Rad Alt Accuracy In Turns

[LPO Beck]

I'm early in Primary training. I think I might be developing a bad habit already. In the pattern I have been referencing my rad alt as the "primary" altitude instrument. Backed up, of course, by the regular altimeter. Anyone who has flown at Whiting knows the "HONE" chart for MSL altitudes in the patterns to the North. Which is good, and not necessarily difficult to recall in the aircraft.

However, instead of doing the rudimentary math calculations, why not reference the rad alt? Every pattern we fly is 1100 AGL for the break, 800 pattern, ~450 at the 90, ~200 for roll out. I don't think anyone would disagree that it's a tool that can be utilized along with HONE. But, my only reservation is how accurate it will be in turns? A 30 degree bank will make the ground "farther" away. Yahoo tells me that the antenna sends out a cone, and displays an altitude for the first wave returned (no error). But thought there might be some T-6 brainiacs around that know for sure.

Thanks.

 

[Pags]

As a helo guy the Radalt was my primary altitude reference and is far more accurate than a baralt. Don't nuke it, the designers took into account the fact that the aircraft would need to turn.

 

[xj220]

We use the radalt all the time on station and we're going up to 60 sometimes. PFM? I don't know, but it works (most of the time) and that's all I really care about.

 

[joe dirt]

I use them together when in the landing pattern. Also, I'm sure you know the radar altimeter is only displayed at bank angles less than 30 degrees, pitch angles less than 15 degrees and less than 2500 AGL.

 

[zippy]

I'm early in Primary training. I think I might be developing a bad habit already. In the pattern I have been referencing my rad alt as the "primary" altitude instrument. Backed up, of course, by the regular altimeter. Anyone who has flown at Whiting knows the "HONE" chart for MSL altitudes in the patterns to the North. Which is good, and not necessarily difficult to recall in the aircraft.

However, instead of doing the rudimentary math calculations, why not reference the rad alt? Every pattern we fly is 1100 AGL for the break, 800 pattern, ~450 at the 90, ~200 for roll out. I don't think anyone would disagree that it's a tool that can be utilized along with HONE. But, my only reservation is how accurate it will be in turns? A 30 degree bank will make the ground "farther" away. Yahoo tells me that the antenna sends out a cone, and displays an altitude for the first wave returned (no error). But thought there might be some T-6 brainiacs around that know for sure.

Thanks.

Couldn't tell you what the HONE equation is. I honestly never bothered to learn it. If you can nerd out a way to circumvent HONE that relies on a device that will show you fluctuating readings throughout the pattern due to terrain features and turns, you can probably just learn the 3 different altitudes for the fields you fly to (since some are the same) and use your primary flight instruments to fly them like everyone else. I don't say that to be a dick, but gamesmanship wise you don't want to do things that are new, dumb, or different from the norm while being a flight student.

 

[Gatordev]

To tag onto zippy's post... The HONE equation is just a tool to remember the pattern altitudes, it's not an actual correct depiction of the topography of the area. One if the airfields has ~150' elevation but is counted as one of the "100'" fields. Just fly (and report) the BARALT.

Sea story to illustrate the point: When flying all over southern Guatemala, we were working with the Army. There were several passes that everyone had to go through that fed into Guatemala City, which sits on top of this very tall plateau. I think GC is around 5000' MSL. We all were working off of a freq to make traffic calls in the transit areas (which were the passes). The Army guys would call out RADALT altitudes like, "12 is 500' approaching the lake pass." It was a completely useless piece of data, because they could have been flying over the road and been at one BARALT or over the mountain range and seeing another BARALT, all while seeing "500'" on their RADALT. We had no idea a) what actual altitude they were at and b) where to look for them.

But at least I got to shake the hand of the President of Guatemala...

 

[LPO Beck]

Couldn't tell you what the HONE equation is. I honestly never bothered to learn it. If you can nerd out a way to circumvent HONE that relies on a device that will show you fluctuating readings throughout the pattern due to terrain features and turns, you can probably just learn the 3 different altitudes for the fields you fly to (since some are the same) and use your primary flight instruments to fly them like everyone else. I don't say that to be a dick, but gamesmanship wise you don't want to do things that are new, dumb, or different from the norm while being a flight student.

