Video and Discussion - Burley, ID accident. Was "Gryder"

[John Collins]

The VDA and or the +V extends all the way out to the IF(IAF) and may be intercepted anywhere after passing the IF(IAF). It is formed by the angle between the TCH and JAMID, it does not start at JAMID. If one wishes to use the +V, it is easiest to just remain at the IF(IAF) minimum altitude, intercept the +V and follow it all the way down to the MDA.

 

[John Collins]

Because it would no longer be a straight-in approach. My guess is if you move HIKLO closer you will need a steeper descent to get to MDA. The missed and MDA are typically not at the same point in space, that's a DA. You need time to see the airport on a NPA.

Moving the location of the FAF 0.5 NM closer to the runway would not affect the VDA, since the VDA is determined by the step down fix to be 3.75 degrees with a TCH of 40 feet The Jeppesen chart shows the VDA crossing the FAF altitude 0.5 NM past the fix HIKLO at 6000 feet. So if you intercept the GP at 6000 feet, you will be 4.5 NM from the runway. See the profile view of the Jeppesen chart.

 

[Trogdor]

Moving the location of the FAF 0.5 NM closer to the runway would not affect the VDA, since the VDA is determined by the step down fix to be 3.75 degrees with a TCH of 40 feet The Jeppesen chart shows the VDA crossing the FAF altitude 0.5 NM past the fix HIKLO at 6000 feet. So if you intercept the GP at 6000 feet, you will be 4.5 NM from the runway. See the profile view of the Jeppesen chart.

View attachment 107138

 

[Trogdor]

That's true. I guess I was thinking equal or greater than a half mile. I was John looking at the same Jepp plate.

 

[Kyle N]

Who do you fly for?
It does appear that the people who speak with the most certainty on subjects of aviation tend to have the least experience.


That approach shouldn’t exist in its current form right now. The letters even from the FAA show that there are major issues with the approach, this lady wasn’t flying her 182 in clear blue and 22 to get her 6 in, she was flying for hire in bad weather conditions most here wouldn’t drive in, let alone fly in, flew a approach that shouldn’t exist and had a bad outcome. Could she have done better, sure, could the FAA and town have done better very much yes.


The same video in the start of this subject?

That was visual, it was not first student solo weather, but visual, his camera skills do not appear that good, but most times he put the camera outside I could see the ground for miles, straight IFR isn’t dependent on weather, if you mean straight IMC that is not what it looks like.

I'm talking about the point from about 44:00 onward. Yes they took off special VFR, but when they went to Burley and flew the actual LNAV approach it was clearly in and out of the clouds the entire time, IMC (yes I meant IMC not IFR).

The pilot even made a comment "I probably should have flown in the right seat" because he likely isn't instrument rated and didn't know anything about the approaches. They were staring at the gauges, it was obvious they were in the clouds most of the time and broke out fully just prior to the MDA.

They weren't talking to ATC so I doubt they picked up an IFR clearance. Especially seeing as Dan kept saying "if we were IFR".

 

[Jackk]

I'm talking about the point from about 44:00 onward. Yes they took off special VFR, but when they went to Burley and flew the actual LNAV approach it was clearly in and out of the clouds the entire time, IMC (yes I meant IMC not IFR).

The pilot even made a comment "I probably should have flown in the right seat" because he likely isn't instrument rated and didn't know anything about the approaches. They were staring at the gauges, it was obvious they were in the clouds most of the time and broke out fully just prior to the MDA.

They weren't talking to ATC so I doubt they picked up an IFR clearance. Especially seeing as Dan kept saying "if we were IFR".

I’ll have to re watch it, but on the approach in the video I could see the ground for miles.

As to why he said right seat, probably a inexperienced pilot, those are not conditions for a low time infrequent private pilot.

 

[Turbo-Arrow-Driver]

I'm talking about the point from about 44:00 onward. Yes they took off special VFR, but when they went to Burley and flew the actual LNAV approach it was clearly in and out of the clouds the entire time, IMC (yes I meant IMC not IFR).

The pilot even made a comment "I probably should have flown in the right seat" because he likely isn't instrument rated and didn't know anything about the approaches. They were staring at the gauges, it was obvious they were in the clouds most of the time and broke out fully just prior to the MDA.

