Seaplane down off Miami Beach

[Onan the Clumsy]

Something on CNN at the moment but couldn't be sure if it was an amphib, floatplane or what. They got divers out checking. They said it happened about 15mins ago so not the 195 from Sunday.

[Two's in]

Dec 19 3:17 PM US/Eastern

MIAMI BEACH, Fla. - A propeller plane carrying at least 17 people crashed Monday off Miami Beach, and at least two people were killed, authorities said.

The plane went down shortly before 3 p.m.

"We're still trying to get people out of the water," said Javier Otero, Miami Beach Fire Department support services chief.

He said two people were confirmed dead.

[Onan the Clumsy]

gotta link (http://www.miami.com/mld/miamiherald/13443321.htm) from the Miami Herald

Plane carrying 19 people crashes off Miami Beach; fatalitiesAssociated PressMIAMI BEACH, Fla. - A propeller plane carrying at 17 passengers and two crew members crashed Monday just off Miami Beach, and there were some fatalities, authorities said.
The Chalk's Ocean Airways plane crashed into the water shortly before 3 p.m., said Miami Beach Fire Department support services chief Javier Otero. He said there were two confirmed fatalities and some survivors.
"We're still trying to get people out of the water," Otero said.
Otero said the plane was one that regularly schedules flights to and from the Bahamas, but he did not know immediately whether the aircraft was incoming or outgoing.
Television helicopter footage showed a debis field in Government Cut, the channel that ships take into the Port of Miami past South Beach. Law enforcement boats and helicopters were in the area doing searches. The were joined by others in private boats, on Jet Skis and on surfboards.
Chalk's Ocean Airways was founded in 1919. Its floating planes take off in the water. Chalk's aircraft have been featured in TV shows like "Miami Vice."

[20driver]

They fly some old Gruman amphibs (Widgeon's?) as a shuttle to a casino in the Bahama's. They have being covered in several articles in Flying etc

[PaperTiger]

... Gruman amphibs (Widgeon's?)...

Grumman Mallards converted to turbine (PT6) power.
Witnesses (FWIW) report 'explosion' followed by wing failure.

[er340790]

BBC: Seaplane crashes off Miami Beach

A plane carrying 16 people has crashed into water near Miami Beach in Florida, killing at least 12 people, US Coast Guard officials have said.

Fourteen passengers and two crew were on the seaplane, believed to fly regularly to and from the Bahamas.

The craft crashed into Miami's main shipping channel shortly before 1500 local time (2000 GMT).

Scuba divers, speedboats and helicopters are combing the crash site, trying to rescue any survivors.

Witnesses told local television that the airplane seemed to explode in the sky before it fell into Government Cut, the entry to the Port of Miami.

"There was a huge explosion in the sky, a big ball of smoke," eyewitness Frank Amadeo told local television, Reuters reports.

"It just sort of spiralled downward," he added.

The propeller-driven Chalk's Ocean Airways plane, equipped with pontoons for taking off and landing on water, crashed just off the southern tip of Miami Beach.

[rotornut]

cnn.com has the video of the rescue.

[1800-how'smyflying]

http://www.airliners.net/open.file?id=955591&WxsIERv

[visibility3miles]

19 Said Killed in Plane Crash Off Miami
By LAURA WIDES-MUNOZ, Associated Press Writer 12 minutes ago

A propeller-driven seaplane carrying 20 people crashed off Miami Beach within sight of the city's high-rises Monday, killing at least 19 of those aboard, authorities said. Witnesses said the plane blew apart in the air, and the FBI joined in the investigation.

Scuba divers and rescuers in speedboats struggled to reach the victims but found no sign of survivors as evening fell.

The Chalk's Ocean Airways plane — a twin-engine Grumman G-73T Turbine Mallard — went down around 2:30 p.m. after taking off from Miami for the island of Bimini in the Bahamas, crashing in a narrow channel used by cruise ships, the Federal Aviation Administration said.

The Coast Guard said 19 bodies were found. The plane was carrying two crew members and 18 passengers, including three infants, authorities said.

Because of witness reports of an explosion before the plane went down, the FBI sent agents to assist in the investigation, but there was no immediate indication of terrorism or sabotage, said Judy Orihuela, spokeswoman for the FBI's Miami field office.

"It's too soon to say whether we are going to get involved," Orihuela said. "We're just going to check it out."

Sandy Rodriguez, 14, said he saw the plane flying low with white smoke trailing from it and flames coming from the bottom. The right wing then fell off as the plane went down behind a condominium tower on Biscayne Bay in Miami Beach, he said.

"It exploded in the air and one of the wings flew out of there. The other part of the plane was on fire and it just went straight down," said Maurice D'Giovianni, 42, a surfer who was in the water at the time.

Coast Guard spokesman Dana Warr also saw the crash from the Coast Guard office on Government Cut. "Everything looked normal, I saw the aircraft take off like it does every other times. I didn't think anything of it when I saw the black smoke from the pier, until I then heard the Coast Guard alarms go off," he said.

The National Transportation Safety Board sent a team to investigate.

The plane went down in Government Cut, a channel that cruise ships and freighters take past South Beach into the Port of Miami. The channel is up to 30 feet deep near the crash site, but parts of the plane could be seen in shallower areas.

The skies were cloudy, but there was no rain or lightning in the area at the time of the crash.

Coast Guardsmen and emergency workers wearing protective suits hauled bodies up from rescue boats, rushing to find victims before darkness fell. Law enforcement speedboats, divers and helicopters took part in the search and were joined by others in private boats, on personal watercraft and on surfboards.

Chalk's Ocean Airways flies between Miami and the Bahamas, using planes that take off and land on the water. Chalk's aircraft have been featured in TV shows such as "Miami Vice." Its seaplanes take off in view of the port and the multimillion-dollar homes that dot islands in the bay.

Founded by Arthur "Pappy" Chalk in 1919, the airline thrived during Prohibition, taking bootleggers, their customers and customs agents to Bimini. According to the airline, its most famous regular passenger was Ernest Hemingway, who flew to Bimini to go big-game fishing.

One of its planes was hijacked to Cuba in 1974 and the company has since had a policy of not carrying enough fuel to get to Havana.

