Question. RAAF Hercules in six turn spin in 1968

[Centaurus]

In 1968 a RAAF Hercules inadvertently entered into spin during a training flight from Richmond. The QFI was Flt Lt Bruce Clarke. It was suspected a prop governor defect on the No 1 prop may have been a factor in the loss of control. Clarke recovered from the spin in IMC after six turns and losing 6000 ft. Does anyone have any more details of this incident - preferably factual rather than speculation.

[Brian Abraham]

Recall reading the article in "Spotlight" of the 707 spin/crash. The 130 spin and a RAAF P-3 spin were also mentioned. RAAF flight safety should be able to help. Have found them most helpful in the past.

Edited to add I found this at E Story.doc - Windows Live (http://cid-bd39e7fe1464ac00.skydrive.live.com/self.aspx/Public/E%20Story.doc)

THAT EVENTFUL DAY

23 SEPTEMBER 1966

My fourth flight “solo” as a fully qualified Flight Engineer with No 36 Squadron, flying on a Lockheed C-130A “Hercules” aircraft. It was an afternoon training flight and was planned for 2 X 2:00 hour sessions starting with a 1300 Hrs take off.


The crew were: -
Captain Flt Lt Bruce Clarke Q.F.I – I.R.E
Copilot (conversion training) Flt Lt Arch Streeter
Flight Engineer Sgt Barrie Wallis
Loadmaster Sgt Les Wells

The aircraft was: -
RAAF Hercules A97-207

The base was: -
RAAF Richmond, NSW

It was proposed that after the first 2Hr training session the pilots would change over, with engines running and the second session would carry the same S.N.C.O’s. We were planned to take off at 1300 Hrs so the Flt Eng and Loadie preflighted the aircraft and when the pilots arrived we were briefed by Flt Lt B.C. Clarke as to the content of the training mission. He said that we would be going out to the training area to the North West and demonstrate and practice “Stalls”, both clean then dirty.

We were the only aircraft in the training area at that time on that day so, B.C. said we were planned to do these stalls at 5,000 ft AGL over the Blue Mountains, however for this session we would go up to 15,000 ft to save time, and after recovery from the last stall we would carry out a practice medium level ADF approach. All done we “started and departed” and in transit to the training area the Loadie Les Wells secured the cargo compartment of loose articles that could become missiles during the stalls.

Almost to the training area B.C. Clarke called Les and checked the condition of his domain, and when told all was ready, B.C. told Les to come forward and strap into the vacant Navigator seat for the practice stalls. The layout in this session was Arch Streeter (who was on a conversion course) was occupying the left hand normal Captains position and the Co Pilots seat was occupied by Bruce Clarke. When the Flight Deck was also made secure we started our first stall, a simple “clean” stall which was demonstrated and an effective recovery carried out. During the stall Bruce Clarke demonstrated that when in the stall even though the aircraft was normally stable, very little lateral control was available however on the application of power the aircraft would actually climb out of the stall if necessary.

During the next stall Bruce Clarke entered the stall by closing all throttles to the Flight Idle position and raised the nose. When in the stall which was charted to occur at 95Kts, Bruce Clarke demonstrated the absence of lateral control by rolling the ailerons from full left to full right without the aircraft responding and when the speed decreasing past the stall figure Bruce Clarke said that the longer the aircraft is left in the stall the buffet gets worse and all control is lost.

Just past this point the aircraft rolled to the Left and Bruce Clarke attempted to pick up the dropping wing, but with no lateral control the aircraft rolled to onto its back and entered a spin. At this point Bruce Clarke announced that we had rolled into a spin and he had taken standard recovery action. So we went down and during that spin, after what seemed an eternity Bruce said that the aircraft was not responding but standard recovery action held on.

Again after what was a lifetime to us new members, the aircraft responded and the spin stopped, Bruce Clarke said we were out of that but now we have to get it on the ground. I carried out a visual inspection from the cargo compartment but nothing was out of the ordinary much to my surprise. We made a speedy return to Richmond and once on the ground logged the aircraft in for a high “G” inspection. At the bottom of the spin at the pull out which was between 7000 and 8000 ft we pulled 3.2 positive “G”.

