Overview

Throughout the MASC training course you will learn about the Military Air System Certification Process (MACP) to gain the knowledge that is needed to certify new air systems and design changes. You will be putting this knowledge to the test through a series of exercises that follow the MACP. The purpose of these exercises is to reinforce your learning and improve your confidence in its application.

You will be split into syndicates of mixed experience and roles and work together through five workshop exercises that allow you to put your new knowledge into practice.

The exercises relate to the certification of design changes to a fictitious aircraft, the C-18 Common Baseline Tanker/Transport (CBTT). The C-18 CBTT is based on the fictitious Aero A-2X8 civil aircraft which is EASA Type Certified.

Exercise Scenario Brief

Background

Following your recent promotion, you have been assigned as the Certification Manager for the Common-Baseline Tanker /Transport Delivery Team (CBTT DT).

The CBTT concept was launched in response to the recent UK Defence Capability Review which criticized Defence’s approach to Air Transport and Tanker, in particular the cost of maintaining the  several bespoke and expensive fleets currently in Service.

CBTT Strategy

The CBTT strategy was to introduce a single fleet of Air Transport and Tanker aircraft, all derived from a single common Type Design.  Thus, this CBTT fleet would consolidate the roles currently undertaken by several fleets, as follows:

  • Tactical Transport [replacing A400M]
  • VIP / Command Support Air Transport (CSAT) [replacing Envoy IV]
  • Strategic Transport / Tanker [replacing Voyager]
  • Strategic Transport [replacing some C-17 roles]

Image of 4 different aircraft to be replaced by the CBTT fleet

CBTT Type Design

The winning bidder for the CBTT contract was Aero Ltd, a UK-based company who design and manufacture a proven family of commercial aircraft called the Aero A-2X8 at their Filton factory.

Cross section image of the Aero A-2X8: in construction, blueprints, in flight.

 

 

Various series of these aircraft fulfil the short haul (A-248), long-haul / freighter (A-258) and executive (A-268) markets and are widely used by several airlines around the world.

The Aero A-2X8 series received EASA Type Certification against the requirements of EASA CS-25 (Large Aeroplanes) in 2005 (A-248), 2006 (A-268) and 2009 (A-258).

 

 

 

Military Derivatives

As part of the contract award to Aero Ltd, the MOD required several military derivatives of the company’s A-2X8 aircraft.  Designated the C-18 CBTT, these military varients were as follows:

  • C-18 Mk 4 Pax / Freight Transport
  • C-18 Mk 5 Stretched / Extended Range version of Mk 4
  • C-18 Mk 6 VIP / CSAT version of Mk 4
  • C-18 Mk 7 Cargo version of Mk 5

3 variations of the C-18
KC-18 Mk8

In addition to the obvious difference between the civil and military aircraft (paint scheme, military markings etc), the MOD’s aircraft also have a number of military capabilities installed, as follows:

Table detailing the military capabilities of the C-18 variants

The conversion of the civilian Aero ‘green’ A-2X8 aircraft into the military variants, including the design, certification and installation of the above military capabilities, was also undertaken by Aero Ltd.  Consequently, these military variants are also listed on the Aero A-2X8 Type Certificate, with Special Conditions added to the original A-2X8 Type Certification Basis as required (ie for IFR etc).

Military Certification

Military Certification of the C-18 was undertaken by the C-18 Type Airworthiness Authority following an assessment of the A-2X8 Type Design against the required military

configuration, role and environment (CRE) and the requirements of Defence Standard 00-970 (the UK MOD’s benchmark Certification Specification).  Additional

 requirements were added to the TCB where ‘military deltas’ were identified.

Noting that EASA is recognised as an Accepted Certification Authority (ACA) by the MAA, the TAA only needed to undertake a limited risk-based sample of the civil

Certification activity before seeking the necessary compliance evidence for the military delta requirements.  The TAA’s resultant Type Certification Exposition (TCE) was reviewed by the MAA who subsequently issued their Military Type Certificate (MTC) for the C-18 Air System.

The Scenario

You are a member of the air system Delivery Team and will be assisting the Type Airworthiness Authority to certify the design changes by following the MACP. You will work in syndicates across five exercises to practice your new knowledge and skills.

Design changes to be considered:

  • Installation of 'Identify Friend or Foe’ (IFF) Mode 5 and ADS-B; an information sheet on these systems is given below.  
  • Addition of a 'Troops and Kit' (TaK) conversion (Exercises 4 and 5 only).

Information: IFF Mode 5 and ADS-B

What is IFF Mode 5?

IFF is an acronym for ‘Identify Friend or Foe’. It is a command and control system that allows ground and air systems to identify other systems and determine their bearing and range. It is an active system that sends and receives signals. By sending a signal to another system and receiving a reply, a system can be identified as ‘friendly’. If no reply is received, the system is identified as potentially hostile.

Mode 5 is the latest standard of IFF required by all NATO forces. It is military only and integrates with the civilian ADS-B system to provide GPS capability, in addition to the ‘regular’ radar-based system.

It provides a higher level of security encryption and works at longer ranges than previous standards. The Mode 5 standard employs spread-spectrum radio transmissions that are difficult to intercept or jam and encrypts data with keys that change every few seconds.

Image source: dote.osd.mil

What is ADS-B?

ADS-B stands for ‘Automatic Dependent Surveillance-Broadcast’. It is a GPS surveillance system that allows an aircraft to use satellite navigation to both determine its position and broadcast it.

This allows the aircraft to be tracked by Air Traffic Control in areas with poor radar coverage such as oceans, as well as giving the crew better situational awareness. It is required for peacetime flight through civil airspace and is an automatic system, requiring no action from the crew during normal use.

Image source: shop.jetvision.de 

 

Exercises

In Exercise 1 you will utilise AET Tool 8I (Major/Minor Change Record Template) to determine whether the change  is classified as either Major or Minor.

In Exercise 2 you will tailor the Type Certification Basis for the design change, using your knowledge to select the appropriate requirements. This process is described within MACP Phase 2.

Exercise 3 will see you identifying the Means of Compliance for demonstrating compliance with the TCB for the design change and proposing the Level of Involvement for the MAA, as part of the Certification Programme creation in Phase 3.

In Exercise 4 you will prepare an Equivalent Level of Safety argument for the change, where compliance cannot be directly shown. This is part of the Type Certification Exposition in Phase 4.

Exercise 5 will see you take on the MAA’s role as regulator. You will review an Equivalent Level of Safety argument as part of the Type Certification Review. Each syndicate will have a different scenario to review and will present their findings to the other course delegates, tutors and experts. 

Details of each of the exercises are given in the separate exercise briefs.