Twin Otter Incident 05-11-2005

[diverdriver 5]

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IDENTIFICATION
Regis#: 669JW Make/Model: DHC6 Description: DHC-6 Twin Otter (UV-18, CC-138)
Date: 05/11/2005 Time: 1672

Event Type: Incident Highest Injury: None Mid Air: N Missing: N
Damage: Minor

LOCATION
City: ABINGDON State: VA Country: US

DESCRIPTION
ACFT WHILE TAXIING, STRUCK AN AIRPORT HANGAR, VIRGINIA HIGHLANDS AIRPORT,
ABINGDON, VA

INJURY DATA Total Fatal: 0
# Crew: 1 Fat: 0 Ser: 0 Min: 0 Unk:
# Pass: 0 Fat: 0 Ser: 0 Min: 0 Unk:
# Grnd: Fat: 0 Ser: 0 Min: 0 Unk:

WEATHER: UNK

OTHER DATA

Departed: Dep Date: Dep. Time:
Destination: Flt Plan: Wx Briefing:
Last Radio Cont:
Last Clearance:

FAA FSDO: RICHMOND, VA (EA21) Entry date: 05/12/2005

Seems it was a ferry flight to DelMarva. Any more info would be appreciated.

Twin Otters have some pretty long wings and can catch even the seasoned pilot in a tight area.

Damage listed as minor but an email that went out seemed to question whether it would fly again. So how bad is the damage really?

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[JohnRich 4]

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Seems it was a fairy flight...

Ahem... that would be "ferry".

[diverdriver 5]

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Ahem... that would be "ferry".

Ahem... that would "edited".

[Buried 0]

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Seems it was a fairy flight...

Ahem... that would be "ferry".

so they do exist!

Where is my fizzy-lifting drink?

[JohnRich 4]

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Seems it was a fairy flight...

Ahem... that would be "ferry".

so they do exist!

I started to add a comment about a plane full of fairies, but then figured I better not go there.

Of course, I was going to be talking about the mythological type, but I know someone else would pervert that.

[bob.dino 1]

How strong are a Twin Otter's wings, structurally? As in, how much damage do you have to do to one before the plane is a write-off?

Is all the structural strength in a single spar, or is there something fancier?

(I realise this is a pretty open-ended question; feel free to answer with as much or as little as you like).

[thesaint 0]

Hummm Im not a pilot or an engineer but I do know that most aircraft wings and air frames period are built only to take stress in ways related to flight. Any other type of stress is always bad. For example a 727 will lift almost 200 people with no problem but will still have places on the wings labeled "no step".

"If a thousand people agree on a dumb ideal, it's STILL a dumb ideal."

Skully Bro #1 - POPS# 10440

[RhondaLea 4]

News clip:

http://tricities.com/servlet/Satellite?pagename=TRI%2FMGArticle%2FTRI_BasicArticle&c=MGArticle&cid=1031782667645

ABINGDON – No one was hurt Wednesday when a private airplane hit the roof of a hangar at Virginia Highlands Airport and spilled fuel across the runway.

The pilot, Keith May, 45, of Laurel, Del., apparently misjudged the distance between the hangar and the wing of his skydiving plane as he tried to park, said Ronald Deloney, the airport’s manager.

The wing hit the roof and separated from the plane as May landed and taxied down the runway, Deloney said.

Volunteer firefighters sprayed foam on the runway to soak up spilled fuel and stalled the engine by spraying it with water, Volunteer Fire Chief Joey Burke said.

Airport officials removed airplanes from inside the hangar in case the fuel caught fire.

"My concern was since the engine wouldn’t shut down and there was raw fuel there would be a fire," Deloney said. "The pilot had made several attempts to shut it off from the top of the plane, but it didn’t work. With the engine running there was the chance that the wing would come off and that would have been a big mess."

The collision only ripped a few shingles off the roof, he said.

Damage to the airplane could amount to more than $5,000, according to the Virginia State Police.

[Hooknswoop 19]

Looks like the wing ripped away from the fuselage where it attaches to the fuselage which explains why the pilot was unable to shut down the engine (broken control cables). TO's have belly tanks, not wing tanks. Any fuel spillage from the wings would be from fuel lines to the engine, not if it was broken, how did the engine continue to run?

Derek

[EvilLurker 2]

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Damage to the airplane could amount to more than $5,000, according to the Virginia State Police.

...who have obviously never had an aircraft repaired, or left out a couple of 00's

[Hooknswoop 19]

It is the picture or does it look like the engine is angled down, as if the entire wing is bent downwards?

Derek

[bob.dino 1]

Looks that way to me too. Ouch.

[diverdriver 5]

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Looks like the wing ripped away from the fuselage where it attaches to the fuselage which explains why the pilot was unable to shut down the engine (broken control cables). TO's have belly tanks, not wing tanks. Any fuel spillage from the wings would be from fuel lines to the engine, not if it was broken, how did the engine continue to run?

Derek

Actually there are TOs with wing tanks. I believe all -300s have wing tanks in addition to the main belly tanks.

Yah, seems like the cables were snapped if he couldn't shut it off with the condition lever or the firewall emergency cutoff. Very odd.

Sad to see a nice bird damaged so bad.

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[PhreeZone 20]

How bad does water damage those PT-6's? Would it need a whole new turbine since they basically drowned it to shut it down?

