C-Astral Checklist and Dry Run
This week, the primary focus was on the C-Astral Bramor aircraft and associated payloads. Being that we are likely to start fieldwork soon, additional dry runs needed to be conducted, similar to last week. However there was a few major focus items that were different from last week:
1. Time
- We wanted to track how long it took us to complete the dry run. We assumed it would take us longer the first time through, and less time any additional times.
- We were ready to accept around 45 minutes as successful, as that would be more than enough time to set-up, fly, and clean up in the field. We expect that if we could reach the 45 minute mark, we will improve further throughout the season.
2. Role Familiarity
- We wanted multiple people to have exposure to each role. While not everyone needs to have familiarity with every role, it is critical that multiple people can accomplish any given task. This will provide redundancy should someone be missing.
- By multiple people being familiar with a given role, crew members could potentially notice if something is being done incorrectly by another member, or double check another crew member's work.
- We also worked on formally determining what the roles would be.
3. Identifying risky steps, or steps that need more clarification
- It is important for us to know where failures are likely to occur.
- It is important to know which steps, if failed to be completed correctly, would have the most detrimental results.
- Risk of failure can be assessed in two ways: steps that are difficult to complete correctly and steps that are poorly understood. Identifying both of these types is critical for safety.
- A plan to mitigate risk would need to be established.
Run Through: Time
On Wednesday, we successfully completed two dry runs. Each was timed, with a few critical considerations to determine accurate equivalent of time spent in the field. First, all components of the system was stored as it would be when we first arrive at a site. Second, during deliberation of certain steps, we paused the time as this style of deliberation would not occur in the field.
The time it took to complete each run was as follows:
TRIAL 1 - 56 Min, 48 Sec
TRIAL 2 - 38 Min, 02 Sec
The time results indicates that we were far more efficient our second time through. We were also more efficient than we decided we were required to be to operate in the field, with about a 7 minute improvement on our planned maximum amount of time. While this is good news, more practice is necessary for us to be consistent with our timing; as I would assume we will lose additional time next dry run just by being out of practice, and also our first time in the field.
Run Through: Role Familiarity
After our first trial run, we formally decided on crew requirements and what the permanent roles will be:
1. Pilot in Command - In charge of the operation. PIC has authority to cancel a mission at anytime for any reasonable consideration. This crew member actively operates the aircraft. This is the only crew member who directly handles the GCS. Handles all aspects of the run through focused on the GCS.
2. Co-Pilot - Acts as second in command. Reads the paper checklist during setup and post-operation. During run up, this crew member double checks other people's work. This crew member has authority to cancel a mission at anytime for any reasonable consideration. During operation, this crew member stands directly next to the pilot in command and acts as the primary visual observer. This crew member also provides operational advice to the PIC to help manage workload. If radio communications are being used, this crew member acts as the communicator for the PIC as well as directs communications in general.
3. Visual Observer - This crew member is a designated visual observer that, during operation, will separate himself from the rest of the crew to add to the total amount of area visible by the crew. This crew member is also primarily responsible for monitoring the area for air traffic. During set up, this crew member is to aid the equipment manager in any way needed.
4. Equipment Manager - The crew member primarily responsible for setting up equipment such as the catapult or the aircraft. Can request help from any crew member, especially the visual observer. Should work in close alignment with the PIC who is completing the digital elements of set up and the CP who is reading the checklist. During flight, this member acts as a secondary visual observer. This crew member is also in charge of retrieving the aircraft on landing and leading the post flight checklist. This crew member is also responsible or launching the aircraft off the catapult.
In each run through roles were assigned as followed (number corresponds to above numbering system):
Trial 1
1. Todd, 2. Kyle, 3. Evan, 4. Ryan
Trial 2
1. Evan, 2. Thomas, 3. Ryan, 4. Todd
Additional crew members can be brought in during our system as needed. They will likely assist the equipment manager and observers.