Two years later, the airline was sold to Resorts International, which owned properties on Paradise Island. Donald Trump bought it in 1988 and sold it a few months later to Merv Griffin. The owner as of 1995 was Seth Atwood of United Capital Corporation of Illinois/Atwood Enterprises.

According to its Web site, Chalk's operates 17-passenger Turbine Mallards.

According to FlightSafe Consultants' Airline Safety Web site, Chalk's has had no known fatal accidents. Similarly, the NTSB database shows no fatal accidents for Chalk's since 1982, when the database started.

The airline had no comment after the crash.

[alexmcfire]

There´s a pic of the aircraft just before it crashes, seem pretty badly on fire, see http://edition.cnn.com/2005/US/12/20/miami.crash/index.html

[con-pilot]

Christ, it looks like it was shot down, it wasn’t of course, but the early video I saw showed a wing on the breakwater and it showed definite smoke and fire damage.

How horribly sad.:sad:

[OVERTALK]

First thoughts on the Chalk Mallard accident is that those PT6 turboprops wouldn't take kindly to the maritime operating environment. Think sulfidation of turbine blades. You wouldn't need a large drink of water down an intake, just the relentless attack of salt to eventually weaken a blade or its fir-tree root. It's like rust.
I'll mount a photo of a sulfidated blade if I can find one. The only protection is to run a rinse-rack using very clean water. P-3 Orions and S-3 Vikings do that all the time at NAS rinse-racks (aka birdbaths). If a PT6 high-revving turbine wheel let go, or even just spat a blade and achieved a nasty imbalance, it could probably take the whole wing with it. That scenario accords with what's been reported thus far (smoky engine + explosion + wing separation).
Sulfidation, if not addressed continually, can create real havoc with a turbine engine, particularly if it's got a reverse pitch capability to help induce and ingest the salty marine air.

AFAIK all the Allison explosions were similar sudden events.... and wholly uncontained. The last one on my last squadron was anyway.

[rigpiggy]

PT6's are probably the most reliable turbine out there with a MTBF allowing Commercial IFR SE flight, please don't hijack. Don't know the frequency, but compressor washes and borescopes are mandatory. BTW there was a Beech 99 in AK that lost a blade. tore the engine off the mounts. The chances of a Grumman product losing a wing without fire or other ancillary cause is quite slim

[OVERTALK]

http://www.tsb.gc.ca/en/reports/air/2003/A03P0136/a03p0136_photo_1.jpg Photo 1.
Sulfidation of number 1 GP turbine

During the examination of the engine, it was installed in an approved engine test facility where a full test was attempted; however, the engine vibrated excessively and the test was aborted. Some smoke was evident during the spool down of the engine. The engine was then disassembled for inspection. Of the 38 blades on the number 1 gas producer (GP) turbine, 29 were damaged significantly. One was broken off close to its root, and most of the others were missing pieces. Examination of the remaining fracture surface of the blade that broke close to its root showed indications of a progressive failure (fatigue crack). The other fracture surfaces showed failure by overload. More detailed examination of the GP turbine blades showed extensive sulfidation corrosion1 (see Photo 1). The blade surfaces were flaking and there were fatigue cracks in many of the blades. The turbine first-stage nozzle labyrinth seal was damaged and the outer fibreglass packing was partially missing. There was soot at the joint between the turbine nozzle and number 1 GP turbine and thick, black, wet soot around the labyrinth seal and on the turbine coupling.

On 10 February 2000, Rolls-Royce Allison issued a Commercial Service Letter, Hot Corrosion-Sulfidation, describing hot corrosion (sulfidation) and suggesting that operators look for it. However, no periodic maintenance inspection was directed by Transport Canada (TC) and none was implemented by the operator with regard to sulfidation corrosion.

Engine compressor washing is recommended in corrosive and dirty environments. It is also prescribed when engine performance has depreciated, as noted from power assurance checks. However, there has been concern that some tap water can in itself be corrosive. Operators rarely do compressor washes when their helicopters are operating away from a salt environment. They will wash compressors when they can see dirt building up at the air intake, or when an engine is performing below specifications. It is not clear if compressor washing effectively cleans the GP turbine wheel.

[Ignition Override]

OVERTALK: You mentioned catastrophic failures of Allison engines.

A C-130B of the AFRES Squadron at Colorado Springs, CO, lost a plane and crew in the 90s. An engine lost a turbine blade, which might have sliced straight into the left wing, and into a fuel tank.

There was too little time to get to a low enough altitude and airport before the wing exploded. :ugh: At least there seem to have been no passengers onboard.

[North Shore]

Not sure that the PT6 and sulfidation of the blades is an issue here...there are several companies, most notably Harbour Air and West Coast Air, based in the harbour in CYVR that use DHC-3t and DHC-6 products on a daily basis, and have done so for many (20+) years. The engines go through a compressor wash every day. I'm sure if they had a problem with turbine wheels letting go, then Transport Canada wouldn't be letting them fly single-engined (DHC-3t) over what amounts to open water...nor would the companies expose themselves to that kind of liability. 'Course, Chalk's might not wash evey day?

[zakpeegoodus]

One of the Chalks pilots told me a few months ago that the company had had a few engine failures in the last year! Adequately maintained PT6 turboprops have proved reliable in the maritime environment. Given that, and his comments, it will be interesting what final conclusions are drawn.

We don't wish these things on anyone, and yet we may wish someone else was flying....

[SaturnV]

Video of the plane crashing into the sea with the trailing burning wing can be seen on
http://www.cnn.com/2005/US/12/20
/miami.crash/index.html

Look for the link to a 1:56 minute clip titled "Witnesses Recount Plane's Final Plunge".

[lomapaseo]

One would have to speculate pretty far on ones imagination, to suggest that a turbine blade failure could tear off a wing.

The historical data simply does not support it and neither does rumors nor hearsay.

[A2QFI]

I flew Folland Gnats in the 60s at a seaside location in North Wales. I recall a procedure called a LIX wash whereby some anti corrosion fluid was sprayed down the engine, while it was running, about once a week. I don't recall any corrosion induced engine failures; this was the Bristol Orpheus engine.

[Iron City]

So they haven't found all the bodies yet and we have a probable cause. Don't know whay there is an NTSB then, just call pprune.