Good call @joe dirt - angles over, or right at 30, will be common so that alone is a good reason to stick to the hard numbers for each field.

@zippy

H - Holley (+0)
O - Others; Brewton, Barin, etc (+100)
N - NSE (+200)
E - Evergreen (+300)

 

[Swanee]

In a jet you'll reference the radalt in the pattern.

 

[zippy]

Good call @joe dirt - angles over, or right at 30, will be common so that alone is a good reason to stick to the hard numbers for each field.

@zippy

H - Holley (+0)
O - Others; Brewton, Barin, etc (+100)
N - NSE (+200)
E - Evergreen (+300)

I know what it is, and had 4 versions of the FWOP to learn it if I wanted to. It always amazed me that students at Whiting had to be spoon fed airfield elevations through an equation that involves useless, outdated information (they haven't used Holley since at least Hurricane Ivan), instead of just learning the information the big boy way. Don't nuke the pattern/break/delta altitudes. Just learn them individually. That way when they change (Like they did, and then changed back, at NSE) you don't have a meltdown trying to figure out what altitude you're supposed to be at coming into the break at a field.

 

[croakerfish]

I'm early in Primary training. I think I might be developing a bad habit already. In the pattern I have been referencing my rad alt as the "primary" altitude instrument. Backed up, of course, by the regular altimeter. Anyone who has flown at Whiting knows the "HONE" chart for MSL altitudes in the patterns to the North. Which is good, and not necessarily difficult to recall in the aircraft.

However, instead of doing the rudimentary math calculations, why not reference the rad alt? Every pattern we fly is 1100 AGL for the break, 800 pattern, ~450 at the 90, ~200 for roll out. I don't think anyone would disagree that it's a tool that can be utilized along with HONE. But, my only reservation is how accurate it will be in turns? A 30 degree bank will make the ground "farther" away. Yahoo tells me that the antenna sends out a cone, and displays an altitude for the first wave returned (no error). But thought there might be some T-6 brainiacs around that know for sure.

Thanks.

I always just set the altitude bug trucking in from the initial point, then all you have to do is see if the bug is above or below you. No math required.

 

[Gatordev]

In a jet you'll reference the radalt in the pattern.

That works well over water or at a place like Jax or Oceana, but what about a place like Mirramar? Serious question, because we can't go off the RADALT in a helo because of all the terrain changes. Not a huge deal, as you can just look out the damn window, but you can't use pattern checkpoints based off the RADALT.

 

[PhrogLoop]

My question is: what are we doing staring at instruments in the pattern?!?! Keep that head on a swivel...drag a bug spot across the horizon in a turn and CLEAR!

 

[MIDNJAC]

That works well over water or at a place like Jax or Oceana, but what about a place like Mirramar? Serious question, because we can't go off the RADALT in a helo because of all the terrain changes. Not a huge deal, as you can just look out the damn window, but you can't use pattern checkpoints based off the RADALT.

Miramar is pretty flat around the pattern until you get a couple miles east. That said, unless you were doing FCLPs to the mid runway lens on the left, the pattern was at like 70000 feet for the right to deconflict the inner/outer patterns.....so just like oceana, you aren't flying a cv pattern anyway so it's not like you are flying an approach turn, just making a shuttle descent to land.

 

[zippy]

My question is: what are we doing staring at instruments in the pattern?!?! Keep that head on a swivel...drag a bug spot across the horizon in a turn and CLEAR!

Integrated instrument scan (well their best attempt): keeps their eyes moving which prevents them from focusing on one aspect (Airspeed, altitude, spacing, power, AOA, runway) and flying into the ground (and many have tried). All the stuff that we eventually take for granted as pilots don't always come naturally in the beginning.

 

[PhrogLoop]

Integrated instrument scan (well their best attempt): keeps their eyes moving which prevents them from focusing on one aspect (Airspeed, altitude, spacing, power, AOA, runway) and flying into the ground (and many have tried). All the stuff that we eventually take for granted as pilots don't always come naturally in the beginning.

I'm with you, completely. I instructed in T-37s and T-6s and taught an agressive scan, but the OP is referring to what he should be referencing IN the turn. I always taught that even early students should make altitude corrections straight and level (when it's easier and more effective) and shift to a primarily outside scan to clear in a turn.