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-   -   Yak-11 "Czech Mate" crash at Bakersfield (https://www.pprune.org/accidents-close-calls/648686-yak-11-czech-mate-crash-bakersfield.html)

India Four Two 3rd Sep 2022 03:28

Yak-11 "Czech Mate" crash at Bakersfield
 
Sherman Smoot was killed in his highly-modified 2800HP Yak-11, following an engine failure after takeoff at Minter Field, Bakersfield.

https://www.ksby.com/news/local-news...in-kern-county

According to Juan Brown, the engine lost oil pressure, the engine seized and the aircraft stalled and spun while attempting to return:


treadigraph 3rd Sep 2022 12:52

Very sad news...

Mr Optimistic 3rd Sep 2022 15:36

The impossible turn.

Less Hair 3rd Sep 2022 18:18

At Bakersfield there is plenty of space all around to land ahead with a high wing load beast like this. Forget about the plane and stay alive.

212man 4th Sep 2022 15:56


Originally Posted by Mr Optimistic (Post 11290238)
The impossible turn.

only if you don’t have enough energy. Turnbacks were routinely taught by the RAF, the aim not necessarily to land back on the runway, but at least inside the perimeter, on flat ground with ready RFF access. A better option that the spare bedroom of 23 Acacia Avenue.

Pilot DAR 4th Sep 2022 19:02

For every airplane, there will be an altitude/energy combination from which a gliding turnback can be accomplished. It will be different for every type. If the maneuver is being trained within a safe margin for error, and the pilot is practiced, it maybe the thing to do in the case of an EFATO if there is no good option ahead. For most pilots, it has been proven again and again in fatal outcomes, to be very unwise.

elro 4th Sep 2022 19:32

Prop clearance was minimal and required tail wheel first landing at high speed, as mentioned in the video above.
Seems as though a turn-back to the field was initiated to prevent any inevitable off-field landing damage.
Rip to the highly regarded pilot.

212man 5th Sep 2022 10:35


Originally Posted by Pilot DAR (Post 11290804)
For every airplane, there will be an altitude/energy combination from which a gliding turnback can be accomplished. It will be different for every type. If the maneuver is being trained within a safe margin for error, and the pilot is practiced, it maybe the thing to do in the case of an EFATO if there is no good option ahead. For most pilots, it has been proven again and again in fatal outcomes, to be very unwise.

Entirely true, of course, and an expansion on my point. It just bugs me to see the myth that it is 'impossible' constantly perpetuated.

B-757 5th Sep 2022 10:51


Originally Posted by Pilot DAR (Post 11290804)
For every airplane, there will be an altitude/energy combination from which a gliding turnback can be accomplished. It will be different for every type. If the maneuver is being trained within a safe margin for error, and the pilot is practiced, it maybe the thing to do in the case of an EFATO if there is no good option ahead. For most pilots, it has been proven again and again in fatal outcomes, to be very unwise.

​​​​​​... This exactly.. 👍.. Unfortunately, there will be many more to come , who will make the turn.. One time..

Fly safe,
B-757

rnzoli 5th Sep 2022 14:28


Originally Posted by 212man (Post 11291099)
Entirely true, of course, and an expansion on my point. It just bugs me to see the myth that it is 'impossible' constantly perpetuated.

"To err on the safe side" is probably nowhere more appropriate than in these cases. I heard instructors teaching this turn as "impossible" for their students, in order to relieve them from the mental pressures of trying turn back during an EFATO. To save a cheap-ish training aircraft with a turn-back, when their skills might not be there to pull it off, simply does not justify the the risk of a fatal accident. So to remove any doubt, they call it "impossible",
But actually, in some circumstances, it is possible of course.

Pilot DAR 5th Sep 2022 15:38

In the case of am EFATO in most GA types and their less than ideally practiced pilots, the "impossible turn" is so in part because the pilot was climbing out at Vy or slower, so not only did the pilot need to accelerate to Vy or a suitable gliding speed, but if you're going to include a turn involving G, even faster to assure a margin faster than stall speed in the turn. It takes a lot of altitude after the startle factor of an EFATO to build up that additional speed, to assure a margin for pulling G in a turn. By the time most GA types have that speed and altitude, they're in downwind - from which, yes, the turn is probably now safely possible!

When authoritative training material, and the airplane flight manual give technique and limitations for a turnback after EFATO, and the pilot is trained and current, then sure, turn back. For all other circumstances, it should be considered impossible.

biscuit74 5th Sep 2022 17:24

I was taught to use essentially the same technique as used on a winch launch failure in a sailplane. First, get the nose down and establish glide speed plus a safe margin. While the aircraft accelerates, decide which option to go for. Once you have speed, manoeuvre if necessary - but if in doubt, land straight ahead as best possible. (And if manoeuvring, keep speed up well up and turn tightly). Ideally, think this through immediately before take-off so it is at the front of your mind.