To add a little data. The PT-6 was originally designed as a stationary power unit for water pumping in very hot dry foreign places. In it's aviation use it is a reverse flow turbing, that is, it takes air in toward the lower rear of the engine and then the air flows foward to the first stage compressor. There is a huge amound of centrifical separation that occurs and tends to shed rocks, bolts, and other FOD before it gets into the engine. How anything but massive fire hosing of water would get through this I don't know. Please don't compare PT-6 to T-56, Orpheus, and other stuff like that. The TF-34 on the S-3 aircraft has a phenomenol reliability record and is maintained as has been previously suggested with frest water washdowns etc.

In many installations (Beech King Air etc) of the PT-6 the engine oil provides the power for the prop pitch control so if the engine fails in a mode that results in oil pressure or quantity loss the prop feathers.

Sympathy to the Chalk organization, pax and families. It is bad enough to get it like that, but to have lots of holiday pics on CNN of it...must be horible for the families.

[PPRuNe Pop]

I recall that the PT-6 even with flights over the sea, from one island to another required a regular compressor wash.

[rigpiggy]

http://roger.ecn.purdue.edu/.../ jets/tprops/pt6.html

hopefully this pic works. The PT6 is equipped with inertial separators, on most a/c these are selectable either by Bowden Cable or electric actuators. these are used in icing conditions and most ground situations to avoid FOD/Ice ingestion. The actual engine inlet is annular, but is normally fed by a bottom pitot or ramp inlent. Further to the CS prop control, engine oil pressure is boosted from around 100 psi to about 750 psi and enters the prop hub thru an gland system into a single acting hub. With loss of oil pressure a spring will drive the blades to a feather position. The normal failure mode for the PT6 is due to a leak in the P3 line of of the prop governor to the FCU, the engine then falls back to min flow around 55%. good for electrics and bleed air but essentially produces no power. Thankfully the AFX system will normally feather the affected side. Several days back we had an low speed reject, due to a lose fuel line. the Captain shutdown after clearing the runway.

[barit1]

One would have to speculate pretty far on ones imagination, to suggest that a turbine blade failure could tear off a wing.

Agreed. FAR's require containment of a turbine blade failure, and the resulting imbalance should be within the ultimate load capability of the mounts.

A DISK failure, however, is something else entirely. I've seen it cut a fuselage in two. (However, the fuselage appears intact in the CNN video)

Do we know what brand props are used on the G-73T? If there is a fine-pitch failure mode (i.e. runaway), that might be a major issue.

[vapilot2004]

I've seen those Chalks flights takeoff from the sealane right from the Macarthur Causeway leading to Miami Beach many times. Almost went aboard once - ended up on a Metro gambling junket instead (30.00 US round trip to Nassau).

They are a good outfit - never lost a passenger til now, although 2 crew were lost near a cayos.

Link to the beauty of flying Chalks from Miami to the Carribean:

http://www.worldairroutes.com/Chalks.html

This is a repost- my original was deleted .

http://h1.ripway.com/eisler99/519_picture.gif

[Sheep Guts]

PT6 shelling
Overtalk,
I can see your point of view. I have witnessed Compressor blade failures and seizures and and Turbine blade failures. But I think everytime the Autofeather did the trick. Do these Turbine Mallards come with autofeather. Also I never heard a turbine failure resulting in uneven running and moving the engine off its mounts. They usually go "pop and stop". More than likely the reason for this would be some sort of prop failure, tip loss or blade loss. And lastly of all the PT6 failures Ive heard none of the Compressor blade, Turbine blades failures, have resulted in the engine shelling its components through the casing. I maybe wrong but never heard of it. The Casing that contains these whirling parts is extremely strong and tested.

Sheep

P.S. A few questions to be answered. Probably only from A&P Mechanics or LAMES that have worked on or have done the PT6 conversion.
1. Does the PT6 Mallard rebuild come with Autofeathering Props and also does it come with Fire Bottles? I am assuming for 135 ops it would be mandatory in such an aircraft?

[UNCTUOUS]

https://engineering.purdue.edu/AAE/Research/Propulsion/Info/jets/images/jets/tprops/pt6a.gif

[FlyVMO]

Saw the video on CNN last night, I actually found it hard to watch. Poor souls never had a chance going in at that angle. May they rest in peace.

Mere curious speculation:
I was thinking maybe an engine fire might have heated the wing spar to the point of failure? Didnt such a failure down a turboprop in Canada a few years back, after a landing gear fire in the gear well started from a brake dragging on T/O?

[RatherBeFlying]

The CNN amateur video shows the a/c going down trailed by what looks like a wing section in flames.

This could be a structural failure that ignited fuel by arcing of breaking electrical wires.

[PaperTiger]

Mere curious speculation:
I was thinking maybe an engine fire might have heated the wing spar to the point of failure? Didnt such a failure down a turboprop in Canada a few years back, after a landing gear fire in the gear well started from a brake dragging on T/O?That was a Metro: http://www.tsb.gc.ca/en/reports/air/1998/a98q0087/a98q0087.asp and (correct me if I'm wrong) there are no hydraulics in a Mallard's wing, the wheels retracting into the fuselage which appears undamaged in the video.

[FlyVMO]

PaperTiger-
Thank you for the clarification-and for posting the link to the Metro incident.
My suggestion though, was not that a hydraulic or landing gear issue caused this, but simply that heat from a fire could cause a structural failure of the wing. From the TSB report on the Metro incident-"The initial event in the break-up sequence was the failure of the front wing spar, caused by intense heat." Of course a fire may ignite due to an unkown number of circumstances, but an engine nacelle is one of the more susceptible locations for obvious reasons. I really need to stop speculating though....I think I'll bow out till the NTSB has had a chance to do their job.

[Dockjock]

Regarding PT6 operations in salt water, several companies in Vancouver and Seattle have used turbo beavers, otters, and caravans for years. The standard (I believe) is a compressor wash after every flight day. There is a freshwater garden hose hookup on the PT6 for this purpose. I'm sure any seaplane operation worth its, er, salt would do same.

