink pages...

 

[Nevets]

Not a controller, but last week I had to turn down 2 offers for direct because out enroute net ceiling was lower than the grid MORA. I use the ISA # and A/I factor that's on the release and go from there.

As far as terrain clearance and drift down go, as soon as you're "light" enough to drift down above the grid MORA for the conditions you can go off route.

The place I work also has generic TC/DD charts for certian areas of the country that can pretty much let you take any reroute as long as your an an airway.

I know this wasn't what you were looking for but I'm currious if you've seen stuff you couldn't take after looking at the MORA's and generic pink pages...

I did calculate the enroute net ceiling. It was lower than the grid MORA. There are no specific or generic sector charts for the area I was in. I was simply unable to accept a reroute and the controller was extremely unhappy about it.

Im under the impression that controllers don't understand or don't care about the limitations of our aircraft and are unable to comply with their instructions because of it. Im hoping this was an isolated incident (although its happened twice to me in a certain center's airspace) and that other controllers in other facilities do in fact know about these rare situations and how they deal with it. Because I don't appreciate being bullied or threatened and having to call every time it happens to explain the situation and following it up with ASAP/ASRS.

 

[ERJFO]

I did calculate the enroute net ceiling. It was lower than the grid MORA. There are no specific or generic sector charts for the area I was in. I was simply unable to accept a reroute and the controller was extremely unhappy about it.

Im under the impression that controllers don't understand or don't care about the limitations of our aircraft and are unable to comply with their instructions because of it. Im hoping this was an isolated incident (although its happened twice to me in a certain center's airspace) and that other controllers in other facilities do in fact know about these rare situations and how they deal with it. Because I don't appreciate being bullied or threatened and having to call every time it happens to explain the situation and following it up with ASAP/ASRS.

Where were you at? What did they want you to do?

 

[Nevets]

Where were you at? What did they want you to do?

I was in California. I wanted to stay on my route until I was past the 16800 Grid MORA.

 

[CRJCptn]

just out of curiosity, the E145 (based on your profile) will not hold 17000 on one engine? (16800 MEA)

 

[Booker]

just out of curiosity, the E145 (based on your profile) will not hold 17000 on one engine? (16800 MEA)

Not at ISA and MATOW. You'd need to be down to about 43,000 pounds (EP/LR) to make 16,800.

 

[CRJCptn]

thanks for the response.

 

[ERJFO]

just out of curiosity, the E145 (based on your profile) will not hold 17000 on one engine? (16800 MEA)

It depends largly on if we use anti-ice on or off charts. In most of the airplanes if we use icing off we can go anywhere in North America, right now I'd imagine we're all using the A/I on charts.

 

[Hold West]

Im under the impression that controllers don't understand

You're exactly correct. Say MORA, enroute net ceiling, or drift-down to 99% of US controllers and they won't have even a glimmer of an idea what you're talking about.

In 23 years, I've never received any training from FAA on any of these topics.

 

[ERJFO]

You're exactly correct. Say MORA, enroute net ceiling, or drift-down to 99% of US controllers and they won't have even a glimmer of an idea what you're talking about.

In 23 years, I've never received any training from FAA on any of these topics.

That's why I just say "we can't take that right now for terrain".

 

[Nevets]

That's why I just say "we can't take that right now for terrain".

Yeah, that's what I said, among other things. I also suggested that I could climb or descend but the controller was having none of it. He even threatened me with a pilot deviation if I didn't accept his clearance! Another controller asked me if I was declaring an emergency and asked me to squawk 7700! Oh well, I guess I will have to try to educate them one at a time.

 

[Coool Hand Luke]

Yeah, that's what I said, among other things. I also suggested that I could climb or descend but the controller was having none of it. He even threatened me with a pilot deviation if I didn't accept his clearance! Another controller asked me if I was declaring an emergency and asked me to squawk 7700! Oh well, I guess I will have to try to educate them one at a time.

Nevets, nice job on standing your ground despite the strong arm tactics.

 

[Cardinal]

unable to comply with their instructions because of it.

I disagree.

Half our routes were driftdown critical in the B1900 over the Rockies, so this was an unending source for checkride angst, FAA consultation, and continual study. But our philosophy as passed down by our FSDO and POI was quite clear: Traffic and Weather were valid reasons for deviating off a driftdown route. If a controller wanted you to do something else you just did it. If the instruction was just a generous direct-down-the-line, we'd come back with a "we need to stay on the route today" and all parties were satisfied.

He even threatened me with a pilot deviation if I didn't accept his clearance! Another controller asked me if I was declaring an emergency and asked me to squawk 7700!

Yikes. You probably should have. Which outcome would you prefer, the certainty of center-punching a thunderstorm / another aircraft or stay away from the high mountains where there is an extremely remote (1/eleventy billionth) chance of an engine failure and marginal terrain clearance?

What if you had two aircraft nose to nose, same altitude, both on driftdown routes. Better to just have a midair, quoting 121.191 on the way down? The example is extreme, but makes the point. When a conflict, however minor arrises, driftdown should be the first constraint thrown out the window.

 

[Nevets]

I disagree.

Half our routes were driftdown critical in the B1900 over the Rockies, so this was an unending source for checkride angst, FAA consultation, and continual study. But our philosophy as passed down by our FSDO and POI was quite clear: Traffic and Weather were valid reasons for deviating off a driftdown route. If a controller wanted you to do something else you just did it. If the instruction was just a generous direct-down-the-line, we'd come back with a "we need to stay on the route today" and all parties were satisfied.

Unfortunately for me, our FOM does not provide as much discretion. We are able to deviate from the route as long as its within 5 miles either side of the route.

Yikes. You probably should have. Which outcome would you prefer, the certainty of center-punching a thunderstorm / another aircraft or stay away from the high mountains where there is an extremely remote (1/eleventy billionth) chance of an engine failure and marginal terrain clearance?

What if you had two aircraft nose to nose, same altitude, both on driftdown routes. Better to just have a midair, quoting 121.191 on the way down? The example is extreme, but makes the point. When a conflict, however minor arrises, driftdown should be the first constraint thrown out the window.

It was not a situation in which our FOM requires us to declare an emergency and I didn't feel like it was either. So I declined. They asked me to squawk 7700 and that is fine with me if they wanted to declare the emergency. As long as I was able to stay on the route. In this particular instance, it was not weather related (I would do a 180 before punching through a thunderstorm). It was due to flow. I offered to slow down for them, but that wasn't good enough either. As for the traffic scenario, I offered to climb or descend. I think they just didn't like that I was not going to accept their clearance. The guy even told me that I'm required to accept his clearance because that is regulation and it supersedes my terrain clearance regulation. Needless to say, I very respectfully on the frequency disagreed with him.

Without it being an emergency, I'm not going to knowingly throw out any regulation out the window.