Article
Crossair Flight Operations News, The Crossair Flight Operations Publication, 10/2001, pages 20-23.

 


Electronic Loadsheet for Embraer 145

Christoph Regli
Pilot Embraer 145
Dipl. Inf. Ing. ETH


Abstract

Experience has shown that a precise and conscientious mass and balance calculation is critical on the Embraer 145 fleet operated by Crossair. FliteERJ, a Palm computing platform based application, is a slim, straight forward designed electronic loadsheet that provides a decent way to cross-check any manually computed loadsheet and assists the decision-making process during the preflight planning phase significantly.


Introduction

Various reasons lead to a nose heavy balance of the Crossair Embraer 145 fleet. In a first phase, ballast was loaded into the cargo compartment as standard. However, a survey disclosed that in most cases the flight envelope constraints can be satisfied through means of row blocking and consideration of the hand luggage in the cargo compartment in case the DAA procedure [1] has been applied, thus eliminating all adverse concomitants of ballast loading [2]. Only in exceptional cases ballast is the sole way to stay within the envelope.
As a consequence of this, it is not uncommon that a Crossair Embraer 145 takes off at the edge of the flight envelope. At outstations without DCS loadsheet calculation, the F/O plays a crucial role in determining the mass and balance for the subsequent flight. As errors may happen, a backup calculation is strongly recommended.
Critical passenger and load distributions occasionally require some imagination and a quick index tables handling in order to produce a valid mass and balance log without having to load ballast. A task which the personnel that provide the DCS loadsheet is not always capable to perform.


FliteERJ

An electronic mass and balance computation tool has been developed based on these needs. The main goal was the implementation of the complete M&B section of the PIH behind a reasonable user interface. The outcome is a user-friendly application that helps to improve the economic result of any flight by giving a quick and helpful hand on mass and balance related decision-makings concerning row blocking, ballast requirements, underload / through tankage, and shows hints on how to resolve out-of-trim situations.
A closer look to the application gets down to the three main screens, naming the payload, M&B and the envelope pages (figures 1-3). All pages have associated help texts available online that provide answers to questions that may arise during the daily use.

FON 1.
[Figure 1]

On the payload screen, the passenger figures and cargo loading are entered. As soon as an input value has been modified or entered, the loadsheet is recalculated, displaying any result in no time. Any implications are immediately visible. Baggage masses can be specified either directly or through the number of pieces, using standard masses. The service index adjustment is an option that has to be enabled when the DAA procedure [1] has been in effect. It adds the corresponding index to the calculation [3].

FON 2.
[Figure 2]

The M&B page deals with the DOM/DOI of the aircraft and the fuel figures. The aircraft tail number can be selected from a list. Is a new aircraft not yet incorporated or has the BOM/BOI changed, the possibility to manually enter the values is provided. The DOM/DOI finally is calculated based on the pantry code selection.
On devices with color screens, any zero fuel, ramp or landing points that are beyond the flight envelope are written in red digits, or are marked with a vertical line at the right edge on black-and-white screens.

FON 3.
[Figure 3]

The graphical envelope representation simplifies the interpretation of the result. FliteERJ indicates the resulting MACTOW and pitch trim as well as the actual underload respective to the MZFM and MTOM/RTOM. The light blue lines are the ballast and the fuel trend vectors showing the variation of the T/O point with different cargo and fuel figures.

FON 4.
[Figure 4]

The envelope result page precisely describes the result of the current configuration and, should any point be outside, gives hints on how to re-join the envelope. The application computes which rows have to be blocked or how much ballast is required. Beyond that, it shows a set of further ideas to increase the resulting index, e.g. to switch on the service index adjustment if applicable or to change the cabin version and class distribution of the passengers.

FON 5.
[Figure 5]

The rough estimate form is used to check the trim and loading in a more general way, e.g. during the preflight planning phase while determining the extra fuel or any ballast requirements. The tools notes 100kg for each passenger and considers the worst case class distribution, i.e. all passengers are placed in business class. It computes the underload and the minimum load according to the 'Minimum load calculation tool' [2].


Row Blocking Algorithm

As an implementation detail, FliteERJ first tries to reseat Y class passengers only. If this doesn't lead to success, it reseats as many Y rows as necessary to achieve maximum index correction, and tries to correct the remaining index with C class rows blocking. Finally, if this wasn't possible either, only C class rows are blocked, as the last priority for marketing reasons [4].
The following example shows that the algorithm leads to a minimal number of rows to be blocked: Let the cabin version be K (28C/21Y) and the passenger distribution 16C and 8Y and suppose the index to be 7 units outside the flight envelope.

