OHTA.ca

Can anyone point me in the direction of case law supporting a margin of error for aircraft radar?

Thank you!

Its called the stop watch method. You calculate the time it takes to travel a known distance, and then that figure is punched into a calculation.

The speed obtained is the average speed over that time.

The formla is

S (speed). = D (distance)

__________ (divided)

T. ( time)

I know it doesnt answer your question but hope it helps

Thank you very much for the information.

Do you know if Disclosure should include information from both the officer on the ground and the officer in the plane? Would both be required to attend at Court?

Thank you again!

Yes to both. The officer on the ground is charging the person based on the person in the planes information. Both would be required to attend court.

paul1913 wrote:Its called the stop watch method. You calculate the time it takes to travel a known distance, and then that figure is punched into a calculation.

The speed obtained is the average speed over that time.

The formla is

S (speed). = D (distance)

__________ (divided)

T. ( time)

I know it doesnt answer your question but hope it helps

the officer makes no calculations, the stop watches that are used, automatically do the calculation and display the speed...FYI

Is there a requirement for the officer to prove that the stop watch was calibrated (same as for a radar unit)? What about the human error component? If the bear in the air starts the stop watch a fraction too late and stops it a fraction too early then the recorded speed is higher than the actual. The difference between 51 over and 49 over might be substantial?

hwybear wrote:

paul1913 wrote:Its called the stop watch method. You calculate the time it takes to travel a known distance, and then that figure is punched into a calculation.

The speed obtained is the average speed over that time.

The formla is

S (speed). = D (distance)

__________ (divided)

T. ( time)

I know it doesnt answer your question but hope it helps

the officer makes no calculations, the stop watches rthat are used, automatically do the calculation and display the speed...FYI

Either use the time / speed chart or radar/lidar to do it for you. Ive never myself done the actual calculations myself.

Let me throw a curve ball out here. The Aeronautics Act states that a commercial air service is any use of an aircraft for "hire or reward". Hire or reward is further defined as any payment , consideration, gratuity or benefit directly or indirectly charged, demanded , received or collected by any person for the use of an aircraft. (Aeronautics Act 3.(1)) A search of the aircraft registration database shows that none of the OPP aircraft are commercial aircraft.

Thusly - the aircraft was used in contravention of the federal regulations and therefore the charge should be withdrawn.

Comments?

It's some creative thinking, but I don't think the OPP's use of the aircraft would qualify as commercial air service. The OPP aren't ferrying passengers or requesting compensation for their services.

riggyzomba wrote:The Aeronautics Act states that a commercial air service is any use of an aircraft for "hire or reward". Hire or reward is further defined as any payment , consideration, gratuity or benefit directly or indirectly charged, demanded , received or collected by any person for the use of an aircraft. (Aeronautics Act 3.(1)) A search of the aircraft registration database shows that none of the OPP aircraft are commercial aircraft.

Thusly - the aircraft was used in contravention of the federal regulations and therefore the charge should be withdrawn.

I can answer this one (I work in the aviation industry).

There are three possible things that the Certificate of Registration could state: Private, Commercial, and State. The OPP's airplane is not a Commercial Air Service; it is a State aircraft. Other things that would fall in this category include the Forestry Service, the Department of Fisheries and Oceans, the RCMP, etc. Commercial Air Services include flight instruction, aerial survey, airlines, etc. Any aircraft used in the service of the state, even if monetary penalties may be assessed as a result of its use (e.g. speeding tickets, or F & O busting people for illegal fishing), do not fall into the category of "hire or reward," because the actual purpose of the aircraft in this case is enforcing the law.

This post started off asking about the margin of error - can we get back to that?

Is there a requirement for the officer to prove that the stop watch was calibrated (same as for a radar unit)? What about the human error component? If the bear in the air starts the stop watch a fraction too late and stops it a fraction too early then the recorded speed is higher than the actual. The difference between 51 over and 49 over might be substantial?

I don't even think they would use a stopwatch when a Genesis II Select Directional radar unit has the capability of measuring speed over distance built into it. All they need in the aircraft is the remote and the display box. Set the proper distance between the marks on the highway and simply start and stop when a motor vehicle hits two of the marks. All that is left for any doubt or question would be if the officer was starting too late and stopping too early.To get around this I'd make it a habit of not stopping it until the rear of the vehicle passes the line. This always gives the advantage to the driver.

Decatur wrote:I don't even think they would use a stopwatch when a Genesis II Select Directional radar unit has the capability of measuring speed over distance built into it. All they need in the aircraft is the remote and the display box. Set the proper distance between the marks on the highway and simply start and stop when a motor vehicle hits two of the marks. All that is left for any doubt or question would be if the officer was starting too late and stopping too early.To get around this I'd make it a habit of not stopping it until the rear of the vehicle passes the line. This always gives the advantage to the driver.

With either the watch or your set up here, human error is present in the reading, the officer needs to press a button at the correct time<<<<.

As to the original question, seeing as no one here seems to have direct knowledge, I would ask in court.

Something to this effect, "What sort of certainty do we have that the measuring device the officer in the plane was using was functioning properly at the time?"

Every other speed measuring device used by the police has some sort of self test, these should as well.

Just my 2 cents........

A stopwatch IS USED in the aircraft. The stopwatch does the calculation and shows the officer the speed. The stopwatch is tested by 2 means:

- obtaining a speed of a cruiser going thru the "zone" and then confirming the speed on watch vs cruiser

- there is a "800" number that is called which tells time (I don't know the number off hand), however start the watch and it counts time and stop same on the voice recording

One has to remember the aircraft method is way more in favour of the defendant, as it is a minimum distance of 500m, at 100km that is 18sec, the defendant speed is an average over that whole duration.

Comparatively, just as accurate is radar, which is normally only 2-3 sec of tracking or lidar which is less than 1sec of targetting.

So if you're doing 151 km/hr, the time thru the zone is 11.92 sec but if you're doing 149 km/hr, the time thru the zone is 12.08 sec - difference of 0.16 sec. Given the distance between the officer in the plane and the subject vehicle it could be argued that the accuracy of the officer's reaction time resulted in too high of a speed recorded. I'm thinking that the difference in penalty between 151 and 149 is fairly high?