I’m wondering how difficult it would be for a modern fighter jet to be devised so that, in scramble/intercept situations, you could instantly turn the thing on and be headed to the runway within seconds - like a car, turning a key and then the car’s engine is immediately turned on and revved up.
Probably no fighter jet today does it that way, but how hard would it be for a fighter jet - or commercial airliner, for that matter, to be invented so that it’s a turn-a-key-and-all-is-read-to-go?
I guess a low-tech solution would be to have several of them, together with a large team of technicians, working cyclically so that, at any given time, at least one of them is fully ready to go.
It always surprised me that it’s so hard to get a fighter jet on standby ready to go, yet many WWII aircraft were basically kept like that all the time, particularly during the Battle of Britain.
I presume the question accepts the occasional losses that would come from not doing basic checks.
The spinny bits of the engine (turbine, shaft, compressor) need time to acquire momentum. The only way I see would be to use (jettisonable) rocket boosters possibly combined with a catapult/some kind of pulling device to get it airborne while the engines are revving up. A bit like missiles that use a rocket booster for the first stage and with an airbreathing engine for the second stage. Not going to happen though. Combat aircraft would only need to take off so quickly in a tiny sliver of circumstances which aren’t worth preparing for. If the enemy is close enough that you need fighter jets to take off in seconds, launch missiles from the surface.
Piston engines are like a trot. Jet engines are like a gallop.
IIRC, SAC had bombers loaded, crewed and running at idle 24/7 for some time during the cold war. All they had to do was snap their helmet strap and firewall the go sticks, they were stationed around the runway ends with a clear shot at it and only had to make a slight correction while still at a slow speed to be aligned with the runway.
Lot of $$$$ to do that for long periods of time and hard on crews. IMO
AIUI, fighter jet engines, being considerably smaller than pasesnger jet engines, spool up quite a bit more quickly. That’s not really the limiting factor for what the OP is talking about.
Here’s footage from an inter-service fighter jet scramble contest. There’s one or two crew members prepping the plane on the outside, while the pilot is going over details in the cockpit. After that, it’s a matter of getting to the runway and taking off (not shown). The spooling up of the engines after getting to the runway doesn’t take more than a couple of seconds.
I think that’s probably the limiting factor. If you rush through a procedure that has a bunch of steps which (if skipped) could crash the plane, the odds of screwing up increase; if you (the military leadership) are willing to tolerate the increased losses in return for the decreased response time, then maybe it’s worth it.
Yeah, keep the motor running … I’m not sure what the warm-up time is for jet engines … but cars it’s recommended 30 seconds minimum …
This might be urban legend … but I’ve heard during the Cold War a certain number of B-52’s were loaded and in the air loitering around their fail-safe points waiting for the “go” code to go nuke them Commies …
With the SAC bombers it wasn’t like they were shot from a slingshot. It took a few minutes to get the crews in position and engines spooled up. This from the SAC Wiki page: SAC’s Emergency War Order (EWO) required the first aircraft to be airborne within 8 minutes and all aircraft to be airborne within 15 minutes after notification.[56]
Of course for many years SAC had bombers and an airborne command post in the air 24/7.
I am not a pilot, military or otherwise, but don’t planes have a lot of things that are locked, blocked, set at neutral, etc. when the plane isn’t in use? And don’t the pilots/crews have to make sure all those things are set to operate, the gauges are reading correctly, the control surfaces go up /down, left/right etc.?
There isn’t just one big master “Go” button, right?
On cockpit alert we could be airborne in IIRC 120 seconds beginning with a cold inert aircraft. Admittedly one that had a bunch of time spent prepping it ahead of time. “Cocking it” in the argot. But one cocking session is good for a 12 hour day. The hard part of cockpit alert is just sitting there all damn day. Which is why it isn’t used except in pretty extreme circumstances.
If the crew isn’t in the cockpit then you’ve got a much longer process to run from the alert shack to the jet, get in, and fully strap in. That becomes the limiting factor.
There are much larger delays in the entire kill chain from detecting the target to deciding it’s hostile to deciding to launch to getting to a shooting position to shooting. It’s not obvious to me that the place to look for improvements is in reducing the aircraft start time further.
