My Spin Crusade

It has been about 50 years since I did my first spin in an aeroplane, about 35 years since I started teaching spins to other pilots and about 15 years since I started teaching other instructors how to teach spins.

In the last ten to twenty years in Australia there have been two significant and related improvements to the knowledge associated with spinning. The first is the internet – before Google it was just so difficult to get good information. The flight manuals mandated by CASA’s predecessor were to a fixed template of limited scope which did not include information on spin recovery procedures. The flight manual developed by the manufacturer overseas and approved by the FAA, if from the USA, was required to be discarded.

How lucky was I to have the opportunity to fly a brand new Pitts S-2A in the ’80s. It came out of the box with its original flight manual, the first time I had seen one despite flying Pitts for about ten years. We had some handling notes based on the Pitts Owners and Service Manual plus that silly Australian-specific flight manual. (In another article later I will go into more detail as to why it was silly.) Guess which was the only document which described the recovery technique from a flat spin? This was in the days long before the Beggs-Mueller technique. I’ll never forget one unintentional spin from a lomcevak in practice for an airshow “why doesn’t this stop spinning” I was thinking. When I flew the airshow the next day I flew that lomcevak at quite a much higher altitude.

Flying schools were required to provide pilots with handling notes which were “accepted” by the local office of CASA’s predecessor – there was no standard so the content was variable – even for the same type between different flying schools. The text of handling notes would often conflict with the original flight manual! There were some generic POHs available for sale for the more common types but pilots, of simple types especially, were not directed to them. These were the days before personal computers so every document had to be laboriously created and printed.

Finally, around 2000, CASA changed the flight manual system to discard the Australian-specific manuals and revert to the original. However many owners found it difficult to acquire flight manuals applicable to aeroplanes 20 to 30 years old by then and gave up. I still see a lot of aerobatic aircraft with the old Australian-specific manuals or the wrong manual of some sort – importantly, the aircraft does not have the correct flight manual which is one of the documents legally required – and it is important.

Over these years I have become concerned with the number of spin endorsed pilots who don’t know the correct spin recovery technique. The number of instructors with spin training endorsements who do not know the correct spin recovery technique makes me angry. People whisper in my ear about their scary experience when a spin takes a very long time to recover and I ask what technique they use – when they tell me I respond with “You are very lucky that you did not die using that technique!”

CASA’s Flight Instructor Manual is quite clear:
“To recover, first ensure that the throttle is closed, ailerons neutral and the direction of turn identified. This is followed by application of full opposite rudder. After a brief pause ease the control column forward progressively until the spinning stops. Centralize the rudder and ease gently out of the resulting steep dive, levelling the wings.”

The FAA’s Airplane Flying Handbook is more comprehensive:
“In the absence of the manufacturer’s recommended spin recovery procedures and techniques, the following spin recovery procedures are recommended.
Step 1—REDUCE THE POWER (THROTTLE) TO IDLE. Power aggravates the spin characteristics. It usually results in a flatter spin attitude and increased rotation rates.
Step 2—POSITION THE AILERONS TO NEUTRAL. Ailerons may have an adverse effect on spin recovery. Aileron control in the direction of the spin may speed up the rate of rotation and delay the recovery. Aileron control opposite the direction of the spin may cause the down aileron to move the wing deeper into the stall and aggravate the situation. The best procedure is to ensure that the ailerons are neutral.
Step 3—APPLY FULL OPPOSITE RUDDER AGAINST THE ROTATION. Make sure that full (against the stop) opposite rudder has been applied.
Step 4—APPLY A POSITIVE AND BRISK, STRAIGHT FORWARD MOVEMENT OF THE ELEVATOR CONTROL FORWARD OF THE NEUTRAL TO BREAK THE STALL. This should be done immediately after full rudder application. The forceful movement of the elevator will decrease the excessive angle of attack and break the stall. The controls should be held firmly in this position. When the stall is “broken,” the spinning will stop.
Step 5—AFTER SPIN ROTATION STOPS, NEUTRALIZE THE RUDDER. If the rudder is not neutralized at this time, the ensuing increased airspeed acting upon a deflected rudder will cause a yawing or skidding effect. Slow and overly cautious control movements during spin recovery must be avoided. In certain cases it has been found that such movements result in the airplane continuing to spin indefinitely, even with anti-spin inputs. A brisk and positive technique, on the other hand, results in a more positive spin recovery.
Step 6—BEGIN APPLYING BACK-ELEVATOR PRESSURE TO RAISE THE NOSE TO LEVEL FLIGHT. Caution must be used not to apply excessive back-elevator pressure after the rotation stops. Excessive back-elevator pressure can cause a secondary stall and result in another spin. Care should be taken not to exceed the “G” load limits and airspeed limitations during recovery. If the flaps and/or retractable landing gear are extended prior to the spin, they should be retracted as soon as possible after spin entry.
It is important to remember that the above spin recovery procedures and techniques are recommended for use only in the absence of the manufacturer’s procedures. Before any pilot attempts to begin spin training, that pilot must be familiar with the procedures provided by the manufacturer for spin recovery.”

I have added the bold to some of the above text so let’s consider those items further.

The spin recovery procedure described is generic and it is essential to use the procedure provided by the manufacturer – remember that they have undertaken substantial flight tests to determine the behaviour in a spin and to prove the recovery technique. To emphasise this, all pilots, especially all spin instructors should read the ATSB’s report of the 2014 accident to a Chipmunk at https://www.atsb.gov.au/publications/investigation_reports/2014/aair/ao-2014-114/

The first four steps in the FAA’s Handbook are identical to the NASA Standard Spin Recovery Method (see AIAA Paper 86-2597) which has been distilled by Rich Stowell into the PARE® mnemonic.

