L-29 crash at Argentine Airshow 12/11/23

[treadigraph]

Another low pass and roll goes wrong...

https://aviation-safety.net/wikibase/347812

[DogTailRed2]

The L29 seems to have suffered quite a few accidents over the years in civilian use.
Suffering the same fate as the Hunter perhaps. Fast ship in the wrong hands?

[markkal]

The L29 seems to have suffered quite a few accidents over the years in civilian use.
Suffering the same fate as the Hunter perhaps. Fast ship in the wrong hands?


Pilots have very likely missed or failed to compute the "enegy gates" to execute the maneuver. I dont know what they intended to do, if it was a barrel roll ( probably not as they interrupted it while inverted unless they were disoriented or incapacitated) or more likely a reverse cuban 8 ( Pull to 45 degrees up pause then pull through then level off) .

For a normal roll even with the "pause" while inverted would have been a non event, they would have ended up upright though nose low with plenty of height available, they had plenty of energy available after that high speed low pass.

But -and here lies the risk- with this same energy to spare on the reverse cuban 8 after inverted the "energy gate" was busted: way too low and fast. Closing that portion of the loop while inverted was impossible, the radius arc ( It increases at the square of the velocity, double the speed quadruple the radius) was too large and there was not enough room to allow for it other than stall under g while pulling to avoid hitting the ground.

When "energy gates" are not considered in advance, any non compliance or improvisation is a big risk, then the maneuver should be aborted; From inverted complete the half roll and recover straight and level. You may well have luck in a light aerobatic Extra aircraft with his quick roll rate and ligher wing loading, but no chance on a heavy underpowered military jet trainer.

The laws of physics are non negotiable. Speed and height did not permit that closure of the maneuver. It should have been aborted.

There is a similar, very similar incident of an italian eurofighter which hit the sea in the same fashion,in Pratica di Mare some years ago, just google for it.

It was much higher that this L29 probably in excess of 10'000 feet but with much higher closing speed it 3-400 knots I would assume, the radius to close the maneuver was immense, and while pulling out agressively with the sea appraching the Eurofighter stalled under heavy G and pancaked, The L29 likewise stalled dropped a wing and flipped.

More than" fast ship in the wrong hands", fast ship without proper training and improvisation.

[FullOppositeRudder]

https://www.youtube.com/watch?v=4vmvkRsiwUQ

[fdr]

that is a bit odd. The control authority is there at all times, they convert a simple upward vector aileron roll into a.... whatever that was. The attitude was never high enough to consider doing a half roll and pull through reversal, part of a cuban, but, then they drop the nose and run out of ideas. The last video segment suggests there may have been a very late short duration stall or it was hesitation by the pilot who was seeing the planet coming up quickly in his windshield. Assuming the pilot had any competency in aerobatics, it is a strange flight path. It isn't G-LOC, and if there was an aileron restriction early on while inverted, that cleared prior to impact, so seems odd, unless a harness/control interference may have occurred. Sad outcome.

[treadigraph]

Wouldn't say it's odd, rather just another in a sad litany of low passes and rolls that have seen the nose drop while inverted followed by an unintentional dive with no way out. Most notorious I can recall is the Biggin Hill Invader in 1980.

[DogTailRed2]

Wouldn't say it's odd, rather just another in a sad litany of low passes and rolls that have seen the nose drop while inverted followed by an unintentional dive with no way out. Most notorious I can recall is the Biggin Hill Invader in 1980.
Hurricane at Shoreham being another.

[Pilot DAR]

Hurricane at Shoreham being another

Hunter?

The hunter was a slightly different situation, being an unrecovered loop, rather than roll, but similar theme....

[megan]

DAR, DT2 is referring to a Hurricane crash at the show in 2007, there used to be a video of the event but all I can find now is post crash, occurred during a mock dog fight with a few other participants.

https://www.youtube.com/watch?v=B5RpmviJ918

Accident report extract.The Hurricane aircraft, G-HURR, was taking part in a flying display and was following another Hurricane in a tail chase. Both aircraft flew past the spectators along the display line at a height of approximately 200 ft before tracking to the north-west and climbing. The lead Hurricane climbed to approximately 1,100 ft above ground level (agl), pitched nose-up about 45º and rolled to the left through 270º, before pulling into a right turn to rejoin the display line. The second Hurricane, which was approximately 700 ft agl, pitched nose-up about 15º, before rolling to the left. As it reached the inverted position, the roll stopped, the nose dropped and the aircraft entered a steep dive. It struck the ground, fatally injuring the pilot. The aircraft was destroyed by the ground impact and subsequent fire.The pilot appeared to have attempted to follow the manoeuvre flown by the leading pilot. Although the airspeed was adequate, the aircraft had insufficient nose-up pitch attitude at the point of entry to ensure the safe execution of the manoeuvre in the height available. When the aircraft was inverted, the roll stopped, the nose dropped and insufficient height was available to recover from the dive.

[treadigraph]

I was present at the Hurricane accident but didn't see it, but the video clip I saw looked nearly identical to the Firefly crash at Duxford which I did witness. Both aircraft were being flown fairly conservatively.

I used to feel a bit uneasy watching one pilot loop a vintage fighter apparently somewhat slower than Ray Hanna, Brian Smith, et al tended to do. I'm sure he had speed in hand and probably his mostly flatter displays didn't require quite as much energy management as the other exponents did but it still made me look away. Glad to say he and his aeroplanes are still with us, though he no longer flies displays.