They weren't talking to ATC so I doubt they picked up an IFR clearance. Especially seeing as Dan kept saying "if we were IFR".

Most of their flight seems to have been at 5500 MSL, with terrain in that area around 4100-4200MSL. Check the sectional. I suspect they were mostly in airspace with Class E starting at 700AGL, perhaps a short time with Class E at 1200, and during the approach, surface Class E. That's 3sm vis, 500' below, 1000' above and 2000' horizontal cloud clearance. The visibility is horizontal flight visibility at their altitude (right?) -- so slant visibility to the ground isn't what matters. We don't have much camera footage of flight visibility, although it's clear from a couple of shots out the pilot's window that they had less than 2000' horizontal clearance at some points.

 

[exncsurfer]

Most of their flight seems to have been at 5500 MSL, with terrain in that area around 4100-4200MSL. Check the sectional. I suspect they were mostly in airspace with Class E starting at 700AGL, perhaps a short time with Class E at 1200, and during the approach, surface Class E. That's 3sm vis, 500' below, 1000' above and 2000' horizontal cloud clearance. The visibility is horizontal flight visibility at their altitude (right?) -- so slant visibility to the ground isn't what matters. We don't have much camera footage of flight visibility, although it's clear from a couple of shots out the pilot's window that they had less than 2000' horizontal clearance at some points.

I didn't really get the point of flying in those conditions, it would have made a better video in my opinion it it had been clear and they had better shots of the instruments and a better shot of what the approach looks like out the window at the proper approach angle. The camera showing the two guys staring at the panel and out the window didn't do much demonstrating.

 

[Turbo-Arrow-Driver]

More proof of Gryder's lying.

I found the ADS-B data for the demo flight in FlightAware, and plotted their approach versus the fixes. Turns out, they were about 200' high at JAMID and that would have put the VDI close to, or at the bottom of the screen.

So, Gryder's assertion that the VDI took a dive south at JAMID is complete nonsense, it was already way south when they got to JAMID.

 

[John Collins]

How did you determine the actual MSL height, since ADS-B altitude data is a pressure altitude? Did you adjust for the altimeter setting at the time? Did you take into account the temperature? If it was snowing, it was cold and the pressure altitude would indicate higher than the true altitude. If you have access to the geometric altitude, it also needs to be adjusted by adding the geoid difference for the location, approximately add 48 feet.

 

[luvflyin]

Moving the location of the FAF 0.5 NM closer to the runway would not affect the VDA, since the VDA is determined by the step down fix to be 3.75 degrees with a TCH of 40 feet The Jeppesen chart shows the VDA crossing the FAF altitude 0.5 NM past the fix HIKLO at 6000 feet. So if you intercept the GP at 6000 feet, you will be 4.5 NM from the runway. See the profile view of the Jeppesen chart.

View attachment 107138

I would change ‘the VDA’ in “…Jeppesen chart shows the VDA crossing the FAF altitude 0.5 NM past the fix HIKLO…” to an ‘extension of the VDA.’

 

[luvflyin]

How did you determine the actual MSL height, since ADS-B altitude data is a pressure altitude? Did you adjust for the altimeter setting at the time? Did you take into account the temperature? If it was snowing, it was cold and the pressure altitude would indicate higher than the true altitude. If you have access to the geometric altitude, it also needs to be adjusted by adding the geoid difference for the location, approximately add 48 feet.

By geoid difference I assume you mean curvature of the earth. Or is there some other thing that enters into this?

 

[Sluggo63]

I've been following this thread. It's a good discussion... I have an idea of how I think it should work in my airplane, but now I'm not sure...

This caught my eye though

Yeah, the FMS in my aircraft computes an advisory vertical path from the FAF to the runway. It doesn't take into account stepdown fixes. If there is one, it is up to you to do the shallow/steep thing. Common cause of busted checkrides and PCs in the sim, at least that's what I've heard.