All four actions of PARE® must be done for the spin to stop. There are some other actions afterwards.

It is particularly annoying to see stuff like the following text on a website such as https://blog.globalair.com/post/aircraft-spins-101.aspx
“Recovery procedures are specific to the aircraft flown and are found in the pilot operating handbook of each aircraft. In light aircraft, the spin recovery procedures follow a typical pattern and can be remembered by the common acronym PARE®.
P – Power: The throttle should be moved to the idle position to reduce thrust.
A – Ailerons: Ailerons should be neutralized.
R – Rudder : Full opposite rudder input should be applied until the rotation is stopped. If the aircraft is rotating to the left, right rudder should be applied. Once the spinning stops, the rudder should be neutralized.
E – Elevator: Quick forward pressure should be applied to break the stall and gain airflow over the wings. Once the aircraft gains lift, back pressure should be applied gradually so as not to stall again.”

Please, if you are going to use PARE® to recall the spin recovery technique then get it right. True, neutralise the rudder once the spin stops but that won’t happen (in a typical fully developed spin) until after the next step of moving the elevator. That website suggests that you use the elevator to “break the stall” after the spinning stops however CASA, NASA and the FAA are quite clear: When the stall is “broken,” the spinning will stop. It is true that some aircraft have a rudder powerful enough to stop the rotation by itself in a fully developed spin but here we are discussing the generic technique.

Let’s move on to consider some examples of specific techniques.

For the Cessna 152:
1. VERIFY THAT AILERONS ARE NEUTRAL AND THROTTLE IS IN IDLE POSITION
2. APPLY AND HOLD FULL RUDDER OPPOSITE TO THE DIRECTION OF ROTATION
3. JUST AFTER THE RUDDER REACHES THE STOP, MOVE THE CONTROL WHEEL BRISKLY FORWARD FAR ENOUGH TO BREAK THE STALL. Full down elevator may be required at aft center of gravity to assure optimum recoveries.
4. HOLD THESE CONTROL INPUTS UNTIL ROTATION STOPS. Premature relaxation of control inputs may extend the recovery.
5. AS ROTATION STOPS, NEUTRALIZE RUDDER AND MAKE A SMOOTH RECOVERY FROM THE RESULTING DIVE.

Pretty much exactly what the FAA describes as the generic technique.

The Cessna 150 is similar. I recall a flight with one instructor trainee who was an experienced pilot. Upon recovery from his spin demonstration he applied full opposite rudder and continued to hold the yoke full back. The aeroplane simply kept spinning. He gave me a quizzical look and I responded with: “Just move the yoke forward.” He was testing me as he had some bad experiences with instructors previously.

Now for the Super Decathlon Flight Manual:
Recover with Positive Movement of Stick to Neutral Position & Opposite Rudder Until Rotation Stops – Then Neutral Rudder & Smooth Recovery from Dive to Level Flight.
Free Release at Control is Not Adequate for Recovery.
Positive Movement of Controls by the Pilot is Required for Spin Recovery.

The Operating Manual has this additional information:
1) Throttle – Closed
2) Ailerons – NEUTRAL POSITION
3) Rudder – FULL DEFLECTION in the opposite direction to the rotation
4) Elevator – POSITIVE FORWARD TO NEUTRAL (free release of the elevator control is not adequate for recovery)
5) Rudder – NEUTRALIZE when rotation stops and positive control and flying speed is restored
6) Nose Attitude – RAISE smoothly to level flight attitude
7) Throttle – only after recovery from diving attitude, then as required

Again, pretty much exactly what the FAA describes as the generic technique.

Other variants of the Decathlon are the same. I recall a flight with one instructor trainee. As a flight examiner I had previously failed him on his test for the spin training endorsement because of his dangerously incorrect knowledge – he was adamant that PARE® meant power off, aileron neutral, opposite rudder and elevator to pull out of the dive. He had absolutely no idea what the flight manual said about spin recovery. On this flight I gave him an opportunity to demonstrate recovery per his earlier briefing to me. After a couple of turns we were definitely in a fully developed spin and, a surprise to him, it simply continued spinning … and spinning. Stick forward and it recovered!

I have seen that wrong explanation of PARE® so often from spin-endorsed pilots that the standard of spin instruction makes me angry. I have experimented on occasion and not corrected someone during the briefing so I could observe their performance in flight. With the opposite rudder they inadvertently relax the back pressure and the stick moves forward enough to recover the spin. Another factor is that they do not let the spin develop fully – in the incipient spin stage the aeroplane is very easy to recover.

As some people very well know, there are some spin modes for the Decathlon where it takes a positive push to move the stick from the aft stop. Read those instructions in the manual again – it specifically addresses this characteristic.
PARE® is the thing to remember but get the detail right.

I have a short quiz about spinning on my website at http://ozaeros.net.au/?page_id=252 (the password is quiz). Why do so many people have the incorrect understanding of PARE®? Why do so many people believe that the elevator is used to unstall the wings only after the rotation stops?

I long ago ceased wondering how this situation arose. A combination of a few things but the root cause is people taking a shortcut to getting the qualification. Instructor trainees don’t bother to read the Flight Instructor Manual or the Flight Manual.

