1+45 Convention

[Timothy]

Garmin use 1+45 to represent what I might call 1h45, or possibly 1:45 (though that’s a bit confusing, as it looks like a time of day, rather than an elapsed time.)

I thought that that was maybe a Garmin thing, but I’ve been reading John Deakin’s book Full Throttle and I see that he uses the same convention (he also uses “ded reckoning”, which I consider to be an affectation, but we’ll let that pass).

So does anyone know anything about the history of that convention?

[India Four Two]

I can't help you with the history, but in Canada, the convention for flight-planned ground stops is ".....CYYC 0145 CYYC ...."

[megan]

uses “ded reckoning”, which I consider to be an affectationThe term "dead reckoning" was not originally used to abbreviate "deduced reckoning," nor is it a misspelling of the term "ded reckoning." The use of "ded" or "deduced reckoning" is not known to have appeared earlier than 1931, much later in history than "dead reckoning," which appeared as early as 1613 in the Oxford English Dictionary. The original intention of "dead" in the term is generally assumed to mean using a stationary object that is "dead in the water" as a basis for calculations. Additionally, at the time the first appearance of "dead reckoning," "ded" was considered a common misspelling of "dead."

Could give a link to a lengthy explanation but don't want to load the Mods with work.

[Timothy]

Could give a link to a lengthy explanation but don't want to load the Mods with work.

Sorry, I know about ded reckoning, and it’s easy to look up, that was a read herring.

It’s 1+45 that fascinates me. What fascinates me much more is that no-one seems to know.

I’m attending a Garmin seminar this evening, I’ll ask them to ask!