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Reports of a plane crash at William Creek.


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Fly the aircraft, usually the uncomplicated answer. If you look at a lot of threads on aviation forums they start with a simple enough statement. That statement is then dissected and miss quoted, the armchair experts then become involved with some theory on how they would never crash and how things should be done better. It's best if you can make the subject as complicated as possible, bringing aviation law into it, that's always good for another couple of pages. Then there's usually somebody who takes offence at a comment/phrase/statement/opinion, personal insults then swap for the next few pages.

Ultimately interest in the thread wains, nobody agrees because they know their opinion is right (Or a rite).

Fly the aircraft

A bit facile but I have nothing to do this afternoon besides waiting with the Batphone, mebe I should find something useful to do instead of pot stirring :oh yeah:

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Fly the aircraft, usually the uncomplicated answer. If you look at a lot of threads on aviation forums they start with a simple enough statement. That statement is then dissected and miss quoted, the armchair experts then become involved with some theory on how they would never crash and how things should be done better. It's best if you can make the subject as complicated as possible, bringing aviation law into it, that's always good for another couple of pages. Then there's usually somebody who takes offence at a comment/phrase/statement/opinion, personal insults then swap for the next few pages.

Ultimately interest in the thread wains, nobody agrees because they know their opinion is right (Or a rite).

Fly the aircraft

A bit facile but I have nothing to do this afternoon besides waiting with the Batphone, mebe I should find something useful to do instead of pot stirring :oh yeah:

Well you're right of course with all of that; forums are one of the worst mediums for over-analysis and red herrings, but what fascinates me is why both student and qualified pilots keep asking questions that their instructors should have been able to answer in less than three minutes.

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We all have a bad day!

Had one today.... two F-ck ups because I didn't look at the real problem.

I thought I knew the solution and instead of assessing the whole problem went straight for the fix.

Thank god I went flying yesterday, at least the whole brain (even though small ) was working.

As my Grandfather said "hindsight's a wonderful thing"

Same as flying! it's easy to have the right answer after the event.

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We don't have any knowledge of the loading of this RV-6A, and that can make quite a difference to the way the nosewheel might contact the surface. If the aircraft is loaded sufficiently in the rear compartment, then the trim should be about midway for a full flap, powered approach. 70 kts on final is a little fast, 60-65 is better for a dirt strip. If a little power is left on during the round-out, then the nosewheel can be held off until speed reduces down to around 40 kts, or even less if you really hold full back elevator plus some power. Glide approaches, or cutting the power over the threshold, will often result in 3 point touchdowns, or worse, because of loss of elevator command.

 

Back of the drag/power curve approaches will ensure your landing will be on mains only, and at a manageable speed. Get your instructor to demonstrate this in the RV, and learn how to fly it.

 

Pilots must be positive in holding the nosewheel off. Brakes should not be used until you park the aircraft!

 

One of the common habits I see in pilots transitioning into RVs is that they feel-the-need to plonk the aircraft on the ground and get the brakes hard on asap - often resulting in huge pressure onto the nosewheel. You'd think they were about to select the thrust reversers! It more often than not takes me hours to get them to use good old aerodynamic braking with the nosewheel way off the deck.

 

One item that I do teach is to taxy the aircraft up the strip with flaps still down + power and don't let the nosewheel down until it is needed. This 'fast taxy' could save your day on a soft wet/sandy strip as the good power/weight performance of the RV allows you to literally drag it through bad patches.

 

 

In closing, I'm going to list a few DO'S with nosewheel RVs:

 

1. Spend money on good training

2. Keep your loading balanced - RV's land best with some baggage compt load

3. Avoid glide approaches - use power sufficient to hold the nosewheel off - right down to walking speeds

4. Keep approach speeds down to Vref for your individual aircraft and loading

5. Keep off the brakes

6. Don't allow yr nosewheel on until you have milked every last control out of the elevators

 

happy days,

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If anyone can see the mud tracks, soft soil marks, or boggy ground in this pic (obviously taken not long after the incident), then I'd be obliged if you could point all that "soft soil" out, so I can put my coke bottle glasses on, and pick it up.

 

To my amateur crash investigator eye, I'd have to say that the nose leg assembly is in need of more strengthening - or a major redesign.

 

As KGW says, the fact the owner had already tried to "heavy up" the design, and it still failed, speaks to me of a re-think needed in the design of the nose leg structure.

RV-6.thumb.jpg.51e7981d5d89b24bea5e6e30090ee314.jpg

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Have a look in the mid background, blow it up to 500% and see if you can see the discontinuation of the wheel tracks which also should not be there.

Maybe that's not on the runway, maybe the runway doesn't have any other ruts etc. Maybe he's tried to strengthen the design because he uses the point and shoot landing method. I've landed on outback dirt runways where the passenger said he couldn't feel us land, and others where the main suspensions have gone to full bump then launched me and the strips can vary a lot of there's been recent rain, but I think Poteroo's advice is good.

