When I was told a formation endorsement would make me a safer flyer, I thought, ‘Ok, I’m up for that!’ I had the idea that, apart from finding out what a close aircraft coming towards you looks like and how to avoid it, formation would hone my stick and rudder skills in my Victa Airtourer. That was all true, and it also gave me a better understanding of control inputs and secondary effects on the Victa’s flight performance.
Having another aircraft up close and personal with you soon lets you know how coordinated (or uncoordinated) you and your aircraft really are, and how your aircraft responds to inputs.
Using rudder to get into position, I was able to really see how its use also initiates roll. Using ailerons resulted in roll and then yaw. With throttle input, pitch would change and yaw would be initiated. All this lived experience AND knowledge got me to thinking – how could I use all this secondary stuff to my advantage in an unsafe situation?
Secondary effects are sometimes called undesirable or adverse effects. We are trained to identify and control them. However, secondary effects, and the use of other control inputs not directly related to the primary control surface in trouble, such as throttle, trim, mixture, and even doors, windows, and passengers, can be really useful in an emergency.
Below are 4 occurrences from the ATSB database where pilots have experienced the partial or full loss of an elevator, rudder or aileron, and an example of a jammed throttle. Of course, every occurrence has its own set of factors that requires a customised response, but perhaps these examples and some suggestions from instructors will get us thinking.
Elevator failure
In September 2011, a Cessna 210N in flight near Bourke aerodrome suffered a fracture in the rear attachment brackets of the horizontal stabiliser. The pilot had trouble controlling the elevator and consequently, experienced altitude instability.
As a primary control, the elevator is all about pitch, and a secondary effect is increased or reduced airspeed. Countering the loss of pitch control with elevator trim may or not be an option, depending on your aircraft and the circumstances.
When looking for other means to control pitch, understanding what other factors cause an aircraft to pitch up or down is a good place to start. Sheldon Jones, an instructor for 15 years, including in aerobatics and formation, says adding power causes the nose to pitch up and reducing power means the nose will pitch down.
‘If I had a stuck elevator, I’d be looking to use trim, but mostly power, using thrust to assist in the turns instead of pulling back on the elevator,’ he says.
Power has a strong pitch tendency but also yawing and rolling. ‘I would investigate a speed that gives you better control,’ Jones says. ‘However, with the propeller rotating clockwise, the secondary effect will be roll and you’ll need rudder and aileron input to control that.’
Other tools to consider include lowering or raising gear, extending or reducing flap, and moving passengers further back in the aircraft to move the centre of gravity back and pitch the nose up.
Rudder failure
In December 2019, during descent near Moorabbin, a Cessna 152 crew observed the aircraft yawing and rolling to the left uncommanded and no control input was available from the right rudder.
Rudder primarily controls direction through yaw, however, its secondary effect is roll, so if a rudder jams, you’ll experience significant yaw and then roll.
Although the chances of experiencing a jammed rudder in your typical GA aircraft are slim – it’s more likely in aerobatic aircraft – using opposite aileron, effectively configuring a sideslip, you can override the yaw and roll generated by the rudder, if the authority of the aileron is greater than that of the jammed rudder. However, again, the secondary effects of thrust will be useful.
Bryan Greenfield is a grade 1 instructor and Qantas pilot with about 18,000 hours flight time, including in formation and aerobatics training. ‘With conventional centreline-thrust aircraft and a clockwise (from the cockpit) rotating propeller, to control direction without rudder you can use throttle or thrust,’ he says.
‘For a clockwise rotating propellor, thrust application will assist in controlling a left yaw, and thrust reduction for controlling a right yaw. However, you’ll require elevator input to counteract the pitch moment from thrust.’
If the rudder failed but was not jammed in a left or right position, and then there’s no pressure on the rudder pedals, you could keep flying using ailerons and throttle to bank and maintain stability of the aircraft.
Aileron failure
Near Merredin ALA in Western Australia, a Grob G115 passing 5,000 feet on climb rolled sharply to the left and significant control input was required to maintain level flight.