Yesterday is history
And tomorrow is a mystery

Parachutemanuals.com

[diverdriver 5]

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How bad does water damage those PT-6's? Would it need a whole new turbine since they basically drowned it to shut it down?

Well, good question. See, PT-6s are set up so they DON'T shut down when injesting water (fly through rain showers/storms?) The reverse flow is supposed to prevent a shut down that way. Now, if enough water went in there while the engine was at idle speed that could theoretically do damage to the compressor blades. I think they might want to at least bore scope the compressor but I don't have an A&P so I might be wrong about what is needed before operating again. From the pictures it also might seem that they will need to remove the engine before trying to run it again. A compromised wing is not something you want a large spinning, vibrating mass hanging from.

I'm just surprised that the emergency fuel cutoff switch on the fire panel didn't shut down the engine. Must have tweaked it something good.

Seems this will be later classified as an accident since the wing was wrenched. I'll include it once the NTSB puts a report out.

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[sdctlc 0]

How fast must he have been taxing when he hit the building to cause the wing to separate at the root mlike that?? Also that is one strong wing design that it broke there? WOW!

Scott C.

"He who Hesitates Shall Inherit the Earth!"

[Hooknswoop 19]

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Actually there are TOs with wing tanks. I believe all -300s have wing tanks in addition to the main belly tanks.

And since it was a ferry flight, that would explain the fuel in the wings. Does the -300 engines feed from the belly tanks like -200 and -100's?

Derek

[RhondaLea 4]

Just for the record, even though it's not relevant to what is actually under discussion, Keith is a great pilot.

http://groups-beta.google.com/group/rec.skydiving/browse_thread/thread/65b893e904db6a87/69890b68f5514000?q=engine+out+DelMarva+group:rec.skydiving&rnum=1&hl=en#69890b68f5514000

http://groups-beta.google.com/group/rec.skydiving/browse_thread/thread/4d9ac15a066a9412/3306fc0b1a668c5f?q=group:rec.skydiving+insubject:Skydive+insubject:Delmarva+insubject:Thanks+insubject:Skydive+insubject:Virginia&rnum=1&hl=en#3306fc0b1a668c5f

[Kris 0]

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How fast must he have been taxing when he hit the building to cause the wing to separate at the root mlike that?? Also that is one strong wing design that it broke there? WOW!

I'm guessing not fast at all. That's an awful lot of mass in momentum to try to bring to a sudden stop, even at only a few mph.

Sky, Muff Bro, Rodriguez Bro, and
Bastion of Purity and Innocence!™

[tandemking 0]

Twin Otters have 2 belly tanks and a small engine supply tank in the nacelle. I flew TO's at Eloy for 2 winters and I can tell you they do not have wing tanks. If the engine continued to run after the incident it wouldn't have run for long as I believe the nacelle tank holds less than 10 gallons. However, if the engine was at idle it could have run for more than 10 minutes. I'm fairly certain there's nothing in the POH about how to shut off an engine after the wing has been separated from the airplane. D'OH!

[JohnMitchell 16]

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For example a 727 will lift almost 200 people with no problem but will still have places on the wings labeled "no step".

I never thought of it that way, but that's really quite ironic. No wonder some people are nervous flyers! I'm surprised Seinfield never riffed on that one.

[Hooknswoop 19]

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Twin Otters have 2 belly tanks and a small engine supply tank in the nacelle. I flew TO's at Eloy for 2 winters and I can tell you they do not have wing tanks. If the engine continued to run after the incident it wouldn't have run for long as I believe the nacelle tank holds less than 10 gallons. However, if the engine was at idle it could have run for more than 10 minutes. I'm fairly certain there's nothing in the POH about how to shut off an engine after the wing has been separated from the airplane. D'OH!

Ah, that explains it. Thanks.

Derek

[rehmwa 2]

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Just for the record, even though it's not relevant to what is actually under discussion, Keith is a great pilot.

Just not so much that day. Poor guy - I bet he feels terrible about it.

...
Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

[diverdriver 5]

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Twin Otters have 2 belly tanks and a small engine supply tank in the nacelle. I flew TO's at Eloy for 2 winters and I can tell you they do not have wing tanks. If the engine continued to run after the incident it wouldn't have run for long as I believe the nacelle tank holds less than 10 gallons. However, if the engine was at idle it could have run for more than 10 minutes. I'm fairly certain there's nothing in the POH about how to shut off an engine after the wing has been separated from the airplane. D'OH!

Hmmm... don't have wing tanks huh? Might want to do a search on -300 Twin Otters and let me know what you find.

Nacelle tank? I know it has a high pressure pump that supplies the engine but I didn't know there was a whole nuther tank up there on -200 Otters.

I'll have to reference my Flight Safety manual again when I get a chance.

I flew Twin Otters for Skydive Chicago full time for 2 years and many more part time. Over 2,000 hours in them and I've gone through the Flight Safety course for Twin Otters. Just for reference of course.

You're probably right about nothing in the POH for wing seperation however there is that catch all switch called "Emergency Fuel Cutoff" that (considering this was an emergency) should have been employed. Will be interesting to find out if it was and if it was why it didn't work to shut the engine off.


edit to add link for DHC-6-300 schematic. Look at item 81. It's on the left wing tip and the description is "Long Range Fuel Tank -Customer Option". They hold 44 gallons (88 total).

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[AndyMan 7]

Here's a closeup of the schematic.


_Am

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You put the fun in "funnel" - craichead.