Forced Landing VH-UST 6 Feb 2023

[old man emu]

1 hour ago, RossK said:

It might actually be able to get off in the area they have (600m), that would be impressive.

Couple of things. 

The grass  is short. CASR Part 139 says grass length up to 150 mm is OK to call a  grass runway serviceable. The Coefficient of Friction for short grass is 0.35, which is about half the CofF for a bitumen topped runway.

 

Do they still teach the technique of  lowering about 10 degrees of flap, hold the brakes while going throttle to the wall, release brakes and rotate and climb over the obstacles at best angle of climb speed. Once clear of obstacles, climb away as usual.

 

A very accurate weight and balance calculation would be important because some aircraft misbehave when flown very light. 

 

2 hours ago, RossK said:

Can't ever see CASA allowing them to do it though.

That's probably correct. A "wings off" job and onto a trailer. Could be a chance to inspect the spar attachment points and get the insurance company to pay for the time to do that little job. 

[RFguy]

Is it still there this afternoon ?

 

[CT9000]

8 hours ago, old man emu said:

Couple of things. 

The grass  is short. CASR Part 139 says grass length up to 150 mm is OK to call a  grass runway serviceable. The Coefficient of Friction for short grass is 0.35, which is about half the CofF for a bitumen topped runway.

 

Do they still teach the technique of  lowering about 10 degrees of flap, hold the brakes while going throttle to the wall, release brakes and rotate and climb over the obstacles at best angle of climb speed. Once clear of obstacles, climb away as usual.

 

A very accurate weight and balance calculation would be important because some aircraft misbehave when flown very light. 

 

That's probably correct. A "wings off" job and onto a trailer. Could be a chance to inspect the spar attachment points and get the insurance company to pay for the time to do that little job. 

That old teaching method of short field take off is not necessarily the best way of getting off the ground in the shortest distance. 

[old man emu]

11 hours ago, CT9000 said:

not necessarily the best way

That implies that in some circumstances, the method I described does work. What factors would you consider for a better way in this or other circumstances?

[RossK]

14 hours ago, RFguy said:

Is it still there this afternoon ?

 

My sources say it's gone

[CT9000]

4 hours ago, old man emu said:

That implies that in some circumstances, the method I described does work. What factors would you consider for a better way in this or other circumstances?

The initial acceleration of an aeroplane is slow and so uses up runway. If you start your run at right angles you can be doing say 10kt. as you line up, also start with no flap because you will accelerate better clean then pull flap- at lift off speed, then gain speed in ground effect before you start to climb.  This process takes more skill but uses less distance but you would not let a low time pilot try to fly the plane out of this sort of tight spot.  I am not being critical of the standard teaching method of short field but saying that with a bit more skill you can improve on it.

[spenaroo]

Ive been taught all of it at different points.
the use ground effect and zoom climb over the obstacle for the end of the runway at hot days.

rolling entry into the runway... watching the speed not to tip or slide.
full brakes, full throttle release and go.

never been taught that one is always better then the other.
like a slip or flaps to adjust height on final. its multiple tools to use as comfortable

[old man emu]

    

From 1836 The Priors of Prague by William Johnson Neale: "there are more ways of drawing a cat out of a well than by the bucket!" 

 

Well! more ways may be found than one, To kill a Witch that Will not drown."

 

[kgwilson]

A maximum performance takeoff is still taught in GA & I was requested to do one in my last RA BFR. Brakes on, 10 deg flap, full power, release brakes, keep the weight off the nosewheel & get off the ground at pretty much stall, lower the nose slightly to pick up speed then climb at best angle till clear. Getting rid of friction with the ground is the No 1 priority, then its all power and aerodynamics.

[CT9000]

49 minutes ago, kgwilson said:

A maximum performance takeoff is still taught in GA & I was requested to do one in my last RA BFR. Brakes on, 10 deg flap, full power, release brakes, keep the weight off the nosewheel & get off the ground at pretty much stall, lower the nose slightly to pick up speed then climb at best angle till clear. Getting rid of friction with the ground is the No 1 priority, then its all power and aerodynamics.

Not trying to create an argument but rolling onto the runway will shorten the required distance as will not using flap until desired lift off speed. Early backstick also increases drag.

[facthunter]

That's where you have soft ground. Any weight you take off the wheels helps. Split flap BAD Simple flap so so and Fowler GOOD. If your mainwheels are too far back the down load on the Horizontal stabiliser is the same effect as extra weight. Flying in ground effect is efficient and do that till you have  a safe speed and don't try to fly over trees till you are SURE you Can. You can turn in ground effect if it's necessary but naturally it requires you do it well.  Nev

Edited February 8, 2023 by facthunter

[CT9000]

As usual thanks for your input Nev.

[kgwilson]

1 hour ago, CT9000 said:

Not trying to create an argument but rolling onto the runway will shorten the required distance as will not using flap until desired lift off speed. Early backstick also increases drag.

Assuming that you can roll onto the runway I agree. When you must stop for whatever reason including being told to by the instructor then this does not apply. From a standing start I have tried to accelerate with neutral elevator or just a smidgen applied and increase it as speed builds & found I am off a bit earlier with the latter option. I want the mains to unstick as quickly as possible & can get this at about 35 knots (1 up), then reduce AoA, quickly build to about 70 knots & then go for best angle of climb.

[old man emu]

Sounds like we are talking about two different situations - muddy surface or short distance. Or do the same techniques apply to both?

