Sling loading aeroplanes

[Big Foot]

Anyone have any experience with this?
Interested in how to rig the aeroplane so it doesn't fly itself.

[Sir Niall Dementia]

I have; it tried and I thought I was about to get a BN2 up through the belly of the aircraft!

After that we started deploying full flap on the aeroplane, leading edge baffles if available and flying slower. It's the stol types that are the the problem, if you had a fast jet it wouldn't matter.

A check on the stall speed is a bloody good idea and don't fly faster than that.

SND

[Outwest]

Tie cargo nets over the wings and elevators.

[SASless]

Tying cargo nets, 4x4 Timbers, or anything to act as “Spoilers” is a necessity. Use a long line to keep the load (airplane) well beneath the helicopter is the preferred method. Adding a drag chute incorporating a swivel also helps stabilize the load.

SLOW is good.....if the load begins to fly....release it and head home for Tea.

I had the unpleasant task of retrieving the bodies of five CHinook Crewmembers who had an O-1Bird Dog airplane fly up under the nose of the Chinook then back and up into the Aft Rotor System.

They were going way too fast and the underslung airplane departed from a stable ride too quickly for the Crew to respond.

[JohnDixson]

Only have one data point to support the advice given by SAS and SND: In 1970 took a CH-54 to the NJ docks to retrieve a F4U-4 Corsair for installation at Bridgeport Airport (whence the Corsair began its storied history).

A military airplane designed for carrier use, it had hardpoints for lifting and we rigged it to provide a slight nose down in flight attitude, Used wood for spoilers and a drag chute. Gear was down and we did not touch the flaps (wanting less lift). Aircraft was intact with engine and prop, so weighed approx. 9500 lbs as I recall.

In spite of all that preparation, the Corsair wanted to weave in a sort of Dutch roll at speeds above 50KIAS*, so it was a slow trip home, along the south coast of Long Island till west of the Hamptons etc. Good thing we had filled all the fuel tanks in the Crane.

* started out very slow, then incrementally increased speed, 10 kts at a time, to see how the plane would behave. Word of caution here: high volume/low density or aerodynamic shaped loads can sometimes exhibit satisfactory stability (relative term) a bit beyond where you can fly them comfortably and safely.

Note: “ Whistling Death “ is a great read by the Corsair project test pilot, Boone T. Guyton. The story of the development and testing of the Corsair, and supporting the USMC/USN units personally during the war. The Corsair equivalent of the excellent Spitfire book by Jeffrey Quill.

[SASless]

Minimum lift on the airfoils is the objective.....you do not want the airplane to “fly”.....you want it to “ride”.

[JohnDixson]

Sorry SAS, Typo: “ nose down “ not, “ node down “.

[roscoe1]

https://cimg0.ibsrv.net/gimg/www.gmforum.com-vbulletin/960x1200/061206_f_2298c_006_960x1200_5e1e66d31ff2df8c015b64e3199a1607 14d360e1.jpg
A drogue parachute is often used to keep the nose aligned with the nose of the helicopter.

[ShyTorque]

I was once tasked by a certain civil aviation department to take them to a newly constructed major airport (not yet open) to find and recover an entire inboard flap that had fallen off a passing Boeing 747 the previous night. We found it (slap bang on the numbers of the main runway) in an intact condition. It was far too long to fit lengthways in the aircraft so CAD, who sent a couple of investigators along, wanted me to under-sling it in a net. I point blank refused because there was no way of predicting how it would travel, although I had a good inkling that it would behave exactly as the designer intended - i.e. it would fly)!

I got my crewman to lash it down laterally across the cabin floor, upside down and backwards, leaving both doors open and each end sticking out in the airflow. I flew it back like that at 50 kts, without any drama (just wish I had a photo to show for it).

[treadigraph]

CH-47 or CH-53 tasked with slinging a wingless C-46 from Miami airport to US Naval museum 1990s. Somewhere west of Fort Lauderdale, C-46 starts to spin, And spin. until its dropped...

[Aesir]

One can also sling them upside down. This one was very well behaved at 60kts.

https://cimg6.ibsrv.net/gimg/www.gmforum.com-vbulletin/617x711/screenshot_2018_07_07_00_28_35_59d864f9426b2c8d430ea5c1ff141 1e5afa2279e.png


Cessna 206 slingload

[Evil Twin]

One can also sling them upside down. This one was very well behaved at 60kts.

https://cimg6.ibsrv.net/gimg/www.gmforum.com-vbulletin/617x711/screenshot_2018_07_07_00_28_35_59d864f9426b2c8d430ea5c1ff141 1e5afa2279e.png


Cessna 206 slingload
Fella I knew in NZ did that with one under an AS355, only problem for the plane owner was that it had run off the end of the runway at Thames airfield into the sewage settlement ponds from where it was recovered.

[Thilo]

Hi Big Foot

I slung out two 210s and a 206 during the last year. We removed the engine and wings each time.

I don't seem to be able to post pictures for some reason. Let me have your email and I'll send.

Thilo

[ring gear]

I agree with Sasless,

We slung a IAI Arava of the PNGDF from Madang to POM in '96 under a KA32 upright and with wings attached. Used a 200' line, timber and nets strapped to the upper wing surfaces to destroy lift and empty cargo nets as trailing stabiliser drogues...worked well the whole way over the mountains to Pt Moresby....