Run Through: Risky Steps
During each run through, a few specifics items were decided to need additional focus. Some were due to the difficulty associated with the task and the importance of the task for safety. Others were chosen due to potential confusion.
High Risk/Important Steps for Extra Attention
1. Parachute Attachment/Parachute System
As can be seen in figure 1, the parachute system has many parts that need to be attached correctly without significant error. if any individual part is set up incorrectly, this could be catastrophic for the flight. This includes mounting the hatch, attaching and storing the catapult, testing the release servo, testing the launch spring, and attaching the hatch cable. If any of these are done inappropriately, or not tested correctly, the entire aircraft could be lost.
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| Figure 1: All the components of the parachute system deployed. Parachute being tied to hatch cable, to be placed in parachute hatch. |
2. Pitot Checks
The pitot static system on the aircraft is critical for safe operation. Any debris in the system could lead to incorrect reporting of airspeeds and altitude to the computer system, which could lead to the aircraft crashing. To check if there is debris in the pitot tube, there are two white tubes on top of the aircraft left of the nose (looking from the rear of the aircraft)and a crew member simply has to blow into one of the tubes. However, it is difficult to tell which tube to blow into. We even had a crew member attempt to blow into the pitot directly, which you are not supposed to do. The checklist is not particularly descriptive, so we ma edit the checklist for this reason. We may also add an additional pilot check in the post flight checklist.
3. Catapult Set Up
The catapult system has enormous risk of failure and thus to safety. Once under tension, or even just when attached, there is many ways at which the catapult could injure someone. In addition, if the catapult is configured incorrectly, there may not be enough force delivered to the aircraft on takeoff for it to successfully enter stable flight conditions. If the cables are tangled in any way during set up (which occurs easily) the aircraft may not receive the requisite energy and the release of tension likely to send the tangled cables flying off the catapult, potentially risking crew members' safety. While adding the cables, if cables are not attached alternating in sides, then tension could become too strong on one side of the catapult and potentially injure a crew member. If a crew member, while attaching the cables, places their hand in the sled path (a natural placement for leverage) they are risking losing their hand if the sled was to misfire. If under tension, people walk towards the sides or front of the catapult, they are directly risking their well being, thus crew management matters at all times. The safety/launch pin for the aircraft is very small, and thus maybe could be accidentally pulled or at least removed from the safety notch with little effort. In general, there are many safety concerns with the catapult, especially to the well being of crew members, and thus should be given additional consideration.
Confusing Steps Needing Additional Attention
1. Camera/Sensor Set Up
The camera steps in the checklist are not particularly detailed and are actually for a slightly different RGB sensor than what we are using. We will likely need to spend time fine tuning the checklist and verifying each individual item for our system. In addition, as can be seen in figure 2, there is not much room to work in setting up the sensor as power is delivered via the aircraft.
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| Figure 2: Sensor Set-Up in the main bay. |
2. Camera/Sensor Triggering
The camera triggering settings in the ground control stations are a little bit confusing. In particular, how selecting different sensors impacts flight parameters and if the sensor can be triggered at all. During the day we were able to dig further into this topic and discovered that the aircraft can trigger and control the RedEdge Altum sensor, which is fantastic as many platforms can not accomplish this task. However, performance of this setting should be investigated further.
3. Waypoint Control
Having the opportunity to be PIC, I attempted to interact with the different way point controls. However, the means to open up more detailed information about a waypoint, or assign critical points such as the landing point, is very similar (if not identical) to how normal points are placed. This led to me accidentally creating dozens of points which the aircraft may have flown to in an actual operation. I believe I may have discovered some partial work around solutions in the process, but more validation of this is needed.
Upcoming
After we return from break, we will begin finalizing techniques indoors so that we can begin flying missions. This includes practicing ground control measurements and more dry runs. Perhaps also converting shape files over into actionable flight plans. We expect to have our first data collection flights by the end of the month.
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