Santa Barbara Skycrane crash

[John Eacott]

With fairly severe fires around Santa Barbara, there was a dramatic Skycrane crash over a week ago. Various reports are in the Santa Barbara Independent (http://independent.com/news/2007/jul/08/zaca-fire-copter-crashes/), with this photo:

http://media.independent.com/img/photos/2007/07/08/heli11.JPG



and the Santa Barbara News-Press had some exclusive photos taken by Ted Williams: I only have a scan of the front page,



http://www.eacott.com.au/gallery/d/226-1/SB+S64.jpg

http://www.eacott.com.au/gallery/d/230-2/Ted+Williams+photo.jpg


:eek: :eek: :eek:

[Perro Rojo]

Without knowing how fast the film was it's hard to say but it doesn't look like the tail rotor is turning.

[topendtorque]

Without knowing how fast the film was it's hard to say but it doesn't look like the tail rotor is turning.


looks like it is in the first photo, but not in the second one.
Looks like he could have dropped his lunch box on the cyclic, but man was he still hangin' in there on the collective, by the look of the coning angle??

Wind on the day?? looks like by the grass that he was right into the prevailing wind, rising ground, laden or mt??

how many left now? not all that many to start with and there's been a few bite the dirt in recent years

[Bushfire]

The photo sequence of the crash can be found at

http://www.wildlandfire.com/pics/zaca-helo/zaca-helo.htm

[John Eacott]

Bushfire,

Thanks! Looking at this photo, I wonder if the nosewheel castor angle would have been of any significance: is this a normal taxi angle, or more effect than cause?

http://www.wildlandfire.com/pics/zaca-helo/10.jpg

[WASALOADIE]

Possible Dynamic Rollover?

[FH1100 Pilot]

It's wierd. Watching that series of pictures is like watching the Zapruder film of the JFK assassination...

What strikes me as odd is that shot as the ship has started to go over but the blades haven't hit yet. There are two groundcrewmen standing off to the left of the aircraft. One of them apparently has a helmet on (guy from the helicopter, maybe?). The other (the truck driver?) has already started to beat feet outta there. Helmet-guy seems blithely unaware that his(?) helicopter is rolling over without him.

My guess is that the ship was not quite ready for take-off and got into an unintended liftoff/rollover of some sort, perhaps like that Puma in New Orleans after Katrina. News reports say that a "pilot and copilot" were rescued from the ship, which causes me to wonder: How many people normally crew a Skycrane in flight? Secondly, do Skycranes have a low-rpm "ground idle" setting? In other words, were they at 100% NR?

Just asking.

[206Fan]

Flipn hek, not a pleasent site.. Theres normally a 3 man crew on the cranes, pilot/co-pilot and the tank operator in the back cab, wel watever is attached to the crane the operator in the back handles it while the pilots concentrate on the flying!

[Scissorlink]

Another set of blades gone


SL

[Cyclic Hotline]

The Crane is flown with a two man crew, the rear seat is seldom, if ever used, since the advent of vertical reference operations. It was most typically used for construction over any other operation and would certainly never see use in firefighting.

Initial reports suggest the focus of the investigation is on maintenance activities on the main rotor servo. Heavylift is now reportedly removed from the Forest Service contract and their remaining 54A and 53D grounded.

This also shows one of the great hazards in this design, the exposure and relative structural weakness of the cockpit from the rest of the airframe.

Amazing sequence of pictures! Incredibly lucky for everyone in the aiercraft and on the ground.

[JimEli]

early in the sequence of photos, it shows crewman climbing the main gear supports, and appear to be examining something on the top. is the helo running at this time?

[206Fan]

Yup engines are running, seems to be plenty of space between the ground crews head and the main rotor blades anyway.

[Cyclic Hotline]

Yes, the machine is running, this is a standard procedure on the Crane as everything is visible, and the deck is a mass of lines and fluid systems. There is a guy up on both sides.

They were extremely lucky not to have been up there when it rolled over!:uhoh:

[SierraEcho]

Read at another forum that a control tube snapped causing the rollover.

[QNH1013.2]

Look at the extreme "dihedral" on the blades in the following pic (The blades aren't flat). Looks like this excessive angle has been caused by a large control (cyclic) movement at low RPM which does indeed look like some kind of control snapped. If the helmet guy wasn't standing there, it would look like it was taking off, but possibly at low RPM. The nosewheel looks like it does because it's turned to starboard due to the pressure applied to it.

http://www.wildlandfire.com/pics/zaca-helo/10.jpg

[Mast Bumper]

FH1100 Pilot,
take this for what it's worth, since I haven't ever flown a 54 or 64, but have much experience flying other heavy type 1 Sikorsky helicopters on fires.
We always hot-refueled at 100% flight idle and NOT at ground idle, since many systems require AC power and the AC generators drop offline below a certain NR. You would have to start up the APU if you wanted to reduce the throttle quadrants to idle and still maintain power to the various systems and cockpit indications.
I've spent much time at a helibase next to a 54/64, but can't seem to remember if they reduce power to ground idle during refueling or keep it at flight idle. Maybe someone with the appropriate experience could enlighten us.