What aircraft is this, @dmspilot? Are you saying if you pull a Non-ILS approach out of the FMS and it has a step-down, your FMS doesn't protect that? That really surprises me. I know it's an emphasis item for us, that we choose the right approach so the step-downs are present when they should be. This will get you when you are flying an ILS when the GP is NOTAM'd OTS. Guys will mistakenly pull the ILS out of the FMS to fly it with VNAV guidance (which won't have the step-downs), versus pulling the LOC, which will (for us).

I had to do some hunting to find a LOC with stepdowns, and I grabbed the ILS/LOC 24L at LAX. Here's the profile view.



You can see the FAP is SUTIE with a stepdown at CORTY.

Here's what it looks like when you load the LOC approach into our FMS.


You can see you the FMS protects the stepdown at CORTY with a 740A.

Edit: Man... those pictures are bigger than I wanted. I need to remember to shrink them next time.

 

[Turbo-Arrow-Driver]

How did you determine the actual MSL height, since ADS-B altitude data is a pressure altitude? Did you adjust for the altimeter setting at the time? Did you take into account the temperature? If it was snowing, it was cold and the pressure altitude would indicate higher than the true altitude. If you have access to the geometric altitude, it also needs to be adjusted by adding the geoid difference for the location, approximately add 48 feet.

I took them at their word that they were maintaining 5500 MSL in the video during the early part of the approach, and that they had the proper altimeter setting.

No allowance for temperature, but being only 1500AGL or less, I didn't think temperature would make a huge difference. Since you bring it up however, I'll work that out and post back if that turns out to be wrong. Sounds like it was close to freezing, perhaps 33-35F.

ADS-B data prior to and just after HIKLO showed an average altitude of 5800, so I deduced the correction was 300 feet. The readings closest JAMID were 5600 (before) and 5325, so with a 300' foot correction, 5300 and 5025. The glideslope at JAMID is 4800, so I concluded they were about 200' high there.

Edit: I computed the altitude error due to temperature and it's on the order of 25-30 feet, so I think the point is still valid.

 

[PaulS]

I've been following this thread. It's a good discussion... I have an idea of how I think it should work in my airplane, but now I'm not sure...

This caught my eye though



What aircraft is this, @dmspilot? Are you saying if you pull a Non-ILS approach out of the FMS and it has a step-down, your FMS doesn't protect that? That really surprises me. I know it's an emphasis item for us, that we choose the right approach so the step-downs are present when they should be. This will get you when you are flying an ILS when the GP is NOTAM'd OTS. Guys will mistakenly pull the ILS out of the FMS to fly it with VNAV guidance (which won't have the step-downs), versus pulling the LOC, which will (for us).

I had to do some hunting to find a LOC with stepdowns, and I grabbed the ILS/LOC 24L at LAX. Here's the profile view.
View attachment 107154


You can see the FAP is SUTIE with a stepdown at CORTY.

Here's what it looks like when you load the LOC approach into our FMS.
View attachment 107153

You can see you the FMS protects the stepdown at CORTY with a 740A.

Edit: Man... those pictures are bigger than I wanted. I need to remember to shrink them next time.

The g1000 will give you an advisory glide path for a non precision rnav approach in some cases. When coupled, the autopilot, gfc 700 in my case, will follow the glide path. The glide path can and will in some cases descend you below the required step altitudes on some approaches. Cirrus notifies you of this possibility in their training. The pilot has to stay on top of it. The fms has the steps on it. Personly when coupled, I do the descents manually. Vnav is an option too, which will respect the steps. The problem with vnav, and the glide path, for that matter, is it will get you to your mda at the missed approach point. I was taught it's better to get to the mda further back on the step to give a better chance of seeing the runway further away with low ceilings.

 

[Sluggo63]

The g1000 will give you an advisory glide path for a non precision rnav approach in some cases. When coupled, the autopilot, gfc 700 in my case, will follow the glide path. The glide path can and will in some cases descend you below the required step altitudes on some approaches. Cirrus notifies you of this possibility in their training. The pilot has to stay on top of it. The fms has the steps on it. Personly when coupled, I do the descents manually. Vnav is an option too, which will respect the steps. The problem with vnav, and the glide path, for that matter, is it will get you to your mda at the missed approach point. I was taught it's better to get to the mda further back on the step to give a better chance of seeing the runway further away with low ceilings.