[rigpiggy]

unctuous thanks that was the pic I was trying to load the pt6 has 3 governors. one for the FCU, two for the prop, and one for prop runaway ie: the hydraulic overspeed governor. The N1 or FCU controls fuel flow governing N1 speed set on a rear mounted accesory pad. prop governor sets speed of prop with the FTG set at normally 106% of selected prop releases p3 bleed air which reduce fuel flow on the FCU mounted on the top of the reduction gear box primary prop gov/FTG are combined, the HOG releases prop hub oil to govern as a last ditch in Prop overspeed situations. Don't know if the Turbo Mallard has the centripetal start lock system, this allows props to start in the ground idle position.

Anyway guys we hijacked this thread long enough lets move this to a separate thread. My Heart goes out to the families. My Condolensces

[PaperTiger]

My suggestion though, was not that a hydraulic or landing gear issue caused this, but simply that heat from a fire could cause a structural failure of the wing.That's undoubtedly true, but I don't see how it fits in this case. The Mallard crashed immediately after takeoff so even had there been an engine fire it surely would not have destroyed the wing in what couldn't have been more than a minute or two. To me the video is sadly reminiscent of that of the P4Y breakup a couple of years back. Pure speculation (so spare me the finger-wagging !), but it looks to me like a structural failure precipitated the explosion/fire and not the other way round.

[atakacs]

Just wondering...

Are those planes fitted with CVR / FDR ?

--alexT

[con-pilot]

I believe that it has a CVR only. Unrecovered as yet.

[RiverCity]

(Non-reporting journo here.) In these older aircraft, is it possible within reason to retrofit them with FDR's? In my radio station, we can take any paramaters we wish from the meters into whatever state-of-art devices come on the market, with little difficulty. Are there any basic FDR's which can be hooked up this way to at least give some clues in the event of an incident?

[international hog driver]

Just saw the video on the news here tonight and I am extremely saddened.

I have a couple thousand hours Twin Otter on floats and several thousand more on wheels and all I can say is that seeing that video on the news here tonight has been one of the most distressing I have seen and reminds me of one of the main reasons I got out of the float game.

Structural failure was the biggest worry I have ever had having seen how some of the aircraft we flew were cleaned. Little wonder DHC mandated stainless control cables. I later flew the –6 Island hopping and even their we washed the bird at the end of every day.

Where ever or for whatever reason….. once that wing let go it was game over.

I love old planes and I love the sea but unfortunately they don’t mix, nothing will replace the Mallard, or even the Twin Otter on the few remaining niche jobs that exist and require these specialised machines.

Condolences to all involved

[FlyVMO]

PaperTiger
I see your point. Now that you mention it, the C 130 wing failure in 02 comes to mind as well-although there were other issues invloved there anyway.
http://ntsb.gov/ntsb/brief.asp?ev_id=20020621X00954&key=1

[Standby Scum]

One no-go item on the Twin Otter is the PT6 Beta Back-up system which dumps the oil if the prop. spring busts so the prop. doesn't 'go into reverse'.

[SaturnV]

The news media report the plane was built in 1947. No mention of flight hours, maintenance record, or time since a last "C" check.

[westhawk]

No shortage of speculation here!

That's quite understandable and predictable. Some of it even makes some sense if you assume a couple of facts that are not yet in evidence. We shall see which of the speculations are on point once a few more things have been established as fact.

There is a high probability that physical inspection of the wing at the point of separation/failure will reveal the means by which the structure was induced to fail. Evidence of corrosion, fatigue, overload or overheat will remain at and near the point of failure. Examination of the engines will reveal whether or not an uncontained rotor failure and case rupture or any other occurance caused a fire. More video of the aircraft flight prior to the wing separation may come to the attention of investigators than has been seen on television so far. If the installed CVR yields useful audio, crew conversation and background sounds may be of investigative value. The focus of speculation on the causes of this crash will be narrowed in incremental steps as the NTSB releases individual details of it's initial field phase inspection and subsequent lab analysis of recovered components. A press briefing has been scheduled for 19:30 EST at the Biscayne Bay Marriott. Perhaps some useful information will released at that time.

Westhawk

[jondc9]

I hearby invoke every conceivable caveat that any lawyer would need for me to say this:

the right wing fell off, the fuel inside ignited, the fuselage and left wing largely intact fell out of control to the water where everyone was killed (all due respect to those poor people)

the right wing simply fluttered down to the sea/jetty. from what I have seen the right engine is largely intact as is the prop, though it is curled at the ends (rotating upon hitting?)


Why did the wing come off?
1. metal fatigue due to a harsh salt water environment, age or yet to be known reason.
2. explosion causing failure of the wing...fuel? engine? sabotage?

3. Odd situation like WHIRL MODE on Lockheed L188 electra back in the 50's.

what should be done: immediate inspection of all similiar aircraft with all non destructive methods.

OK, let's quit pussyfooting around.

The CVR may have a terrible metalic ripping sound on it and an oath by one or both pilots.

thoughts?

jon

[barit1]

jondc9 - well put.

But assuming the initial failure was the wing spar, what was the ignition source? It would have to be a high-energy spark if electrical.

[westhawk]

The CVR may have a terrible metalic ripping sound on it and an oath by one or both pilots.

And maybe some conversation between the pilots about a problem which they may have noted prior to the structural failure. We won't know unless or until that information is made available. One of the first things to be determined is whether a fire caused the failure or whether the wing failure caused the fire. The surfaces where the separation occurred will reveal the answer. Not much has been presented so far to support either theory. But it will.

Westhawk

[visibility3miles]

I was annoyed that the CNN newscasters intently commented that the pilots chose a poor place to land, as their experts told them the water was rough in that area.

Once you have lost a wing, do you really have any choice at all as to how or where the plane will land?

Also, aside from knowing how to prevent this from happening again, does it matter if the wing was on fire before or after it came off the plane? From the video, it looked like it was burning briskly, but I don't know how fast a fire could start.

Condolences to all the souls on board. A very sad way to start the holiday season for their family and friends.

[SmoothCriminal]

Rather Shocking !!