In really rough country, that turn back if feasible can be a life saver - but then in really rough country, gaining altitude as close to the field as possible is also a good plan !

mnttech 5th Sep 2022 17:34

Juan Brown updated his video post I see

UPDATE 3 Sept- Sherm reached about 1000', radioed in 'loosing oil pressure'. Turned back towards the airport to land runway 12. Lowered the landing gear for landing. Loud 'Bang' was heard, aircraft pitched down steeply to impact
Seems if the gear was dropped he would have thought the aircraft could make the runway.

421dog 5th Sep 2022 18:11

Sherm was a consummate pilot.
if anyone could have pulled his a:: out of it, he would have.
im glad he died doing what he loved.

DownWest 6th Sep 2022 07:16


Originally Posted by 212man (Post 11291099)
Entirely true, of course, and an expansion on my point. It just bugs me to see the myth that it is 'impossible' constantly perpetuated.

Quite:
We had a EFTO with a Mooney at Peterborough. I was A&E in the right seat and got busy with the engine. The CPL in the left seat had a lot of experience in different types of light aircraft (actually had two previous dead sticks there, but with plenty of height and speed)
Ahead didn't look to comfortable, so he elected to turn back. Not enough height to do much of a circuit, or to get back on the c/line, so landed across the runway (grass).
There was a hedge in the light, so he said "If you think we can clear it, get the gear down" This model had the manual gear, so I unclipped the lever and as the hedge went out of sight under the nose, banged it down, just in time for contact. No damage. ( Failure was the injection unit)

But, the Yak, with all its mods, a very different beast. Any idea of the stall speed?

Niel Williams did the test flight in a Yak 11 back in the 70s. It had been acquired and restored by Personal Plane Services. But had no notes on performance of handling. (The Russians, when asked, said point blank, " You don't have a Yak 11")
He commented on looking round it that the wings had 'tip stall' written all over them. The test flight was 'interesting'...He wrote it up for Pilot Mag(?)
DW

India Four Two 6th Sep 2022 07:38


Niel Williams did the test flight in a Yak 11 back in the 70s.
That would have been a standard Yak-11 with a 31' wingspan and a 700 HP Shvetsov Ash-21 seven-cylinder single-row radial weighing 1100 pounds.

Czech
Matę had clipped wings (?) and a 2800 HP PW R2800 eighteen-cylinder two-row radial weighing 2400 pounds.

treadigraph 6th Sep 2022 07:53

I think I saw a clip of Czech Mate landing in Juan Brown's video with no flaps - I know several unlimiteds have been flapless to save weight, etc...

ShyTorque 6th Sep 2022 08:11

RAF instructors on single engined trainers were required to practice turn backs every month as part of their continuation training and a crew briefing was given across the cockpit about intentions in “ the event of an EFATO”. I flew from a grass airfield and got very used to the manoeuvre but I soon realised that in any wind above 10 knots it was usually better to land within 30-45 degrees of the climb out track because of the landing ground speed aspects of a turn back.

A turn back in 15 knots of headwind results in an extra 30 knots of ground speed over a straight ahead landing. Making the “impossible” turn only to run into something at 30 knots after landing is still going to hurt a lot.

sycamore 6th Sep 2022 17:51

It constantly amazes me that large warbirds that are operated nowadays ,do not fit a `feather prop`system,as any failure generally leads to the prop going into a `fine-pitch` situation,leading to excessive `flat-plate`drag,and upsetting the aerodynamics .I know single -engined aircraft with `Constant-speed` props ,in event of losing oil pressure should have the prop lever pulled back to as `coarse` as possible,for as long as possible,as it will improve your glide angle and reduce the rate of descent,but it seems it doesn`t necessarily appear in POHs,or people are not aware of it..I know people will say it wasn`t designed in warbirds originally and would require a modification to a seperate oil tank,and pumps,but then most BIG engines are mainly ex-civilian off airliners,so should be capable of retro-fit....
It was always in the forefront of my mind ,watching the oil pressure gauge in a big s/e TBM during air displays.....

treadigraph 6th Sep 2022 19:24

Sycamore, as I recall, Steve Hinton's biggest problem when he crashed in Red Baron was the prop blades going flat when the Griffon seized. Thank God he survived a crash that turned the Mustang into confetti. When he stuck a Griffon 56 in a Spitfire PRXIX to go after a time to height record, he ensured he could control the prop pitch if the engine quit... he wrote up the story behind the Spitfire installation and was kind enough to let me nick it for the mag I was involved with at the time.

