NTSB and Skydiving

[JohnRich 4]

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32 airplane crashes that involved parachute jumpers since 1980... which claimed the lives of 172 people...

27 years, 32 crashes, 172 dead friends.

Those are very disturbing numbers.

I smell a "60 Minutes" news investigation coming, just around the corner.

The NTSB news announcement:
http://www.ntsb.gov/Pressrel/2008/080916.html

The detail board meeting presentations (pdf and powerpoint):
http://www.ntsb.gov/Events/2008/Parachute-Jump/presentations.htm

[HurlinGirlie 0]

I got this comment about this in an email from that silly ass Zing who got himself banned for life from this place ...

"We are fucked!"

[buzzer 0]

Some more info.
Engine:
Microscopic examination of the right engine’s fractured compressor turbine blades revealed features consistent with overload. Additional damage was observed in engine sections beyond the compressor turbine section along the engine’s gas path. Also, several of the right engine’s compressor turbine blade tips were missing. The overload fractures on the blades in the compressor turbine section and the damage beyond that section were consistent with mechanical damage caused by separated compressor turbine blade tips migrating within the engine. Because no preimpact anomalies were observed in engine areas forward of the damaged compressor turbine along the engine’s gas path, there is no evidence that an ingested object, such as a bird or debris, initiated the overload events in the compressor turbine section. Therefore, the initial blade separation originated within the compressor turbine section.

Engine Failure procedure:
I don't have much time in an Otter but the basic procedure assuming you are going to continue flying and not land immediately is to maintain minimum controllable single engine airspeed (This is paramount above all), maintain heading by using rudder and banking into the live engine, advancing power levers, power lever of dead engine to idle and then feathering the prop of the dead engine. Flaps can be retracted incrementally based on speed and obstacles.
In this case the pilot didn't maintain airspeed. That is what lead to the type of impact the killed. The pilot had to have banked into the dead engine as well since the crash occurred right of runway centerline. I appears he did feather the dead engine. If you are a pilot and are down to one engine, you maintain airspeed at all costs even if you have to make a controlled crash landing. Of course we can pick this all apart and never know what was really going on in the cockpit.
The NTSB stated that less injury or deaths would have been likely for those who would have tightened their seat belts (for those who were wearing one).

[Andy9o8 0]

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Tandem Skydiving: Is an easy, safe and enjoyable way to experience the excitement of skydiving without having to learn how.

If we're going to advertise skydiving as a "safe" thrill ride, is there not a duty to ensure that the elevator that takes these thrill seeking passengers to altitude is maintained according to a fairly high standard (ie what the manufacturer recommends)?

Absolutely.

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The argument that skydiving involves only people who are aware of the risks they are taking and therefore the standards can be lower doesn't wash anymore, certainly not in the face of advertising that claims skydiving is safe and that it can be done without having to learn a thing about it.

Agreed 100%. Also, FWIW, a DZ having an ad touting the "safety" of its tandem skydiving is, in my professional opinion, an excellent way of making the waiver the passenger signs virtually worthless. And that exposes not just DZ's and DZO's, but TI's and packers, also - personally - to added potential liability.

Translation: to all TIs and tandem rig packers: look up all the ads your DZ has for tandem jumps - web, phone book, wherever. If they tout the activity as being "safe", then those waivers the meat bombs sign just might not be worth shit toward protecting you - or your personal assets.

[billvon 2,380]

> If you are a pilot and are down to one engine, you maintain airspeed
> at all costs even if you have to make a controlled crash landing.

Absolutely. It can be almost impossibly hard to point the nose at a treeline and fly into it, but over the years I've (unfortunately) seen a lot of aircraft crashes, and in each case it's clear what the pilot tried. Two examples -

A friend of mine was flying a C172 when he lost power on takeoff. He pushed the nose down and went directly into a stand of trees. Both wings sheared off, the tail wrapped around a tree - and he shuffled away from the crash (broken ankle, broken arm.)