Given a cockpit alert at an end-of-runway alert pad, the limiting factors from the horn going off to airborne are the time to get the engine from stationary to start RPM, the time for it to light off and settle at idle, and the time for the IRS to wake up & know where it is and how it’s aligned in space. Those were ~15 secs plus ~10 secs for the engines, and ~1 minute for the IRS in my era using an early version of a fiber-optic ring laser gyro. I hear modern semiconductor gyros are a lot faster these days.
Machine elf’s vid in #6 is pretty good although they cut out some slack time where nothing obvious is happening. They were also doing a lot of ground crew steps during the scramble that we’d have done during cocking if it was for real.
The pilots ain’t checkin’ shit. It’s jump in, two switches to get the engine(s) turning, then strap in like a mofo (8 connections, 10 actions). About halfway through strap-in, bump the throttle(s) from off to idle, finish strapping in while engine(s) light off and spool up to idle, close the canopy while waiting for the IRS-driven instruments to go live, then release brakes, stuff the throttle in the corner and go kill Commies. The ground crewman’s job is to yank the boarding ladder, yank one safety pin unique to F-16s, yank the chocks, and get out of the way.
Ref kunilou’s very cogent question, the cocking process does many of those checks. After which the airplane is powered down in a carefully planned manner, then left absolutely undisturbed.
The other half of that equation is that kind of airplane is designed to be left in one of two states: normally shut down that requires a boatload of steps to get started and tested, versus cocked, where everything is left switched on and ready to go, just waiting for electrical and hydraulic power to appear. Sorta like the difference between booting your PC and resuming it from suspend. With some of the same attendant risks of queertrons appearing.
From your article:
15-20 minutes warm up is bad. You’re responding to someone that said 30 seconds, which is appropriate.
No, the statement was “30 seconds minimum”, when most of the articles out there put that closer to the maximum.
[Ital added].
Not to say I don’t like it as an inscrutable bit of RAF banter. But I would like to scrute it.
I’m not being snarky at you personally, but such doubt (which of course SD is a place for), classifying the notion as a possible ‘legend,’ and dismissive facetiousness (in this context) of “nuke them Commies”—each three singly and in combination–is astounding.
I hope Cpt. (?) Runt asked Lt. Col. Hog if he could use his plane. Or Hog Runt’s helmet, which I think is far less an indiscretion.
“Firewall the go sticks” is ancient pilot slang for “apply maximum power”. cf “Balls to the wall”, “clank power”, “front left corner.”
See also Operation Chrome Dome - Wikipedia for more about SAC at the height of lunatic Tom Powers’ authoritay (sic). I shudder to think what would / will happen if the US military had somebody like that near the top at the same era when we had somebody like Trump at the very top.
I’ve had 4 engine 747’s off the ramp in less than 10 minutes with or without an airstart. And that’s taking my time. If there was a need to block out quicker they would start some of the engines while taxiing. I’ve watched military tankers take up about the same amount of time.
Cold war b-58 bombers were airborne in 5 minutes. Starting the aircraft takes no time at all. All the prep time is in mission planning and there is none for a defensive fighter. Get it off the ground and point it at incoming planes. It needs a crew that is in a building on standby and a fueled/armed plane.
Here’s an interesting read about reducing reaction time by simply eliminating the take-off altogether: Zero-length launch - Wikipedia. Some of their referenced websites are pretty cool too.
The tale is told about… I think it was Eisenhower, that when he became President, one of his military staffers bragged that they could get X number of planes airborn with 8 minutes of warning time. Ike looked at his watch, and said “Do it. Starting right now.”.
Side topic to the OP question, but it seems that one of the limiting factors is getting the pilot/crew into the plane & ready to go; or the difficulties of trying to have a crew sitting there all day waiting.
So how about the new pilotless planes (‘drones’) that the Air Force is using: how quickly can one of them be launched?
And it seems some of them are like the cold war planes – they can stay in the air for hours cruising above enemy territory, ready to be immediately vectored in when needed. (This seems to assume pretty complete air superiority. In such a case, the OP’s scenario of a fighter plane wouldn’t really apply.)