Aircraft Emergencies

The blog post is a component of Skydive GB's Jump Pilot training in the UK, focusing on the GA8 Turbo Airvan utilised at their dropzone. Its contents, comprising observations and remarks, are specific to Skydive GB's operations and aircraft and might not align with practices or standards at other locations.

I acknowledge areas of agreement with the conclusions of other individuals and groups. However, it also highlights differences in perspective. Due to the diversity of variables and scenarios, the stance is that managing aircraft emergencies cannot be addressed with a one-size-fits-all method. A notable discussion point is the jump door, an aspect that has sparked various opinions elsewhere.

The jump door should remain closed! It’s an opinion that differs from the status quo, but here are my reasons as to why… 

Let's journey back in time, not quite to the extent of living in a shoebox in the middle of the road, but to the early days of my skydiving adventures. I started jumping in 1987, 36 years ago as I write this. Back then, in the UK, our skydiving aircraft lacked what you'd call proper jump doors. Instead, we had gaping holes where the doors should be, hastily covered with gaffer tape over the remnants of hinges. Imagine enduring -25°C (-13°F) temperatures while perched in the open doorway of a small Cessna. We yearned for something better.

Gradually, we started equipping aircraft with makeshift jump doors, fashioned from roll-up canvas featuring zips or Velcro. We also used fibreglass plugs stored inside the aircraft, which we could slide down to cover the opening. Yet, the seasoned jumpers, who usually found themselves at the back of the aircraft, which to us pilots is the front, often preferred no doors. Trained to exit in emergencies, they boasted of their ability to deploy their reserves and exit at 500ft if needed. Most of them had started with round canopies, and the round reserve was known for their quick deployment.

However, the desire for in-flight doors persisted. We reached a compromise: the door would not be closed until reaching 1,000ft or above post-takeoff, allowing for rapid exits in emergencies. This threshold was later increased to 1,500ft, as some makeshift doors proved cumbersome and slow to open.

Views and aircraft we use have significantly changed over time. Modern aircraft like Cessna Caravans, Twin Otters, and PACs are often equipped with internal roller doors (up & over) made of Lexan or plastic. These are a marked improvement over the older canvas, zips, and fibreglass doors, being much easier to operate. Consequently, it's now standard practice to close these doors before take-off. In fact, suggesting taking off with the door open today would provoke quite the opposite reaction from what it used to.

It's essential to acknowledge that different aircraft models use various door types. Some, like Skyvans, PC6 Porters, AN28s, and CASAs, come with factory-fitted doors. For the GA8 Airvan, the type we use, the door has specific operational limits concerning flight speeds. The GA8 Airvan's externally fitted sliding door can remain open up to a maximum speed of 120 knots. However, when it comes to operating the door (opening or closing), the maximum speed is restricted to 80 knots at 24mb or less, which is not at full throttle.

Now, when reading through briefings for other dropzones and aircraft, they often include a hypothetical aircraft emergency scenario. This typically involves engine failure with an off-airfield landing, resulting in the fuselage becoming buckled and preventing the door from opening. Back in my day, we simply referred to this as "crashing in a field!" but that's not a positive and politically correct statement, so forget I said that. Following this scenario, there is usually a list of recommendations on what to do. One suggestion is to open the door on descent in case of fire, ensuring it does not become jammed shut due to the buckling.

Indeed, no one wants to be trapped in a burning aircraft, and understandably skydivers seated at the back (near the pilot), who are likely to have tandem students strapped to them, straining to see past a sea of heads, would prefer an open door. However, those sitting on the floor by the open door, with hedges, road signs, stone walls, bits of undercarriage, sheep, and other livestock potentially flying past or entering through the open door, would likely prefer it shut during the off-airfield landing and fuselage buckling stage. Regarding the fire, if you watch any video of an aircraft crashing with a post-crash fire, you might again want the door closed during the initial fireball explosion bit.

For the Airvan, in the event of engine failure, like all aircraft, the protocol involves pitching the nose down to regain and maintain the best glide airspeed. The optimal speed range is roughly 70 to 80 knots considering variations from empty to full load. It's best to use 80 knots for simplicity, as this aligns with other critical flight speeds and allows for door operation.

However, what if an engine failure occurs due to a fire? Like the Airvan, most jump aircraft aren't equipped with in-air fire suppressants. The standard guidance in Pilot Operating Handbooks (POH) is to shut everything off that might be the cause of the fire and land as soon as possible (Engine, electrical, etc. Please read the POH for the exact course of action). The POH delineates two scenarios: 'land as soon as practical', which implies returning to an airfield or making a prompt diversion, and 'land as soon as possible', indicating an urgent need to land, whether in a farm field, on a road, or any viable spot.