If they are using the incorrect technique surely it would become obvious during the flight exercises? It should and does but only if the aircraft has entered a fully developed spin. If spin exercises are limited to about one turn then the aircraft will recover easily, typically by relaxation of the pro-spin controls. If the aircraft is let develop spiral dive characteristics then the autorotation typically ceases by itself.

I have also seen trainees who were taught the correct information and then get off track by themselves. i.e. the training did not sink in – what’s that about assessing competence per the flight instructor standards? I know that it is not easy however it is important to do more than just present the knowledge in a pre-flight briefing, demonstrate spin recovery and observe the trainee repeat that technique on the one flight.

An earlier ATSB report is interesting in this context http://www.atsb.gov.au/publications/investigation_reports/1978/aair/197805178/
“The pilot was an experienced flying instructor and aerobatic pilot and held a general authorisation to conduct aerobatic flying below 3000 feet but not below 500 feet above ground level. …
… after completing his aerobatic display, which commenced with a spin, he commented that the spin had been made with engine power on and more height had been lost during this manoeuvre than he had intended. …
On the next morning … At a height variously estimated from 2000 to 4500 feet above ground level … Engine power was then heard to decrease and the aircraft entered a spin, probably to the left although one of several witnesses believed it was to the right. As the spin progressed, the nose attitude appeared to steepen to the near vertical. After making four complete turns, and after the fifth turn commenced, the aircraft struck the ground ….
It was established that it was the normal practice of the pilot, when performing aerobatics, to set the altimeter of his aircraft to indicate the height above ground level. The altimeter of VH-ERB was found to be set to indicate the altitude above mean sea level …
The probable cause of the accident was that the pilot, for reasons which have not been established, did not take timely action to recover from an aerobatic manoeuvre at a safe height.”

There is one common factor in both of these accident reports. The Chipmunk in 2014 had the obsolete Department of Transport Flight Manual. “In Australia prior to 2002, CASA and its predecessors prepared, approved and issued AFMs for light civil aircraft. The flight manual in use for UPD was one such manual, approved specifically for that aircraft by CASA’s predecessor in 1988. It did not include guidance on spin recovery.”
VH-ERB also had one of those flight manuals with nil guidance on spin recovery.

The observed steepening of the nose attitude indicates an accelerated spin which results from moving the stick forward before opposite rudder leading to a delayed recovery. It is unfortunate that the investigators did not seek out the spin recovery procedure that the pilot would’ve been known to use.

The only safety issue identified by the ATSB in that 2014 Chipmunk accident report was addressed to the specific flying school:
“The spin recovery methods taught by the flying school were inconsistent across instructors and training material, and were not always appropriate for the Chipmunk aircraft type used by the school.”
My opinion is that it is a much more general reoccurring safety issue which needs to be addressed regularly. I’d reinforce the contents of the CASA Flight Instructor Manual (supported by the FAA Flying Handbook) and the Flight Manual of the specific aircraft used. Of course, it is essential to have the current correct flight manual – I still see those old Department of Transport flight manuals in aerobatic aircraft! My opinion is that instructors should also read the book Stall, Spins and Safety by Sammy Mason – they need to know more than the minimum knowledge that their students must be taught. I find it amazing that inexperienced instructors and instructor trainees can just invent stuff, or at best apply some quite specific bit of information as if it was generic gospel – very dangerous.

Finally, PARE® per Rich Stowell from his excellent book Stall/Spin Awareness:
1. Power – Off.
2. Ailerons – Neutral (+ Flaps Up).
3. Rudder – Full Opposite and Held.
4. Elevator – Through Neutral.
Hold these inputs until rotation stops, then:
5. Rudder – Neutral.
6. Elevator – Easy Pull to Straight and Level.

Remember that, it is really not that hard to get it right.

Loops, Voices and the Fear of Death

This short story by Richard Bach written back when I started flying aerobatics has stuck with me for many years – it is available now in his book “A Gift of Wings”.DavidAirtourerEarly70sThat was the theme for my talk to the Aviation Medical Society of Victoria on 13th August 2016.

Here is my powerpoint presentation which will give you a taste of what I was talking about: LoopsVoicesandFearITAug16

Check out the links to the videos too.

Stay in Control: Incipient Spins

I avoid discussing incipient spins at the same time as fully developed spins to make it quite clear that the recommended recovery actions are quite different.

Let’s see what CASA has to say on the subject in their Flight Instructor Manual.

Chapter 9 Stalling:

“Show that lift increases until the critical angle is reached. …..  Smooth airflow then becomes turbulent and lift is decreased. This is the stalling angle.”

Interesting to note in CASA’s article at http://www.flightsafetyaustralia.com/2016/03/angle-attitude-stallspin-crashes-and-how-to-avoid-them/ that:

“There’s an interesting characteristic of angle of attack in most general aviation aircraft: critical AoA, the onset of a stall, begins at a 17 degree AoA or so, but maximum lift development occurs just before reaching the critical angle of attack.” Hmmm – a different definition of critical angle perhaps?

The Flight Instructor Manual Chapter 9 goes on:

“RECOVERY WHEN THE WING DROPS

Use the standard recovery, i.e. simultaneous use of power and forward movement of the control column. In addition rudder must be used to prevent the nose of the aeroplane yawing into the direction of the lowered wing. The ailerons should be held neutral until control is regained, when the wings should be levelled.”

Unfortunately, some CASA documents refer to this as an incipient spin! It is but it isn’t really!