[Lascaille]

Cessna 206 slingload

You really were there? Dude... (Not intended as any sort of accusation!).

This was really a serviceable aircraft?

This just seems iffy as anything.

It was picked up from a normal position and then inverted? Nosed down? What supported the aircraft during the inversion, the leading edge of the wing? It would seem feasible to lift it from the gear alone and let the tail drop, but what manufacturer would confirm that an aircraft can hang inverted from its gear?

Inverting it beforehand - probably needing two cranes - seems viable but then what? 'Dear Cessna, we have inverted our C206 for reasons. Please advise as to where we should place the jackstands. Urgently.'

I'd love to hear this story.

[malabo]

Airplanes under helicopters are frequent flyers around here. Lots of backcountry adventure and misadventure. Cargo nets on wings, 40-50 knots, some riggers tie a tree to the tail for extra stability. A350/407, 100’ line.

https://cimg0.ibsrv.net/gimg/www.gmforum.com-vbulletin/2000x1504/8ce6ab18a3ebc561b0cf623a_66b8f53cda2bafabca9b53003fc7dced63e c63ad.jpg

[Big Foot]

Good stuff.
Some good advice there thanks.
Good to know it can be done, most of stuff you hear on this is nearly always a pretty bad ending.

[Jelico]

I had a job last year that I initially thought was to retrieve a fixed wing, turns out it was a gyrocopter, so probably a fair bit easier to move than a plane. I did call a local legend pilot who had done it many times under a Lama, and he gave similar advise to the posts above: Strap some timber or anything to the top of the wing to spoil the airflow and therefore lift. Use a long line (minimum 100 ft). Sling the aircraft in a nose down attitude, and as mentioned above add some sort of drag /drogue chute to keep everything moving straight. I think that was pretty much it.

Small gyrocopters as it turns out sling surprisingly well

[Saint Jack]

OK, I know this is a thread drift but I'll be quick.... The photo in Post #8 of a Chinook carrying a stripped-down DC3 reminded my of a very similar event I witnessed when I was working for Bristow in Iran. It was at the Galle Morghe airfield in the south of Tehran, I heard the distinctive sound of a Chinook and went outside just in time to see the Chinook place the DC3 on the ground very gently, BUT, whoever rigged the DC3 used a VERY big drogue parachute to keep it stable. I'm sure it worked well - until the Chinook pilot released the hook - at this point the downwash kept the drogue chute deployed and, slowly but surely, the DC3 began to roll backwards. It accelerated slowly then slowed as the Chinook climbed away. It rolled some 30-40 meters and came to a halt without hitting anything.
The comment in Post #9 about lashing a 747 flap section laterally across the floor also reminds me of the time, again in Iran, when I was working on a seismic operation in the marshes at the southern end of the Iran/Iraq border. the customers personnel moved around in locally-hired canoes which were about 7-8 meters long. These were too difficult (and fragile) to sling-load so we would open both sliding doors of the 205/212 and lash them to the floor - never had a problem.

[Aesir]

You really were there? Dude... (Not intended as any sort of accusation!).

This was really a serviceable aircraft?

This just seems iffy as anything.

It was picked up from a normal position and then inverted? Nosed down? What supported the aircraft during the inversion, the leading edge of the wing? It would seem feasible to lift it from the gear alone and let the tail drop, but what manufacturer would confirm that an aircraft can hang inverted from its gear?

Inverting it beforehand - probably needing two cranes - seems viable but then what? 'Dear Cessna, we have inverted our C206 for reasons. Please advise as to where we should place the jackstands. Urgently.'

I'd love to hear this story.


Haha... well I really did not expect anyone to think that we actually inverted the airplane to transport it but I can see how that could happen. Sorry that I was not clear in my post and I sincerely hope no one else will consider doing that. But seriously the airplane had crashed and was totally wrecked and will never fly again and that was the position we found it in. The accident investigation board asked us to transport to better suitable area for ground transport after doing a preliminary inspection althoygh the cause of the accident was pretty straightforward case of mismanagement of fuel tanks.

But it sure did behave pretty nicely upside down under the helicopter :)

[Arnie Madsen]

This is my favorite

From Pete Peterson (free) PDF book .... "A Flying Story"

https://cimg5.ibsrv.net/gimg/www.gmforum.com-vbulletin/993x664/pete_peterson_book_flying_story_a803d547b87b7f5069b499efad65 581d5373897f.jpg

https://cimg7.ibsrv.net/gimg/www.gmforum.com-vbulletin/996x667/pete_peterson_book_flying_story__69ca11cd721aed8efb70a4b9060 ea397bf004261.jpg

.

[Arnie Madsen]

.
Regarding above photos ...... Anyone wanting further reading go to this helicopter pilot history blog ....... partway down the page is the link for the Pete Peterson (free) PDF book ..... some pretty good reading and helicopter history 1950's and on ..... northern Canada etc .... apparently Pete is in California and about 96 years old.

http://viking.twolaneroads.com/pete-peterson-a-flying-story-3/comment-page-1/#comment-779