Jump pilots are adept at rapid descents, a crucial skill in such emergencies. If a fire threatens the aircraft's critical structure, a rapid descent will see the airspeed rise beyond the door operating limits specified in the POH for the Airvan's factory-fitted external door. In these situations, any attempt to open the door could be disastrous. A door that detaches mid-flight could cause catastrophic damage to the aircraft's tail, compounding the emergency.

The Airvan's sliding door operates differently from those found on aircraft like the PC6 Porter or Finest. Unlike the backwards-sliding doors on some planes, the Airvan's door slides forward under the wing. While the BN Islander's doors also slide forward, they move horizontally along rails, not like the Airvan.

The unique feature of the Airvan's door is that it's designed to fit snugly into the fuselage. This means that when it's opened, the front part protrudes into the airflow and prop blast as it manoeuvres around the door frame. This critical phase of the operation imposes restrictions on airspeed and engine power settings. Once the door clears the frame, it moves along the side of the fuselage and aligns with the airflow, which allows for an increase in airspeed and power.

Let's take a step back. Picture yourself climbing to altitude, and suddenly, an issue arises with the aircraft. It's expected that the pilot will communicate with the Jump Master to determine the best course of action. In the era of smaller piston aircraft, the Jump Master in the UK would likely be kneeling, facing forward, almost in line with the pilot, making communication straightforward.

However, in larger aircraft, relaying messages—such as informing someone about changes to jump configurations or wind conditions for students—can be challenging and often resembles a game of Chinese whispers. And that's under normal conditions. Trying to communicate very time-sensitive information while dealing with the added workload of an aircraft emergency is going to be exceptionally challenging.

As pilots, we're trained to always aviate, navigate, and communicate, especially during an emergency.

'aviate' means to get the aircraft under control, ensuring it's flying or gliding correctly at appropriate speeds.

'Navigate' involves assessing the aircraft's position and heading and choosing the best options for landing.

'Communicate' refers to making radio calls to inform ground personnel and other air traffic that priority is needed in the airspace and airfield. Once these are under control, and if time permits, the pilot informs the passengers about the situation.

In skydiving operations, there's an additional option: all people in the back can exit and descend independently. Therefore, while 'aviate' remains the top priority, some form of communication with the back of the aircraft is crucial. However, this can't be a complex message relayed through multiple people, especially when they might be wearing helmets, listening to music, or have earplugs in. Any confusion or delay could become an unwanted distraction. To minimise this, communication is reduced to two clear and loud calls from the pilot: "Brace, Brace, Brace" or "Exit, Exit, Exit". These commands are straightforward and unmistakable, providing clear instructions without the need for elaborate communication in a critical situation. Some jump aircraft are fitted with lights, typically Red for opening the door and Green for exit. Some aircraft have a yellow light. Which will have other meanings depending on the DZ. At the time of writing, we don't have lights on the aircraft, but if at any time we did, then turning on the green light with the "Exit, Exit, Exit" will helpclarify the message.

At this point, I can imagine various questions and scenarios being considered.

It's quite straightforward for an EFTO (Engine Failure on Take Off) that jumping is not an option. At Skydive GB, we often climb over the sea, where jumping is generally inadvisable due to the cold waters and rocky shoreline. Our drop zone (DZ) has fairly flat terrain, but if you're flying a display team away from our airfield, the ground below might be closer than the altimeters indicate.

To illustrate with an extreme example, a few years ago in Switzerland, I was sitting by the door as a jumper as we climbed to jump altitude. Around 7,000ft, I looked out the window to see a man and dog waving at us. Well, the man was waving, and the dog looked to be barking. Looking straight down, we were only about 800ft above the mountain, somewhat different from the 7,000ft shown on the altimeter. We were flying close to the cliffs as another aircraft was on its jump run through the valley. In such a scenario, if we had experienced engine failure, anyone attempting to jump could find themselves at an insufficient height to deploy their parachute safely.

The command "Brace, Brace, Brace" clearly instructs jumpers not to exit the aircraft, especially when jumping could be unsafe. This instruction frees the pilot from worrying about managing the open jump door flight restrictions. It ensures all jumpers understand the situation and are ready to secure themselves and adopt the brace position. This allows the pilot to focus entirely on the aircraft's emergency response procedures without needing to deal with an open door, unexpected exits and associated CofG changes.

Naturally, if you have the situation under control and can provide additional useful information to those in the back, then do so. However, this should never come at the expense of losing focus on the three primary tasks: aviate, navigate, and communicate (via radio). Maintaining these priorities is essential and should not be compromised by other distractions.

The "Exit, Exit, Exit" command indicates that the aircraft is within safe door operating speeds, and it's then the jumpmaster's responsibility to assess the situation and manage the exits. After the jumpers have left, the pilot can focus on the important task of safely landing the aircraft. Remember at the very least, the pilot's role includes being in a sufficient state of well-being to inform the insurance company where their new fixer-upper aircraft is located.