Ailerons control roll and their secondary effect is yaw, notably the opposite of rudder. If you lose aileron control, rudder could be your saving grace.
‘In the event of an uncommanded left roll, for example, liberal use of your right rudder will cause a right yaw, followed by right roll,’ Andrew Smith, flight instructor and chief executive of Warnervale Air, says. ‘You may need to adjust elevator input as well, as the nose will initially yaw above the horizon.’
In the case of jammed ailerons, you would hope your rudder has greater authority over the aircraft’s roll than that generated by the jammed ailerons. But if you didn’t have any aileron control, that is, they’re loose or fixed at neutral, you could easily turn the aircraft on rudder alone.
‘It is best practice to make all turns toward the dropped wing, which will just require a reduction in rudder pressure,’ Smith says. ‘Turning the other way will be incredibly difficult, nearly impossible, depending on the extent of the issue.
‘Thought should also be given to small rapid movement of the stick or yoke, left and right, which may help dislodge any foreign object fouling the external controls or internal cabling.
‘Every situation is different and will require judgement from the pilot once they have absorbed all of the information available to them. Extensive knowledge of the systems on our aircraft is an incredible tool in these types of situations.’
Jammed throttle
In 2016, a Grob 115 near Merredin in Western Australia experienced a throttle lever jammed at full power during initial climb. The student pilot secured the engine on short final approach and conducted a glide approach.
Jeremy Miller, flight instructor with 30-years’ experience and a specialist in upset prevention and recovery training, has personal experience of a jammed throttle in a Nanchang. During a training session with a student, both moved the throttles in opposite directions at the same time, kinking the cable. ‘Luckily we had a fairly high power setting and could maintain height,’ he says. ‘So we turned the magnetos on and off to slow down enough to get the gear down and land.’
Controlling speed and altitude by cutting or restoring power to the engine is not a new technique. Qantas’ first aircraft, the Avro 504K, didn’t even have a throttle; instead, a blip switch was used to cut power to the engine to reduce thrust and turn it back on for bursts of power, making flying a constant exercise in power management.
None of the above suggestions for these 4 occurrences is necessarily correct or best – it depends on the situation, the aircraft and whether the control surface or input in question is stuck, jammed or just loose. That’s why knowing your aircraft, your basic flight skills and remaining calm are key.
Every situation is different and will require judgement from the pilot.
Keep calm and carry on
From 2010 to 2024, there were 259 aeroplane occurrences citing partial or full loss of ‘flight control’ in general aviation. Of these, 7 aircraft sustained substantial damage, one aircraft was destroyed and only 3 minor injuries were reported. So losing all or part of an aircraft’s control system is not uncommon, but is eminently survivable.
A controllability problem can develop rapidly and you may have to act quickly, but it’s important to remain calm and avoid rushing to land. If you have altitude and fuel in your tank, you have time. Time to settle down, trouble shoot properly, call for assistance and plan a safe landing. ‘Aviate, navigate, communicate,’ Greenfield says. ‘It’s a term that’s overused for a reason – it works.’
Jones says the key to remaining calm is knowledge. ‘Having knowledge of the secondary effects and the tools available to you in your aircraft will keep you calm enough to realise that you have more options than you might think!’
Miller says troubleshooting is about flight skill, knowledge and creativity. ‘You need knowledge and also to think outside the square,’ he says. ‘How do I control yaw, pitch, and roll, with my aircraft and what can I do, or use, to affect each of those movements?’
Smith says planning to land is just as important as regaining control. ‘With the aeroplane under positive control, you may be better placed flying to a longer, wider runway for the landing, where there is more scope for excursions on landing and possible emergency services help, than landing at the closest, or most well-known airfield.’
All agree that your second chance is to use your flying skills, knowledge of secondary effects and your aircraft’s systems, to regain control. ‘Also, never give up, keep trying things until you work out what works,’ Miller says. ‘And in these events, you should be worried about preservation of life – saving the aircraft is secondary.’
If you have altitude and fuel in your tank, you have time.
