> was the only known person to survive a fall from the top of a cumulonimbus thunderstorm cloud.
Perhaps that's technically correct but Ewa Wiśnierska rose from ground level to 10km to the top of a cumulonimbus thunderstorm and came down 4 hours later 60km away. It's an amazing story.
> The next day, our flight profile was duplicated on the SR-71 flight simulator at Beale AFB, Calif. The outcome was identical. Steps were immediately taken to prevent a recurrence of our accident.
Wow! Super impressive that they could simulate that. Didn't know that was possible, especially in 1966.
Is there any current simulation software (available to the public / off the shelf) in which you could accurately simulate something like the situation from the story?
A bit of searching failed to turn up anything on how the simulation was done. I'm curious if it was all digital, like a modern simulator, or if it included analog simulation.
It was built by Link, which had been building flight simulators since 1929 [1], so certainly had extensive experience with analog simulators.
According to Wikipedia's article on analog computers [2],
> Analog computers were widely used in scientific and industrial applications even after the advent of digital computers, because at the time they were typically much faster, but they started to become obsolete as early as the 1950s and 1960s, although remained in use in some specific applications, such as aircraft flight simulators, the flight computer in aircraft, and for teaching control systems in universities. More complex applications, such as aircraft flight simulators and synthetic aperture radar, remained the domain of analog computing (and hybrid computing) well into the 1980s, since digital computers were insufficient for the task
It sounds like the '60s, then, were well before digital flight simulators were common.
I'm going to have to guess that CFD simulation above mach 1 that is good is probably not something that is publicly available but from reading RUAG's website they use open source software[1]. From my experience with CFD in F1 the main issue you have with CFD is correlation but maybe driving a car around a track is harder to simulate than going really fast in "clean" air.
This reason is what leads me to think that it is a major issue and is why both China and the United States started going into mach 5+ with autonomous craft to gather data for correlation.
For low speed flows like in F1 the viscous effects are much larger and this can make flow prediction more difficult. It’s actually pretty easy to predict the shockwave pattern from 1D theory without the need for CFD [0]. The boundary layers are much thinner and you can assume inviscid flow at first. At hypersonic speeds the interactions get more complex however and you’re dealing with a lot more materials science challenges so CFD is important in predicting thermal loads and shock boundary layer interactions.
The CFD simulation in F1 isn't really a track simulation. Normally a straight or curved domain (for car in yaw) is used. Computational limits in the rules mean simulating dirty air, like when following a car, is incredibly inefficient.
The test itself wasn't fatally flawed, it snowballed when they had an unrelated engine malfunction.
Several minutes into cruise, the right engine inlet’s automatic control system malfunctioned, requiring a switch to manual control... Without proper scheduling, disturbances inside the inlet could result in the shock wave being expelled forward–a phenomenon known as an “inlet unstart.” That causes an instantaneous loss of engine thrust -- TFA
It wasn't unknowable or even an unexpected situation, those engine unstarts were common until they worked out the control system dynamics. They were moving fast and killing test pilots right at the beginning of being able to use computers to simulate flight. Exhaustive simulation of all circumstances might not have been possible with the available computer time, or honestly it is quite possible nobody thought to do it.
Test pilots though are generally aware of and on board with the risks. Unfortunately simulation isn't all it's cracked up to be and very often aerodynamic models are trustworthy only after they have been validated experimentally for the specific scenarios they apply to even now. Nevermind half a century ago.
Right, the engine unstarts were a common and expected problem, but the key is that I don't think they were in any way predictable, other than being limited to certain condition regimes that included basically everything except subsonic flight.
That would be a lot of unknown conditions to test for.
I’m not sure if this is the same person but it sounds about right. The cowboy-pilot whose ranch he landed on died about 20 years later in a plane crash:
They were kinda useless, operationally-speaking. Half the crew members were on the lower deck and surrounded by significant hull structure, and so couldn't eject. The first two shuttles were only designed around a crew of 2 where this design made more sense.
Irrespective of that, the ejection seats only work for a very limited period of the shuttle's operating envelope. IIRC it's something like only the first 2 minutes of flight where the ejection seats could be used. And in most cases where you'd be able to eject, the solid rocket boosters were still firing and it was theorized that as the shuttle passed a pilot who had just ejected, the exhaust gases would ruin the parachute and/or kill an ejecting pilot anyways.
By the time the SRBs burnt out, the shuttle was too high/fast to eject.
> The first two shuttles were only designed around a crew of 2 where this design made more sense.
Only the first I think, unless you're count Enterprise (which couldn't go to space.) Challenger (the second orbit-capable shuttle) never flew with less than four crew.
Incidentally, the ejection seats of questionable worth in Columbia weren't without NASA precedent; the Gemini program also used ejection seats which similarly had a pretty narrow window of usefulness at best. One of my favorite pictures ever is this shot of the Gemini capsule with both hatches open, giving a pretty clear view of how the seats would have worked: https://upload.wikimedia.org/wikipedia/commons/e/e2/Armstron...
Think of the situation that puts the commander and pilot in- they're the ones flying the shuttle; no one else can eject.