Chapter 13 of the Flight Instructor Manual is Spins and Spirals. I can’t see a specific definition of incipient spin there but anyway:

“RECOVERY AT THE INCIPIENT SPIN STAGE

Brief the student that you will be demonstrating the entry to the spin in the normal manner. Point out that before the spin develops fully you will be recovering by ensuring the throttle is closed and the controls are centralised followed by recovery from the ensuing unusual attitude.”

Fine.

But on the following page, in the same chapter:

“RECOVERY FROM THE INCIPIENT STAGE

Carry out the pre-spinning checks. From a straight glide use the controls as for the entry to a fully developed spin. As soon as the aeroplane has stalled and commenced to yaw take the appropriate recovery action. Increase power, apply sufficient rudder to prevent further yaw and ease the control column forward sufficiently to un-stall the aeroplane. Point out that if power is to materially assist recovery action it must be applied before the nose of the aeroplane has pitched too far below the horizon otherwise its use will only increase the loss of height.”

Power can also aggravate the autorotation if the pilot mishandles the other actions.

Let’s see what CASA has published in their CAAP 155-1 Aerobatics: absolutely nothing on incipient spin recovery!

It seems that we must go to the USA’s FAA Airplane Flying Handbook free online at https://www.faa.gov/regulations_policies/handbooks_manuals/aircraft/airplane_handbook/ for a definition of an incipient spin. It is interesting that, in Chapter 4 Slow Flight, Stalls, and Spins, they discuss cross-control stalls including a skidding turn which still does not feature in CASA’s documentation.

“During the turn, excessive rudder pressure should be applied in the direction of the turn but the bank held constant by applying opposite aileron pressure. At the same time, increased back-elevator pressure is required to keep the nose from lowering. All of these control pressures should be increased until the airplane stalls. When the stall occurs, recovery is made by releasing the control pressures and increasing power as necessary to recover.”

It goes on to define the incipient spin as:

“INCIPIENT PHASE

The incipient phase is from the time the airplane stalls and rotation starts until the spin has fully developed. This change may take up to two turns for most airplanes.”

FAAspin2

Then it defines  the fully developed phase:

“DEVELOPED PHASE

The developed phase occurs when the airplane’s angular rotation rate, airspeed, and vertical speed are stabilized while in a flightpath that is nearly vertical. This is where airplane aerodynamic forces and inertial forces are in balance, and the attitude, angles, and selfsustaining motions about the vertical axis are constant or repetitive. The spin is in equilibrium.”

Quite clear to me!

The APS Emergency Maneuver Training Pilot Training Manual is also a good resource which is free online.

“RECOVERY Stall Recovery (See Exercise #5)

􀀴 Push

􀀴 Power*

􀀴 Rudder

􀀴 Roll

􀀴 Climb

* Power selection considerations will be discussed during ground Training”

This is amplified on their website at http://apstraining.com/the-incipient-spin-recovery/

“STALL RECOVERY PROCEDURE

An example of a stall recovery for most general aviation aircraft and most other aircraft types and classes is as follows:

PUSH: Reduce AOA (forward movement of the control column) to allow the wing to reduce AOA below critical AOA, reduce drag and to immediately transition from stalled fight to normal unstalled flight. Common tendencies are to either over-push causing excess nose drop below the horizon increasing altitude loss or a fore-aft pumping motion of the yoke causing one or more secondary stalls.

POWER: Smoothly add up to full power (usually) to increase airspeed and minimize altitude loss. We can do stall recoveries all day with the power at idle, however, an idle power setting is not assisting us in minimizing altitude loss. Keep in mind that there are certain situations that selecting power to idle in the stall recovery is the proper action. Examples include high-torque single-engine prop aircraft and in a Vmc situation in a multi-engine aircraft.

RUDDER: If there is any roll/yaw motion associated with the initial stall and the wing is still at or beyond critical AOA, the rudder should be used to stop the yaw-roll couple from developing. The amount of rudder used is only enough to coordinate the flight condition and should be accomplished in one application. Pumping or cycling the rudder is not a desirable technique especially for large aircraft. Note that the rudder is not used to roll the aircraft wings-level in a stall recovery. Common errors in the use of rudder vary from not using it all to using it far too much, for too long. Rudder is critically important in an uncoordinated stall condition (such as a cross-controlled stall) to ensure the stall is not allowed to develop from a stall to a spin.

ROLL: When the wings are clearly unstalled and coordinated flight has been regained. The aircraft’s flight attitude must be immediately be re-oriented to a wing’s level condition by rolling with aileron and coordinated rudder to the nearest horizon. Again, the aircraft should not be rolled by use of rudder alone at this stage. The primary roll control in normal flight is through the proper use of ailerons.

CLIMB: With the wings level in coordinated flight, aft yoke movement should be immediately applied to initiate recovery to a climbing attitude. The amount of elevator movement applied must ensure the aircraft remains below critical AOA at speeds below Va and at a load less than the limited load factor of the aircraft at speeds above Va.

Essentially, the first three steps of the stall recovery (1-2-3) are directly focused on safely recovering the aircraft from the stall and the last two steps (4-5) are to recover from any resulting unusual attitude. It is important for the pilot know and understand that these processes can not be successfully reversed. The stall must be solved first, regardless of the flight attitude of the aircraft, then followed by solving the unusual attitude.”