[Pilot DAR]

DAR, DT2 is referring to a Hurricane crash at the show in 2007

Fair enough, another low level aerobatic crash I did not know about!

[sablatnic]

Fair enough, another low level aerobatic crash I did not know about!

Now we are at it, there was a similar SAAB Gripen crash in Thailand a few years ago.
https://www.youtube.com/watch?v=Q7u4cJLN-Xg

[DogTailRed2]

You could also add the Duxford P38 crash although that one goes firmly in the `unexplained` category. Outcome the same.

[Dr Jekyll]

There was yet another similar looking crash of a T28 in Hungary earlier this year.

[megan]

The deadliest airshow crash of all time, 77 killed, including 28 children, 543 injured, 100 0f whom were hospitalised, the two pilots survived with minor injuries.

https://www.youtube.com/watch?v=Oc_LlmW2i0Q

[Bksmithca]

The deadliest airshow crash of all time, 77 killed, including 28 children, 543 injured, 100 0f whom were hospitalised, the two pilots survived with minor injuries.

https://www.youtube.com/watch?v=Oc_LlmW2i0Q
Megan correct me if I'm wrong but did North America and Europe establish more stringent rules regarding no flight paths directly over the crowds.

[megan]

The pilots stated that the airbase map they had received differed from the actual layout they found at Sknyliv airfield, where they had been also denied an extra rehearsal flight before the show for financial reasons. Although the root cause of the crash was found into the pilots violating the plan and performing “difficult maneuvers they had not done before”, other factors, including a small flying zone and inappropriate zoning by the show organizers who had allowed spectators to gather so close to the flight line were blamed for the tragedy.

The court found the two pilots and three other military officials guilty of failing to follow orders, negligence, and violating flight rules. Two of the three officials were sentenced to up to six years in prison; the third received up to four years, a military court sentenced pilot Volodymyr Toponar and co-pilot Yuriy Yegorov to fourteen and eight years in prison, respectively.

[treadigraph]

Megan correct me if I'm wroI'm but did North America and Europe establish more stringent rules regarding no flight paths directly over the crowds.
I think the Frecce Tricolari crash at Ramstein tightened up a lot of rules regarding overflights of or manoeuvres towards crowd lines. As far as I know, the Red Arrows still start their display with an overflight from behind the crowd but at 500' or whatever. I recall a foreign Jungmann flying in towards the crowd at a display and pulling up into a stall turn well inside the safety line, commentator Brendan O'Brien saying something like "please don't do that there...". Believe it was the same pilot who died flying the same aircraft during a display in France the following weekend.

The Biggin Hill Invader crash (pilot plus six passengers) triggered a ban on passengers being carried at air displays - nevertheless I've seen two back seaters die in subsequent accidents whose presence may not have been necessary.

[Less Hair]

Maybe it would be the right thing to think about what these displays are good for? Showing off by individuals? Scare the crowds? Get spectacular pictures for marketing or news? Show aircraft outside of their normal envelope?
These mostly are veteran aircraft and sometimes veteran pilots, some not with military background and not current like say flight instructors on type. The airframes can be old and fatigued and engines limited or just too precious to risk crashing (well, not an L-29).
From my point of view it would be wiser to limit displays to more moderate manoeuvres like takeoff and landings low flybys fast and slow and some moderate turns. Even during their day many military types had their limits and risks why trigger extreme manoeuvres today when the same frames are worn out and old? Look how Shuttleworth's Edwardians got so old.
Without wanting to spoil the fun but with so many historic aircraft crashing and lost I'd prefer a more moderate style. This should be made a regulation. If not by the authorities then by the insurers. I know somebody privately owning (and keeping) a Mustang and what kind of training and experience the insurance requires before a single pattern.

[Dr Jekyll]

Maybe it would be the right thing to think about what these displays are good for? Showing off by individuals? Scare the crowds? Get spectacular pictures for marketing or news? Show aircraft outside of their normal envelope?
These mostly are veteran aircraft and sometimes veteran pilots, some not with military background and not current like say flight instructors on type. The airframes can be old and fatigued and engines limited or just too precious to risk crashing (well, not an L-29).
From my point of view it would be wiser to limit displays to more moderate manoeuvres like takeoff and landings low flybys fast and slow and some moderate turns. Even during their day many military types had their limits and risks why trigger extreme manoeuvres today when the same frames are worn out and old? Look how Shuttleworth's Edwardians got so old.
Without wanting to spoil the fun but with so many historic aircraft crashing and lost I'd prefer a more moderate style. This should be made a regulation. If not by the authorities then by the insurers. I know somebody privately owning (and keeping) a Mustang and what kind of training and experience the insurance requires before a single pattern.
What examples are there of old aircraft crashing because they are old or 'worn out'? The most common single factor appears to be misjudgement of speed and/or altitude at low level, and this can happen to current military pilots as much as anyone else. EG The Mountain Home Thunderbirds crash.

[Less Hair]

The Swiss Ju 52 comes to my mind. It could not out climb a mountain valley under hot and high conditions. The wreck revealed serious structural aging that had gone unnoticed before.

[Jhieminga]

... but which had nothing to do with the crash. Also, that was an airframe that was still used commercially (in a sense) and therefore had a very different usage background than a typical warbird.