Technically, I think the VNAV GP will get you to the MDA at the VDP, which is typically prior to the MAP.

 

[PaulS]

Technically, I think the VNAV GP will get you to the MDA at the VDP, which is typically prior to the MAP.

Even the vdp is a little late. Generally what I'll do is follow the gp until the last step, then click the vs button, and increase my descent rate. Works well. But honestly, in the soup I opt for the precision approach.

 

[Kenny Phillips]

After all of this, I'd give a week's pay to see what the pilot saw in the last 30 seconds.

 

[John Collins]

By geoid difference I assume you mean curvature of the earth. Or is there some other thing that enters into this?

GPS determines a geometric altitude based on a model of the earth's surface. It is a smooth spheroid defined by WGS84. The model is very good, but just a model and does not adjust for variations in local gravity. The adjustments are called the geoid. The geoid is normally contained in a database and is used to adjust the geometric altitude to an equivalent MSL altitude at a particular point. At my airport, the geoid is about 110 feet, so I would need to add 110 feet to the geometric altitude to get an equivalent to MSL. Normally when displaying GPS altitudes, GPS systems will correct for the geoid, but in the case of ADS-B, the geometric altitude is not corrected, as there is no need to do so for its purpose. I can use ForeFlight to display the ADS-B raw data and view both the pressure altitude and the geometric altitude. The pressure altitude needs to be adjusted by the local altimeter setting to determine MSL and the geometric altitude needs to be adjusted by the local geoid to get an equivalent MSL altitude. ADS-B altitude is always expressed to the nearest 25 feet, but when the altitude encoder only produces a value to the nearest 100 feet, that is the precision of the pressure altitude. Geometric altitude is always to the nearest 25 feet.

 

[John Collins]

That’s not necessarily true. Some people are authorized to use the MDA as a DA on certain non-precision approaches with VNAV glide path guidance.

That is true, but only certificated operators using an opspec and there are specific criteria that the airport and approach must meet. KBYI RNAV 20 does not meet them. Here are the restrictions:

c. Authorized Approaches. The certificate holder may fly all part 97 nonprecision straight-in IAPs listed as authorized in their C052, Table 1, columns 1 and 2 using an MDA as a DA/DH if the approach being flown meets one of the following requirements and its subcomponents:
(1) Serves a runway that has a published RNAV IAP (“RNAV” or “GPS” in title) with a published LNAV/VNAV DA/DH and—
(a) Has the exact published final approach course as the RNAV IAP.
(b) Has a published glideslope (GS) or vertical descent angle (VDA) coincident with or higher than the GS on the published RNAV IAP.
(c) Is selected from a certified database and displays a final approach Flight Path Angle (FPA) that matches the GS or VDA on the published IAP to be flown.
(2) Serves a runway that has a published ILS, MLS, LPV, or RNP AR IAP and—
(a) Has the exact published final approach course as the ILS, MLS, LPV, or RNP AR IAP.
(b) Has a published GS or VDA coincident with or higher than the GS on the published ILS, MLS, LPV, or RNP AR IAP.
(c) Is selected from a certified database and displays a final approach FPA that matches the GS or VDA on the published IAP to be flown.
(3) Serves a runway to an airport operating under 14 CFR part 139 with a Visual Approach Slope Indicator (VASI) or precision approach path indicator (PAPI) vertical visual guidance system.
(a) The GS or VDA on the published final approach course must be coincident with or higher than the GS on the VASI or PAPI.
(b) The published final approach course is within plus or minus 10 degrees of the runway centerline course or within the lateral restriction from the runway centerline course placed on the VASI or PAPI, whichever is less. This restriction will be published in the Airport/Facility Directory.
d. VNAV Path Angle. The VNAV path angle must be greater than 2.75 and less than 3.77 degrees for Category A, B, and C aircraft, and greater than 2.75 and less than 3.50 degrees for Category D aircraft.
e. Operational Restriction. An MDA may not be used as a DA/DH if the requirements specified in this operations specification are not met. The certificate holder may use a continuous descent final approach (CDFA), but will begin the missed approach at an altitude above the MDA that will not allow the aircraft to descend below the MDA.