CASA’s recovery technique from a stall with a wing drop is fine for the usual practice straight stalls but note that rudder is really superfluous as forward movement of the stick will unstall the wing and the dropped wing can then be easily rectified with aileron. Some of you may be aware that aircraft certification requirements mandate use of the aileron for roll control at the stall – but note that is only for aircraft certified in recent years – we still fly many aeroplanes which were NOT certified to those requirements. Mishandling at the stall, say the classic skidded turn at low height, is quite different however in that the entry to the post-stall gyration is much more aggressive – this is the one that everyone should be wary of and know the immediate correct actions for recovery. Messing up an aerobatic manoeuvre is a similar situation although the altitude is generally higher.

The Super Decathlon is an example of a type certified to an older version of FAR 23 and it has this statement in the Operating Manual:

“The Super Decathlon stall characteristics are conventional. The stall warning horn will precede the stall by 5 – 10 MPH depending on the amount of power used. There is very little aerodynamic buffeting preceding the stall.

Aileron control in a power on stall is marginal. Large aileron deflections will aggravate a near stalled condition and the use is not recommended for maintaining lateral control. The rudder is very effective for maintaining lateral control in a stalled condition with the ailerons placed in the neutral position.”

An inadvertent stall/spin entry requires immediate action to unstall the wing and to remove the aggravating control deflections. Move the stick forward and get rid of aileron and rudder input. In other words:

Centralise the controls.

If you are in something like a Pitts then it is essential to close the throttle – reduction of power tames this aeroplane. If in something more docile then power is a secondary consideration so initially don’t need to do anything with the throttle. If centralising the controls doesn’t have an immediate effect then you are on your way to a fully developed spin so remember those actions from my other article – the first action is power to idle so this is the time – do it now. If centralising controls is having a positive effect then you now get to decide what to do with the throttle.

Consider the accident to a Cirrus in NSW in May 2014 – the ATSB report is at https://www.atsb.gov.au/media/4920573/ao-2014-083_final.pdf

“The PIC then took control of the aircraft and stated ‘watch this’. He selected 50% flap, rolled the aircraft into a left turn at about 25° angle of bank, reduced the power to idle, and raised the nose of the aircraft. The passenger in the front seat queried the use of flap and the PIC confirmed it was intended. As the aircraft approached the stall, the PIC pointed to the vertical speed indicator. As he did this, the right wing dropped rapidly and the aircraft entered a spin to the right. The PIC reported that at this time he performed his normal recovery procedure from this manoeuvre: maintained a neutral aileron control position, applied forward pressure on the control stick to pitch the aircraft nose down, rudders neutral and applied power. He reported that he moved the throttle lever forwards to increase power however there was a distinct hesitation in the engine response. The passenger in the front seat reported that on about the third rotation of the spin, the PIC said ‘I’m sorry’ ……….”

So, the pilot responded to the post-stall gyration by centralising the controls and applying power however the autorotation continued to develop into a spin. Application of power can have a significant adverse effect and aggravate the post-stall gyration. Reduction of power will eliminate that aggravating effect.  If you know that application of power will not make the situation worse and you think it will reduce the height loss then by all means do it – but be absolutely sure that you are correct. Of course, this particular pilot had a parachute to recover the aircraft so a better option earlier on.

Finally, it is very important to know how your particular aeroplane type behaves at the stall. What is the best thing to do in the type that you normally fly if you inadvertently start to spin at a low height? You must also consider your own experience and level of competency. How will you react if the aeroplane suddenly departs controlled flight at low altitude? It is all very well to know of a procedure to recover with minimum height loss but of little use if you mishandle the procedure and make it worse instead with application of power. A typical situation is the forced landing approach following an engine failure when your stress levels are already very high. Of course, in that situation, you don’t have power available to you anyway. APS has identified these common reflexive actions in initial stall/spin training – so, if a spin is suddenly encountered with nil training then expect one or more of these to occur which will make life much worse. e.g. “• Involuntary swearing and sweating • Continuing to hold the elevator control aft because of a dramatic, nose-down flight attitude • Inadvertently applying opposite aileron as a wing dips at the stall break, or as the airplane starts to roll into an incipient spin • Wildly shoving the elevator control forward”.

The bottom line, in my opinion, is to remember this set of immediate actions for recovery from an inadvertent spin entry:

  • Centralise the controls
  • Close the throttle
  • Recover from the ensuing unusual attitude

Stay in Control: Fully Developed Spins

From the 1944 book, Stick and Rudder: An Explanation of the Art of Flying by Wolfgang Langewiesche:
“Almost all fatal flying accidents are caused by loss of control during a turn!”
From the ATSB in 2007:
“general aviation fatal accidents … most prevalent type of accident was a UFIT”
From CASA in 2007:
“Three quarters of aviation accidents in Australia result from problems with the operation or handling of an aircraft.”

From CASA in March 2016 at http://www.flightsafetyaustralia.com/2016/03/angle-attitude-stallspin-crashes-and-how-to-avoid-them/

“According to the Australian Transport Safety Bureau (ATSB), in 2014, the number of aircraft ‘control problems’ involving general aviation (GA) aircraft was the highest [it has been] in the last 10 years. This was significantly greater than the 10-year average; however, it was consistent with the general trend (since 2010) of increasing aircraft control occurrences in GA.”

The situation is similar in the USA http://www.faa.gov/news/safety_briefing/?cid=TW112

“The March/April 2016 issue of FAA Safety Briefing focuses on the leading cause of general aviation accidents — loss of control.”

Similar situation in the UK. GascoLOCs

CASA’s article goes on to state: “Whoever’s data you use, it’s clear that we need to know a lot more about stalls and spins, and how to avoid them.” And then: “To recover from a spin, lower the angle of attack (push forward on the controls) and stop the yaw (apply rudder opposite the direction of spin until rotation stops).” Really, is that really what CASA is promoting as the spin recovery technique after telling us that we need to know a lot more about stalls and spins?