[DogTailRed2]

In 40 years of going to airshows and being aware of the accidents that have happened I've never heard of a fatal accident to a warbird caused by fatigue. Pilot error, poor maintenance occasional engine failure yes. The only fatigue I can remember was a ww1 replica so a modern aircraft.

[Less Hair]

There is a wiki list not of airshows but structural failures in general. My point was better don't stress old aircraft with extreme maneuvering.
https://en.wikipedia.org/wiki/List_of_aircraft_structural_failures

And Airshow crashes:
https://en.wikipedia.org/wiki/List_of_air_show_accidents_and_incidents_in_the_20th_century

[Jhieminga]

There is a wiki list not of airshows but structural failures in general. My point was better don't stress old aircraft with extreme maneuvering.
https://en.wikipedia.org/wiki/List_of_aircraft_structural_failures
That is a very unhelpful list... structural failure is a side effect of an airframe breaking up, but it's the reason for the airframe breaking up that is the pertinent issue in an accident investigation. That list contains everything from design issues to mis-handling of a manoeuvre and everything in between. You cannot draw any conclusions from that.

'Don't stress old aircraft' appears to be a good point, but I think it should be phrased slight differently: 'don't over-stress old aircraft'. Any airworthy airframe is more than capable of handling normal stresses. There are loads of manoeuvres that can be carried out safely by any airworthy craft. Actually, the phrase should be 'don't over-stress any aircraft'.

We shouldn't be discussing this, we should await the results from the accident investigation and start from that. It is way too soon to come to any conclusions on what we should or should not do based on this particular accident.

[EDMJ]

The Swiss Ju 52 comes to my mind. It could not out climb a mountain valley under hot and high conditions. The wreck revealed serious structural aging that had gone unnoticed before.

It had not "aged", it had corroded due to shoddy maintenance. The accident report basically found that the operator for years had done everything wrong; maintenance, flying standards, everything that they could possibly ignore, neglect and/or do wrong they did...

[Less Hair]

Apart from maintenance done wrong, wreck parts from the inside of the structure, normally inaccessible, were analyzed and found to be badly corroded and fatigued.

[DAHenriques]

You could also add the Duxford P38 crash although that one goes firmly in the `unexplained` category. Outcome the same.
If you mean the Hoof Proudfoot crash he was wearing a kneeboard that we believe interfered with the yoke during the backside roll recovery.
Kneeboards are a VERY bad idea when mixed with level 1 aerobatics.....ESPECIALLY with a yoke involved as is the case in the 38.
Dudley Henriques

[DogTailRed2]

Slightly off topic but wasn't there an ex Battle of Britain (or maybe just a display) pilot who used to stall roll the Spitfire?

[treadigraph]

Do you mean flick roll? Bob Stanford Tuck certainly included it in his wartime repertoir, from memory at something like 100-120kts.

Always fascinated by the Zlins 526s etc which almost seemed to take a deep breath as flick inputs are applied. Extras and the like are so twinkle quick it's hard to say what happened.

Edit: got a feeling I've heard that Tony Bianchi performed an Aresti sequence in Patrick Lindsay's Mk1 back in the '70s probably at Booker. Whether he included a flick I know not.

[DogTailRed2]

Maybe flick roll is the term. I was told you stall one wing and then convert it into a (flick?) roll or something like that.

[DAHenriques]

It's really nothing more than a snap roll, or more accurately an induced spin in the horizontal plane. It's not a maneuver we usually do in WW2 propeller driven fighters but can be done if done carefully and with good stick and rudder skills.
Airspeed is critical as initiated with too much airspeed the aircraft can easily be over g'd.
In the combat sense it would be considered a defensive maneuver used to shake an attacker out of a guns solution and cause an overshoot in the plane of the defender's turn.
Generally however, (I displayed a P51D on occasion) we don't consider flick rolls as a normal display maneuver as it's an energy loss maneuver leaving you with little maneuvering energy to continue on with a display routine.
Dudley Henriques

[treadigraph]

Dudley, in some 50 years of watching WW2 fighters displayed, I've certainly never seen one snap/flick rolled!

The first flick roll I can recall seeing was probably Neil Williams in Aerobatics International's other Pitts (think 'ZPH had a broken longeron at the time and was rebuilt with a new fuselage), might have been Mike Riley or James Black, but Williams was certainly there and flying. Second aircraft I saw flick rolled was a Chipmunk at the same show. Only warbird I've ever seen flick rolled was a Harvard performing a nicely flown avalanche quite recently.

[DAHenriques]

Dudley, in some 50 years of watching WW2 fighters displayed, I've certainly never seen one snap/flick rolled!