 

[dmspilot]

Are you saying if you pull a Non-ILS approach out of the FMS and it has a step-down, your FMS doesn't protect that? That really surprises me. I know it's an emphasis item for us, that we choose the right approach so the step-downs are present when they should be. This will get you when you are flying an ILS when the GP is NOTAM'd OTS. Guys will mistakenly pull the ILS out of the FMS to fly it with VNAV guidance (which won't have the step-downs), versus pulling the LOC, which will (for us).

That is correct. Stepdowns are not even in the database. FMZ-2000 on the E145.

 

[John Collins]

What aircraft is this, @dmspilot? Are you saying if you pull a Non-ILS approach out of the FMS and it has a step-down, your FMS doesn't protect that? That really surprises me.

The FMS is likely one used in air carrier operations and they simply don't fly into airports where this is an issue as they mostly operate into part 139 airports. I also presume the FMS has baro-vnav available for vertical navigation and is not likely to have a WAAS GPS used for vertical navigation. Also, an air carrier can be approved for an opspec that allows a DA to be used in lieu of an MDA, but only when the runway meets certain conditions. These conditions are not met at KBYI and KBYI is not a part 139 airport.

 

[exncsurfer]

After all of this, I'd give a week's pay to see what the pilot saw in the last 30 seconds.

Lets build some stacks spewing IMC into the air on this approach path, good idea right?

 

[Salty]

View attachment 107190

Lets build some stacks spewing IMC into the air on this approach path, good idea right?

Don’t fly below mda if you can’t see the runway clearly. Good idea, right?

 

[Sluggo63]

The FMS is likely one used in air carrier operations and they simply don't fly into airports where this is an issue as they mostly operate into part 139 airports. I also presume the FMS has baro-vnav available for vertical navigation and is not likely to have a WAAS GPS used for vertical navigation. Also, an air carrier can be approved for an opspec that allows a DA to be used in lieu of an MDA, but only when the runway meets certain conditions. These conditions are not met at KBYI and KBYI is not a part 139 airport.

I fly for a large air carrier and the photo I posted of the LOC 24L at LAX is directly from our FMS trainer. We have non-precision approaches in our database and the stepdowns are part of the procedure in the box, so you can safely VNAV down to a MDA as DA (or DDA, if the approach doesn't meet the requirements for MDA as DA).

I'm surprised that @dmspilot's FMS in the E-145 doesn't have the stepdowns. They are much more likely to have to actually fly one in their set of airports than I would in my long-haul international flying.

That being said, I've had to do more than zero non-precision approaches on the line. The last time was in Narita (Tokyo) when, on downwind the tower said the ILS to 16R was OTS and to expect vectors to the VOR. VOR?!?! Oh crap... wasn't expecting that.

 

[Todd82]

How new is this stack? All approaches are flown by aerial mapping planes and then mapped (lidar, stereo imagery, etc) to be checked for obstructions (namely tree growth but this would count too) on a continuing cycle. If it penetrates or even comes close to the approach surface, the proper actions are taken (cut the tree, edit the approach, etc)

 

[Clip4]

The great thing in the US is we have an independent NTSB that will report on the cause of this accident and they do a comprehensive investigation commercial aircraft accidents.

 

[Kenny Phillips]

The great thing in the US is we have an independent NTSB that will report on the cause of this accident and they do a comprehensive investigation commercial aircraft accidents.

And sometimes return questionable results.

 

[Salty]

The great thing in the US is we have an independent NTSB that will report on the cause of this accident and they do a comprehensive investigation commercial aircraft accidents.

It’s been 5 months they’ve been looking at my O-360 that stopped running with no catastrophic mechanical issues apparent and no injury accident. Anybody want to bet on how useful the final report is going to be to anyone?

 

[hindsight2020]

It’s been 5 months they’ve been looking at my O-360 that stopped running with no catastrophic mechanical issues apparent and no injury accident. Anybody want to bet on how useful the final report is going to be to anyone?

