I live in Western Canada and we used to hear sonic booms all the time in the '60’s. However, I don’t recall hearing one in the last 40+ years.
Last ones I heard were on 9/11 when they launched F-16’s from the local base. They were in a hurry to get somewhere. Never got a straight story on it.
Like many others, I recall them as a kid in the early-mid 60s. We lived near a NAS but 60+ miles from the ocean. When fishing 40-50 miles off the Outer Banks I’ve heard them several times. Many (most?) videos claiming to be showing aircraft going Mach 1+ are actually just showing water vapor around the jet that can form at much lower speeds. LSL Guy may chime in here but I think it may take a while to go supersonic after taking off. Maybe out of hearing range if you live near the field? I have no idea what that range might be.
Depends on how big a hurry you’re in.
In a modern interceptor if you just leave full power in, keep going straight, and don’t waste speed in climbing you’ll bust the Mach within at most 5 miles of the edge of the airport. On a cold day more like 3. Which is to say within a minute after liftoff.
More typically the runway isn’t pointed the direction you want to go, and it’s faster and more fuel efficient (= greater intercept range) to climb at a more moderate speed, say 350 knots, then accelerate and break the Mach once you’re pointed the right way at a decent altitude, say 20,000 - 25,000 feet.
If the runway’s really pointed just the wrong way the quickest thing is basically a half-loop from a standing start ending up at 10 or 15,000 feet going the other way still right over the airport. Roll right side up, leave the power in to accelerate in a shallow climb and you’re off to the races.
Such fun.
Interesting. That’s some serious acceleration. A bit off topic but we have ANG F16s locally and is seems they almost always do at least one and sometimes several low passes or touch and goes (I can’t see if they ever actually "touch’) when returning from wherever they’ve been training. Sometimes they’ll climb very steeply to a pretty high altitude (10K?) and then drop just as quickly. Is that SOP pretty much everywhere, traffic permitting? I guess one can never have too much practice at landing In any case, it looks like a fun ride.
The acceleration is pretty fantastic. It’s like a crotch rocket motorcycle that just keeps pulling. On a cold cool day we used to hit 400 knots by the far end of the 2-mile long runway if we just sucked up the gear, stayed at 10-20 feet and left it in full afterburner. Assuming not also carrying a draggy load of bombs. Which would be the configuration for an air interception anyhow.
Those “touch and goes” probably weren’t. At least in my era we’d go down into the flare then go around. They didn’t want us wasting precious tires. At least the F-16 had a problem with tires and brakes overheating; they’d been miniaturized as much as possible then a bit more. Then the aircraft got heavier in later models. So minimizing the accumulated heat load from even a no-brakes touch and go was important, especially in warm climates.
We’d typically do 3 low-approach/go-arounds at the end of each mission if we had enough fuel. If not, we’d cut it short.
The climb to 10K then spiral back down is a simulated flame-out landing or “SFO”. In a real engine-out situation you’d aim to arrive over the middle of the runway at 10,000 feet above runway elevation doing the best glide speed of IIRC 200 kts. Then you’d make a single continuous 360 degree turn hanging gear and flaps as you went around the corner, slowing towards a fast approach speed of IIRC 150-ish while aiming to impact at/near the threshold if you’d planned the energy right. Then approaching maybe 100 feet you’d pick up the nose, bleed the speed back and touch down at the more typical 120ish at the normal touchdown point. The key thing was to arrive on short final with excess speed to ensure you had energy to stop the descent and positioned not too far long or short so you ended up on the runway, but not too far down.
For practice we’d zoom up to the same spot, chop the power to idle, stick out some speedbrakes to offset the idle thrust and do the same maneuver.
This youtube is from a flight sim game, but is a pretty fair representation of an SFO pattern. It’s even where I used to fly out of.
It’s an expensive minute. I saw a video the other day with an F-16 pilot who indicated that in full afterburner, the fuel burn rate is something like 60,000 pounds per hour, so that one-minute sprint eats about a 1000 pounds. To put that in context, the F-16 only carries about 7,000 pounds of fuel in its internal tanks.
Yeah. I once calculated that I could run the thing out of fuel in about 6 minutes if I tried.
On a somewhat related topic, does anybody else remember military convoys of dozens or maybe 100 military vehicles cruising down the interstates? I remember them from the early-mid sixties but can’t remember the last time I saw one. I’d imagine it relates to the cost of fuel.
Definitely remember sonic booms as a kid, 1980’s. Lived 100 miles away from Whiteman AFB growing up, and sonic booms were normal.
I’ve certainly seem convoys of dozens in somewhat recent years. Not that noteworthy. Hundreds? Never.
I certainly have recently seen convoys of dozens within the past year or so on I 80 in Nebraska.
Depends greatly on where you live.
When I lived along an interstate that ran between an Army National Guard mechanized unit and the nearest active duty Fort with a big exercise area, I’d see a convoy of a couple dozen vehicles many weekends during the summer.
Where I live now if we see a convoy of military vehicles on the freeway we either just had a natural disaster or martial law has been declared.
I remember at least one boom from space shuttle reentry — Long Beach, CA, early 80s.
A boom caused by a Navy plane 50 miles offshore was also audible here in 2014:
It was a lot more common when I was a kid in the 70s; usually Marines from Pendleton. Now, I rarely see more that half a dozen; likely National Guard. That does remind me of a railway crossing I was held up at near Pasadena, CA in the early 80s. Well over a hundred flat cars each with two army tanks. Some even had soldiers riding on top.
OP. I, too, lived in the Chicago suburbs in the 60s, and I remember frequent sonic booms, especially from about 1966-1968. (We moved to a suburb farther west in 1968, and I didn’'t hear them as often.) I got to wondering about them a few years back and found this 1964 NYT article:
Sonic Booms to Jar Chicago as B‐58’s Fly Test Attacks
Sonic booms triggered by one of the Air Force’s fastest bombers, flying simulated nuclear attacks, will rumble over the Chicago area for three months beginning on Jan. 4.
The Strategic Air Command said today that this metropolitan complex was the biggest densely populated target ever used by SAC for such an extended [training] program.
The booms will result from the high‐speed flights of the dart ‐ shaped, 1,300 ‐ mile ‐ anhour [sic] B‐58 Hustler bombers, which will test for pin‐point accuracy on simulated targets that will be alternated from day to day, between 6 A.M. and 10 P.M.
[bolding mine]
The article said the corridor would run from Waukegan to Onarga. While the article said the booms would last for three months, I’m assuming similar training exercises continued well beyond that time frame. Oddly enough, I don’t recall hearing them at school, only in my own neighborhood.
Nice find! You may have stumbled on the reason for a substantial (or even sole) amount of the sonic booms we would have heard in the 60’s in that area. According to wiki, the B-58 operated close by:
Bunker/Grissom is here:
So we’ve got a mach 2 nuclear bomber parked north of Indianapolis from 1964-1970 at a flight training school. Damned right we’d hear some sonic booms for six years in the Chicago 'burbs during that time period.
Edit: and Lake Michigan is right there as an uninhabited area to scoot a B-58 at high speed. That must have been a frequent flight path.
Ha, brilliant.
Ok, ‘Sonic’…
I was born in the mid 1970s, so I’ve never heard a sonic boom (other than cracks of whips).