Another friend of mine lost power shortly after takeoff in a C182. He knew the owner of the plane would kill him if he landed it in the sod farm next door - so he traded airspeed for the runway. He actually put it almost dead center on the runway after stalling it while turning final. He died, JM was paralyzed, one student was broken up pretty badly, two other students minor injuries.

There's an old saying that it's better to crash under control than to hit the runway out of control, and I've never seen a better example.

[NickDG 23]

Andy's right . . .

Anyone who advertises any form of student skydiving as safe is an idiot. If it applies to you, you can tout professionalism, experience, modern gear, or whatever else, but don't ever say it's safe because that's an outright lie.

Ever wonder why no one particular airline advertises flying with them is safer? They used to do it during the early days of commercial aviation. But eventually one after another they all had fatal accidents. And now in aviation it's considered bad luck to advertise safety. They are very content for the PAX to worry more about lost bags and blown schedules rather than even think about safety.

Passenger flight, hang gliding, paragliding, skydiving, or anything else aviation related, when people fly - people die. It's always been that way and it always will . . .

NickD

[danielcroft 2]

Not to cast aspersions on the deceased but, in the light of the findings of the NTSB and that the MO accident triggered the SIR, what was the experience level of the pilot? It seems that if we're talking about an inexperienced or under-trained pilot that the findings regarding recurrence training are on the mark. If however, this was an experienced and current pilot, how does regulating for more training account for a simple mistake (with tragic results)?

[skydived19006 4]

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maintain minimum controllable single engine airspeed (This is paramount above all),

I am a low time pilot, with zero twin time. Is it not also important to maintain minimum controllable single engine airspeed (I forget the V?? for this), until at some appropriate altitude (300', 500', more)? Otters generally climb at 90 +/-, but from looking at the airspeed colors, the single engine speed is something well above 90.

Correct me if I'm wrong, but keeping the airspeed up while low would give the pilot a little more time to react.

I'd also think that our Twin Otter pilots would have sim time. The only way to practice these procedures, and I'd think impossible to insure a plane without this training.

Experience is what you get when you thought you were going to get something else.

AC DZ

[billvon 2,380]

> Is it not also important to maintain minimum controllable single
>engine airspeed (I forget the V?? for this)

Vmc, or blue line.

I would also add that generally losing the left engine is worse than losing the right engine, since everything is working against you when you lose the left engine, and it is more likely that you'll run out of rudder if you push the limits of Vmc. (I don't recall which engine failed in this case though.)

[NoShitThereIWas 0]

Hey Buzzer,
I do have a question you may be able to answer. With regard to maintaining airspeed with the left engine... what about V1 and V2? I was under the understanding that the left engine was unable to climb because it was a dash 21 model. I am not an expert with aircraft or engines and will definitely run your post among friends who are but I was told that a dash 27 or 34 would have returned them home safely and been able to continue a climb, increased airspeed and turn-around for a safe landing.

To answer the question about the pilot, he was a very experienced pilot with close to 30 years under his belt, also flew for American Eagle as an FO, was a DZO and on the World Champion Crew team.

Knowing him the 2.5 years I did, my experience of him was that Scott was very well respected and trusted as a highly competent jump pilot among skydivers. I have flewn on many of his loads, Cessna and Otter.

Roy Bacon: "Elvises, light your fires."

Sting: "Be yourself no matter what they say."

[buzzer 0]

Daniel, I don't know anything about the pilot of that airplane. Even an experienced pilot needs to review and practice emergency procedures. When it's something you may only do one or several times in your life...all the normal flying you do doesn't help much to keep you ready for an emergency. Keeping up on those skills is left completely up to the pilot for jump ops under current rules. But when can you just go take the jump plane up and burn fuel to practice? Having some rules that requires you to practice and/or demonstrate proficiency would help much in this area...for all pilots.

[pirana 0]

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Just to muddy the waters a bit more, I found the following on a craigslist ad this morning (bold emphasis added by me) -

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Tandem Skydiving: Is an easy, safe and enjoyable way to experience the excitement of skydiving without having to learn how.

Discover the thrill of freefalling and take the ultimate plunge! Skydiving is the most thrilling and breathtaking ride offered in the world today.