To answer a few questions raised here;

The G73T has
- Autofeather
- Main fuel tanks between the fuselage and the engine
- Wing Aux if fitted, outboard of the engine
- Floats carry fuel as well, although Chalks carried water ballast in there at times ?!
- Wing carry through spar stops at the inboard of the engine and the rest of the wing becomes a spar itself
- Beta equipped PT6-34, specially designed props to stop on the locks for immediate use on water start-up
- Hydraulics on the wings; Reservoir and Accumulator in the left wing, flaps gear and brakes operated by hydraulics
- Chalks CVR, GPWS equipped, am not sure on the FDR
- Comp wash carried out at the end of the flight day
- Inertial Seperater equipped
- One of the fuel filters is located at either leading edge between the engine and the fuselage
- Engine can be run only direct to the main tanks

Just another speculation, although I hate to;

One of the fuel hose could've come off between the main tank and the engine (submerged fuel pumps) and with high pressure wouldn't take much time to pump enough fuel into the wing section to blow it up with the exhaust sliding over the wing :ugh:

Smoothie....

[Nardi Riviera]

Seems like (http://www.aviationtoday.com/cgi/am/show_mag.cgi?pub=am&mon=0703&file=0703oceanairways.htm) Chalks know what they are doing.

Salt water operation is a very tall order, though. :ouch:

[westhawk]

Also, aside from knowing how to prevent this from happening again, does it matter if the wing was on fire before or after it came off the plane?

Aside from knowing how to prevent this from happening again, no, except perhaps to help identify and understand the sequence of events that occured. If a fire precipitated the failure, the steps taken to prevent future occurances might be quite different than if the failure occured for other reasons like corrosion, fatigue or something else. That was the only reason I had for thinking it may be important to know. Time will tell.

Best regards,

Westhawk

[jondc9]

I am so reminded of a C130a that lost a wing in california in June of 2002. It was captured on video too.. Also the RAAF has a special "patch" made out of boron fibre for their C130's.

kudos to the in depth data on the fuel system...do you mean to say that there is no crossfeeding? most 2 engine planes have a method of feeding the right engine from the left tanks and vice versa.

In 1974 I think chalks was hijacked to CUBA. AFter that time they claim not to carry enough fuel to get to cuba ( semi hard to believe)

IF the fuel ignited first causing seperation we might have something like TWA800 on our hands.

I listened to the CNN reporting quite closely. No one indicated that landing would be rough IF THE WING HAD COME OFF. Early reports showed a possible engine failure and a post crash flip over.

PS! CNN just reports metal fatigue cracks noted according to NTSB.

jon

[Kaptin M]

The journalistic trolls are quite apparent in preceding posts, aren't they!

[CanAV8R]

Having flown sea planes in warm climates in the past I am not at all surprised that this accident happened. You can actually see corrosion forming in front of your eyes if you look hard enough. My speculation is spar failure but we will leave it up to the experts. A few guys I flew with really liked to chuck the airplane around ie pulling a few G's, and my reaction was you can do it but with me watching from the dock.

This is truly a sad event for all involved.

[RatherBeFlying]

CNN Report (http://www.cnn.com/2005/US/12/21/miami.crash/index.html) The examination of the wing root has found indications of a fatigue crack in the wing spar," said Mark Rosenker, the acting chairman of the National Transportation Safety Board, which analyzed the wing. "This crack appears to extend through a majority of the spar at the location of the separation

[rigpiggy]

I think what they mean is that fuel is only fed from the main tank, I;d imagine that the Aux's and Xfeed dump into the main tank which then feeds the engine. someone with more knowledge on the a/c is sure to correct me if I'm wrong


kudos to the in depth data on the fuel system...do you mean to say that there is no crossfeeding? most 2 engine planes have a method of feeding the right engine from the left tanks and vice versa.http://images.airliners.net/photos/middle/1/4/5/338541.jpg


can anyone blow this up to read the fuel panel

[jondc9]

THE PROOF OF THE PUDDING my fellow aviation people will be this:

When the NTSB takes the intact wing and fuselage and checks that wing for metal fatigue in the spar as in the seperated right wing.

You can all imagine...if the other wing shows stress problems/metal fatigue etc that's one thing. if it doesn't then what happened to the right wing?

I would also want to compare a grumman mallard that spent its life in a nice fresh water lake rather than the harsh salt water.

Even with spot on fresh water rinsing...yikes!


too bad we only chat like this after a crash!

jon

[barit1]

Hey jon - you want that Grumman should have designed it so both sides will fail simultaneously? :}

I'm not privy to TT, cycles, or inspection practices on this G73 - but a gross fatigue indication, discovered within a few days of the accident, sounds very much like a red flag that should have been found LONG ago.

FWIW - The early Martin 202 had a fatigue trap built into the lower sparcap, and an early fatal crash was due to it breaking. It was designed within a year or two of the G73, and several years before the Comet. There was not nearly the fatigue awareness in the design community that we have today. Let's just say the Mallard was more successful in this regard than either the Comet or the 202.

[CaptW5]

There were also spar problems with the Beech 18 (C-45); needed a sparstrap if I'm not mistaken. Also several B-26 (A26) firefighting aircraft were found to have broken spars.

[Bigears]

rigpiggy , from top left, the switch says 'left fuel pump off/on' then underneath 'left engine from left tank 190 gals' and 'left engine from right tank 190 gals' . The other selector reads 'right from left' and 'right from right'.
The two centre items are marked 'ignition' and 'fuel cap'.

[SaturnV]

Chalk has voluntarily grounded the four aircraft in its fleet similar to the Grumman Mallard that crashed, and will conduct heavy inspections.

[ironbutt57]

We are all test pilots:cool:

[Big Pistons Forever]

Rigpiggy:

The picture you posted is for the original piston engine Mallard, not the Frakes turbine conversion Mallard that Chalks flys.

[rigpiggy]

Cheers Big Ears. my eyesight or computer skills are obviously not up to par.

BPF I just went to the largest pic I could find. if somebody has a G73T cockpit photo pleas post it.

[SmoothCriminal]

With regards the fuel feed system;
- Main Tanks to Engine....crossfeed available,, the aux if fitted and the float fuel will have to be pumped into the mains on the respective side to be of any use

The flying boat in this scenario was not fitted with FDR and ironically the CVR is reported to have not recorded anything.

Latest NTSB reports say cracks were found in the spar at the root of the wing!! Goodness,, seems like the cracks were so internal and critical to find that it probably would've needed dye tests to reveal them (once again, NTSB comments!!)

Anyone with more technical knowledge/information on these sort of spar inspections....?!?! especially for the one's that operate on the salt water for over 20k hrs ?! cycles may be around 1 per hour.