In June 2014 there was a serious spin accident involving a Chipmunk and the ATSB noted that: ” Furthermore, the pilot was taught a spin recovery method that was not effective for recovering from such spins in the aircraft.” It is interesting to note that CASA’s Part 61 MOS requires spin trainees to know “standard spin entry and recovery techniques for the aircraft being flown” only – wouldn’t it be good if they knew something about other types perhaps requiring different techniques. We will see that the above spin recovery technique promoted by CASA is generally ineffective in recovery from an inadvertent spin. So, perhaps loss of control is destined to remain the main cause of fatal accidents!

I’ll send you off to read the relevant text of two other CASA documents next:

  • CAAP 155-1, Aerobatics “7.22 Standard Spin Recovery:
    • Close throttle;
    • Centralise ailerons;
    • Identify if the aircraft is spinning, the direction, and whether
    upright or inverted;
    • Full rudder opposite to rotation (opposite to yaw);
    • Pause;
    • Elevator forward for upright and back for inverted as required
    to unstall;
    • When rotation stops – centralise rudder;
    • Roll wings level and recover to level flight.”
  • CASA Flight Instructor Manual Note the conflicting actions for recovery from an incipient spin on pages 52 and 53 – aha, that’s what happens with something done by a committee combined with a lack of knowledge of what an incipient spin is! For a fully developed spin: “To recover, first ensure that the throttle is closed, ailerons neutral and the direction of turn identified. This is followed by application of full opposite rudder. After a brief pause ease the control column forward progressively until the spinning stops. Centralize the rudder and ease gently out of the resulting steep dive, levelling the wings.”

It is interesting to compare the spin recovery instructions in the CAAP with that in the Flight Instructor Manual – now we have three different sets of spin recovery instructions from CASA with diddly squat explanation from the regulator. It is interesting that one method has elevator applied before the rudder and the other two have rudder applied before the elevator but, in one case a pause between the actions and in the other a “brief pause”. Why? How long is a pause? How long is a brief pause?

Now to look at some more comprehensive notes which are available free online.

The APS Emergency Maneuver Training Pilot Training Manual is free online. See Page 26 for common reflexive actions in initial stall/spin training – so, if a spin is encountered with nil training then expect one or more of these to occur which will make life much worse. e.g. “• Involuntary swearing and sweating • Continuing to hold the elevator control aft because of a dramatic, nose-down flight attitude • Inadvertently applying opposite aileron as a wing dips at the stall break, or as the airplane starts to roll into an incipient spin • Wildly shoving the elevator control forward”

Also read these pages in particular:

  • Page 78 for incipient spin recoveries
  • Page 80 for fully developed spin recoveries – remember PARE!
  • Page 83 for aggravated and inverted spin modes – remember PARE!
  • Page 86 for inadvertent spin entries – remember PARE which is:

NASA Standard Spin Recovery: P.A.R.E. Recovery
“Power” – Reduce power to idle.
“Ailerons” – Neutralize the ailerons (select flaps up). Do not allow ailerons to be deflected in either direction. “Rudder” – Determine direction of the spin and then push full rudder opposite the rotation of the spin and hold until rotation stops.
“Elevator” – Immediately following the completion of pushing full opposite rudder to full control deflection, then:
UPRIGHT SPIN: Push elevator forward through neutral INVERTED SPIN: Pull elevator aft through neutral Some aircraft may required full elevator deflection to effectively reduce angle of attack sufficiently to recover.

Hold these inputs until rotation stops, then immediately:

“Rudder” – Neutralize the rudder (very important, holding opposite rudder deflected during recovery increases the risk of entering a spin in the opposite direction).
“Elevator” – Since the nose is now pointing straight down (whether recovering from a developed upright or inverted spin), airspeed will build rapidly. Smoothly but aggressively pull to the prebriefed G-load to effectively bring the nose back to the horizon.”

Isn’t that much clearer and more sensible than any of the CASA explanations?

Of course, I must end with the usual disclaimer about some aircraft types requiring something different and that would be specified in the Flight Manual. Off course, the Beggs-Mueller or Finagin Antispin Recovery Technique (FART) methods are useful if you are absolutely sure that it applies to the type in all spin modes.

Camera & EFB Mounts

I was aware of an STC for GoPro cameras to be mounted externally on specific aircraft types however I knew that it wasn’t cheap so not viable for the typical GA aircraft owner. So, while visiting Oshkosh in July 2015, I was pleasantly surprised to see this company: Flight Fix http://www.flightflixcameras.com/ They mentioned that in the USA allowed their mounts to be used externally without an STC or other engineering approval as they were temporary. That surprised me as I had seen an FAA Safety Briefing on the subject http://www.faa.gov/news/safety_briefing/2014/media/janfeb2014.pdf

FAAsafety1

FAAsafety2

There are some inconsistencies with this internal FAA memo of about the same time: FAA-camera-memo 13Mar2014. I see that many are taking that memo as equivalent to law. Good that the FAA has since clarified that in their May/June 2016 Safety Brief:13263750_10154192052598454_919621119467713188_n

CASA’s view of the requirements for external camera installations is defined in Reference 1 (at least for certified airplanes).

CASA231

Quite clear isn’t it.