The first flick roll I can recall seeing was probably Neil Williams in Aerobatics International's other Pitts (think 'ZPH had a broken longeron at the time and was rebuilt with a new fuselage), might have been Mike Riley or James Black, but Williams was certainly there and flying. Second aircraft I saw flick rolled was a Chipmunk at the same show. Only warbird I've ever seen flick rolled was a Harvard performing a nicely flown avalanche quite recently.
When it comes to snap rolls the Harvard or AT6 as we call them here in the states is an exception .he Harvard does a beautiful snap roll due to the wing sweep outer leading edges on the wings. We snap the old T6 all day long. In fact, I've displayed the T6G in airshow displays and snapped it myself.
WW2 fighters on the other hand are a different story. They can of course be snapped and the "flick roll" as done on the Spitfire can attest, but generally speaking, we don't "snap" these aircraft as a general rule.
A normal display routine for a WW2 fighter during an airshow is performed within an envelope within +5g and -1g. In the case of the Mustang there is a negative g limit due to oil pressure loss. Generally true for other WW2 era fighters as well.
Dudley Henriques

[megan]

Dudley, in some 50 years of watching WW2 fighters displayed, I've certainly never seen one snap/flick rolled!Some where in the library there is a story written by a WWII Spitfire pilot, who having trouble with an enemy on his tail, basically flick rolled the aircraft into a spin, one wing was so twisted by the exercise that the slowest he was able to fly was some 150 knots, wing being so twisted that he ran out of aileron control.

An accidental flick into a spin was said to be some thing that saved inexperienced P-51 pilots when pulling a tight turn to evade the enemy behind.

[DAHenriques]

Some where in the library there is a story written by a WWII Spitfire pilot, who having trouble with an enemy on his tail, basically flick rolled the aircraft into a spin, one wing was so twisted by the exercise that the slowest he was able to fly was some 150 knots, wing being so twisted that he ran out of aileron control.

An accidental flick into a spin was said to be some thing that saved inexperienced P-51 pilots when pulling a tight turn to evade the enemy behind.
In combat you do what you have to do. Generally speaking when defensive a "flick roll" could be a last ditch maneuver to force a shooter into an overshoot.
The airspeed at which a "flick roll is initiated" is critical. Too fast and you can easily over g the airplane. So slowing it down to where you can safety "snap it" is the key.
Because ANY snap roll in ANY airlane is an energy loss maneuver, doing one in combat should be considered a "desperation" maneuver, not something you would wnat in your normal "bag of tricks" as a combat pilot.
Dudley Henriques

[markkal]

In combat you do what you have to do. Generally speaking when defensive a "flick roll" could be a last ditch maneuver to force a shooter into an overshoot.
The airspeed at which a "flick roll is initiated" is critical. Too fast and you can easily over g the airplane. So slowing it down to where you can safety "snap it" is the key.
Because ANY snap roll in ANY airlane is an energy loss maneuver, doing one in combat should be considered a "desperation" maneuver, not something you would wnat in your normal "bag of tricks" as a combat pilot.
Dudley Henriques


What a priviliege and a pleaseure to have such an authority as Mr Henriques posting in this forum, I advise all of you to get acquainted with him via google and read his many artcicles and posts.
He his one of the last "Gurus" of aviators and pilots with such an experience, knowldege and narraitive. Welcome

[treadigraph]

Here's what Bob Tuck had to say about flick rolling a Spitfire, as recounted to Larry Forrester in Fly for your Life:

"One thing they seemed to appreciate was a favourite trick of mine. I came in over the hangars at around 800 feet fairly slow, at about I35, and then did a stalled flick-roll. It was really very easy, if you knew the Spit well. She literally stalled around her own axis and fairly whipped round.

Mind you, you had to be careful that you started to correct and check the roll at the right instant, otherwise she'd stay stalled, and go into a spin. When you did this properly, you wouldn't lose more than a couple of miles an hour-and she'd carry on at exactly the same height as if nothing had happened. It was a very pretty thing to watch from the ground."

The Americans were chary of aerobatics at low speed. This was largely due to the fact that their fighters were apt to stall and spin without any kind of warning, whereas the Spitfire gave her pilot ample notice by juddering and rocking gently several seconds before she was liable to drop a wing. They said they'd never seen anything like that before, and from the way some of them looked at him it was clear they thought he was a case for the psychiatrist "Messerschmitt happy" was a phrase he heard somebody murmur.

[DAHenriques]

Here's what Bob Tuck had to say about flick rolling a Spitfire, as recounted to Larry Forrester in Fly for your Life:

As an American fairly familiar with flying WW2 fighters I would say without hesitation that were I to go up on a display that included "flick rolls" I would choose as my mount to do that a Spitfire over all other planes of choice, preferably a clean Mk 9 or earlier. Mitchell designed the perfect fighter for the BOB mission. Granted it was the Hurri's that bore the brunt of the battle but the Spit was indeed something else when it boiled down to a good old fashioned dogfight.
I never got to meet Tuck but Bader and I were friends for years. I also got to know Winkle fairly well and we had a wonderful time trading letters back and forth where he would go on and on about the high Mach dive testing they did after the war. Douglas was no slouch when it came to arguing a point and we would go at it tooth and nail comparing my Mustang and his Spitfire. LOL. Douglas mentioned doing "flick rolls" in the Spit, usually at reduced gross weight and at low airspeed. He agreed with me that the 51 was a bit heavy even at 1/2 fuel to be doing snap rolls. It was easy to load up a 51 with excessive pitch rate. I have to admit I never actually tried to do a snap in the Mustang. It was considerably heavier than a Spitfire and carried a lot more fuel.
I will say also that some of the finest pilots I have ever known were friends from Great Britain. What they did during the BOB in my opinion has never been equaled in the annals of aerial combat.
RIP Douglas and Eric. I truly miss you both very much.
Dudley Henriques

[Pilot DAR]

I have questions: What is/is there a difference between a flick roll" and a "snap roll"? I understand a snap roll to be a spin on a horizontal axis (essentially, the inertia of the airplane carries it along the horizontal path long enough to enter and recover a one turn spin along a horizontal axis - which I have been taught is a snap roll). Was I taught correctly? The forgoing description make the flick roll also sound like a well recovered horizontal spin to me....

