Help on the limitations of F/A-18 Hornet?

Question

I need information on one limitation of a F/A-18 Hornet for my physics assgnment.

Answer 1

Which limitation? Speed, maximum g, weight? What is your physics assignment? Add some details and I'll take a crack at it.

Alright, now we can get something done. The limitation that prevents both structural damage and injury in a fighter like the F/A-18 is the maximum G limit. When an aircraft maneuvers, it is acted on by centrifugal force, measured in G units. One G being equal to earth's gravity. All aircraft have a G limit imposed for structural safety, as exeeding a certain amount of force will cause structural damage or failure of critical structures. These limits are particularly high for fighter aircraft, but they can still be exceeded with devastating results. While I can't find any published limits, the F/A-18EF (currently the most advance F-18) likely has a limit if +10/-4 G. Most modern fighters are in this range. If the pilot were to pull more, say +12 G, the aircraft will flex and bend too much. This could result in the plane being damaged and grounded, or possibly cause a breakup in flight. Aircraft have been known to shed their wings under intense G loads. There is another factor to consider, though. These G loads put a tremendous amount of stress on the pilot. The onset of high g-forces causes the blood in the body to begin pooling in the lower extremities. Above 6G, most people will lose conciousness due to reduced blood flow to the brain. Fighter pilots use a suit that compresses the torso and legs much like a blood pressure cuff, along with breathing and straining excercise, to help force blood back upward. This only increases G tolerance to 9G or 10G, however. Essentially, exceeding these tolerances can cause  pilot blackout or airframe damage. Far exceeding these limits (say, more than +15G) are almost guaranteed to destroy the plane or possibly cause severe injury to the pilot. Basically, your limitation in this case is on violent maneuvers within a set range.

Answer 2

There are many relevant limitations that can be exceeded with respect to operating a fast jet aeroplane - the consequences of which can pose a risk to the pilot. I'll just pick a random few that may be appropriate to structural failures resulting from excessive forces:-

- High g turns

Highly dynamic manoeuvres can exert a great deal of force on aircraft surfaces. Without correct servicing and inspections, cyclic fatigue mechanisms can come into play, which over time - can lead to structural failure.

You can also achieve the same by busting the g limitations on the aircraft (whether laterally, longitudinally or normally). G limits are there for a reason, and if you exceed them by manoeuvring too aggressively or sustaining turns for too long - you will again overstress the airframe.

-High Sink Rate Landings

If you thump an aircraft on to the deck that is too heavy, or at a decent rate that's too high (or both!) - then the landing gear is at risk of being overstressed, and can even fail. If you push it further, the forces can act as a moment and break the wings / tailplane. It has been done plenty of times, and there are plenty of pilots who have suffered spinal injuries in this fashion.

- Spinning / Stalling

If a pilot is to deliberately, or accidentally depart an aircraft into a spin or a stall via careless control inputs or as part of an aerobatic display - then you bring into play all the forces associated with dynamic manoeuvres. Some spins and stalls are divergent (i.e the response of the aircraft will increase over time) and may be unrecoverable.

- Ejection

All of the above situations can end with emergency egress from the aircraft. Ejection is always risky given the forces involved in punching the pilot clear from the aircraft. Again, some pilots can seriously injure themselves as they are ejecting from the aircraft. Not a structural failure as such, but it will generally be the consequence of a major structural failure - and yet still poses a risk to the occupant.

Hope this helps.

Answer 3

How about:

1. Altitude (the engine will fail from lack of oxygen)

2. Range (the plane will run out of fuel and potential crash, forcing the pilot to eject)

3. Climb rate (the plane will stall, and the pilot will pass out from the excessive G force)

Hope that helps!

Answer 4

Capable of landing on an Aircraft Carrier while it is going 30 knotts.