A Very Sad situation in the aviation History of flying boats in particular....:ugh:

Smoothie....

[jondc9]

Ok

NOW we know the mallard had the plumbing to crossfeed fuel it can easily be understood that these lines may have broken and allowed the fuel to go "vapor" and ignite...either electrical bits or the hot bits of the engine(which seems quite intact as is the prop on the right side)

I will say I think that the wing came off and THEN all the fuel on the right side caught fire.

I will say that I think that some time ago some odd sort of stress happened which grew over time to the disaster we have seen. Could sal water corrosion be a part? sure. But maybe not.


HOW many on the forum remember the DC10 at chicago that went down in the late 70's because a crack in the mount was made by using an unapproved maintenance procedure in swapping engines?


The DC10 was grounded for about 3 weeks and a few others were found with cracks. (other factors to be sure in this crash)


Metal Fatigue is not new, stress cracks are a small section of metal fatigue.

I encourage you all to either read, "No Highway" by nevil shute, or see the movie called, "No Highway in the Sky" starring Jimmy Stewart. Both made PRIOR to the
COMET disasters of 1954 (age not a factor there!)

And to all you Britishers out there! You should be very proud of Mr. Nevil Shute and the work of the Royal Aircraft Establishment.

Oh, by the way, WW2 in the pacific would not have been won without Grumman Fighter planes like the Wildcat, Hellcat, BearCat, TigerCat. Neil Armstrong and Buzz
Aldrin would not have landed on the moon without the Grumman Lunar (excursion) Module.


Maybe all planes should be made with a time bomb on board. Big clock warns when it will go off to everyone getting on board.

20 year countdown and then get away from the thing!

Trouble with grumman is that this plane was too well made. 50 plus years is alot.

jon

[barit1]

Trouble with grumman is that this plane was too well made. 50 plus years is alot.

jon, at last you have said something both easy to agree with, and pertinent to this investigation.

The rest is OT and/or fanciful.

[Techman]

I doubt the age of the aircraft is a factor. The inspection procedures and intervals might be.

[Sonic Zepplin]

I used to operate these aircraft for the company and they are a thrill to fly.

Old airframes, but heavy maintenence daily.

As for the spar, Grumman mandated that the spar for the larger ALBATROSS be replaced after a number of hours, replaced with TITANIUM spar at the cost of a million plus.

Very sad day for aviation indeed, highly probable that the oldest operating airline in the US will be closed for good.

My thoughts and prayers to the crew, passengers and their families.

Let the legend live in memory

[SmoothCriminal]

Just to clarify on the stated Albatross spar issue;

The military versions were HU-16's with no spar life on them.

Grumman bought back or rather acquired around 16 I think back from the market and built them to 0 time naming them the G-111's. These had a Titanium spar cap installed and another emergency door installed and was certified for Charter. All these G-111's have a service life on them. Chalks operated few of these and now they are all parked in storage awaiting to go to a new home. The lowest time one is around 30 or 40 hrs or something like that !!

There's one G-111 for sure flying around happily operated by Mirabeela Yachts. This one used to be PK-PAM in Indonesia years ago.

Most of the other Albatrosses flying around are HU-16's either under a restricted or a experimental category.

Smoothie....

[vapilot2004]

"We've always had wings"
I keep telling myself it was sheer coincidence, random ad inserts just when I looked in. Not the work of some soulless prankster at CNN. Nor Honda tempting the gods.


Sorry, probably not a coincidence. There is such a thing in the strange and often soul-less world of advertising called targeted ads. In CNN's case when there is news regarding a particular and pre-chosen subject, a related ad is automatically broadcast. The saddest part is that Honda Motor Corp will actually pay extra for this 'premium service' and have requested the insertion.

Until someone complains to Honda (Ad execs at CNN could care less), the airing of the Honda Jet ad will be paired with aviation matters (or whatever other key words trigger the insertion) including the video of that most unfortunate loss of the Mallard and her PAX and crew will continue in and out of rotation.

Once full convergence occurs (digital television , internet access and on-demand programming in one box/system) you can expect more specific ad-revenue generating insertions like this based on what you watch, when and likely even where you surf the net.

Not a pretty picture - but it's the future in the capital driven world of advertising.

[barit1]

jon:

While Nevil Shute Norway was in fact an aircraft design guy (dirigibles, I believe) with an appreciation for fatigue, and likely had some anticipation that future fatigue casualties would happen, Nevil Shute the author got much undeserved credit for guessing it would happen to (specifically) the Comet.

Americans and Brits (and others) all came to appreciate the durability of the Wildcat and Hellcat from the "Grumman Iron Works". But the Bearcat never saw WWII duty, and at least two F8F's broke up during postwar aerobatic exhibitions.

And Grumman's lunar vehicles were examples of outstanding performance-to-weight engineering, with just barely enough fatigue life to last one mission (that's certainly NO criticism of Grumman, just stating what they really accomplished!)

And the DC-10 problems were not fatigue-related at all, but overstress damage during unapproved maintenance procedures.

So, precious little of your original tome really addresses the current G-73 problem.

[AntiCrash]

December 22, 2005

Cracks Found In Crashed Mallard's Spar

By Russ Niles
Newswriter, Editor

Investigators have found a major fatigue crack in the spar of the wing that separated from a Chalk's Ocean Airways turboprop Mallard on takeoff from Miami on Monday. The wing was recovered Tuesday and fatigue was quickly apparent. "We've seen fatigue. We don't know why that fatigue appeared. That is what we're trying to determine," Mark Rosenker, acting chairman of the National Transportation Safety Board, told reporters Wednesday morning. "This crack appears to extend through a majority of the spar at the location of the separation." A total of 19 passengers, most of them from the Bahamas, and the pilot died. Rosenker suggested the crack may have been hard to spot on a routine inspection. "Inspection maybe would have found that [metal fatigue], but there would have had to have been a very serious type of inspection to have understood it and found it," he said. The airline has suspended regular service but airline officials say there is still strong demand for flights and they hope to resume service by Friday. Chalk's has been in operation since 1919 and had three Mallards before Monday's crash.