[DAHenriques]

I have questions: What is/is there a difference between a flick roll" and a "snap roll"? I understand a snap roll to be a spin on a horizontal axis (essentially, the inertia of the airplane carries it along the horizontal path long enough to enter and recover a one turn spin along a horizontal axis - which I have been taught is a snap roll). Was I taught correctly? The forgoing description make the flick roll also sound like a well recovered horizontal spin to me....

Basically it's a simple case of semantics. In the United States we call it a snap roll and in GB it's a "flick roll". At least that has always been my understanding.
The execution is the same really. You slow the aircraft down to a speed where an accelerated stall will produce the stall below the limit load factor. You execute the roll by quickly inducing an accelerated stall with rapid back pressure. As the stall breaks you apply full rudder and in some aircraft full aileron as well to couple the airplane at the stall break. Timing is critical. Get it just right and the aircraft should break cleanly into the roll. You simply maintain control pressures and watch it go around. As you reach level flight again you quickly neutralize all controls to stop the roll.
Each aircraft may behave a bit differently doing a snap roll. It's one maneuver where you have to practice to find the sweet spot where it all comes together to do the roll. You can't initiate early or too late either. There is just that one spot where the stall break and your control application all come together.
Practice.........practice.........practice. It's all about the timing !!!!!!!
Dudley Henriques

[megan]

One and the same I've always thought DAR. An ocean separating common language again? Flight manuals of US WWII aircraft used to have a page at the back with a glossary of words with the respective US/UK meaning eg battery/accumulator

[Pilot DAR]

Thanks for the clarification, (and language lesson). Bill Loverseed used to tell me about flick rolling the Gnat, and in describing it, it sounded like a snap roll. Though I did a lot of flying with him, none was in aerobatic capable types, so I never had training from him in those maneuvers. I used to snap roll the C-150 Aerobat regularly, just for fun. It's decent at snap rolls, though on the lower edge of aerobatic in the main.

[DAHenriques]

Thanks for the clarification, (and language lesson). Bill Loverseed used to tell me about flick rolling the Gnat, and in describing it, it sounded like a snap roll. Though I did a lot of flying with him, none was in aerobatic capable types, so I never had training from him in those maneuvers. I used to snap roll the C-150 Aerobat regularly, just for fun. It's decent at snap rolls, though on the lower edge of aerobatic in the main.
I've always said that if you perform decent aerobatics in the Aerobat you are doing a good job. The "Bat" requires a whole different level of stick and rudder technique. It's a fun little bird and does the basic stuff well. Just takes a bit of "handling" as they say. :-))
Dudley Henriques

[treadigraph]

As an American fairly familiar with flying WW2 fighters I would say without hesitation that were I to go up on a display that included "flick rolls" I would choose as my mount to do that a Spitfire over all other planes of choice, preferably a clean Mk 9 or earlier.

I forgot to mention that Tuck was flying a Mk V at Wright Patterson during and advisory visit to the USA in late '41; he said she was well worn as seemingly every pilot in the USAAF had had a go on her!

Re the semantics, i certainly heard the commentator at Biggin Hill in '76 (John Blake) describe it as a flick roll; a couple of years later my mum gave me James Gilbert's "The Fliers World" for Christmas - an Englishman who cut his teeth as an editor for Flying in the US before moving back to the UK and acquiring Pilot. In the book, written for an American audience, he describes his Jungmeister performing a snap roll, so never any doubt in my then young mind that we had two terms for the same manoeuvre! Isn't the American hammerhead a British stall turn? I'd actually always thought a hammerhead was either a push or a pull instead of a yaw at the top of a vertical climb, but listening to various US show commentaries, I suspect I was wrong! :)

(Speaking as an enthusiastic warbird and aerobatics watcher!)

[TheAerosCo]

I agree with previous posters that a snap roll and flick roll are the same thing. Also, a Hammerhead and Stall Turn are also the same as each other, although the former is a much better term since the aircraft is never stalled during the manoeuvre. (A humpty bump is where you push or pull at the top of the vertical instead of yawing as you would in a hammerhead).
Strictly speaking there is a difference between a flick roll and a "horizontal spin". For starters, a flick can be performed in any attitude. It also differs in that with conventional light aircraft (i.e. not swept wing of which I have no knowledge) a spin will generally have both wings stalled and to maintain the spin you will have full elevator deflection and full rudder. For an ideal flick, the initial pitch is to just at or below the critical angle off attack such that the yaw induced with the rudder then causes one wing to stall and the other to be unstalled. The elevator should then be "unloaded", i.e. moved towards neutral in order to increase the roll rate due to angular momentum effects and to reduce drag. As Dudley says, getting this all just right and finding the sweet spot is the tricky part! Power helps during the figure to energise the tail feathers and counteract the increased drag, but this also creates large stresses on the airframe due to gyroscopics. This and torsional aerodynamic effects are often why maxiumum allowable flick roll entry speeds are relatively low, apart from the need to avoid exceeding the normal aircraft g limits.