As a jump pilot, you aren't expected to be fully versed in the specifics of safe exit altitudes, nor are you likely to know the details of the equipment used or the exact experience levels of the jumpers. If you issue the "Exit, Exit, Exit" command and receive a negative response from the jumpers, switch to the "Brace, Brace, Brace" command and manage the situation accordingly. Nowadays, many jumpers hesitate to exit from as low as 500ft, and some might even refuse at 2,000ft. Due to this, we've increased the mandatory restraint height to 2,000ft, meaning all jumpers are required to keep their restraints on below this altitude. If a flight is descending due to poor weather or other reasons, all jumpers should have their restraints refitted by 2,000ft or higher.

In the Airvan, the restraints are designed so nobody can exit while still secured. This design also means that it's impossible to open or close the door while restrained, as the door latch is located towards the rear of the door. Therefore, if a jumper were to open the door, it would indicate they've removed their restraint. This action could lead to operating the door outside its designated limits and cause an unexpected shift in the aircraft's centre of gravity.

I started this blog by highlighting the importance of being aware of other aircraft emergency briefings, many of which are accessible online. It's important to remember that visitors to our DZ may be used to different protocols adapted to the specific aircraft and locations they typically jump at. For instance, they might have learned to open the door during an emergency landing due to the door's design and material, such as metal slats. At Skydive GB, every jumper, whether a regular or a visitor, receives a comprehensive drop zone briefing. This includes details on aircraft loading, door operations, weight limits, and procedures for handling emergencies.

Let us Recap with a management list:

1. Aviate: pitch for airspeed
2. Navigate: turn to the airfield and assess your descent. Locate suitable alternatives to make a landing.
3. Communicate: make your 'Pan' or 'Mayday' call.
4. Assess the issues with the aircraft.
5. Once you are able to do so, issue initial instructions to those in the back. Either "Brace, Brace, Brace" or "Exit, Exit, Exit"
6. Aviate: work through the list again.

*you may not have time to work through this list, so abbreviate as required. IE: Aviate, Navigate, Brace, Brace, Brace.

Door mechanisms can vary significantly – while some doors have latches to keep them open, others lack this feature. Holding a door open while in a brace position is impractical and potentially impossible if the fuselage buckles, given the forces involved. Even if someone could cover their face and hold the door simultaneously, the likelihood of keeping it open under such conditions is minimal. Additionally, a door that slams shut might easily jam even if the fuselage does not become buckled, defeating the purpose of trying to keep it open in the first place.

Some countries do not have a dedicated Jump master. Some countries refer to the position as the loadmaster and require that individual to sit by the pilot for easier communication. In the UK, tandem students are hooked up to their instructors before take-off, while in some countries, they don't connect until above 2,000ft. Not being attached means that both student and instructor have their own restraints and can exit the aircraft quicker once it has come to a halt after an emergency landing. Some countries use sideward seating (Twin Otters) which is impractical for a tandem and student to be hooked up in. It’s a little ironic that the countries that don’t hook up see those that do as being in a more dangerous position in low-level aircraft emergencies, and those that do hook up feel the same about those that don’t for the same reasons.

For piston aeroplanes, engine failure doesn't significantly affect handling during descent, unlike in turbine aircraft. The lack of propeller drag in turbines can cause the airspeed to increase unexpectedly, influenced by the pilot's muscle memory and visual cues. We don’t practice engine failures by completely shutting down the engine, so an actual failure is a first-time experience.

Basic field selection rules remain crucial. If you have enough altitude, plan an abbreviated circuit to ensure your chosen field is suitable. Aim to touch down a third of the way in, be wings level, flaps set, and correct airspeed at a minimum of 300ft. Adjust your approach once you're sure of making the field. If everyone remains on board, reissue the "Brace, Brace, Brace" command to ensure readiness.

My recommendations are subject to various factors and may be influenced by different scenarios. Some countries design their procedures based on logistical considerations such as seating arrangements, restraints, and key personnel positions on the aircraft. Other countries may have adopted similar procedures but implemented them differently or have evolved their methods based on others without fully considering the impact of different emergency plans in place.

I want to emphasise that my opinions are not set in stone, and I reserve the right to change them. My viewpoints have developed over the years through personal experiences and information from others. As time passes, you'll also form your own perspectives, so please don't hesitate to share your thoughts and ideas.

It's important to note that while emergencies are fortunately rare, this rarity can lead to procedures becoming outdated. Regular evaluation of these procedures is essential to ensure the safety of everyone involved.

Incident reports from around the world involving the GA8 Airvan.

https://www.baaa-acro.com/aircraft/gippsaero-ga8-airvan