Next came the investigation as to why a normally docile and well-mannered C-130A would spin. After all the evidence was put together no defect could be blamed, however the mechanics of the Hercules was partly the cause aggravated by humans. To explain this further one has to come to grips with a constant speed Turbo Prop engine. It always runs at the same speed however, to make it function correctly, by adding more fuel to the engine the system will increase propeller pitch rather than increase RPM which is governed and so cause more work to be done, consequently when the fuel flow is reduced to the Flight Idle position the propeller pitch will decrease towards the zero position and stay there. Now with four engines the Flight Idle position in relation to the blade angle was not the same, so that at Flight Idle there were four different power settings.

Next at the Flight Idle position if the fuel is low, this can cause the propeller pitch to decrease below zero degrees and become negative. Obviously this is not a desirable thing to happen so when the “Negative Torque” reaches a set figure the mechanical (NTS) system will physically attempt to increase pitch and thus hold it at a predetermined value, this being -1400 Inch Pounds of Torque.

So now to put this knowledge into our docile C-130A. In the air when starting to practice the stalls, the four throttles were pulled back to Flight Idle and in this case engines 3 and 4 on the right hand side they remained in positive thrust, just how much I cannot remember, then engines 1 and 2 on the left hand side were producing Negative thrust just above the N.T.S. system activation. Now in the air as the speed decreased the stall started and as it was held there we lost aileron control, then a short time later engines 3 and 4 which were producing positive thrust attempted to accelerate that wing, thus producing lift, while engines 1 and 2 were in Negative thrust and attempting to decelerate that wing, thus creating drag. It naturally followed that without aileron control and differential thrust there was only one situation that would occur, and it did.

One outcome was to then make a Standard Operating Procedure requiring that BEFORE entering stalls when the power was reduced to Flight Idle a power asymmetry check was carried out and all engine outputs were aligned.

The aircraft involved in this incident was A97-207 and at the end of the inspection it was found that several rivets on the upper surface of the left Hand horizontal stabilizer had popped and there was speculation that these had popped some time prior to the stalls, nothing else. The aircraft was given a clean bill of health and from that moment onwards it never would fly straight again without cross trimming. I never flew in 207 for another six months but do remember its flying characteristics.

By Sgt Barrie Wallis, Flight Engineer

[Disco Stu]

I heard the pretty much the same story in '69. This aircraft was in the 486 hangar for nearly all my time at Richmond (69-70) and from memory only came out at the time of the Squadron fly past. This happened when for one fleeting moment all 12 aircraft were serviceable at the same time.


DS

[Centaurus]

Thank you very much indeed for those replies. It is exactly what I needed. I talked to Bruce Clarke about this incident shortly after he had arrived to fly 748's in 1969 at 34 Sqn. But time dims the old memory and I recalled (incorrectly as it now turned out) that he was demonstrating asymmetric flight with No 1 throttled back which led to the spin. At least I was half right because he also mentioned the NTS system and the problem it caused.

Bruce joined DCA several years later and around 1982 died of a heart attack at work. Again thanks for the info it was invaluable as his son Glen now in his Forties was interested to know more about the incident.
C.

[Centaurus]

Edited to add I found this at E Story.doc - Windows Live


BA,
I hadn't heard about this E Story - Windows Live, before. Just wondered how you knew the C130 spin story was on that web site? Are there any more flight safety stories or general flying story histories like the one you discovered to be found on that site and if so, how does one go about finding them?
Regards,
Cent.

[MichaelSW]

That Eventful Day
23 September 1966
Loadmaster’s recollections

Scheduled for local training, arrived at the aircraft and pre-flighted same. After takeoff, we went to the training area in the North West. Practice stalls were the intention and up to this time, stalls were not practised at below 5000 feet. Clarkey said we will go up to 15,000 and on attaining this, Bruce said, “Loady, strap yourself in the Nav’s seat”. Just as well, I suppose, as I would have probably been half asleep along four of the seats.

I can remember it being stated that at this weight it will stall at 95 knots, the nose will drop, a bit of shuddering and recovery is by applying power. I decided to watch the Nav’s instruments during the manoeuvre. The airspeed dropped, 100, 98, 96, 94, I felt the nose drop and a bit of a shuddering and swung my eyes over to the VSI on the co-pilot’s panel to see it registering 6,000 ft a minute going down. Everything loose on the flight deck was floating including my feet.