[JEM60]

DA Henriques. I, like Treadigraph, witnessed the P.38 accident. I also heard of the theory re the kneeboard and the yoke interference. However, talking with Steve Hinton at Oshkosh shortly after, I asked his opinion. Apparently, in Steve's opinion, he pulled the first roll [yes, there were two] too early, and realizing his error, went for the second one with too little pitch and speed. He made the point that Mr. Proudfoot was red in the face with anger just before his display, as the BoB Memorial Flight had completely cocked up the timing of his and others displays. As Steve said, that is no condition to go to fly a tight display, and he felt that it was this state of mind that was possibly the cause of his misjudgement?. Who really knows. It was a very, very sad day. I have read your posts with extreme interest. Many thanks for them.

[DAHenriques]

DA Henriques. I, like Treadigraph, witnessed the P.38 accident. I also heard of the theory re the kneeboard and the yoke interference. However, talking with Steve Hinton at Oshkosh shortly after, I asked his opinion. Apparently, in Steve's opinion, he pulled the first roll [yes, there were two] too early, and realizing his error, went for the second one with too little pitch and speed. He made the point that Mr. Proudfoot was red in the face with anger just before his display, as the BoB Memorial Flight had completely cocked up the timing of his and others displays. As Steve said, that is no condition to go to fly a tight display, and he felt that it was this state of mind that was possibly the cause of his misjudgement?. Who really knows. It was a very, very sad day. I have read your posts with extreme interest. Many thanks for them.

Steve is most certainly qualified to make a suggestion on this incident and I have great respect for his opinion.
This being said I'm sure Steve would be the first in line to say that the circumstances involved with the Proudfoot crash are vague to say the least and questions will remain unanswered most likely forever.
Des Barker and I went over this incident in some detail for his book
Anatomy of Airshow Accidents" and both of us watched the film many times over. I wouldn't argue a thing Steve said and certainly these factors could easily have been pertinent concerning the crash.
Both Des and I were deeply concerned with the second roll. Hoof had done a single the day before and everything that should be in place through initiation and completion was there and completely normal. On Sunday for some reason Hoof decided to go for that second roll. Naturally multiple rolls done in sequence pay a price in drag and energy loss. I was looking for just a bit more positive pitch rate into initiation for that second roll and I didn't see it. To my eye it looked like Hoof buried the nose through inverted just enough that it altered the roll arc backside into dishout. What also got my attention was that at ground impact there was aileron still in the equation. It was this that led both Des and I into the kneeboard theory. In short, barring control interference the control application just didn't seem normal to my eye for a pilot with Hoof's experience in the P38. Added to this was the fact that the buckle attachment that secured the kneeboard to Hoof's knee was discovered undone and separated from his leg post accident. IF.......and that's a huge IF........that kneeboard had come undone during that second roll that could easily have been a direct cause for yoke interference.
BUT.............as we say quite a lot when dealing with conjecture...........who REALLY knows ?
Dudley Henriques

Anyway..........both Des and I agreed that the role of the kneeboard Hoof was wearing on his right leg that day might or might not have been a factor.

[DownWest]

In combat you do what you have to do. Generally speaking when defensive a "flick roll" could be a last ditch maneuver to force a shooter into an overshoot.
The airspeed at which a "flick roll is initiated" is critical. Too fast and you can easily over g the airplane. So slowing it down to where you can safety "snap it" is the key.
Because ANY snap roll in ANY airlane is an energy loss maneuver, doing one in combat should be considered a "desperation" maneuver, not something you would wnat in your normal "bag of tricks" as a combat pilot.
Dudley Henriques

Here is an actual acct, told by my father:

Incident at Le Mans - June 1940

Jumped by a one-o-nine at fifty yards
thought he was one of our flight
looked back at his spinner through green fire
how he could miss - his shower of shells
just clearing my perspex
panicky, yanked the stick to my guts, kicked
full right rudder, a hundred feet over the trees.

The Hurricane flicked upwards - he was still there
closer - another dizzying flick roll
with the speed dropping right away
fell into a spin at seven hundred
they said - curtains, less than a thousand
the ground rushed up incredibly, a clearing -
knew I was dead in five seconds, thought coldly,
you bloody fool, you’ve done it now
the air gripped the wings again, levelled
out of the dive, below the trees, frozen
saw the German beside me, going faster
now I had him, fumbled the sight switch on
gun button off safe
he turned his head, did nothing
flew into my three second burst -
a shiver of wings, then slowly, slowly
half-rolled, falling inverted
down to a cornfield, dissolved in flames

He wrote a bit of prose and poetry much later.
Flew in France with 242, back for the BoB with 32, then Spitfires and channel crossings, some with Finucane. Later N. Aftrica.
DW

[treadigraph]

Re the P-38 crash which I didn't witness, TFC's Ken FitzRoy quoted Hoof as saying "never more than one roll", presumably during briefings, and having just reviewed the video I see the rolling element is continuous; at the start of the second roll the nose is on the horizon possibly even slightly nose down with no pitch up so far as I can see. Certainly looks more like a problem than a deliberate attempt at a second roll to me.

[markkal]

What examples are there of old aircraft crashing because they are old or 'worn out'? The most common single factor appears to be misjudgement of speed and/or altitude at low level, and this can happen to current military pilots as much as anyone else. EG The Mountain Home Thunderbirds crash.

