Well, correct me! I am here to learn.
Fair enough.
On 9/11 the NORAD Fighters were on 15 minute alert. That means from the claxon to airborne must be within 15 minutes. They can beat that time, but 15 minutes was the requirement on 9/11.
The time
COULD have been shorter, it has varied from 5 minutes to 10 minutes to 15 minutes over the years. The number of aircraft on alert has also varied over the years. In order to assure a 5 minute response, the pilots would need to be sitting in the cockpit. That is a strain on manpower and other resources. Due to the peace dividend since the end of the Cold War, the required response time had been reduced over the years. Also, the entire Air Defense mission in the US had been turned over to the Air National Guard. That's not particularly important, but merely a statement to illustrate reality and the mindset leading up to 9/11. No Active Duty AF assets were on Air Defense alert on 9/11.
Regardless, for ANY aircraft on ANY type of quick response alert, there is no "walk around", the aircraft are cordoned off or in a shelter and are as "fully cocked" as they can possibly be. For example, any switch that can be in the proper position without manipulation by the pilot is already positioned.
If you're addressing aircraft NOT on any specified "Alert Status", the response time would vary considerably due to a myriad of reasons. Fuel status, location of munitions, number of personnel available, number and type of munitions to load, type of aircraft etc., etc.....
The "troofer crowd" have always been confused by the term "Combat Ready". That is the formal status of all US Military warfighting equipment that is reported to the JCS, daily. That term does not mean they can be ready for Combat on a moments notice.
Next, aircraft performance. The F-15 holds the time to climb record to 50,000 (until the F-22 breaks it) (see Streak Eagle). It was done with a stripped down, cleanly configured aircraft during cold weather. The pilot took his morning constitutional and did not eat breakfast in order to keep the weight to a minimum!!!! Now, even an armed Air Defense F-15 can accelerate after take-off going 90 degrees
STRAIGHT UP. An F-16 is not quite as capable, but nearly so.
One other point to make here. The time to intercept depends upon several factors too. Distance to target being the most notable. Troofers typically calculate the maximum published speed of either an F-15 or F-16 while ignoring (perhaps intentionally) the fact that the aircraft has munitions hanging off the wings and usually fuel drop tanks. The published top speed is for a CLEANLY configured aircraft, not one with munitions or fuel tanks mounted.
I can outline several actual contingencies in which a large number of aircraft have responded quickly, but don't be in a hurry. It's a lazy afternoon just prior to Christmas!