[maxtork]

Back when I crewed a crane we always hot refueled at flight idle not ground idle. I know some of the other companies didn't always follow the rule but we tried to void ground idle as the planetry gears in the main gerbox were not properly oiled at lower speeds. Not sure how much truth there is to it but thts what we got from the guys in the OH shop so we always tried to avoid it anyway.

Also in reference to the dihedral on the blades, I see it as being normal or at least close to it. The E model 64 ( A model 54) normally got a really good cone to the blades on take off. The F model (B model 54) seemed a bit less so but I didn't spend much time on those so I wouldn't swear to it.

Glad they made it out ok at any rate!

Max

[Cyclic Hotline]

NTSB Identification: LAX07LA210
14 CFR Part 133: Rotorcraft Ext. Load
Accident occurred Sunday, July 08, 2007 in Los Olivos, CA
Aircraft: Aviation International Rotors CH-54A, registration: N44094
Injuries: 2 Minor.
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.
On July 8, 2007, about 1608 Pacific daylight time, an Aviation International Rotors CH-54A, N44094, experienced a mechanical malfunction and rolled over during takeoff from a helibase about 4 miles north of Los Olivos, California. The helicopter was operated by Heavy Lift Helicopters, Inc., Apple Valley, California, under a "call when needed" contract for the California Department of Forestry & Fire Protection (CAL FIRE). The purpose of the flight was to support CAL FIRE's wildland fire suppression activities of dispersing retardant on a fire in Santa Barbara County. Visual meteorological conditions prevailed, and a company flight plan had been filed. The helicopter was substantially damaged. The airline transport certificated pilot and the commercial certificated copilot sustained minor injuries. The flight was performed under the provisions of 14 CFR Part 133, and it was originating at the time of the accident.

Witnesses reported that while the helicopter was on the ground at the southeast corner of the Figueroa Helibase on spot number 2, and at operating power, the helicopter began an uncommanded slow rollover to the right. The Federal Aviation Administration (FAA) coordinator examined the helicopter at the accident site.

The FAA coordinator reported to the National Transportation Safety Board investigator that components, which secure one of the three main rotor blade pitch change servo units to the helicopter, were found about 6 feet away from the main wreckage. The components consisted of a nut, bolt, pin, and plate. This assembly secures one of the servo units to the helicopter transmission on one end and the helicopter swash plate on the other end. The FAA coordinator additionally reported that the integrity of this assembly is critical to flight safety, and separation of the servo unit will result in loss of main rotor blade pitch control.

[I Build 92's]

SOP to climp up and look for leaks and such when we were running....even here at Sik. My question though, the article states that the pilot and copilot got out relatively unscathed...what of the maintenance crew man?? Can't see him in the cloud of dirt but you can see him up there in the picture before that.....

[Bushfire]

Skycrane for sale - Paintwork may need respraying

http://www.aigaviation.com/salvage/N44094/SalvageN44094.aspx (http://www.aigaviation.com/salvage/N44094/SalvageN44094.aspx)

[Two's in]

and separation of the servo unit will result in loss of main rotor blade pitch control.

...masterful understatement from the FAA.

[fly911]

"the rear seat is seldom, if ever used"
Does anyone have a picture or video of a SkyCrane rear flight controls installed or better yet, actually being used.
Thanks. Mike, fly911.

.
http://i135.photobucket.com/albums/q140/fly911/gr.jpg

[PT6ER]

The rear seat is used predominently for precision placement of loads and does a remarkable job (driven by very experienced pilots) considered the cyclic is very early fly by wire, the collective is mechanical

[Capt Hollywood]

Couple of vids for you showing rear seat operation.

Skip forward to 3:45 on this clip.
tkhqW2X6sGQ

Skip to 3:54
Sjivx6ZZhE8&feature=related

[Pilot DAR]

At the risk of it appearing that I know somethihg about Skycranes, which I really do not.... It does appear to me that the photos of the poor machine lying upside down, show a tail rotor with very little damage. It certainly does not apear that it was turning when it hit the ground. Would stopping the main rotor as happened, also stop that tail rotor that quickly? Or could some other failure have caused it's stopping before the rollover was finished? Either way, it happened quickly!

[Gordy]

Kenny is here with me in Michigan right now----will ask him in the morning....

[Solar]

Couple of a silly questions but when the rear seat is used does the rear seater have full control and are the cyclic controls reversed?

[Shawn Coyle]

The cyclic works in the correct sense - when you move the cyclic towards the front of the helicopter, the helicopter moves forward.