If the regular theme park rides are too boring for your daring soul, we'll get your adrenaline pumping!

If we're going to advertise skydiving as a "safe" thrill ride, is there not a duty to ensure that the elevator that takes these thrill seeking passengers to altitude is maintained according to a fairly high standard (ie what the manufacturer recommends)? Disneyland is required to maintain their thrill rides to a fairly high standard, aren't they?

I wouldn't compare advertising to operations. No other business does. According to the commercials I see every product in the world is the best. Advertising is all BS with a lot of latitude for creative license. Skydiving is no different.

Reality has proven that even the highest standards of maintenance will not eliminate mistakes and accidents. Even Disney has killed a few people.

" . . . the lust for power can be just as completely satisfied by suggesting people into loving their servitude as by flogging them and kicking them into obedience." -- Aldous Huxley

[danielcroft 2]

Thanks for that. Apparently the jump pilot (RIP) was very experienced. It makes sense that jump pilots should be trained in EPs just like we are, and re-trained. I find myself wondering how much extra expense DZs would be able to bear (sp?) regarding compliance with the suggested training and TBO requirements.

Did I hear it right that the NTSB said that the incidents in skydiving related part 91 flights were about the same percentage as other GA accidents?

[buzzer 0]

Skydived,
Vmc is 83kts with flaps up, slower with flaps out at max gross at sea level on standard temp. day. More on this is better suited to another thread but having extra speed like you suggest can be a good or bad thing depending on conditions.

NoshitthereIwas,
V1 and V2 are used when flying jets and are not applied in general in this type of operation/airplane.
No matter what series engine, the airplane should have been able to keep a climb with one engine out and at max weight using the proper procedure. Yes, the higher powered models would help more. In the accident airplane, we know it was under max weight but we don't know that the good engine was developing full power due to age/wear. It could be a contributing factor but the fact that the pilot stalled the airplane is the primary reason for the fatalities. There are likely other contributing factors.

I won't claim to be an expert. I have read the NTSB report. Although I have many hours, I don't have many in the Twin Otter.

[buzzer 0]

Daniel, Yes I think they did say that, but also said the amount of data was too small to make any certain comparison. IMO, the death rate isn't bad. The NTSB just found they haven't looked at jump operations in some time and needed to look again. Their interest is to suggest ways to decrease fatalities, no matter how safe it may already be.

[Andy9o8 0]

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I wouldn't compare advertising to operations. No other business does. According to the commercials I see every product in the world is the best. Advertising is all BS with a lot of latitude for creative license. Skydiving is no different.

Yes it is.
I have 25 years' experience as a trial attorney. If a tandem accident occurs at a DZ that has an ad touting tandem skydiving as "safe", I can almost guarantee you that that ad will be admitted into the plaintiff's evidence, and will be featured prominently, at trial - quite possibly with devastating effect.

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I wouldn't compare advertising to operations. No other business does.

Also not correct, even outside of an aviation context. There are many subjects of litigation - whether it be the failure of a product, or a design or construction defect in a building - in which pre-sale advertising as to the "highest quality" of a product features prominently at trial. The days when vendors can get away with promising the moon in ads, by hiding behind "everyone knows it's puffery", or "caveat emptor", are long gone.

[JohnRich 4]

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I would also add that generally losing the left engine is worse than losing the right engine, since everything is working against you when you lose the left engine...

Would you explain that, please?

[JohnRich 4]

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I was under the understanding that the left engine was unable to climb because it was a dash 21 model. I am not an expert with aircraft or engines and will definitely run your post among friends who are but I was told that a dash 27 or 34 would have returned them home safely and been able to continue a climb, increased airspeed and turn-around for a safe landing.

Huh? Are you saying that it had a -21 on the left, and a more powerful version on the right? Can you mix engine versions, with different horsepower outputs, on the same plane?

[PhreeZone 14]

Props rotate to the left, losing the left engine makes the torque from the right want to roll the plane to the left. Thus rolling you to the dead engine side and if I understand correctly making it harder to maintain the minimium airspeed needed to climb on a single engine.