FON 6.
[Figure 6]

Obviously those 7 points can not be achieved by blocking Y rows only, so the algorithm blocks rows 11-15 and tries to get the remaining index points by blocking C rows. By reseating the passengers on the first two rows another 4 index points have been gained, so 9 in total. Now the algorithm goes back to the Y class passenger rows and notes that it is not necessary to block five Y class rows but that it is sufficient to block rows 1-2 and 11-12.


Raisons d'Être

FliteERJ can be taken as a basis for any decisions concerning mass and balance. It helps to decide on ballast requirements during a short turn around, even if the station is DCS equipped. There have been cases where the handling agent planned to load ballast, but a closer look revealed that all mass and balance constraints could be satisfied by changing the cabin version.
Secondly, it can happen that manually computed loadsheets contain errors, caused by oblivion of the carry digit while adding or by entering a wrong M&B table. While the F/O calculates the loadsheet, the CMD can insert the data into FliteERJ, set the speed bugs and respective pitch trim and then compares his result with the manual loadsheet.
Finally, an educative effect has been noted. The program immediately displays the consequences of changes of any input values, especially in the graphical representation of the flight envelope. The ballast and fuel trend vectors impressively show the repercussions of modifying the variables that can be influenced by the pilots.


The Platform

A Palm computing device is a palm sized portable handheld computer [5]. The Palm operating system is licensed by several companies like 3Com, Handspring, Sony and IBM. It is one of the most popular personal digital assistants that incorporates a slim operating system refraining from unnecessary overloaded features that distract the user. The device works autonomously for several weeks.
Compared to PDAs with built-in keyboards, Palm devices captivate with their convenient size. They can be used to download and send e-mails when connected to a cellular phone with an infrared port. Palm handhelds are delivered with a cradle in order to connect to a desktop PC where a backup of all Palm data is stored and updated on each synchronization.


Liability Considerations

For liability reasons, FliteERJ is not intended to be used for operational purposes. It backs up manually computed loadsheets and assists related decision-making, but must not be used as the sole mean for mass and balance calculations. For that, the application must be certified by the respective authorities and there must be a possibility to print a hard copy of the computed loadsheet.


Outlook - Flite

Besides FliteERJ, there is another project currently under development, aiming to ease the Crossair pilots' daily life. The FliteLX application combines an electronic flight log together with the FCM flight time and duty record FTDR. The electronic issued crew plan can be downloaded into the application. FliteLX may generate events in the built-in Palm organizer datebook so the user gets an overview of the flight duties when planning the spare time. While on duty, the pilot simply enters off and on chocks times. The flight log keeps track of aircraft immatriculation and crew codes, and there is a possibility to attach a textual note to each flight. Based on this data, FliteLX generates an FTDR entry line. At the end of the month, this will be synchronized with a Crossair FTDR Excel sheet.
There are some aviation tools integrated into FliteLX, e.g. a converter to convert basic units used in aviation, a calculator to add flight times for the private flight log, and a MOTNE, snowtam and de-ice holdover times decoder. It is foreseen to integrate an airport reference database providing information like handling agent, fuel supplier and approach minima. A Palm based phone directory paired with the pilots seniority list is as well planned.


Conclusion

FliteERJ has proven its stability and reliability in the real world environment. A lot of positive feedback has been received up to now, and I constantly work on improving the application according user inputs. Refer to the FliteLX homepage [6] in order to get an overview of the development history. According demand, the loadsheet application can be programmed for other fleets.
The main emphasis currently lies in the development of the FliteLX application. This is rather a large project consisting of several subparts like the electronic crew plan download, the application on the Palm handheld itself and the Excel sheet with a link to the FTDR database from the handheld. At the moment, the Palm application is in alpha test, and a beta version is planned for end of this year, while the public release is expected in the beginning of 2002.
You are invited to visit the FliteLX homepage [6] for further information. Please feel free to contact me should any questions arise.

christoph.regli@bluewin.ch


References

[1] Crossair EMB-145 PIH, Hand Luggage Delivery At Aircraft (DAA). General part, A-1-6-1ff.
[2] Crossair EMB-145 PIH, Flight Crew Information Bulletin: Removal of ballast on EMB 145. Aircraft part, B-0-3-2-1ff.
[3] Crossair Ground Services Circular 5/2001, New procedure for ER4 trim.
[4] Crossair EMB-145 PIH, Technical Log / Manual Loadsheet. Aircraft part, B-6-1-4ff.
[5] http://www.palm.com/
[6] http://www.flite.ch/

 


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Last modified 2001 Nov 08
Copyright © 2000-2005 Christoph Regli