[RFguy]

Wondering whether it flew out in the middle of the night in stealth mode and the pilot weather night vision goggles and 2 x  rocket boosters strapped to each  wheel , I had a look at a few ADSB sites- nothing appears the past couple of days so I can only *assume* it was wings off and trucked out. Might have been picked up with a helicopter in a sling IF it had a clear path out without people  since they have to be able to drop the load....

Edited February 8, 2023 by RFguy

[440032]

Local aircraft recovery crews can whip wings off and make things like that vanish pretty darn quickly.

I know of some Cessna that landed (went splat) short of an airfield a few years ago. It was gone within about 4 or 5 hours from touchdown, the local busybodies and NIMBYs never knew anything happened thankfully.

I suppose the hardest part with a piper is that the wheels are in the wings, how do they sit the fuselage with a noseleg on a flatbed. Don't know.

Recovery crews - it wouldn't have been their first rodeo that's for darn sure.

Edited February 8, 2023 by 440032

[facthunter]

OME. the  variables should be covered at the  time  you're being taught the subject. There are a lot of possible variables that make simple prescriptions insufficient for the whole gambit. Rolling starts, can help. full power on brakes enables a full check of the Power available and a clean "Brakes OFF" action. Terrain after lift off is of great importance. Pick an abort place to apply if the acceleration is below expectation.. Earlier lift off where the surface is slowing you down. It's full of "judgements" as to what technique (or combination) you employ. Flap type. Some just provide drag and only useful when landing. .  Nev

[danny_galaga]

On 06/02/2023 at 7:48 PM, Cc Evangeline said:

This narrative can simply not be true. I was at the trail today and this story came straight from the mouth of an onlooker who claimed “it would’ve been an easy landing”… I disagree. No engine failure is easy. 
 

The news report discredited the story from the moment it displayed footage of the fuel tanks being drained. I’m not sure what they could be draining if there was no fuel? (See image below from channel 9). The news reporter said that they really didn’t have much information so have obviously chosen to use what they had. They have quite clearly spun this way out of context, clearly not with any general aviation knowledge themselves.
 

The Pilot has done an amazing job, and executed his training well. 

Could be taking samples for testing?

[old man emu]

4 hours ago, facthunter said:

It's full of "judgements" as to what technique (or combination) you employ.

Seems that the most important ingredient is a liberal helping of Experience. Over the years we've discussed a multitude of situations and the only thing that I can conclude from all those discussions is that there is no absolute. Flying is never as variable poor as the old y= mx + b equation for a straight line from x = a to x = b.

[facthunter]

The Information is out there and I hope all good instructors play their part. Once the pilot is suitably informed of the facts of various situations  the essential basis for correct Judgement is there and understood. Experience plays some part but finding out the "Hard" way is not as good  as getting the info from other's experience.. By the time a pilot gets qualified as an instructor HE /SHE should be well versed on these types of things. People make judgements constantly in life and the better informed the better the judgements. I've heard plenty of pilots say " Gee I wish I had known that".  Nev.

[RFguy]

In long grass, and slightly downhill , one TO of mine,  it seemingly took forever  to get airborne....

 

My mistake, or suboptimal method was-at the usual bitumen  nose-gets-light runway speed , IE just pulling a little weight off the nosewheel ,  that little bit of extra AoA and hence extra drag was enough to severely reduce my acceleration (when combined with the grass and soil) . 

Edited February 9, 2023 by RFguy

[ClintonB]

1 hour ago, RFguy said:

In long grass, and slightly downhill , one TO of mine,  it seemingly took forever  to get airborne....

 

My mistake, or suboptimal method was-at the usual bitumen  nose-gets-light runway speed , IE just pulling a little weight off the nosewheel ,  that little bit of extra AoA and hence extra drag was enough to severely reduce my acceleration (when combined with the grass and soil) . 

Done the same, too much back pressure, got airbourne, was not happy with performance and pulled of a text book aborted takeoff for real from about 20 feet. Went back and done properly, airbourne in half the distance and climbing. My first time passenger didn’t even take the offer to hop out if worried.

rest of the day went well.

 

[kgwilson]

In my old Archer 2 if the grass was long 2 notches of flap and virtually no back pressure got me off best. I had to do this at Stratford, NZ (there was a Sonex Waiex fatality there 2 days ago) back in the 90s on the short runway (about 550 metres) with 2 pax. I got off and missed the fence at the end......just. Had a decent headwind so that helped.

[RFguy]

I am guessing.. presumably,  with drag proportional to velocity in long grass, you just might not get to the  nil flaps take off velocity. But you might get to velocity = 25deg flap  TO speed....what's that in an Archer2 ? -5 kts ish ?

It would seem  pointless to put flap out until the flapped airfoil was ready to provide lift , as until the airfoil is above the stall speed / in the drag bucket, the highly flapped airfoil is just all drag. 

 

Edited February 9, 2023 by RFguy

[kgwilson]

To be honest I never looked at the instruments. When it felt right I progressively applied back pressure to rotate. The book says The procedure used for a short field takeoff with an obstacle clearance or a soft field takeoff differs slightly from the normal technique. The flaps should be lowered to 25 degrees (second notch). Allow the aircraft to accelerate to 41 to 49 KIAS depending on the aircraft weight and rotate the aircraft to climb attitude. After breaking ground, accelerate to 45 to 54 KIAS, depending on the aircraft weight. Continue to climb while accelerating to the flaps-up rate of climb speed, 76 KIAS if no obstacle is present or 64 KIAS if obstacle clearance is a consideration. Slowly retract the flaps while climbing out.