This is going to take allot time to properly sort out. These guy's are my neighbours at FLL. These aircraft are very well maintained. The very fact that they have had such a safety record and their dependebility are testiments to the viability of the fleet. Many years ago I worked for Walker's Cay and I spent allot of time working on N2954 our Mallard. They are extremely well built and a sea kindly design. The next flying boat I worked on was the PBY. I licensed three of them and Imported two of them. I was luckey enough to amass about fifty hours in them. Just 'cause it's a highly experienced airplane does not make it trash. If it's properly maintained it can soldier on ad infinitum

My company ran twenty vintage airliners hauling the Wall Street Journal. Our mission completion rate was over 99.9% and we never hurt anyone. I only wish I still could operate them now.

[lamer]

Link to NTSB site showing photos of crack. (http://www.ntsb.gov/Pressrel/2005/051222a.htm)

[jondc9]

I encourage you to read nevil shute (norway)'s book, "Slide Rule". While he was involved with dirigibles ( and his was the first to fly from England to Canada) his expertise also includes designing the first retractable gear aircraft in England.

As anyone who knows anything about metal fatigue the first transportation accident due to metal fatigue was in 1842.

Stress and fatigue are kissing cousins for the purpose of this discussion.

You noted that the DC10 crashed for one reason and don't seem to think that the MALLARD could( i say again could, no proof) have crashed because someone backed a forklift into its wing during changeover to turboprop engine.

I see that you have a commercial single engine land certificate.

Good for you. I see you are an engineer. (B&O?) but I digress.

Why did I mention Nevil Shute's great work? so that people who aren't engineers or pilots might get a laypersons appreciation for what happened east of Miami.

If you would like to argue finer points of aviation, you have my e mail address.

I'd like to point out that just a few weeks prior to the Three Mile Island meltdown or near Melt Down a little movie came out called, "The China Syndrome".

Sometimes people who can't prove something still want to shout a warning so that someone might be alert. A book or a film can sometimes do just that.

Nevil Shute did that with "No Highway" and subsequent movie. He also warned us of the terrible consequences of Nuclear War in "On the Beach".

One quote might even help everyone on this forum out:

"airplanes do not crash in and of themselves, perhaps one crash in a thousand is truly an act of God, instead they crash because men are irresolute, careless or reckless" (from "Slide Rule).

so barit1, post what you like. I don't think too highly of what you have said so far.

Oh and I see Bearcat fighters all the time here in Reno at the air races! And they were just coming into use as the bomb was dropped on H and N.


[email protected]

[Fantome]

The fracture photos point to stress raisers from holes, brackets or other drillings. Corrosion played no part whatever in this one.

The Vickers Viscount (VH-RMQ) that lost a wing in Western Australia in 1968 had spar stress raisers from sleeves through the spar that had been bashed in carelessly during major service.

[Airbubba]

Chalk's pilot's husband sets up foundation

BY DARRAN SIMON

[email protected]

Mark Marks last talked to his wife, pilot Michele Marks, on Dec. 18 when they rose before sunrise and he made her coffee. He told her he loved her, and to fly safe.

He found out she died when he saw the report Dec. 19 on TV that a Chalk's Ocean Airways seaplane had crashed off Miami Beach.

The couple's memories always seemed to come on the water's edge.

They met on a nine-day shark behavior ecology course in a South Africa fishing town. He asked her to marry him on the 10th day. Michele became Mrs. Marks on the San Diego coast.

''Everywhere I walk I see her. I smell her,'' Mark Marks told reporters Saturday at their Boynton Beach home. ``She was my soul mate, my best friend and my wife.''

Marks, 42, a renowned zoologist and research biologist who works with white sharks, said his wife of more than seven years loved wildlife and the ocean. He plans to start the Michele Lynn Marks Marine Conservation Foundation to give scholarships to college students for marine research.

The right wing of Chalk's Flight 101 separated from the fuselage in the crash. The seaplane plummeted into the water near the Government Cut jetty off Miami Beach. It had just left Watson Island, heading to Bimini. The 18 passengers and 2 pilots on board were all killed.

The cause of the crash is not expected for some time. But the Federal Aviation Administration issued a bulletin Friday saying it may now require mandatory inspection of all seaplanes. The bulletin said an FAA preliminary investigation showed stress fractures in the 58-year-old Grumman G-73 Turbine Mallard seaplane's right wing support that could have played a role in the crash.

Chalk's voluntarily grounded its four other G-73 aircrafts after the National Transportation Safety Board discovered the fractures.

Mark Marks said he didn't know much about the investigation but has to be patient.

''I really want to know what happened, for her, her co-pilot, the families of the other 15 passengers and three children that died,'' he said. ``I don't know how to honor her better than to find out the truth.''

Michele Marks, 37, loved seaplanes and worked for Chalk's about three years, flying twin-engine Grumman G-73T Mallards.

Chalk's promoted Marks, who had an unblemished flying record, according to the FAA, from first officer to captain this year.

Her husband wore her white gold wedding band with a green emerald around his neck.

The ring was one of the few items he has received from the medical examiner.

``I don't know how I am going to do this without her.''

He sobbed while talking and held a photo of his wife wearing a pilot's uniform.

''This is the single-most difficult thing I ever went through,'' he said.

Marks was teaching the shark behavior ecology course in 1998 when he met his wife. She was a few inches taller and attractive, he recalled. ''Oh man, I'm in trouble,'' he remembered saying when he first saw her.

They married on Sept. 23, 1998 -- her birthday.

She tempered him. He was loud, she was less confrontational. She wasn't the cook or the domesticated one. In fact, she just learned to boil spaghetti. She usually left a trail a clothes on the floor on her way to the shower.

She was the adventurer -- hiking mountains, swiming with white sharks in South Africa.

''She was fearless. She was absolutely fearless,'' her husband said.

He introduced her to hiking. They spent three months hiking across the country on their honeymoon. She was teaching him how to sail.

''I've lost my teacher as well,'' he said. She helped steer the Chondros, a 38-foot Irwin he owned from Naples to South Florida. The Chondros -- Latin for ''cartilaginous fish'' -- is docked at the couple's Boyton Beach complex.

The family held a service for her on Friday. Chalk's employees, mechanics, customs agents, and others from Bimini and passengers who flew with Marks showed up.