Well if it was carb ice or pilot assisted fuel starvation, they ain't gonna find jack. It'd be more useful to tell them that so they can wrap it up, but I respect your 5th amendment rights. /TC

 

[Salty]

Well if it was carb ice or pilot assisted fuel starvation, they ain't gonna find jack. It'd be more useful to tell them that so they can wrap it up, but I respect your 5th amendment rights. /TC

They have all the information I do and more. Including the remaining fuel and the internal carb temp indicated by the JPI. In my report to them, I even specifically called out that I would change my fuel management regiment because fuel starvation was a possible cause.

 

[Clip4]

It’s been 5 months they’ve been looking at my O-360 that stopped running with no catastrophic mechanical issues apparent and no injury accident. Anybody want to bet on how useful the final report is going to be to anyone?

Was your crash a commercial flight?

 

[Clip4]

They have all the information I do and more. Including the remaining fuel and the internal carb temp indicated by the JPI. In my report to them, I even specifically called out that I would change my fuel management regiment because fuel starvation was a possible cause.

Stuck float.

 

[Clip4]

And sometimes return questionable results.

It’s an opinion, but if the approach was incorrect they will discover that fact rather easily. My guess is the PIC descended below MDA without the required visual elements.

 

[PaulS]

I attended an EAA talk by an FAA accident investigator a few years ago. He talked about investigations and specifically made the point to be honest when answering their questions. He said nothing is worse than tearing an engine down or chasing down a supposed airframe issue because the pilot claims there was a malfunction only to find nothing wrong. It's a colossal waste of time.

 

[Salty]

I attended an EAA talk by an FAA accident investigator a few years ago. He talked about investigations and specifically made the point to be honest when answering their questions. He said nothing is worse than tearing an engine down or chasing down a supposed airframe issue because the pilot claims there was a malfunction only to find nothing wrong. It's a colossal waste of time.

Hell, I’ve asked them multiple times what they are doing and why because it makes no sense. They don’t even reply to my queries. I have not gotten a response of any kind, even to acknowledge my contact for over 3 months.

 

[Salty]

Stuck float.

Possible. But why a tear down for that? And would it still be stuck after a hard landing and sudden stop?

carb was overhauled and float SB complied with at same time engine was overhauled 400 hrs previous.

 

[PaulS]

Hell, I’ve asked them multiple times what they are doing and why because it makes no sense. They don’t even reply to my queries. I have not gotten a response of any kind, even to acknowledge my contact for over 3 months.

That wasn't directed at you Salty, you were very up front with what went on with that flight. Hopefully they will figure out if it's OE or something else.

 

[Bell206]

It’s been 5 months they’ve been looking at my O-360 that stopped running with no catastrophic mechanical issues apparent and no injury accident.

I have not gotten a response of any kind, even to acknowledge my contact for over 3 months.

FWIW: Since your prelim report was released rather quickly, it's my understanding there's a backlog of 12 to 18 months on the factual reports. Then another few months to release the final report. One accident I've been following happened 14 months ago and they still haven't released the factual.

I’ve asked them multiple times what they are doing and why because it makes no sense.

But why a tear down for that?

There is a set protocol the NTSB must follow regardless what the circumstances or known facts are of the incident. They can not skip certain steps just because you lived and nothing fell off before you slide to a stop. Since this was a fuel issue every item will be disassembled and checked or function checked to ensure it worked as advertised. Have seen several "smoking gun" causes of accidents only to have that "smoke" get put out due to an underlying cause.

 

[Salty]

FWIW: Since your prelim report was released rather quickly, it's my understanding there's a backlog of 12 to 18 months on the factual reports. Then another few months to release the final report. One accident I've been following happened 14 months ago and they still haven't released the factual.


There is a set protocol the NTSB must follow regardless what the circumstances or known facts are of the incident. They can not skip certain steps just because you lived and nothing fell off before you slide to a stop. Since this was a fuel issue every item will be disassembled and checked or function checked to ensure it worked as advertised. Have seen several "smoking gun" causes of accidents only to have that "smoke" get put out due to an underlying cause.

Thanks for the info. Still doesn't explain why they don't tell me that and instead ignore me. Both the FAA and NTSB. Considering they are holding my property you'd think they'd at least respond with a "screw you".