1. SCOPE

This document describes the functional specifications of a Portable Turn Around and Exceedance Identification System designed for use for a trainer aircraft.

2. DESCRIPTION

A typical trainer aircraft carries close to 5-10 training sorties each day. After each flight a turnaround inspection has to be carried out and also in case certain exceedances/ observations are given by flight crew, the same needs to be analyzed manually in detail using the aircraft SSFDR(Solid State Flight Data Recorder) data (e.g. data recorded by the black box). This leads to significant delays in turnaround of the aircraft and also during manual analysis of the data, key exceedances / anomalies are missed or misinterpreted. The data download also requires the aircraft to be powered ON externally or using aircraft battery so that SSFDR system is powered up and data download can be carried out. This also offers challenge in terms of accessing the cockpit by the ground crew for powering up of aircraft, requirement of ground trolley, junction module, AC mains, etc. All this can be eliminated with a single system which is capable of externally powering ON the SSFDR system, downloading the data and analyzing the same in a single step in order to determine the GO/NO-GO for next sortie of the aircraft.

If the event of an incident on the aircraft following which it is not possible to power ON the aircraft, this system can be used to power ON the unit for performing the data download & report the possible exceedance occurred. This will be useful for incident/crash investigation. Post data download the system deploys analytical and statistical methods to assess the entire flight data for unusual occurrences, system failures, system performance and also for heavy landings. The ground crew can perform the entire operation using the standalone package within 15 minutes and arrive at a GO/NO-GO for next flight decision with the aid of the Portable Aircraft Turn-Around and Exceedance Identification System (PATEI).

3. TECHNICAL SPECIFICATION

The system consists of a ruggedized processing system capable of powering the aircraft SSFDR remotely without accessing the cockpit. The processing system also executes module to download the SSFDR data and audio as well. It further analyses the data for exceedance identification to process and set GO/NO-GO status of the recorded data.

4. PORTABLE AIRCRAFT TURNAROUND AND EXCEEDANCE IDENTIFICATION SYSTEM FUNCTIONALITY

The system shall provide the following facilities to the ground crew, maintenance team, quality inspection team, pilots and designers for quick turn-around of the aircraft.

• Downloading data from SSFDR over USB port, through a quick access connector, without powering ON the aircraft.

• Powering ON the SSFDR unit through the data download loom itself

• Perform automated analysis of the aircraft data and report GO/NO-GO status for quick turn-around for the next sortie.

• Analyses flight data for heavy landing criteria and system failures/exceedance

5. SYSTEM HARDWARE SPECIFICATION

• Ruggedized portable system with USB interface

• 28VDC, 3A power generation for continuous operation for minimum of 1 hour

• Data download & SSFDR power loom

6. SYSTEM PERFORMANCE SPECIFICATION

The system shall power ON the SSFDR and download recorded data through the SSFDR download loom as shown in Figure 1, 2 and 3. Its functional performance shall be as per sections below.

A. EXCEEDANCE IDENTIFICATION MODULE

The Exceedance Identification module is capable of performing a host of functions that aid the user in the quick turnaround of the aircraft. This module is hosted by the ruggedized processor and performs the download of the flight data as well as the audio data from the SSFDR,

i. Flight data analysis and system wise GO/NO-GO annunciation for quick turn-around of aircraft

ii. Exceedance analysis based on the set limits (user or default) and event reporting

iii. Aircraft trend based on the system performance

iv. Validation of primary sensor data with secondary sensor data

v. Landing performance analysis

vi. G-limit analysis for Fatigue life monitoring of the airframe

vii. Synchronized audio replay for quick analysis

viii. Plot generation with highlighted exceedance points

ix. Report generation for analysis summary

x. Database generation for aircraft .

xi. Archive of information to database for trend analysis over multiple sorties

xii. Regional language setting (language: Hindi) to support ground crew/technicians/ maintenance crew The Exceedance identification module will consider the following state conditions to determine the GO/NO-GO criteria for further flight testing or training

• Engine Performance

a. Engine temperature

b. Engine RPM

c. FADECfail

d. Over temperature or Surge

e. Oil System Failure

f. Engine Vibration

g. Fuel Filter contamination

h. Fuel Over temperature

i. Engine sensor Failures

• Landing Performance

a. Heavy Landing

b. High speed landing

c. Deployment of flaps at excess speeds

• G-limit Exceedance

• Primary sensor/system failure

a. Hydraulics

b. Electrical

c. Avionics

7. EXAMPLE CASE: EXCEEDANCE IDENTIFICATION MODULE

The Exceedance identification module can perform data analysis consuming less time to identify the exceedance compared to conventional methods of data download and analysis. Figure 4 shows the sample of Exceedance grid for engine parameters for a particular selected sortie. The parameter can be selected to plot and visually evaluate the trend of the parameter along with the exceedance if present. Figure 5 shows the conventional method of plotting the parameter of interest (engine RPM). The anomaly in the engine rpm is very much likely to go unnoticed here. Figure 6 shows the data analysis and exceedance identification where the anomaly that has been unnoticed by the conventional method is detected and indicated clearly. The plots clearly project the correlation of the exceeding parameter.

The results of the analysis performed on the recorded data are shown below for a trainer aircraft sortie number (#1282). After processing the recorded data, the color coded status indications for individual systems, sub systems and parameters computed from the recorded data are show. Figure 7 shows the data analysis of air data validation. The result of the analysis is shown red since the range 90 to 160knots and the range 160 to 350 knots has deviations from the limits. Figure 8 shows the data analysis of landing performance of the selected sortie, the result is satisfactory. Figure 9 shows the exceedance highlighting for Altitude parameter.

8. SUMMARY

Portable Aircraft Turnaround and Exceedance Identification System (PATEI) is a complete exceedance identification and data analysis system for designers, ground crew, pilots, test director, etc. The PATEI has the capability to identify the exceedance and allows the user to quickly correlate the same with related system parameters. This enhances the data analysis and the chance of an anomaly going unnoticed is reduced. The total time consumed in data analysis can be brought down significantly by the use of this system. The functional performance of the system and the deviation from the expected factors are analyzed. A report is generated for the user and recorded in a database. The trend of the parameter and the aircraft shows the history of the aircraft performance. The summary of the analysis report can be used by maintenance crew and quality inspectors for quick turn-around.

CLAIM:

We claim that

1. Portable Aircraft Turnaround and Exceedance Identification (PATEI) System provides quick turn-around of the aircraft by facilitating fast download from the aircraft using battery pack.

2. PATEI has a single electrical loom that is used for powering the Crash Data Recorder as well as downloading the data from the Aircraft without powering ON the aircraft.

3. PATEI has an Exceedance Identification module that is capable of performing automatic analysis of the flight data within a short span of time and generate GO/NO-GO status for the next flight, thereby reducing the turn-around time significantly.

4. PATEI has an Exceedance Identification module that is capable of generating Exceedance reports for sorties being analyzed automatically and archives the reports to a database for future use in analysis of trends.