Yesterday is history
And tomorrow is a mystery

Parachutemanuals.com

[diablopilot 2]

How'd Zing get banned?

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You're not as good as you think you are. Seriously.

[NoShitThereIWas 0]

Nope, I think both engines were -21s. But not sure.

Roy Bacon: "Elvises, light your fires."

Sting: "Be yourself no matter what they say."

[riggerpaul 1]

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I would also add that generally losing the left engine is worse than losing the right engine, since everything is working against you when you lose the left engine...

Would you explain that, please?

It is because of an effect call "P-factor".

At high angles of attack, the downswinging propeller blade is generating more of the total thrust because it has a higher angle of attack than the upswinging blade.

On many twin engine aircraft, both propellers turn the same way so that they don't need to have different setups for the right and left engine. On the Twin Otter and on many other aircraft, the props turn clockwise as seen from the cockpit.

The downswinging blade of the left engine is therefore closer to the aircraft centerline than the downswinging blade of the right engine.

If you lose the right engine, the left engine will try to yaw the aircraft to the right.

If you lose the left engine, the right engine will try to yaw the aircraft to the left.

The right engine's yaw moment to the left is much greater than the left engine's yaw moment to the right, because the right engine's downswinging blade is further from the centerline.

This makes flying on the right engine alone more difficult than flying on the left engine alone.

Therefore, the left engine is considered the "critical engine". If you lose the left engine, things are much tougher than if you lose the right engine.

[billvon 2,380]

>Would you explain that, please?

In simple terms, a bunch of factors make a plane try to turn left (assuming the usual direction of rotation for both props) when you are taking off. That's why pilots have to stomp on the right rudder during takeoff.

If you lose the right engine, the plane wants to turn right, because the left engine is still pushing hard on the left wing. This counteracts the normal tendency to turn left. So instead of a lot of right rudder, now you need some amount of left rudder to keep the plane pointed straight ahead.

If you lose the left engine, the plane wants to turn left - so you need even _more_ rudder to counteract its desire to turn left. If you are below Vmc, then the rudder may not have enough authority to stop the turn, and you will continue to turn until either you encounter the ground or you can get airspeed above Vmc.

(This rudder correction also gives rise to the 'dead foot - dead engine' guideline, which is the fastest way to tell which engine you have lost.)

>Are you saying that it had a -21 on the left, and a more powerful version
>on the right? Can you mix engine versions, with different horsepower
>outputs, on the same plane?

Although I've never heard of that, it is not uncommon to have two engines (one nearing a rebuild, one with a new hot section) that deliver somewhat different amounts of power on the same airplane. Rudder trim allows the plane to fly normally with such an imbalance.

[chutejump 0]

There is much more to turbine engine operation than what is being discussed here, A Turbine is in reality a heat pump, this pump is effect by ambient temperature and density altitude, If you take most Pratt & Whitney engines with the times that were given by the NTSB, and if they are in need of a hot section or past hot section inspection times, than throw in a hot July day (density altitude off the chart and high temperature) these engines will not make full engine power setting % on the ground in static operation. This aircraft might possibly could not have been able to maintain level flight even with a lightly loaded plane in a single engine situation, this would leave no option B for the pilot, he was looking for a place to set down. Yes! a pilot should follow all emergency proceedure when dealing with a failure, but to keep the aircraft in the air, requires that the palne is still capable of maintaining flight with what is left after the problem is recognized.

.

[airdvr 197]

Diverdriver has an excellent spreadsheet on his site www.diverdriver.com.

According to his site it gets even more interesting. Since 1982 265 accidents involving jump planes that warranted NTSB posting. Granted they don't all involve fatalities, but it's an eye opener just the same. I also remember him posting something about the rate of jump plane incidents vs. GA incidents, and our was a much higher percentage IIRC.

I had the unfortunate privelege of watching Aerohio's Otter prang from under canopy. Very lucky we didn't add to the list.

Frankly I'm surprised this investigation hasn't happened before now. This buzzard has been circling the nest for a while

Please don't dent the planet.

Destinations by Roxanne