RCP 2021-005

Interesting that the accuracy of altimeters vs theodolites discussion has come full circle. Back in 2007 there were some pretty heated online discussions that centered on how altimeters were not accurate because of calibration, sensitivity, ambient conditions etc, whereas theodolites were so sacrosanct that they were brought down Mt. Pinkbook by Moses Himself. I agree with this proposal; optical tracking was always iffy from a practical standpoint, and there was a major inconsistency in that some events would be tracked to peak altitude and others tracked at ejection.

This seems to be an unnecessary change to me.  It appears that most people prefer flying altimeters, but where is the problem here?  

In general, I am in favor of freedom.  The rules as stated currently allow the CD to determine whether or not to use trackers or altimeters, so why make a change and deny someone the ability to use trackers if they choose (And have the needed equipment and staffing)? 

NRC already requires altimeters for those events, so I say, there is no need for this RC.

Given the technical improvements in altimeter size and weight along with new motor introductions, I suggest retiring all the records to the Hall of Fame, and opening things up to set new records!

This works for me.  I still like the idea of occasionally doing it optically, and showing/teaching it to interested newcomers, but for records, yes, altimeters.

I support this rule change to use altimeters only for altitude tracking. I do not support using the highest altitude for National records whether optically tracked or using an altimeter. I have never personally used optical tracking to determine maximum altitude but I have talked to people who have and the process seems much more prone to error due to baseline layout, cloudy skies, and human error. I would support maintaining recognition of any optically tracked records that are higher than altimeter based as they are now. I do not think it makes sense to recognize as a National record an altitude established using a more error prone technique.

I agree with eliminating Theodolite tracking and freezing the records with this method on the date of the change, and moving forward only using altimeters for altitude tracking.

I like this proposal.  

Hi Bob,

When this was put in place over 10 years ago, lightest altimeter was around 12g. And 18mm.  So legit for separate records.  Now altimeters are superior to optical tracking.  10 years ago, I'm with you.  Now, I disagree.  Let the performance stand.  Not letting the optical performance stand is like saying stopwatches that were not accurate to .001 are no longer legit.  And this has nothing to do with if I may or may not have that record.  Let the optical records be beaten as have been for years.  Performance over tech always.  That's what we are about.  :)

I think the removal of theodolite tracking is warranted. I do not however like the removal of all of the optical tracked records. I think they should be retained and frozen at the date a new rule is enacted. I do not agree with Chad's idea to keep the higher record of the two as it is not apples to apples, which I am assuming was the reason to have separate records in the first place.  A quick look at the records shows optical almost always exceeding altimeter until you get to d motors where you have the issue of seeing it and the loss of resolution for optical tracking.

TARC has been using altimeters for altitude measurement for nearly 20 years and has shown that their use is a functional replacement to theodolites and simplifies range operations. Not to mention that implementation will eliminated track lost or non-converging flights that work to the detriment of the flier.

I agree with Dr. Kidwell's proposed change. 

Agree this is the way to go from here on forward. I do have two points to consider. 

First, remove the 'must be returned' part from 20.4.  There is no reason a Flight Sketch altimeter needs to be physically 'returned' to a table.  If it's lost/in tree/etc, correct altimeter can be verified by its unique serial number via bluetooth link.  And there are sure to be several other altimeters that can be read without bringing it 'back' available in near future.

Second, I would like to see that the higher performance record be the one that stands, in cases where there are both 'optical' and 'altimeter' records, with the lesser being retired.  For example, if C Div. B ALT records are 500 meters optical and 450 meters altimeter, then the 500 meter record stands with 'optical' listed in the altimeter type column on records list.  The 450 meter altimeter record would be the one retired in this case.  If those numbers were reversed, then it would be the altimeter record that stands and the optical that would be retired.  In this way, we are preserving that actual highest performance, not by how it was recorded.  Also, with probably the exception of 1/8A events, altimeters are now higher performance than tracking powder; no way you're getting a powder cloud for less than one gram of dust. :)

A couple of typos - "Scope" in 20.1 should be bolded - but this change is way overdue. I think there are only a handful NAR members left who can do proper optical tracking. 

This is a sensible change. I do not see anyone wanting to track optically ever again.