Reference 2 is quite general with much more information and includes the following clear statement regarding camera installations:

CASA2108

With respect to external camera mounts it is consistent with Reference 1. It also provides some guidance on internal camera mounts. Note that there is nothing in either of those Advisory Circulars which distinguishes between permanent and temporary installations as far as the requirement for needing specific approval – as an engineer I don’t have a problem with that.

Let’s move onto Electronic Flight Bags. From an engineering point of view the considerations are quite similar to a camera of about the same size. Obviously we are only interested in internal installations so we have all of the requirements from Reference 2 to consider.

But now look at Reference 3.

CASA2331

If attached to the aircraft structure then an EFB mount requires approval. Let’s consider two simple aeroplanes for discussion.

Firstly, the Airtourer. Where can we mount an EFB that is not aircraft structure?

I know that windscreens and windows have been used by some people however, being a former student of Henry Millicer, I know that the canopy and windscreen take about 20% of the total lift so therefore they are both part of the structure. The instrument panel must support the instruments and avionics up to the design loads so also a structural part. The instrument panel coaming supports the instrument panel and, as Henry told me, in an accident it was designed to fail at a particular load to allow the instrument panel to move forward.

Doesn’t leave many options for the Airtourer apart from the internal cabin trim.

Secondly, the Citabria/Decathlon series. Is the windscreen and skylight part of the structure? I’d say so as there are quite high loads on them in flight. Instrument panel, as above, needs to support instruments and avionics so that is structural. Interior trim is not really viable. Window and door maybe? There are some very nice steel tubes in the cabin however that is primary structure so definitely cannot be used to attach an EFB notwithstanding that people hang onto them during aerobatics. Not many options there to mount an EFB either.

Para 7.4.1 refers to temporary as “not considered to be airworthy” and must be stowed during take-off and landing, turbulent conditions etc. Presumably somewhere there is an exemption for temporary EFB mounts (whether temporary or permanent) to be attached to non-structural parts without approval? I cannot find it on the CASA website.

Furthermore, it gives Velcro and suction mounts as examples of temporary mounts but no other guidance – I have seen GoPro mounts which require a screwdriver which I would regard as temporary?

From and engineering point of view, the mounting of a small camera internally is quite similar to an EFB. We don’t appear to have any exemption (not that I believe one exists for EFBs) allowing pilots to temporarily mount small cameras internally on non-structural parts. Regardless, pilots like to get video in situations where Reference 3 would requires it be stowed.

So, any camera mounted on an aircraft, whether external or internal and whether permanent or temporary requires approval.

Personally, I use a kneeboard for my main EFB and my backup EFB goes in a pocket.

I hold a camera or fix it to my headset rather than mount it on an airframe part.

Finally, Flight Fix told me that they expect to have an STC within a year (i.e. at Oshkosh in 2016) for their external camera mounts.

PS Feb 2016: I have just seen this very sensible CAP 1369 Policy and guidance on mounting cameras on aircraft from the UK CAA.

References

  1. CASA AC 23-1 v1.0 Airspeed airworthiness standards for the installation of equipment that protrudes into the airflow
  2. CASA AC 21-08 v1.0 Approval of modification and repair designs under Subpart 21.M
  3. CASA CAAP 233-1(1) Electronic Flight Bags

Clothes Maketh the Aerobatic Pilot

I like to follow CASA’s recommendations on what to wear at https://www.casa.gov.au/standard-page/what-wear
“In the improbable event of an emergency, the clothes you are wearing can play a significant role in your safety. People wear synthetic blend fabrics …. However, they ignite quickly, shrink, melt, and continue burning after the heat source is removed.
…..
Wearing clothes made of natural fibres such as cotton, wool, denim and leather offer the best protection during an evacuation or fire.
….
Avoid leaving large areas of the body uncovered. …. Wear non-restrictive clothing as this allows you greater movement.
….
The most common injuries to feet during accidents or emergencies can be prevented by wearing suitable footwear. Wearing fully enclosed leather low-heeled laced or buckled shoes, boots or tennis shoes is recommended.
…..”
So, the standard issue pilot shirt and trousers with synthetic underwear is not good for one’s survival in an accident where a fire is likely to occur (I know, it always happens to some-one else).

I sometimes use Nomex gloves too – apart from the safety considerations it overcomes those unpleasant, sweaty hands on slippery control sticks.

Plus: there are times when extras such as a Nomex flying suit, crash helmet and/or parachute should be considered.

Transitioning to a Decathlon

The 8KCAB series are fairly simple airplanes, mostly 1940 technology with a few bells and whistles. Pilots seem to cope with the fancy bells and whistles fairly well but my observation is that there needs to be more effort by pilots new to the type into learning some very basic stuff.

The park brake. There is a placard adjacent to the park brake knob which clearly explains how to operate it. There are instructions in the Airplane Flight Manual and the Pilot Operating Manual. So, why do so many pilots tell me that they have set the park brake yet the airplane moves freely when given a gentle tug.

Weight and balance is a fairly important topic, not really critical in the Decathlon as on a typical training flight with the usual weights of pilots then it is generally within the permitted envelope – just follow maximum weight limitations. Yet, pilots seem unable to actually determine the weight and balance for a particular loading. The method in the Airplane Flight Manual is expanded upon in the Pilot Operating Manual with a sample calculation which is easy to follow. So simple that it can be done on the back of envelope.

SuperDWB

The thing that catches most people out is that the Manuals use Imperial units whereas stuff generated in Australia is mostly metric and if a new approved loading system is not provided then pilots need to work with the system in the Manual. There is plenty of help online to convert from one set of units to another. Some people use a simple Excel spreadsheet. Compare your calculations with the sample then proceed with your own – if it looks inexplicably different from the sample then it is probably wrong.