If they eject, they are essentially abandoning the rest of the crew to die. It's the antithesis of the captain going down with his ship.
Initial unpowered glide tests were the only flights where ejection was even likely survivable, and this was the reason the seats were ever installed in the first place. (Only on the first two orbiters.) Any other use was an extreme long shot.
Of course all the abort modes ended up being fairly convoluted and unsurvivable to some extent, except abort to orbit.
The "contingency" aborts were especially absurd, which depended on burning off most of the remaining fuel (which would take longer, given it would likely be used in the event of an engine failure), then orienting the shuttle into a position where the crew could attempt a midair bail out. Think about that.
RTLS was a close second, for single SSME loss in the first 4 minutes. It was a 25 minute (!) abort process that involved building up enough speed and altitude so that the shuttle could be flipped around and "put in reverse" to return to the launch site. This involved a certain amount of time at near zero horizontal velocity, so the altitude was needed to permit some time of "free fall" while reversing direction. It also put the orbiter well outside of it's survivable stress envelope, and subjected the crew to extreme g-forces. It was highly questionable that even a perfectly functioning shuttle could have executed the abort, let alone a malfunctioning one.
>Astronaut Mike Mullane referred to the RTLS abort as an "unnatural act of physics"
>John Young:"RTLS requires continuous miracles interspersed with acts of God to be successful"
These were abort modes that were considered survivable. There were another set of scenarios that were considered not survivable: LOCV for Loss of Crew and Vehicle.
It was this level of absurdity that led to the NASA culture of basically ignoring some cherry-picked risks, ultimately leading to Challenger and Columbia.
> Think of the situation that puts the commander and pilot in- they're the ones flying the shuttle; no one else can eject.
> If they eject, they are essentially abandoning the rest of the crew to die. It's the antithesis of the captain going down with his ship.
The Avro Vulcan bomber used by the RAF during the cold war had ejection seats for the pilot and co-pilot, and the 3 other crewmen had just parachutes. There were several accidents where the pilots managed to eject successfully but all the other crewmen were killed.
That's also a little different in that the crew could possibly bail before the pilots ejected, at least in theory.
Which is similar to what the shuttle plan turned to post-Challenger, except the ejection seats were already gone.
The commander and pilot were supposed to hold a bail out orientation until the rest of the crew bailed, then put it on auto pilot (assuming it was working) and bail themselves.
Yes, There were at least 4 trans Atlantic runways designated for aborts at any one time during the program, sometimes changing, and always with 2 "active" for any given launch, staffed with a small city of NASA and military response personnel.
From memory, I think there was generally one each in Africa, GB, mainland Europe, and Azores at any given time. Along with additional sites in Bermuda and Canada (or other US East coast sites) on most post Challenger flights, which weren't specially staffed.
The interesting thing about the added sites post-Challenger, Bermuda was at an US military base. But Canada & other East coast sites were normal airports, with no training or added staff. The shuttle would have had to follow the same FAA emergency landing procedures as if it were a Cessna out-of-fuel, including contacting ATC and directly contacting local traffic at uncontrolled sites.
These were viewed as "modified RTLS" aborts, and were realistically not much more survivable than an actual RTLS.
Only the pilot and copilot had ejection seats, the rest of the crew couldn't also have ejection seats (I'm not sure if it was specifically weight, volume, or orientation/configuration that was the limiting factor. I think maybe a combination of all three.) STS-1 through STS-4 (all using Columbia) only had a pilot and copilot, no other crew. For STS-5 and STS-9 when there was more crew, they flew with the ejection seats disabled. After STS-9 the seats were removed.
I don't have a source saying it specifically, but I think they weren't keen on operating a shuttle where two of seven crew could survive but the other five had no chance. It must have also saved weight and space too.
I read that at least one shuttle commander thought the ejector seats would've been useless anyway b/c if you used them while the solid rocket boosters were still running you'd get burned up & lose your parachutes from the SRB exhaust - and your altitude & velocity would be too high to eject by the time you'd be safe from the SRBs
They were zero-zero seats (capable of ejecting at zero airspeed/altitude, aka on the ground), so they conceivably would have been useful during some of the return trip, including sitting on the runway after landing. Understandably that was probably not the part of the flight the astronauts were most worried about though.
Looks like Yeager's site is rate limited, but Google Cache came through for me. I went to an AOPA dinner about 30 years ago where Bill Weaver talked about his F104 Starfighter flight experience. (At that time, the SR71 stuff was probably still classified BYEMAN.) He had many interesting tales to tell and I'm glad that he survived this terrible accident.
>A big red light on the master-warning panel in the rear cockpit had illuminated just as we rotated, stating, “Pilot Ejected.” Fortunately, the cause was a misadjusted microswitch, not my departure.
"Misadjusted switch". The ejection light "just happened" to be misadjusted 2 weeks after you survived force ejection. Uh-huh. Sure mate.
That's a microswitch underneath the chair that checks for presence of that chair. If the switch is no longer depressed the chair is gone or the switch is maladjusted, which can easily happen.