India Four Two 6th Sep 2022 19:51


... he wrote up the story behind the Spitfire installation and was kind enough to let me nick it for the mag I was involved with at the time.
Interesting. Can you post a link?

treadigraph 6th Sep 2022 20:03

Sadly not, it was several decades ago - the story was posted by Steve on the late lamented forerunner to WIX in the very early 2000s (I know it was around the time he turned 50!), from where I contacted him; my hard copy of the mag is god knows where, I might unearth a PDF copy of the Pagemaker file on a DVD but it would take me a long long time searching through hundreds of DVDs to find it...

The Spitfire was PS980 which flew in Europe for several years when Planes of Fame sold her to Christophe Jacquard with the contra prop mod, now reengined with a Griffon 65 and happily rebuilt after turning over in France a few years ago.


meleagertoo 6th Sep 2022 20:04

"The Impossible Turn"
What a crazily misleading expression!
Without specifying all sorts of criteria that statement is as empty and false as baldly stating that sunbathing will kill you with skin cancer. It makes good newspaper headlines but no more than that.

The ability to return to the t/o runway, or even the t/o airfield depends on a myriad of factors. Power-weight ratio, angle of climb, angle of descent in a glide, descent angle in a steep turn, distance from the field the event occurs at.
A Pitts might make a successful return before crossing the far threshold, a DC3 would never manage a glide return from any t/o profile..

I imagine even this bastardised and brutalised machine mightwell make it back if the return was instigated far enough from the field, but there must be a point inside which it physically cannot be acheieved, with the inevitable result.
It's the pilot's job to know his aircraft's performance characteristics and assess whether or not a turnback with a tailwind anding is either possible or prudent. I wonder how much experience any racing pilot has in assessing his aircraft's ability to wrack on a steeply descending 180' turn with a stopped paddle-blade prop and glide to a landing with a g/s far in excess of what they've ever seen before? Blimey! That's really stacking the odds.

The general advice then, that a 180' return to field in EFATO is' impossible' is actually pretty sound. It may not be striclty accurate in all cases but as general advice it will probably save a vast proportion of those so afflicted who might be tempted to defy all wisdom andthe laws of momentum/physics too.



sycamore 6th Sep 2022 21:08

Thanks Treadders; I thought that R-B had a feather system ,but must have got it mixed with the Spitfire one.I really think that the operators of big s/e engined aircraft should really think about prop feathering when re-building,changing engines,etc..Most warbirds have a `pre-oiler`pump system,to pressurise the oil system prior to start,as that is where the greatest wear generally takes place,especially if the aircraft has not been run regularly; however the oil is usually taken from the normal oil tank,so it might need a separate smaller tank....however,an engineer will come along and say `it can`t be done`....!

gums 6th Sep 2022 22:50

Salute!

Looks to this old pilot that he had no other big problems and had the energy/altitude to make the turn back to at least the field boundary. Being with him so familiar with the plane, I go with that starting point.

So some new problem occurred and was beyond his control for altitude, speed, configuration regardless of his skill- thinking of Art back filming Top Gun spin.

RIP, man, see ya at the great rejoin bar.

Gums sends...

Jhieminga 7th Sep 2022 08:29


Originally Posted by treadigraph (Post 11292019)
The Spitfire was PS980 which flew in Europe for several years when Planes of Fame sold her to Christophe Jacquard with the contra prop mod, now reengined with a Griffon 65 and happily rebuilt after turning over in France a few years ago.

Seafire VP441 also had an ex-Shackleton Griffon installed during its restoration and they included the feather button. This airframe hasn't flown much since being restored. Fortunately, they haven't had to use that feather button yet.

Sad to hear of Sherman Smoot's passing... RIP.

uxb99 11th Sep 2022 16:35

Are these accidents exacerbated by effort invested in the aircraft by the team? The pilot feeling indebted to the team to get the aircraft back in one piece?

henra 13th Sep 2022 20:24


Originally Posted by uxb99 (Post 11294895)
Are these accidents exacerbated by effort invested in the aircraft by the team? The pilot feeling indebted to the team to get the aircraft back in one piece?

This surely played a role in the decision making. Plus the fact that an off airport landing with such a beast would have probably nullified the chances of participating in this year's race.

With these huge propellers a simulated engine failure will be light years off from the 'real thing' especially if the propeller due to dropping oil pressure will go to fine-pitch. That will leave you probably with a glide ratio of 5-ish.
At a weight of 7200lbs and a wing area of 15,4m^2 (In another forum someone counted the ribs of the wing and they were the same as the original, so wing area might be same as original) one would end up with a landing speed around >110kts (assuming workable cl max around 1 -if I interpret https://bobistheoilguy.com/forums/at...te2-jpg.115444 right it doesn't even have flaps anymore). At a glide ratio of somewhere around 5 - 7 sink rate would be >2000fpm, maybe 2500fpm. And that would be flying in a straight line. 'A handful' is probably a massive understatement. Between a rock and a hard place springs to mind.


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