There is some good advice on transition to a new type here:  http://www.pilotfriend.com/training/flight_training/fxd_wing/newtype.htm

“You begin by studying and learning the new aircraft’s systems and operating procedures since the bottom line to all flying is knowing everything that we can about the aircraft so we can operate it safely. You will find this information in the aircraft’s flight manual (AFM), owner’s manual, or pilot’s operating handbook (POH). If the aircraft is an older model, it might have a very basic owner’s manual. If so, you need to be aware that the older manuals may not have the same information as some of the newer manuals, nor are the older manuals organized like the newer POH’s or AFM’s. Although the older manuals have less information than the new manuals, they still provide the basic information.

……

Once you have done your homework and thoroughly understand the new aircraft, you should take the aircraft’s manual and checklist out to the aircraft and spend time sitting in the cock-pit to learn the locations of the various controls, instruments, and checklist procedures. Your goal is be become familiar enough with the aircraft to be able to fly it before you ever start the engine. If you are renting the aircraft, this procedure also will save you valuable training dollars.”

Very good advice indeed.

I encounter some pilots who have flown Decathlons for some time but they have never even opened up the Airplane Flight Manual. They tell me that it is in the airplane so at least they know where it is. Perhaps. I know of some airplanes which do not have the FAA Approved Airplane Flight Manual in it – instead they have just that other Pilot Operating Manual – not quite the same with some conflicting information.

Myths of Manoeuvring Speed

“It turns out that our early training on maneuvering speed was badly over-simplified. The truth is that you can’t move all the controls to the stop and it isn’t the same as gust penetration speed. Here’s the unvarnished truth about Va.”

Avweb recently started this topic at http://www.avweb.com/news/features/The-Risks-of-Maneuvering-Speed-Myths-222680-1.html

I explained this further with three articles in the first three volumes of the Australian Aerobatic Club’s Vitamin G magazine.

You may have been told something like the definition quoted in Avweb’s article:

“The maximum speed at which the limit load can be imposed (either by gusts or full deflection of the control surfaces) without causing structural damage.”

Another one that I have seen is:

“Maneuvering Speed is the maximum speed at which you may use abrupt control travel.”

Aerobatic pilots should be familiar with the definition provided by CASA in their CAAP 155-1, Aerobatics, which states:

“Manoeuvring speed (VA) is the speed above which full deflection of the elevator control will exceed aircraft structural limitations. Below VA the aircraft will stall before structural limits can be exceeded.”

All are woefully inadequate definitions of VA and it is particularly disappointing to see that CASA’s advice to aerobatic pilots is also inadequate.

The original articles are:

The fourth and final article is provided here: Ozaeros Maneuvring Speed Myths Part 4

The correct definition is provided by the FAA Special Airwothiness Information Bulletin CE-11-17:

“The Design Maneuvering Speed (VA) is the speed below which you can move a single flight control, one time, to its full deflection, for one axis of airplane rotation only (pitch, roll or yaw), in smooth air, without risk of damage to the airplane.”

Short Field Tailwheel Operations

My tailwheel training course in the Super Decathlon does not conform to CASA’s Part 61 Manual of Standards for the reasons explained below. 

Short Take-off

      • CASA requires take-off power to be fully applied before releasing the brakes – this is contrary to the Manual and is a common cause of nosing over.
      • CASA requires rotation at the manufacturer’s recommended speed and climb at speed for obstacle clearance – rotate speed in the Manual is 43 kts – less than the stall speed and the climb speed in the Manual is 50 kts – very close to the stall speed. The Manual warns of risk of injury or fatality in the event of an engine failure in this situation.

Short Landing

  • CASA requires application of maximum braking after touchdown at minimum speed – this is contrary to the Manual where the instruction is “brake as required” with a warning of injury or fatality due to the risk of nosing over.
  • CASA requires the trainee to calculate the landing distance and promotes the falsehood that the short field performance can be easily achieved by an average pilot – this is not true of aircraft certified many years ago. The Manual states that the landing distance data represents “maximum airplane capability at speeds shown and requires aircraft in good operating condition and a proficient pilot”.
  • CASA requires that the trainee stops the aeroplane within the calculated distance. Landing approach speed in the Manual is 52 kts which is very close to the stall speed. The Manual warns of risk of injury or fatality with this technique and I repeat the above statement – the landing distances in the Manual will only be achieved using exactly those speeds specified with the various risks of damage to the aeroplane and injury or death to the crew must be highlighted.

It is interesting to note that when Decathlons first arrived in Australia they were provided with new take-off and landing charts – so-called P charts. There was a take-off safety speed (that is a very informative term) of 58 kts. The landing approach speed was also 58 kts – about 1.3Vs. Those charts applied to the earlier model Decathlons with a lower maximum weight and have since been withdrawn.

I see that the Manual for the new Xtreme Decathlon is differs from that of the Super Decathlon by specifying more reasonable speeds – similar to these P charts.

CAAP 155-1, Aerobatics

CASA’s CAAP 155-1, Aerobatics used to be a good place to start reading about aerobatics and does include some of the information that you must know but it has a number of deficiencies:

  • it does not adequately explain the structural limitations associated with VA, Manoeuvring Speed
  • it does not have the new, additional underpinning knowledge requirements of the Part 61 MOS
  • it has not been updated with the new licensing regulations of September 2014