Canadian Search Area Definition (CSAD)

Minnesota Wing Air Branch Director Course

What is CSAD?

• Canadian Search Area Definition– A method of determining the POC for a missing

aircraft using statistical information from a series of Canadian studies of crash locations.

Sources of Data

• Several studies of Air Distress Cases conducted by the Canadian Department of National Defense, Operational Research Branch between 1974 and 1987.

• An additional study was made by John Desmarais looking at 1999 cases in the United States. His results were comparable, though not identical, to the Canadian data.

The Goal of the Studies

• Where were missing aircraft found relative to their intended track?– Distance from LKP along the intended track,– Distance offset from the centerline of the

intended track.

Findings• Distance along track (without consideration of how far off course):

– Cases were spread fairly uniformly along the track (97.4%). Why?– There was a concentration of cases near LKP and the destination.– Slightly more cases occurred in the last half of the track. Why?

• Distance offset from track--off course (without considering track distance)– There was no correlation between length of flight (actual or intended)

and the distance offset from track centerline,– 61.8% of cases were found within 5 nm of track centerline,– 78.9% within 10 nm,– 82.9% within 15 nm, beyond which little was gained.

The Goal

• The goal was to define a search area large enough to be very likely to contain the missing aircraft, yet small enough to be able to be searched. Trading off these two elements, the researchers coined the CSAD search area:– A box, 10 nm on each side of the intended/expected route

of flight.– Generates POC = 76.8%

Probability Along Track• Probability the aircraft is between the LKP and a point

(as a percentage of the intended route length) along the route of flight.

Probability of Offset

• Probability the aircraft is within a given distance from the centerline of the intended track.

So how do we use this?

• To use this method, you need:– LKP - Update your search area as your

investigations refine LKP– Destination– Intended or expected route

• We can use CSAD to calculate POC:– POC = (Probability of Offset) / (Probability Along

Track)

Limitations

• It is historical data based on where aircraft have been found in the past. Your pilot may not be “average.”

• Does not take into account clues or other factors.– Works good for initial searches when you have

few clues. Once you have clues, use your judgment and experience.

Questions?