This thread is about a jet trainer. a jet trainer when put in private hands, needs extensive training it's fast and whoever is flying it has to be well ahead, mentally and tactically connected to the aircraft in all phases of flight. When talking about a vintage very high power former WW2 propeller driven aircraft, it may even require more attention.

We are talking about over powered, high wing loaded aircrafts to be maneuvered with G load increases, potential dangerous cross controlled inputs whether intentional or not, often on the back side of the power curve.

Huge props, enormous power, pronounced secondary effects ( P factor, torque, slipstream and precession ) conducive to loss of control not only during take off run where full throttle application could lead to flipping to the side or failure to maintain directional control even with full use of rudder; In flight it can and will bite (Flick or snap) in all areads of the backside of the flight envelope, if not handled correctly plus when maneuvering at low level high turning and loop radiuses due to their speeds have to be reckoned with

These aircraft were already twitchy when they were in service back in time, with so many crashes and damages due to loss of control. Nowadays often they are in the hands of pilots which may not have had the training, the competence required. Even when handled by once competent veterans flying every now and then, they may lack in currency.

Flying these birds calls for proper training and currency. I have owned many aerobatic aircraft including for 17 years a sukhoi 29 which can be described as a mini fighter along these lines. It took me years and specialised training to feel confident at my level, and would need much more training to carry on learning, but am too old for that, though I still fly an Sback XA42.

After 45 years of flying I still approach such aircrafts trying to fly on a regular basis, using brains and humility. If I were to be able to have a go in a Spitfire, a P51 or Corsair I would never even think of it without highly specialised tuition..

A wise old man, by the name of Mr Auguste Mudry, the creator of the famous french Cap's aerobatic aircrafts, back in 1992 at the Yverdon Switzerland world unlimited aerobatic venue, during one our many conversation over the years ( I was one of his customers) struck me with a brief sentence ;
Aerobatics is to aviation what grammar is to a language and dressage to horse riding. But there is an extatic euphoria when bonding with an aircraft during aerobatics which could extend to airshows or any advanced aircraft flying, where the confidence gained may not be at par with the skill required and the lapse of time available in terms of margin at low level when one makes an error. This will almost always kill you..

I have scared myself more than once over the years, and am trying the learn the lesson.....At some times I guess I have been lucky,

[JEM60]

Sorry, Treadigraph. I thought you had. I should have checked back. I video'ed his roll on Saturday. It was superb. I told my friend on Sunday to watch this beautiful slow roll. Then it happened. Despite being there, I had no idea that this was a second roll. Possibly I was looking straight ahead and missed the first one. The P.38 crashed directly opposite me. Apologies for for the mis-reference. Regards, John. P.S. I was asked at Fairford by another Aviation buff as to what I thought had gone wrong. [he had seen it also], and I replied that it looked to me like a control problem. As Mr. Henriques implies, we will never know the answer, but I now head towards the Knee-pad theory.

[DAHenriques]

This thread is about a jet trainer. a jet trainer when put in private hands, needs extensive training it's fast and whoever is flying it has to be well ahead, mentally and tactically connected to the aircraft in all phases of flight. When talking about a vintage very high power former WW2 propeller driven aircraft, it may even require more attention.

We are talking about over powered, high wing loaded aircrafts to be maneuvered with G load increases, potential dangerous cross controlled inputs whether intentional or not, often on the back side of the power curve.

Huge props, enormous power, pronounced secondary effects ( P factor, torque, slipstream and precession ) conducive to loss of control not only during take off run where full throttle application could lead to flipping to the side or failure to maintain directional control even with full use of rudder; In flight it can and will bite (Flick or snap) in all areads of the backside of the flight envelope, if not handled correctly plus when maneuvering at low level high turning and loop radiuses due to their speeds have to be reckoned with

These aircraft were already twitchy when they were in service back in time, with so many crashes and damages due to loss of control. Nowadays often they are in the hands of pilots which may not have had the training, the competence required. Even when handled by once competent veterans flying every now and then, they may lack in currency.

Flying these birds calls for proper training and currency. I have owned many aerobatic aircraft including for 17 years a sukhoi 29 which can be described as a mini fighter along these lines. It took me years and specialised training to feel confident at my level, and would need much more training to carry on learning, but am too old for that, though I still fly an Sback XA42.

After 45 years of flying I still approach such aircrafts trying to fly on a regular basis, using brains and humility. If I were to be able to have a go in a Spitfire, a P51 or Corsair I would never even think of it without highly specialised tuition..

A wise old man, by the name of Mr Auguste Mudry, the creator of the famous french Cap's aerobatic aircrafts, back in 1992 at the Yverdon Switzerland world unlimited aerobatic venue, during one our many conversation over the years ( I was one of his customers) struck me with a brief sentence ;
Aerobatics is to aviation what grammar is to a language and dressage to horse riding. But there is an extatic euphoria when bonding with an aircraft during aerobatics which could extend to airshows or any advanced aircraft flying, where the confidence gained may not be at par with the skill required and the lapse of time available in terms of margin at low level when one makes an error. This will almost always kill you..

