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Hello John Lorbiecki
Well for an honest 5.1 second engine run or less, or which is it 5.0 or 5.1, to hear the engine run on the ground at that time means that you need to set the timer at 4.5 seconds. From 400 feet, it takes approximately .4 seconds for the sound to get back to the timers ear.
Or does everyone set their timer at 4.8 seconds, and go up in flocks so the timer, timers, have no clue as to when anyone’s engine is still running, and just say OK, I did not hear that? Or set up the bunt so the engine is still running as the model bunts, and the timer thinks that since the model has bunted that the engine has quit?
I don’t fly F1C, but I have always had a hard time determining the engine run on flights that I have timed.
Hey….
Yup, timers are anywhere from 4.4 to 4.6 on the ground to get that magical 5.09….. You really do have to take in account the altitude and distance. Makes quite a difference if you are next to the flyer timing the run verses a distance away and timing. That could be where some folks have sworn that a flyer had an over run but they were farther away- 700 or so mph is the speed of sound so it does take some time…
Really hard to bunt with the engine running as it doesn’t gain ya any altitude and will definately take it away!…But there are people that push the runs when you have the gaggle going up all at once. Timing engine runs is, well, an art, I guess you could say. And some people are artists and some are color by numbers…Will never mention ANY names!!!
From Dave Edmondson
“Or does everyone set their timer at 4.8 seconds, and go up in flocks so the timer, timers, have no clue as to when anyone’s engine is still running, and just say OK”
That would suggest they are all, er, what’s the word ? Begins with ‘c’ I think, on the tip of my tongue …….
You can time engine runs sucessfully but it takes practice. If two timekeepers get within a few hundreths then I have always felt the time is accurate. Done this numerous times at different events of different standards with differnt people.
At the recent Euro Champs there were no complaints to my knowledge. The GBR team had two overruns; the team manger also got tham as overruns so good timekeeping.
CHE, it’s not the “c” word, but a competitive advantage….There are some that always push the run (and they are sometimes known) and if they get away with it, then so be it. If not, get out airplane number two and go again…..I am in awe how many AMA flyers leave so much on the table in regards to runs. I am so used to having them within a tenth or so that when the run is almost a full second off I just grin….
Dave Posner (GB – 2nd in 1956 W/C – designer of Dreamweaver) apparently used to stand behind the timekeeper and shout ‘Now’ in his/her ear as the second hand came up to the mark on the stopwatch.
Of course that was in the days when there was time from launching the model to actually do that. With 5 secs there’s scarcely time to blink before the engine has to stop.
John
Back in the 50’s Dave found one of my early Applehoney’s in the crops outside Sherburn-in-Elmet, Yorkshire after I’d left to drive back South. When collecting it I found he apparently lived in one room and shared a kitchen, etc. …. his furnishings – a bed, a large refrigerator and little else .. other than models.
That would be bed-sit living at its finest, I guess, Jim.
The phrase ‘Competitive Advantage’ came up with regard to pushing Engine Run to the limit (where 5.09 on the watch = 5.0 given). We know for a fact that a 5 sec recorded run is actually only 4.6, and we also know the way the rules are written. But, if the e/r is IN REALITY 4.6 secs then the ‘C’ word is definitely out of order – and so is the way the rules are written.
When a F1A is released the signal to start the watch gets to the timekeeper in less than a millionth of a second (less than 10 to the power minus 6 secs). Whereas in power it’s almost half a second!
To my mind we need a system that tells the timekeeper categorically when the engine stops – or we need a set of rules where it isn’t so damned sensitive. Wishing only to spark discussion, I think the rules as they stand provide an unsatisfactory contest.
Currently I don’t have any better ideas, however!
John
There has always been talk about how to get an accurate engine run. Since the advent of the brake, it has made at least the moment the engine stops a bit better, as they do stop now. However, there still is the guy pushing the button. I have seen people time to the bunt, but many of us delay the bunt so that really screws things up.
Some have said that we add a light. Others have said telemetry. But all in all, it still is s human somewhere in the line. We just need young ears and eyes to timer power models now adays…
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