Grass fields

Spank

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Oct 22, 2016
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103
Location
Fort Worth, TX
Is there any concern flying off/basing an M24 at a grass strip? I'm thinking it may be unusually hard on it and not recommended. Would it shorten the life expectancy of the frame, etc.? I've heard some people spool up the blades to take the "bounce" out of them while taxiing. Your thoughts?
 
There have been varying opinions about taxiing with blade rotating and blades stationary.

On tarmac one sentiment is that there will not be much flexing of the blades and therefore having them stationary does not impose too much stressing, but when travelling on grass, it is more likely there will be more flexing and therefor having them spooled up to a RRPM that cones them is better for the blades.
 
With magni having a frame made from Chromo which is among the best airframe material, it will be at least as good as anything else.

wolfy
 
I've lived on a grass strip for the past 6 years and my best advice is to lower the tire pressures and taxi slowly.

You can't taxi downwind with blades spinning unless it's nearly calm.

Eric
 
...You can't taxi downwind with blades spinning unless it's nearly calm.
Eric
You can if you increase your ground speed sufficiently to keep incoming airflow to maintain or increase their rrpms while taxying.

But, it becomes unsettling to the pilot's stomach to taxi that fast w/ higher DW airflow. If you taxi slower than the wind DW (while trying to keep the blades spinning @ a good clip) then you start having the rotors behave badly, shaking the living daylights out of the cyclic.

They don't like the pilot trying to suddenly force them to higher airspeeds than where they are @ w/too little inflow of air. I speak from experience...
 
Flew a Bensen with no prerotator for a while. She had Rotor Hawk blades, later Rotordynes, and I went everywhere with the blades turning. It was a big airfield with little traffic and no tower

Yes the taxi speeds could be high but I had no issues taxiing up or down wind.

This admittedly was an unusual circumstance and at a busy airfield high taxi speeds would be unacceptable. There I taxied slower with a still rotor and patted up at the hold which in light winds could be tricky.

Adapt to circumstance.
 
Learned to fly in Australia on grass strips from a 747 Captain/Gyro CFI. Always had the rotors spinning at about 100 rpm for taxi. Upwind and downwind and crosswind.
 
I always walk the grass field to look for pothole and sod poodles and chuck holes if possible. a can of marking spray paint is helpful.
I have not seen one in the flesh, but my understanding is one hard jolt to a Cavalon is enough to crack structural parts. Not Sure if the M24 is built the same way...
Also keep an eye on the dew on the grass in the early morning flights.....
 
I've lived on a grass strip for the past 6 years and my best advice is to lower the tire pressures and taxi slowly.

You can't taxi downwind with blades spinning unless it's nearly calm.

Eric
Eric
Why do you feel that you can't taxi downwind with blades spinning?
Mike G
 
Eric
Why do you feel that you can't taxi downwind with blades spinning?
Mike G
I typically don't taxi faster than a fast walk on grass or it shakes everything on the aircraft. By lowering the tire pressures and taxiing slowly it keeps from beating up the machine and especially the nose gear. It works for our gyro and for our 172.

Our average winds here are 10-15 with higher gusts. To keep the rotor blades spinning at minimum would mean taxiing downwind at 25-30+ mph. Let's say you land, flatten the rotor, turn around and now need to get to that speed before the rotor speed decays. You're going to need a lot of throttle to get there quickly or else stop and prerotate with your back to the wind? What's your hurry?

We work at keeping our grass strip as smooth as possible and I still wouldn't call it smooth.. If I'm on an unfamiliar, unpaved airfield, there's no way I'm taxiing fast.

Eric
 
OK, but to rephrase Mike G's question, why is taxiing downwind worse with a spinning rotor than other directions?
Won't dissymmetry of lift be decreased taxing downwind as compared to upwind?
 
I always walk the grass field to look for pothole and sod poodles and chuck holes if possible. a can of marking spray paint is helpful.
"Sod poodles"? That's a new one on me but it certaing sounds colorful. Reminds me of dust bunnies.
 
"Sod poodles"? That's a new one on me but it certaing sounds colorful. Reminds me of dust bunnies.

Colorado: Snow Bunnies.
Arizona: Dust Bunnies.
 
I have not seen one in the flesh, but my understanding is one hard jolt to a Cavalon is enough to crack structural parts. Not Sure if the M24 is built the same way...
Also keep an eye on the dew on the grass in the early morning flights.....
I took a pretty good whack landing on a tricky grass runway on Monday in my Magni, enough to make me look everything over. I lost a fleck of paint on one of my composite landing struts so I may have stretched that more than ever before, but otherwise all seems fine.

Totally agree about wet grass, especially if it's even a little bit on the long side.
 
For those of you not aquanted with Western US hunting vernacular....
Sod Poodles = Praire Dogs...vicious little creatures who gang up on you and carry Bubonic Plague and enjoy destroying airstrips almost as much as farmland.
Speed Goats = Pronghorn Antelope, a creature that single handedly created the need for the .220 Swift as it can magically out run any boolets slower then 4000 fps. Tastes best when mixed with pork.
Jackwaggon = Jack Rabbit, a hare faster then your your average cottontail, moves quick enough they appear to have wheels.
Pigs =Javelina, a powerful fierce rodent that has been known to snatch babies from their cribs! So tough an animal they eat cactus needles and spit out the soft parts. Able to tear your kneecaps out from the next county.
Flying Rats = Mourning Doves...self explanatory.
Dogs = Coyotes, they can be very wily.

Hope this helps
 
Colorado: Snow Bunnies.
Arizona: Dust Bunnies.
Not even close to the same!!!
Only one looks incredible with Spanx and a mug full of hot cocoa spiked with Kahlua......
 
Speed Goats = Pronghorn Antelope, a creature that single handedly created the need for the .220 Swift as it can magically out run any boolets slower then 4000 fps.
Thanks for that translation! I have encountered and been mystified by pronghorns. I think they may be the only animal capable of quantum mechanical tunneling (on one side of a fence one moment, and on the other side the next moment, with no apparent warm-up, wind-up, run-up, or jump in between). I brushed one while landing a glider on a grass field once, after a whole herd did that trick on the airport boundary fence. Mistakenly assuming I wanted to catch rather than avoid them, they zigged each time I zagged, a strategy that kept them always returning to my path despite my best efforts to avoid them. A "prong" left a visible mark on the aircraft.
 
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Thanks for that translation! I have encountered and been mystified by pronghorns. I think they may be the only animal capable of quantum mechanical tunneling (on one side of a fence one moment, and on the other side the next moment, with no apparent warm-up, wind-up, run-up, or jump in between). I brushed one while landing a glider on a grass field once, after a whole herd did that trick on the airport boundary fence. Mistakenly assuming I wanted to catch rather than avoid them, they zigged each time I zagged, a strategy that kept them always returning to my path despite my best efforts to avoid them. A "prong" left a visible mark on the aircraft.

I was on a project at a bombing range with pronghorns. They were not hunted there, or afraid of us. They would often lay down about 50ft. from us and just watch....
We were told to not drive near them when they were near a fence, because they "don't jump" and will tear themselves up running against the fence.
The ones I have seen in northern Az. don't let you get closer than 1/2 mile......

I walked out my door into the shop area and literally ran into a javalina trying to get into a bag of cat food. It was 50ft. inside the building!
I harshly said "Get out of here" and it made a sort of hasty retreat...
 
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