[JohnDixson]

Shawn has the control orthogonality correct. As to the question about "full authority": the rear cyclic acts thru the AFCS for pitch, roll and yaw. It has +/- 10 % authority, and that authority is shown on a cross pointer indicator. The 10 % control range can be shifted by utilizing the rear cyclic beeper trim, and the pilot can see where he is on the cross pointer indicator. "Back in the day" they'd make you fly around the pattern backwards from the rear seat before they'd sign you off.

Thanks,
John Dixson

[tony 1969]

Glad no one was hurt
Does the rear facing seat have yaw pedals? cant really see in the clip above. if they are there it appears the pilot is sitting over them rather than having them in front :confused:

[birrddog]

"Back in the day" they'd make you fly around the pattern backwards from the rear seat before they'd sign you off.

One can just imagine the confusion this must cause to unsuspecting bystanders...

The C150 in the circuit being overtaken by a 64 reversing around the pattern...

[JohnDixson]

Tony 1969, as I wrote, the rear cyclic has yaw control integrated. One twists the control and voila-the big ship turns. Before someone raises the obvious: yes, the major challenge is to make clean, single axis inputs.

Thanks,
John Dixson

[maxtork]

John,

If I remember correctly the S64E did not have the yaw function on the back seat controls but the S64F did. I remember riding left seat while setting a radio antenna and the back seat pilot had to ask for yaw adjustments from the pilot flying the right seat. I could be remembering it incorrectly or it may have been something operator specific. I would swear there was some differences though between the E and F model cranes in regards to the back seat controls.

Max

[jonwilly]

Loss of a wonderful cab.
I have always been impressed by the Skycrane since I had the chance to examine one close up when I was a young man.

john

[Graviman]

In sideslip does the system correct for the tail rotor yaw stability or is this just something you get used to?

Thanks.

[JohnDixson]

Maxtorq,

CH-54A/S-64E had a modified S-61 type AFCS, Rear seat accomplished yaw control thru the twisting of the cyclic, but required manual beeping to extend the pitch/roll axis authority range. CH-54B/S-64F had the RH-53D type AFCS. Yaw control was still done thru twisting the cyclic, but the pitch/roll authority range extension was different. My memory is hazy on this part, but I think the range was extended thru a trim reshift if you either got to some threshold of the existing authority or touched the electronic cyclic stops. Think it was the former. Maybe some old Crane pilot can help here. In any case, yaw was available on both, and thru twisting the cyclic. People will notice that on the newer SA fly-by-wire controls now in flight test, the yaw controls utilize electric pedals, making pure single axis yaw inputs a lot easier.

Thanks,
John Dixson

[JohnDixson]

Not sure what you refer to, Graviman. Both models had heading hold in the AFCS.

Thanks,
John Dixson

[tony 1969]

Thanks for the answer John it was in your original post.
I should just learn to read better :O

[PT6ER]

Erickson S64 machines do not have the yaw capability on the cyclic. Yaw control is accomplished by communication with the front seat pilot on the pedals.

[maxtork]

Ah! see I'm not losing my marbles after all lol

Thanks PT6er
Max

[fly911]

There were at least two different configurations in the aft facing pilot compartment. The attached photo depicts what I consider the higher visability version on the green ship and the quarter round plexiglass version in the military example on the left. Can anyone shed some light on which models were outfitted with which configuration? Also, thanks to all those that helped with my last request. Got some great pics and videos from that. Thanks, Mike

http://i135.photobucket.com/albums/q140/fly911/TwoFer.jpg

[JohnDixson]

PT6ER and Maxtork; just guessing, but Sikorsky sold the S-64 FAA Type Certificate to Erickson, and from what you both have reported, it sounds like they modified the rear seat control to remove the directional capability.

Fly911, I think your two pictures depict the two S-64 models, which had differing " back porches" as they used to be called.

Thanks,
John Dixson

[PT6ER]

Sikorsky built long and short cab versions.
For precision placement, the short cab variety is preferred for the already stated visibility increase. Erickson has converted long cab to short cab versions, not sure if that was an original Sikorsky mod or not.
If you want some stomach turning fun, try to get a ride in the back seat while performing the logging mission - hard to believe there is so much relative motion :)

[maxtork]

PT6ER,

You aint just whistling dixie. I've done the back seat thing in a crane and it will sure scramble your eggs! Even on a firefighting mission it can get uncomfortable with the smell of smoke just adding insult to nausea lol

Max

[Maverick Laddie]

Oh yes I can confirm that after 10 hours of flying firefighting missions in that seat it gives you a sensation that has to be experienced to be believed, Hours later standing at the bar for that well earned beer you still have the feeling your moving backwards.

[Heli-Ice]

You just have to admire the crowd on top of that mast!

They ain't no innocent schoolboys up there.