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-   -   Helicopter drops large air conditioning unit onto Oakland street 10Jan2021 (https://www.pprune.org/rotorheads/637969-helicopter-drops-large-air-conditioning-unit-onto-oakland-street-10jan2021.html)

mnttech 10th Jan 2021 20:16

Helicopter drops large air conditioning unit onto Oakland street 10Jan2021
 

Witnesses tell the Mercury News that nobody was hurt when the cables snapped and the unit about the size of a truck fell onto the pavement and sent construction workers running for cover on Saturday.
I don't really know, but that does not look like a snapped cable???? Or the hook was released???

News video

staticsource 10th Jan 2021 20:52

Pressed the hook release instead of the PTT button?🤷‍♂️ If that’s even possible on one of those machines? It is on the 350

treadigraph 10th Jan 2021 21:01


gulliBell 10th Jan 2021 21:52

I wonder if they'll still charge them for the helicopter rental after splattering the load?

rotorrookie 10th Jan 2021 21:59

Hopefully all ground crew escaped unharmed

rotorfan 10th Jan 2021 22:12

I fly for fun, not work, so have never seen a pickle. I would think the pilot must be instantly ready to release the load, but that the switch itself would not be overly sensitive so you couldn't drop the load by being a bit anxious. How much effort does it take to pickle?

ShyTorque 10th Jan 2021 22:54

On all types I’ve flown the load release button is very similar to switches used for trim release/SAS disengage or floats actuation but they are guarded by a flip type cover.

Some switches are actuated by pressing the guard which is flipped over through 180 degrees.

One type I flew (S-76) had the float actuation switch in the place on the cyclic where the load release was on the previous type I’d flown most (Puma). I had to think carefully when carrying out USL work.

tr7v8 10th Jan 2021 23:03

It looks pretty windy there what are the flying limits for a job like that. Done a few A/c moves in/out buildings but all with a rented crane, not a chopper.

Agile 11th Jan 2021 00:31

Interestingly, the rotor coning and blade tip water separation instantly terminate, the millisecond the load is out.

LTP90 11th Jan 2021 00:32


Originally Posted by tr7v8 (Post 10965205)
It looks pretty windy there what are the flying limits for a job like that. Done a few A/c moves in/out buildings but all with a rented crane, not a chopper.

The "windy" conditions you see is the rotorwash from the helicopter.
It could have been a hook failure, an accidental release or a commanded release. I don't see anything that would suggest a reason to purposefully punch off the load. I have seen hooks not lock completely and fail in this manner after taking load for a short amount of time. I have also seen hooks just plain break and drop a load. Or they hit the button accidentally. This ship had been on fire contracts with a tank for the majority of the year, and maybe during reconfiguring it, people forgot what switch did what?

This is one of the reasons I was taught to never turn my back to a helicopter/load, and minimize or eliminate time under a load.

megan 11th Jan 2021 00:50

One event of a load release was caused by a transmission being made on HF radio, load dropped onto a freeway, no one hurt or vehicles damaged.

Bksmithca 11th Jan 2021 01:28

Correct me if I'm wrong but on the Skycranes isn't the load controlled by an operator sitting behind the pilots facing the load. Would he or she not have control of the load release button?

Old Farang 11th Jan 2021 02:41

What ever the cause of the release; that strop is WAY too short!

capngrog 11th Jan 2021 04:02

I at first thought that it may have been a vortex ring state event due to the surrounding buildings; however, in the video, I didn't see any settling of the helicopter as it was picking up the load.

At least it looks to have been an expensive incident instead of a painful (or fatal) one.

Cheers,
Grog

Nescafe 11th Jan 2021 04:29


What ever the cause of the release; that strop is WAY too short!
There aren’t many rookie lift pilots on the sky crane fleets. Maybe they actually know what they’re doing?

mijbil 11th Jan 2021 06:43

Rotor wash
 
LTP90 is very correct about the rotor wash. Years ago I was landing a C172 at the local strip and one of these Skycranes was adjacent to the runway near the approach end. It was running with the rotor disk turning but firmly on the ground. Even with the blades at fine or flat pitch (ie not pulling pitch) there was enough rotor wash that in the flare as I was landing I thought for a split second that I was going to cartwheel and crash as the right wing flipped up about 20 degrees. It felt like 50-60 so I'm guessing at 20 but it was a serious gust when not at all expected.

SuperF 11th Jan 2021 09:01


Originally Posted by Nescafe (Post 10965301)
There aren’t many rookie lift pilots on the sky crane fleets. Maybe they actually know what they’re doing?

Agree. For real precision, its best to be as close to the load as possible. You can't see your ground crews fingers from the top of a 100' line.

old,not bold 11th Jan 2021 11:41

Reminds me of when the Navy first got the Wessex to replace Whirlwinds....first practice landing from Albion on to Lulworth Cove area, full Commando plus us CDO Gunners; my command post Landrover took a dive into the sea when the LH seat pilot said "What's the time" and the RH seat pilot replied "1005" but pressed the hook release instead of the PTT, because they were the opposite way round from the Whirlwind's. That was his story, anyway.

Gordy 11th Jan 2021 16:12


Originally Posted by Old Farang (Post 10965275)
What ever the cause of the release; that strop is WAY too short!

Not really. Most down town lifts with the crane are done on short strops. Part of it has to do with safety zones. We have to have a safety zone typically radius of 1.5 times the maximum eight of the aircraft. If you use a 100' line, that adds 150' radius to your safety zone, and that gets expensive when paying for the cops to close more streets.

Typically these are done at first light on Sunday mornings as there is less people around.


Originally Posted by Bksmithca (Post 10965247)
Correct me if I'm wrong but on the Skycranes isn't the load controlled by an operator sitting behind the pilots facing the load. Would he or she not have control of the load release button?

Not always, but in this case you may be right. FYI, that "operator" is a pilot and is able to control the whole aircraft from that seat.

treadigraph 11th Jan 2021 19:20



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