Instrument approach altitude

[the400kid]

Question regarding regulations. I recently flew the GPS 36 approach into KNEW and started down a bit prematurely once I hit the IF (GODRD). I misread the plate and started my decent after flying over GODRD and was around 2500 by the time I arrived at TOYBO, where the decent actually does start.

I didn't realize this until after I was on the ground. I didn't get a warning from the controller nor did I get a Brasher, but I did file a report with NASA.

My question is, is this a deviation that is enforceable?

Don't worry, I beat myself up enough on this and I know just how serious it was.

 

[RotorDude]

Question regarding regulations. I recently flew the GPS 36 approach into KNEW and started down a bit prematurely once I hit the IF (GODRD). I misread the plate and started my decent after flying over GODRD and was around 2500 by the time I arrived at TOYBO, where the decent actually does start.

I didn't realize this until after I was on the ground. I didn't get a warning from the controller nor did I get a Brasher, but I did file a report with NASA.

My question is, is this a deviation that is enforceable?

Don't worry, I beat myself up enough on this and I know just how serious it was.

Nobody will make a big stink about 100', although near the ground, i.e. at mins, it could actually kill you.
But let me give you a tip that will forever eliminate this type of mistake. Whenever you see a glide slope descent angle (typ. 3 degrees as in this case), you will get a glideslope on the GPS navigator (at least on Garmin). Never descend below that glideslope, but instead maintain your present altitude until you intercept it, and then follow it down to your minimums. This will ensure that you'll never descend prematurely, will be safer, and will give your pax the most comfortable ride.

 

[mscard88]

Yes three whacks on your pee pee! And don't do that again. I believe you're only guaranteed 300' over obstructions.

 

[Velocity173]

Yes three whacks on your pee pee! And don't do that again. I believe you're only guaranteed 300' over obstructions.

Either 300 or 500 ft. My TERPs numbers are all hazy these days.

At any rate, 100 ft low ain't gonna raise eyebrows in the radar room.

 

[luvflyin]

Highly likely that 100 feet wasn't even noticed by either the controller or even appeared on the Radar. Altitude readouts 100 feet off are common. It's not until they are over 200 feet that they are considered not valid. You might have been showing up at 2700 when you went down to 2500.
When I looked at the approach it made me wonder if I had ever seen that before. A minimum altitude at a fix followed by the same altitude at the next fix down the road. All three IAF's leading to GODRO are 2600. TOYBO is 2600. Maybe that 2600 at GODRO shouldn't even be there.

 

[fly@305]

Looking at that the GPS R36L approach at KNEW, why would there even been a 2600' minimum when the MSA is listed as 2100' for 25nm?

Sorry if this is a silly question.

 

[flyingron]

Mode C only can read out multiples of 100 feet. Given the allowable altimeter error, and potential errors in altimeter settings, etc... a mode C readout 100' off isn't going to mean anythign.

 

[Gucci Pilot]

Making WAY bigger deal out of this than you should. Controller isn't gonna say anything unless he notices you getting drastically low. And it is going to be to tell you that you are about to hit the ground, or if it is a traffic conflict with a lower airplane. You have a 300 foot obstruction buffer and approaches are designed so that small mistakes can be made. No one expects everyone to be perfect 100% of the time. 100 feet is really no big deal. A few weeks ago my autopilot got goofy and instead of turning right to track the localizer inbound(was on the right side of the approach course). It turned left thinking it was further right than it was. Caused us to drastically overshoot the localizer course. ATC just said, "See you going left, you ok?" He thought we didn't know where we were and was just helping us out, or that something bad happened to us. Told him the autopilot screwed up and he said, "No problem! If you want you can recapture it or fly the visual, your choice."

 

[BigBadLou]

Looking at that the GPS R36L approach at KNEW, why would there even been a 2600' minimum when the MSA is listed as 2100' for 25nm?

Sorry if this is a silly question.

Ditto.
(I am just a fresh IR pilot with wet paint on my cert so I wonder the same - my brain is telling me that it could be a local noise abatement ordinance)

 

[midlifeflyer]

Making WAY bigger deal out of this than you should. Controller isn't gonna say anything unless he notices you getting drastically low.

Yep, And even then, they are going to typically issue a warning, not file a report.

The altitude deviations that cause the enforcement process to start tend to be outside the approach environment - the ones that can cause loss of IFR separation between aircraft. In the approach environment, once cleared for the approach, there are (or at least should be) no IFR aircraft close enough to you to cause a loss of IFR separation, and nothing to lead a controller to want to get involved in a lot of paperwork.

And even in the en route environment, a 100' deviation, as @Velocity173 put it

ain't gonna raise eyebrows in the radar room.

 

[John Collins]

You would have passed your Instrument check ride as long as you were within 100 feet of the minimum altitude: "Maintains, prior to beginning the final approach segment, altitude within ±100 feet". So if you started a descent at GODRD and only descended to 2500 feet, you must have caught your error really soon or you had a very shallow descent. 100 feet in 3 NM is only 33 feet/NM. Between TYBO and HEBOT is 290 feet/NM. The descent after reaching HEBOT is 318 feet/NM.

 

[FLAAV8R]

Making WAY bigger deal out of this than you should. Controller isn't gonna say anything unless he notices you getting drastically low. And it is going to be to tell you that you are about to hit the ground, or if it is a traffic conflict with a lower airplane. You have a 300 foot obstruction buffer and approaches are designed so that small mistakes can be made. No one expects everyone to be perfect 100% of the time. 100 feet is really no big deal. A few weeks ago my autopilot got goofy and instead of turning right to track the localizer inbound(was on the right side of the approach course). It turned left thinking it was further right than it was. Caused us to drastically overshoot the localizer course. ATC just said, "See you going left, you ok?" He thought we didn't know where we were and was just helping us out, or that something bad happened to us. Told him the autopilot screwed up and he said, "No problem! If you want you can recapture it or fly the visual, your choice."

Thanks Dude.