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I tried to keep it simple in #21. You won't be able to build a nosewheel (and bulkhead) strong enough to cop the POSSIBLE loads it may have to take and you will have control difficulties too if the weight plus energy effect is on it. You don't land, fall or bounce onto the nosewheel if you can possibly avoid it. Poteroo has covered the aspects of it. Nose heavy will reduce elevator effectiveness. Sometimes the rearward location of the mainwheels can be involved also, size of elevators and how they are blanked by (perhaps) flaps. A bit of power can help . KNOW your particular plane. Nev

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Guest Machtuk

Even Vans admits the design is fragile to some degree hence they have modified the design for latter builds as an option for the 7 & 9 & in latter models IE: RV14. After market add ons are also available. Whilst the potential is high that a failure could occur it's mostly pilot technique that has left the training wheel version of Vans designs with a stigma. I've personally seen two failed nose legs, not pretty! In 40 years of driving planes it still amazes me the 'scare' factor out there of conventional U/C flying machines ? The Vans designs are amazing planes for what they are, in a 'conventional' way that is???

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1. Spend money on good training

2. Keep your loading balanced - RV's land best with some baggage compt load

3. Avoid glide approaches - use power sufficient to hold the nosewheel off - right down to walking speeds

4. Keep approach speeds down to Vref for your individual aircraft and loading

5. Keep off the brakes

6. Don't allow yr nosewheel on until you have milked every last control out of the elevators

7. Use a taildragger instead. :amazon:

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A mate has an RV6 taildragger which he built himself in the 90s. He once said to me landing is a bit like Forrest Gump. That went straight over my head & I didn't ask what he meant till later when I thought Ah the box of chocolates "you never know what your'e gonna get". He is a master of the soft shoe shuffle & has never ground looped except on purpose to avoid hitting the hangar door at his very short farm strip. RVs are incredible fast aircraft but glide rather brick like. With only a 24 foot wingspan when approaching a landing area slowing has to begin quite a bit earlier that many other types.

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Just did some searching, and found a lot of RV-6A nose wheel collapses/nose-overs.

If you disregard what each pilot should or should not have done and just look at the engineering of the nose wheel, a few things spring to mind.

The purpose of having a tricycle undercarriage is partly dynamic stability; you get rid of the tail wheelers potential to ground loop, and partly steering, you get one man handling when taxying in cross winds by having steering controlled by the rudder pedals. The RV-6A has a castor nose wheel, so in this aircraft you're back to steering by ruffer and prop. Under those circumstances, I'd choose the tail wheel version.

However in this case we've got what we've got, so I tried to compare the RV-6A trailing link with a Cherokee 140 hydraulic strut.

The hydraulic strut retracts when it hits an obstacle like a small mound or the beck end of a small ditch and the pressure dynamically cushions the blow. The stroke appears to be a lot longer than the trailing geometry of the RV, so you would expect the Cherokee to have a lot less problems woth the nose wheel. Because the strut retraction is near vertical, the forces are acting closer to the mounting, so there's less impact on the aircraft frame.

 

The RV, for dynamic stability needs to locate the nose wheel a long way foward of its mounting point, so a long, rigid strut is required extending forward from the mounting to the aircraft frame. this looks flimsy, and could result in twisting of the frame, butg is a lot stronger that it looks, and isn't blamed in the William Creek end-over.

 

A sprung castor is swung off the front end of this strut; to get stable trailing without shimmy a lot of castor angle is needed, and it has this, but to get castor when mounted off the strut at the front, the trailing sprung fork is below the centreline of the wheel, so quite close to the ground, and when weight comes on, gets lower appearing in one photo as low as the bottom of the rim, and if the tyre pressure is down slightly, will be lower again, and if it hits a rut just after it has bumped down, could possibly be scraping the ground.

 

This is just theory after googling "6A nose gear drawings"

 

What I was looking for were drawings with bump dimensions to compare the RV with the Cherokee 140, but couldn't find any dimensions.

 

The drawings I looked at didn't show any shock absorbers on the RV, and if that was the case, then it had the additional disadvantage of no damping to slow the vertical acceleration down.

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Guest Machtuk

A mate has an RV6 taildragger which he built himself in the 90s. He once said to me landing is a bit like Forrest Gump. That went straight over my head & I didn't ask what he meant till later when I thought Ah the box of chocolates "you never know what your'e gonna get". He is a master of the soft shoe shuffle & has never ground looped except on purpose to avoid hitting the hangar door at his very short farm strip. RVs are incredible fast aircraft but glide rather brick like. With only a 24 foot wingspan when approaching a landing area slowing has to begin quite a bit earlier that many other types.

 

Actually you couldn't be more incorrect there. This is part of the myth or fear that exists out there about conventional u/c machines, they are pussycats as long as you are trained properly and are confident. They have a very effective rudder, use it to your advantage! They don't glide like a brick, they are solid as a rock and when trimmed properly they descend no diff than most GA machines. Slowing down is all about knowing your plane and how to fly using all the tools available. Still I guess that fear will always exist due the 'old wives tales' that do the rounds year after year! I'd never flown an RV before I bought mine, I did no training (didn't need it) in any vans but flew a 280 HP F1 Rocket first up, went like a scolded cat but was a non event in the circuit. The Vans machines are one of the best handling planes all round, bang for buck nothing beats it providing it's got the 3rd wheel where Mr Vans originally intended them to be, ? I'm in love with mine?

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