Military Aircraft Survivability

This extended section of the book can be found on the Web site www. cambridge .org/Kundu and presents a typical military turbofan survivability consideration in the following subsections.

15.10.1 Military Emergency Escape

The subsection introduces a typical ejection seat and ejection sequences as a surviv­ability issue with the following figures.

Figure 15.42. Typical military aircraft ejection seat Figure 15.43. Typical ejection sequence

Figure 15.44. Typical ejection sequence showing separation of seat and para­chute deployment

15.10.2 Military Aircraft Stealth Consideration

The subsection introduces various military aircraft stealth considerations and strate­gies as survivability issues. It covers system integration of operational needs before, during, and after combat (e. g., audio-visual detection, radar signature, heat signa­ture, on-board passive system, use of defensive aids, secure communication, on­board stand-alone navigational system, and returning to home base).

15.10.3 Low Observable (LO) Aircraft Configuration

The subsection deals with military aircraft typical stealth considerations issues such as heat and radar signature suppression as survivability issues. Following are the figures in this subsection.

Figure 15.45. Typical comparisons of radar signatures (sphere versus stealth air­craft)

Figure 15.46. Three stealth aircraft configurations

15.10 Emerging Scenarios

There have been four emerging topics: two concerning terrorist activities, one con­cerning health issues, and one ongoing problem related to aircraft debris on the runway. This section familiarizes future designers with the types of problems they may face related to these topics.

Counterterrorism Design Implementation

Much thought is now applied to ways to counter onboard terrorism. These topi­cal considerations have yet to be determined for implementation. There is concern about the increased weight and cost of an aircraft. Some design-change ideas are as follows:

1. Install a bulletproof flight-deck barrier at the cockpit door. Compartmental­ize the cabin to isolate trouble. Whether these measures are effective must be debated, but aircraft designers must use foresight rather than hindsight.

2. Improve the structural integrity of the cargo compartment/bay against in-flight explosions. The space below the floorboards must be compartmentalized and have a shock-absorbing, impact-resisting shell structure to retain integrity in the event of an explosion.

3. The aircraft flight system must have an automated-recovery ability, homing to the nearest landing field (military aircraft already have this type of system).

Health Issues

The steady annual increase in the number of passengers crossing international boundaries results in health issues that must be addressed. Space must be allotted to treat and isolate patients (like on cruise ships). Until recently, this measure was on an ad-hoc basis; however, manufacturers can increase market appeal by providing health-care facilities, especially for larger aircraft with long flight durations. Cardio­vascular conditions, pregnancies, infections, and other emergency-health scenarios are increasing during international flights.

Damage from Runway Debris

The catastrophic crash of the Concorde was a result of runway debris hitting the fuel tank, which then burst into flames. Vulnerable areas must be protected with stronger impact-resistant materials. This is a relatively simple task but designers must examine the point in new designs, which does incur additional weight and cost considerations.