I have scared myself more than once over the years, and am trying the learn the lesson.....At some times I guess I have been lucky,

A few years back we had a rash of Mustang accidents here in the states.
I've attached an article I did back then concerning the issues associated with flying the P51 that the forum might find of some interest as it seems associated with the issues being discussed.
​​​​​​https://drive.google.com/file/d/1QKnt3PXqixIum9GUTzoTMJz4QP6-h8iG/view?usp=drive_link
Dudley Henriques

[markkal]

A few years back we had a rash of Mustang accidents here in the states.
I've attached an article I did back then concerning the issues associated with flying the P51 that the forum might find of some interest as it seems associated with the issues being discussed.
​​​​​​https://drive.google.com/file/d/1QKnt3PXqixIum9GUTzoTMJz4QP6-h8iG/view?usp=drive_link
Dudley Henriques

Thank you for this very informative post conveying your experience and sharp analytic capacity to explain these complex phenomenons.

I would kindly ask you whether it would be an option given also the excess power available to take off or go around without applying full power. I.E. on a 6 cylinder lycoming 300HP in an Extra 300 you can easily take off or go around with 2'400 rpm instead of 2'700 and 26 inches of MAP instead of around 29 MAP.

Which makes no sense other than for nose abatement on an Extra, but could help tame those adverse secondary effects of torque and prop on a WW2 fighter. Please post more threads and answers on this forum !

[DAHenriques]

Thank you for this very informative post conveying your experience and sharp analytic capacity to explain these complex phenomenons.

I would kindly ask you whether it would be an option given also the excess power available to take off or go around without applying full power. I.E. on a 6 cylinder lycoming 300HP in an Extra 300 you can easily take off or go around with 2'400 rpm instead of 2'700 and 26 inches of MAP instead of around 29 MAP.

Which makes no sense other than for nose abatement on an Extra, but could help tame those adverse secondary effects of torque and prop on a WW2 fighter. Please post more threads and answers on this forum !

Your question is a valid one.
Actually, many of today's civilian operators of Mustangs are already using reduced power on normal takeoffs due to the use of 100LL fuel. It works both ways really. I'm not sure he's the only one but my friend Scott Yoak who owns and flies Quicksilver on our airshow circuit uses the full 61 inches and he uses 100LL fuel.
Basically addressing your question directly, as I always say, nothing connected with flying is written in stone.
The "thing" about handling power in any airplane, and most certainly in something like the Mustang is that the name of that game is control. The prop on a Mustang weighs in at around 450 lbs and strapped onto a V1650-7 Merlin can be a real handful if you get ham handed with the throttle.
We had to deal with the takeoff and go-around issue a while back with the AT6 going supersonic on takeoffs. The question of partial power was front and center. The general consensus at the time was that reducing the power for noise abatement didn't override the obvious advantages involved with altitude gain after takeoff. So most of us just reduced a bit earlier after rotation and smiled a lot and offered free coffee and donuts to the folks living around the field.
A fighter like the Mustang requires a lot of forward thinking when it boils down to things like go-arounds. That's the key really, being one with the airplane.
You simply don't want to allow yourself to fly into a bad situation and misusing power on a go-around falls directly into that category.
The skinny is that instead of thinking of power in a plane like a Mustang it's FAR better to think of power as available through a large range of selection.
So it boils down to common sense. If you have to go around you should be acutely aware of exactly where you are as relates to configuration, available runway ahead, where the power is at that instant......the whole magilla, because if you initiate without having these factors in tow and come in hard and fast from a low power setting to anything around METO or beyond, you could easily end up spoiling your whole day.
So the basic answer to your question is yes. You can certainly select a lower manifold pressure for a go-around.......IF........conditions are favorable for that decision.
It's all a matter of where you are when you initiate and how you are configured. The earlier the better. The deeper you are into the landing in a plane like the Mustang the more careful you have to be with power if needed.
I hope this helps a bit.
Dudley Henriques

[markkal]

Thank you for this very informative post conveying your experience and sharp analytic capacity to explain these complex phenomenons.

I would kindly ask you whether it would be an option given also the excess power available to take off or go around without applying full power. I.E. on a 6 cylinder lycoming 300HP in an Extra 300 you can easily take off or go around with 2'400 rpm instead of 2'700 and 26 inches of MAP instead of around 29 MAP.

Which makes no sense other than for nose abatement on an Extra, but could help tame those adverse secondary effects of torque and prop on a WW2 fighter. Please post more threads and answers on this forum !

Addendum: Having read and reread your excellent article on "the issues asssociated with flying the P51" as per your link above answers all of my questions, Worth of note that the issues concerned are certainly common to all taildraggers WW2 fighters; Therefore they have little in common except the tailwheel with those agile and light 300HP+ overresponsive small aerobatic aircrafts;

[megan]

Thanks for the clarification, (and language lesson)Made me go back for a look DAR, spelling lesson for me, example from AT6 manual.


https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/1500x2000/ab264_6590cb8cd84d79715741fa62b39c3f2a6e20c96d.jpg

[Pilot DAR]

That's quite something Megan. 'Spaines why my aviation language is so scattered; raised in Scottish and English heritage, in Canada, with huge American aviation influence!

So, it's a "snap roll"!

[treadigraph]

Reminds me that when SOCATA first started marketing the TB-10 in the US, a controller cleared a pilot to line up behind the landing To-bar-go. TB-10 pilot acknowledged his taxi instructions and said "by the way, it's pronounced To-bay-go". Another pilot chipped in "so you say Tobaygo, he says Tobargo, let's call the whole thing off..."