Electronic Flight Bag- Your Approved Weight and Balance Solution
EFB solutions need tailoring to commercial organisations to ensure efficiency & compliance. One element of this process is gaining approval to use your EFB as a Weight & Balance (W&B) solution, and with the right information your organisation can tick this box.
In Australia the relevant reference is CASA CAO 82.0 Appendix 9 Para 2.3, which pertains to a Functionality Level 2 EFB software application. The suitability of the application must be validated in writing by a Weight Control Officer (WCO), who will assess the output of the Application to ensure it complies with the Aircraft Flight Manual (AFM). In New Zealand the reference is CAA AC91-20 Para 9.2.3(c) pertaining to a Type B Software Application, and a LAME is approved to conduct the validation. Importantly, the EFB Aircraft Profile must be locked to ensure the end user cannot edit data such as the Empty-Load Data-Sheet information. Web-based software like the OzRunways Enterprise Dashboard will enable compliance by providing an option to lock the profile as described. The dashboard is an inexpensive addition to your company EFB programme and includes many other features.
We liaise with Weight Control Officers regularly for the purpose of Commercial EFB W&B approvals. If you would like the entire process to be project-managed for you, this can be organised through Airspace Flight Solutions. For those organisations wishing to manage the process themselves, we can point you in the right direction.
How is W&B calculated using EFB?
Aircraft profile templates are often provided in most EFB Applications and often include longitudinal & lateral envelopes. For example the OzRunways Aircraft Library is always growing. Please check and amend data to match your specific aircraft if using a template. When creating an aircraft profile from scratch, you will need to enter data into the W&B fields of your created Aircraft. Obtain this data from the AFM, including:
- The correct allocation of Units
- Base data from the Empty-Load Data-Sheet
- Stations & Fuel-Data from the Weight & Balance section
- Longitudinal/Lateral envelope data from the Limitations section.
The OzRunways solution uses a “Charlie Loading System Format” (Weight= Vertical Axis, Arm= Horizontal Axis). Beware, some AFM’s use the Alpha or Bravo system and specify Moment on the horizontal axis. In this instance you must divide the Moment by the Weight for that data point to obtain the Arm. In OzRunways, the Moment-Arm or Moment may be specified within the base data section, and the App will calculate the missing value. You can create multiple W&B Configurations for a given aircraft e.g. if your aircraft has a sling configuration. The relevant configuration can be selected when planning.
The OzRunways User Interface is quite seamless and allows you to copy & edit an aircraft profile to create an additional configuration. This means less manual data input and reduced chance of error. Station weights are also entered and changed during the planning phase, and any station entry with the word “Fuel” in it will be attributed appropriately. As we know, the fuel tank Centre of Gravity (CofG) in some aircraft will not be linear as fuel is burnt. In these examples you can activate the “Use Fuel Tables” feature and enter the relevant arm for each fuel quantity. In aircraft with Main & Auxiliary tanks, ideally the aircraft flight manual will account for the combined Moment and figures can be copied across. In reality this isn't always the case, plus some operators of larger aircraft may even have a SOP for when to switch between Main and Aux tanks. In this scenario, it is recommended you calculate the various arms for the combined Main/Aux tank conditions and load this combined figure into the fuel table, with values from full down to zero fuel.
As always, Human Factors need to be considered to minimise the risk of an incident or accident. When carrying an EFB approved for W&B, the ability to calculate or amend the aircraft CofG is always with you, as opposed to a flight manual potentially under the seat of the aircraft. Interestingly, many report-worthy events related to W&B aren’t necessarily due to the actual aircraft CofG condition. Many events in larger fixed-wing aircraft are due to transcription errors into the Flight Management System with a failure to cross-check, resulting in erroneous thrust and speed settings. Examples over the years have included incorrect units, mistaking ZFW for TOW, and simply missing a single digit such as an Emirates flight at YMML in 2009 where the actual take-off weight was entered as 262 instead of 362-tonnes. Needless to say, the take-off thrust was massively insufficient and the resulting tail-strike could have been catastrophic.
Granted many readers will not be flying aircraft with an FMS, however the Human Factor is real and should not be under-estimated even when entering information into your EFB Application. The Human-Machine Interface or “User-Interface (UI) is extremely important here and has a large bearing on safety. App development teams takes UI considerations like Readability (text size, contrast ration, tap target size), colours, consistent & intuitive layout, work-flows, and reduced number of taps to reach desired information, very seriously. This combined with their CASA Part 175 Data Service Provider Approval ensures you have accurate and timely information when you need it.
As always, appropriate aircrew training is very important to ensure correct procedures are followed, especially when SOPs are unique to an organisation or aircraft. The Airspace Flight Solutions Online EFB Course will equip you with the required knowledge, review it on our website, or contact me direct on andrew@airspaceflightsolutions.com.au with any questions.
Safe Flying!