''I just feel so lonely without her,'' he said. ``She'll never come home, but I want her to come home so bad.''

http://www.miami.com/mld/miamiherald/13481687.htm

[lomapaseo]

The fracture photos point to stress raisers from holes, brackets or other drillings. Corrosion played no part whatever in this one.

That is one hell of a reach to decide whether you see trans granular cracking vs intergranular cracking in that 1 X photo.

Corrosion can occur anyplace, especially in drilled holes after- production where the surface may have a course texture. Of course I would not care to extrapolate from a internet photo. However the two different sides of the hole do appear to have two different types of fatigue initiations at their surface which in my view could possibly consider abusive machining or corrosion on one side and secondary initiation on the other.

[FlexibleResponse]

I’m only a pilot, but I presume that the question on the engineering community's mind is why there are two offset drill holes in this particular location which have removed so much material (say 15% of the width) from the horizontal leg of the lower spar cap. The drill work does not look very skillful in my inexpert opinion.

Again IMHO, I venture to speculate that fatigue induced failure (whether corrosion related or not) would seem to have been an inevitable consequence and just a matter of time and cycles, once these offset drill holes were made.

[LowObservable]

No engineer am I - but I have to wonder at what appear to be two drill holes, not parallel to each other and apparently merging together. I sometimes achieve the same effect in a wall when installing an Ikea curtain rod. It would seem to me that such an action would create a stress concentration.

[PaperTiger]

Frakes Mallards grounded until inspection completed: AD (pdf) (http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/0/84f647438cf632c6862570e70062a9e6/$FILE/2006-01-51%20(Emergency).pdf)

[barit1]

Given the nature of the defect that apparently initated the crack, why is the inspection limited to Turbo Mallards? Why not R-1340 powered ones?

(I could even ask - why limited to Mallards?)

[lomapaseo]

Given the nature of the defect that apparently initated the crack, why is the inspection limited to Turbo Mallards? Why not R-1340 powered ones?

(I could even ask - why limited to Mallards?)



The AD is temporary in nature (data gathering) and only a start. As the data becomes available expect more updates.

A little bit like the B747 pylon issue. We asked the same questions then. Why stop at the B747? With time the answer became clearer as more than a few folks offered up data beyond the B747 giving us back a warm feeling.

[barit1]

My initial impression is that the hole was drilled by a dunce, and is a one-off misstep in someone's poorly-controlled shop. But it could be intentional (sabotage), in which case one would have no reason to suspect only Turbo Mallards.

Perhaps the sleuths can give some estimate of the age of the hole, and that could focus the investigation further. One might surmise that's what's happening now.

[Big Pistons Forever]

The Emergency AD applies to all models of the Mallard. It looks like a bitch because in addition to the spar inspections, all of the skin in the wet bay between the engine and fuselage has to be inspected. This means all the tank sealant has to be stripped, not a nice job.

[PaperTiger]

The Emergency AD applies to all models of the Mallard.It does ? Are you talking about the FAA's AD or has Canada issued a different one ?2006-01-51 12/30/2005 Emergency AD: Frakes Aviation (Gulfstream American) Model G-73 (Mallard) series airplanes; and Model G-73 airplanes that have been converted to have turbine enginesNo piston Mallards that I can see.

[Big Pistons Forever]

The G-73 is a piston Mallard. The turbine one is a G-73T. I believe that Frakes now owns the type certificate for all versions of the Mallard. In any case as far as Transport Canada is concerned it applies to all Mallard.

[AntiCrash]

The pictures posted on the NTSB website depict the worst butchering of a spar angle I have seen to date. The rivet where the angle failed had a converging binnocular hole at an angle, the fastner outboard of that had a tail not bucked properly. It, also was at an angle. This is the worst mess I have seen on "anything" much less on a flying aircraft. Just shamefull.

The first lawsuit was filed today for $50 million, someone is in it for this. I pray they can find the rest of the handywork by this chap before another tragedy impacts the flying public.



Terrible shame this...

[barit1]

2006-01-51 12/30/2005 Emergency AD: Frakes Aviation (Gulfstream American) Model G-73 (Mallard) series airplanes...

I find this MOST ambiguous, confusing, and absurd. Under this rule of nomenclature, a Dakota would be identified today as a Boeing DC-3.

:yuk:

[AntiCrash]

Actually I believe that it would be called "Boeing MD DC-3".

[seacue]

The South Florida Sun-Sentinel newspaper says that the NTSB issued a report today that says there were also fatigue cracks in the left wing of the Mallard that crashed.
http://tinyurl.com/aa67z

Editied to add:
Sorry for posting an old report that the journo seemed to think was just off the press.
Further edited:
...and it was. See AntiCrash.

[Volume]

Not really new news, the preliminary NTSB Report (http://www.ntsb.gov/ntsb/GenPDF.asp?id=DCA06MA010&rpt=p) dated December 19th states
Preliminary metallurgical examination has located evidence of fatigue cracking in the lower rear wing spar cap, along the lower wing skin, and on an internal z-stringer. Additional evidence of fatigue cracking has been noted in the corresponding area on the left wing.
Does anyone know, from which material the lower spar flanges are made on a Mallard ? I suppose it is some corrosion resistant type from the 5000 or 6000 series of aluminum alloys. These are not really good with respect to fatigue, while most of the alloys with good fatigue properties are prone to corrosion.

[matkat]

The G-73 is a piston Mallard. The turbine one is a G-73T. I believe that Frakes now owns the type certificate for all versions of the Mallard. In any case as far as Transport Canada is concerned it applies to all Mallard.
Having read and evaluated the AD(its My job)I can tell You that this AD will apply to ANY Mallard worldwide as the aircraft was built in the US and the AD was issued by the FAA this means that the AD MUST be complied with as it is issued by the state of manufacture.

[AntiCrash]

NTSB Preliminary report issued today (10-01-2006) indicates that the aircraft had cracks in both wings.

[OVERTALK]

http://www.casa.gov.au/airworth/papers/AeroCommander.pdf

The Story Behind 24 Aero Commander airborne wing-sheddings (by 1995) with a total of a further 35 a/c found, on the ground, to have cracked main-spars.


"Despite their robust appearance, at last count 24 Aero Commanders had lost wings in flight, 35 spars had been found cracked on the ground, and hundreds of other spars had defects caused by:
fatigue
corrosion
stress corrosion
static overload