The 2021 Aviation thread

Liquid

NFLTG
4,584
791
Over there
Wouldn't that push the plane down rather than providing lift?
From an above helo, yes!

I think the wind is a helo on the ground and spooled up, throwing off deflected rotor wash like @Waiex191 said...

Something about those micro wind waves look super localized and curved... I could also be suffering from confirmation bias!

 

Ventucky Red

Super Anarchist
11,413
1,213
From an above helo, yes!

I think the wind is a helo on the ground and spooled up, throwing off deflected rotor wash like @Waiex191 said...

Something about those micro wind waves look super localized and curved... I could also be suffering from confirmation bias!
From the AIM  https://airresearch.com/Pilots/AIM-08/Chap7/aim0703.html

7-3-7. Helicopters

In a slow hover taxi or stationary hover near the surface, helicopter main rotor(s) generate downwash producing high velocity outwash vortices to a distance approximately three times the diameter of the rotor. When rotor downwash hits the surface, the resulting outwash vortices have behavioral characteristics similar to wing tip vortices produced by fixed wing aircraft. However, the vortex circulation is outward, upward, around, and away from the main rotor(s) in all directions. Pilots of small aircraft should avoid operating within three rotor diameters of any helicopter in a slow hover taxi or stationary hover. In forward flight, departing or landing helicopters produce a pair of strong, high-speed trailing vortices similar to wing tip vortices of larger fixed wing aircraft. Pilots of small aircraft should use caution when operating behind or crossing behind landing and departing helicopters.

 
A funny helicopter downwash story - from when I was a student in an Enstrom F28A.  We were hover taxiing up to the pumps, where my fixed wing instructor was fueling the PA12 (that I learned to fly in) by standing on the wheel.  My helo instructor says "I got it" and then put a little oomph in the stop and poor Mike was like one of those log roller guys on the PA12 wheel.  Much colorful discussion followed. 

I seriously doubt you would use helicopter downwash to land slowly instead of wind.  The problem is how do you keep from crashing into the helicopter.  Nothing good would come of that.

These STOL machines have very light wing loading, very high power loading, and often devices on the wings to maximize coefficient of lift and delay stall.  A PA18 is an awesome STOL machine stock.  The guys in those videos have just taken the old super cub concept further.

 

Rasputin22

Rasputin22
13,894
3,453
    An old buddy of mine had a Lake Amphibian that he was trying to operate as a tourist beach bus in the Virgin Islands. He lived in St John but was denied use of the official seaplane ramp in Cruz Bay. It had been years since the Grumman WIdgeons had operated from that old ramp and when they left the US Park Service sort of appropriated the ramp since it was within their turf. Bert had to keep his Lake at the big airport in St Thomas which sort of defeated the purpose of having an amphibian. 

    Bert had been very generous with the guys at the airport fire station (cold beer and such) and they would allow him to rinse the salt water off his plane after the rare sea water landings. He had booked a trip running Antigua Race Week crew for the Gran Prix race boats direct from English Harbor to San Juan airport which was a huge timesaver and moneymaker for his operation. He had made a couple of round trip shuttles and returned to STT for a wash down before catching the ferry home to St John. He had brought some Antigua rum to the crash house firemen and finished washing down the trusty Lake and he hopped back in to taxi down to his tie down spot. He noticed a USCG rescue chopper with the rotors still turning just past the fire house at the FBO which was closed but didn't think much of it as he headed back east to his spot. Since the chopper guys couldn't fuel up that evening the headed back for the CG hanger and soon were overtaking Bert in the tiny Lake. Bert was the kind of guy who hated using his wheel brakes so as to not eat up rubber of brake pads and was really creeping along. As he turned onto one of the small narrow bridges over the big drainage ditch the chopper ran up close behind him and they instead of the wheel brakes used the collective to sort of flare their rotor which  pushed a big blast of rotor wash ahead of them and it caught the Lake by the vert stabilizer and spun it like a top. Bert's first clue was that his open canopy slammed shut and he was pushed into the low curb of the bridge which collapsed his nose gear and then the plane skidded on its keel until the main wheels stopped at the curb. He said that the tail went up and the nose was pointed down toward the bottom of the ditch when he heard the chopper add throttle to continue on past him but also throw another blast of rotor wash that was the coup de grace and push the plane over the edge. He said he make eye contact with the chopper pilot what had a 'Oh Fuck what have I done?!' look on his face but kept on going! The Lake smashed its nose into the muck as the rear wheels cleared the curb and the plane did a full pitchpole and ended up on its back. Bert did manage to shut the motor down to avoid a prop strike and also shut down the fuel and was still hanging in his harness straps shutting down the electrics so there would be no  fire risk when the crash wagon showed up. He was just pleading to them to NOT discharge the fire fighting foam from the hoses they were wielding since it is so corrosive that it would ruin the sensitive avionics gear and be an expensive replacement, not to mention the other damage. 

