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).
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.