Experimenter: Fred Roscher
Author: John Parker
The question asked is why the 51 Aerodata recording unit with the accompanying analyses, trending flight log software is significant and worthy of an experimenter award; and why does the Blue Thunder Racing Team use it?
In my mind the answer is painfully obvious. The main theme of the experimenters contest is Design, Built Test. Fred Roscher, CEO of 51 Aero has designed a data recording, telemetry and trending software package that far exceeds the capabilities of other recording options and can be completely tailored to the designer and builder specific needs and desires cost effectively.
It is well known fact that after a flight test the least reliable information you get comes from the pilot. When the pilot says everything went just perfect, the first question is, how do you know? Without a reliable data recording system there is no way to verify that all the temperatures, pressures, speeds, roll and pitch rates and G loads were and that they were within limits throughout the test flights.
The 51 Aero Air Data Computer (ADC) has the capability of recording an unlimited number of inputs giving the designer, builder and tester the ability to selecting as many sensors inputs they think necessary.
At this time the Blue Thunder Teams ADC records 97 sensors or computed inputs plus monitors any sensor error signals. The sensors we are currently using are:
· 21 Temperatures:
· 10 Pressures:
· 4 Voltages:
· 4 Amperages:
· 7 Position sensors:
· 2 GPS positions:
· 2 Fuel Flow:
· 2 Fuel Quantities:
· 1 Oil Quantity:
· 4 Speeds:
The additional displayed and recorded information is computed in the instrumentation and the ADC. An example of computed information is fuel flow. Fuel flow is the difference between the in and out transducers and it computes the total fuel remaining.
The ADC will record roughly 200 hours of flight data before the oldest data is over written. The data can be downloaded and processed after every flight, or after each trip, or at the next 100 hour inspection. Once the data is processed the trending software generates a flight log which keeps track of each flight duration but displays the takeoff and landing times, the dispatcher airport and runway, destination airport and runway as well as the fuel used on that flight. Manual inputs to the flight log can be made to include pertinent information about a flight such as the pilot and passenger names, purpose for the flight and any information the tax man may quire.
The trending software looks at all of the recorded data from the very earliest flight log an watches for changes in the reading which would suggest some sort of corrective action. A long term change of an item such as fuel flow or pressure could indicate the need to change a fuel pump. A subtle change in an EGT over time could indicate some valve work would be prudent.
The telemetry system is the ultimate in safety for initial flight testing of a new or recently modified aircraft. This provide continuous real time monitoring by your ground crews of the flight parameters and can provide guidance to the pilot of just what is going on and if necessary suggest corrective action.
In the pylon racing world, the pilots’ attention is primarily looking outside the aircraft station keeping and flight path maintenance. This is where the telemetry system is essential. The telemetry allows the ground crew to monitor the aircraft systems and advise the pilot should any system parameter starts going out of limits allowing him to make adjustments without looking at the controls. Additionally, the crew can advise the pilot of things might improve his speed such as a suggested adjustment of the fuel mixture or RPM. The analyst pages of the software allows me to review the ground track and verify how close I was to the pylons and show if an adjustment to the flight path would improve performance. The Blue Thunder Crew has had every bit of its share of partial or complete engine failures. In each case the crew has been able to immediately tell me just what happened and what I had left. This information made it possible for a return to a successful forced landing each time.
The sophistication of the 51 Aero data recording system, its flexibility, its cost effectiveness, and the number of analysis pages make it a worthy contender for an experimenter award.