Looking out through the windows, I found the earth to be rotating, and BC said, “I can’t control it. Applying standard recovery action”. Severe “G” forces were experienced and the aircraft levelled out. I thought, “That was interesting”, Not knowing at that time it should not have happened.

BC then said, “Well that proves that you can pull a Herc out of a spin. Let’s get it on the ground before it falls to pieces”. That is when I started worrying. To my knowledge, we pulled out at 4.000. I understand a 37 Sqn bird was above us and his comments to his crew that that was something you do not see a Herc do every day.

After landing, I was walking back to the section when I was met by the other loadmasters coming out saying back to 207, we have to set up centre-seating it is going to Rockhampton, what are you looking so pale for. I said that 207 was not going anywhere as it was US for a complete airframe check and the story came out.

Back in the section, I asked the Loady Leader if I could go home, could Bill Ross drive me as I did not have any transport and on passing through Richmond, I asked Bill to drop me at the RSL club. After a few quick beers I went home.

About seven that evening I told my wife what had happened. “What did you tell me that for, you know I will only worry”. I replied that I thought it best. Next morning, (Saturday) walking together down Richmonds’ main street, we ran into Shorty Heffernam who said, “By Gee, you nearly lost him yesterday didn’t you”. I said, “Now you know why I told you last night”.

Thank goodness we were at 15,000 as we would not be around now to talk about it.


I understand that this is the only happening of a Herc coming out of a spin.

Les Wells.

[Arm out the window]

It probably doesn't count as a fully developed spin, but the story of that one that flicked during an asymmetric circuit, barrell rolled and barely recovered without spearing in is a bloody scary one.
I don't know the full details but have heard various Herc people mention it here and there.

[Centaurus]

RAAF pilots sometimes did some very dangerous things in those days; in some cases more out of instructor enthusiasm than deliberate cowboy flying. Many of us were relatively young and thought we were invincible. The old saying of "if you can fly a Wirraway - you can fly anything" had more than a ring of truth to it. I can say that now because I was just as guilty of being overconfident in my own ability as a QFI as many others. Fortunately with the advent of modern flight simulators things are a lot safer now

[doubleu-anker]

Centaurus

Agreed.

The place to monkey around is in simulator, unless you are a qualified and an experienced test pilot.

Seem to remember a perfectly serviceable B707 was lost through such, shall we say "enthusiasm".

Don't try and reinvent the wheel.

[Brian Abraham]

BA,
I hadn't heard about this E Story - Windows Live, before. Just wondered how you knew the C130 spin story was on that web site? Are there any more flight safety stories or general flying story histories like the one you discovered to be found on that site and if so, how does one go about finding them?
Regards,
Cent. Centaurus, forgive me it's only at this late date I became aware of your query. I stumbled across the link as the result of a google when this thread popped up. Was fully aware of the story, if not the exact details, from a reading of the incident in "Spotlight" or whatever it was called back in those days. See the link no longer works.

[Wiley]

I can confirm it was A97-207, and not 212.

A97-207 always flew a little crooked after that event, requiring a bit of creative trimming to get the desired cruise figures, which on a Darwin-Singapore leg, could really matter. (At the weights we usually carried on a Butterworth or Vietnam service, that sector was so fuel critical we frequently flight planned on a PNR.)

(The A model autopilot was pretty basic, so if I'm being honest, I'd have to say they all required a bit of creative trimming), and if you climbed up into 207's duck's bum area, you could see that some of the stringers weren't quite as pristine and aligned as they might have been. But when you consider the treatment all the A models got in some of the rough strips we went into in PNG, to say nothing of the succession of teenage and not much older than teenage trainee pilots all practising short field landings day after day after day, it's quite possible they all looked like that up in the duck's bum. I only ever looked at 207's duck's bum because I was told to take a look at it by whoever it was who told me about the spin.

Is Arch Streeter still about? Haven't heard a word of him in many years now.

[Disco Stu]

Wiley, appreciate the correction to my memory of something over 40 years ago.

The "A's" set a work ability standard that is now the normal expectation of todays trashies.

DS