    Hard for the fire fighters to ignore training and habit and they hosed Bert and his plane down with the toxic foam. As he hauled himself out of the ditch he turned to see the CG chopper lift off and leave the scene of the accident and return to Roosevelt Roads over on Puerto Rico! He eventually got insurance money from the fiasco but the CG denied any fault for the whole scenario.

 

dyslexic dog

Super Anarchist
3,890
341
Michigan
Thread drift ala the electric plane. I'm in the midst of working out the plan for an electric 74 Ghia that I snatched from under Snaggy's nose. The reason for asking about this here is because a lot of you understand physics. I am in need of an education on Lifepo-4 batteries. Things like CV CC chargers? Where to get a good product? I'm a retired Master Electrician but mostly in the AC realm.

I would have started a new thread but I felt this was a better place to drift. Thanks  and no, I won't show tits. I been here too long.

 

dyslexic dog

Super Anarchist
3,890
341
Michigan
I need to fit them in various places. 3.2v 200ah cells. I need help in dimensions and cost. 
pic of what I bought. 
 

4CE001DB-3AEB-49EA-A8DB-7278FEE6D225.jpeg

 

Ventucky Red

Super Anarchist
11,413
1,213
Thread drift ala the electric plane. I'm in the midst of working out the plan for an electric 74 Ghia that I snatched from under Snaggy's nose. The reason for asking about this here is because a lot of you understand physics. I am in need of an education on Lifepo-4 batteries. Things like CV CC chargers? Where to get a good product? I'm a retired Master Electrician but mostly in the AC realm.

I would have started a new thread but I felt this was a better place to drift. Thanks  and no, I won't show tits. I been here too long.
These folks should be able to help you out.  From what my VW crew is telling me these guys are the best.

https://evwest.com/store/product_info.php?products_id=220

Also, head over TheSamba.com  I am 10000000% sure there is some VW mad scientist that has already worked out all the problems. 

Personally, I would rather see you keep it original, or drop a Subi 2.0 in there, but....  that's just me.

 
Last edited by a moderator:

dyslexic dog

Super Anarchist
3,890
341
Michigan
These folks should be able to help you out.  From what my VW crew is telling me these guys are the best.

https://evwest.com/store/product_info.php?products_id=220

Also, head over TheSamba.com  I am 10000000% sure there is some VW mad scientist that has already worked out all the problems. 

Personally, I would rather see you keep it original, or drop a Subi 2.0 in there, but....  that's just me.
Thanks, I got EV on my list and I bought the car through Samba. It will be able to go back to original without too much effort. 

 

Ventucky Red

Super Anarchist
11,413
1,213
Thanks, I got EV on my list and I bought the car through Samba. It will be able to go back to original without too much effort. 
DD - I am pretty sure you found this video.  Could you journal this... sure some of the motorheads here will appreciate it.




 
Last edited by a moderator:

billy backstay

Backstay, never bought a suit, never went to Vegas
I watched a few videos on the electric conversions, and one was featured on Jay Leno's show.   California company, Zelectric (IIRC) made it, and without changing any of the original parts, so that it could be converted back to original, if someone wanted to down the road. It was an older Porsche 911, and way cool, and fast~!

 

Latest posts




Top