Whiplash hand-launch report with Jett BSE 60L FIRE
06-11-2003, 01:01 AM
#1
Whiplash hand-launch report with Jett BSE 60L FIRE
On my previous one and only flight with my Jett BSE 60L FIRE powered Whiplash off a launcher it nearly pulled the holding pin right through the back of the airplane. I kinda figured I probably had enough power to hand-launch it like my Diamond Dust but wasn't really sure.
I finally had the chance to get out again today and figured I'd give it a try. I was fully prepared to stuff the thing into the ground figuring I was planning on sending the engine back to Dubb for crazy re-timing anyway. What actually happed left me stunned.
The 60L turning a 10X8 at 16,000 static rpm generates tremendous thrust, a lot more than I expected. I fired the thing up, grabbed it between the elevons and took it out for my classic Dustflyer Diamond Dust launch.
Figuring the thing would probably drop to within inches of the ground before I got enough lift to stay in the air I was ready for the worst.
I revved up the engine, brushing the throttle stick against my cheek the way I always do and that crazy motor nearly pulled me over! OK, that's a bit of an exaggeration, but let me tell you it yanked itself right out of my hand!
The torque was nuts, I was in a 45 degree left bank instantly but was able to get things under control. I launched at a 45 degree up angle but could have easily just let it go straight up! It was literally like firing the Whiplash out of a slingshot.
Speed? Here is a case of an airplane doing exactly what it is supposed to do according to "speed calculations." The reason is sufficient thrust. Out of a dive it all depends on how high up you start. I know what 200 mph looks like and I know what 150 mph looks like. I would say I was hitting at least 175+ today.
I very quickly realized I could trade some prop diameter for pitch or rpm. I had more than enough thrust. Unfortunately it was getting late and I had to pack up but before I did I was able to check two more props on the ground.
First a 10X9 APC. No good. It's a strong engine but it's a 60, not a 90. Tried lengthening pipe by 1" to no advantage. Will have to try clipping the prop 1/2".
Next a stock 9.5X8.5 pylon wide blade. 17,500 rpm. Not bad but a clipped APC 10X9 or possibly a clipped MA 10X10 might be just right. Didn't have time to fly it today but definitely will on my next time out.
I finally had the chance to get out again today and figured I'd give it a try. I was fully prepared to stuff the thing into the ground figuring I was planning on sending the engine back to Dubb for crazy re-timing anyway. What actually happed left me stunned.
The 60L turning a 10X8 at 16,000 static rpm generates tremendous thrust, a lot more than I expected. I fired the thing up, grabbed it between the elevons and took it out for my classic Dustflyer Diamond Dust launch.
Figuring the thing would probably drop to within inches of the ground before I got enough lift to stay in the air I was ready for the worst.
I revved up the engine, brushing the throttle stick against my cheek the way I always do and that crazy motor nearly pulled me over! OK, that's a bit of an exaggeration, but let me tell you it yanked itself right out of my hand!
The torque was nuts, I was in a 45 degree left bank instantly but was able to get things under control. I launched at a 45 degree up angle but could have easily just let it go straight up! It was literally like firing the Whiplash out of a slingshot.
Speed? Here is a case of an airplane doing exactly what it is supposed to do according to "speed calculations." The reason is sufficient thrust. Out of a dive it all depends on how high up you start. I know what 200 mph looks like and I know what 150 mph looks like. I would say I was hitting at least 175+ today.
I very quickly realized I could trade some prop diameter for pitch or rpm. I had more than enough thrust. Unfortunately it was getting late and I had to pack up but before I did I was able to check two more props on the ground.
First a 10X9 APC. No good. It's a strong engine but it's a 60, not a 90. Tried lengthening pipe by 1" to no advantage. Will have to try clipping the prop 1/2".
Next a stock 9.5X8.5 pylon wide blade. 17,500 rpm. Not bad but a clipped APC 10X9 or possibly a clipped MA 10X10 might be just right. Didn't have time to fly it today but definitely will on my next time out.
06-15-2003, 12:15 AM
#2
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slinglash
I know that slingshot scenario well, mine does the same with the Jett 50 I got... of course I cheated, mine weighs less than the production model... glad you were able to hand launch without the drop experienced by some planes.. 
