On the premiere episode of the brand-new second season of Curiosity Sunday night at 21:50 on the Discovery Channel (DStv 121), South African viewers can see this remarkable plane-crash of a Boeing 727 in the Mexican desert which was carried out in May by Discovery.
The 170 seater jetliner was filled with crash-test dummies as well as several cameras and other measuring devices, filming exactly what happens inside as the plane is crashing down in the desert and finally giving scientists - and viewers - a microsecond by microsecond view of what is happening, how and why.
Prof. John Hansman, aviation expert, and Chip Shanle, the chase plane remote control operator, both took time to do a conference call with TV critics and journalists about this quite unbelievable Curiosity episode.
For how long after the crash did some of the cameras and measuring instruments still work and did some remain intact or was everything completely destroyed and broken?
Prof: Hansman: We had a bunch of different cameras on the airplane. We had high speed caeras that really only had a few seconds of data that they could take, so they stopped after their data period just because they had so much data. They were still functional. We had distributed around the airplane small cameras that were actually in fireproof boxes in case we had a fire. Most of those still worked, there were a couple that were damaged and several of them actually stopped operating during the shock of impact.
They reset, so we actually had to go back into the data memory to get the data, but the data was in a solid state so we were actually able to recover a lot of the imagery. There were a couple of cameras that were destroyed.
Is there a best seat that you can sit on in a plane during a crash? Is there anywhere in the plane where you may be safer than other areas?
Chip Shanle: It really depends on the specific accident. In this one obviously in the back was safer. In general most accidents, sitting after wing-line is safer, unless of course it breaks.
Prof. Hansman: As Chips says, it depends on the specifics, so there have been cases where sitting in the back has been the worst, but in general the front of the plane acts as a shock absorber for the people in the back.
For you to be able to fly the plane remotely, how much extra equipment did you have to build into it?
Chip Shanle: Actually quite a bit because obviously safety was our primary objective, so we actually had two separate drone systems. One was the primary control system and for that we had two controllers, two separate controllers for the primary control system. That connected into the flight control system that was underneath the floor, just up first class area in the aisle. Then I had a third controller that was a totally separate drone system that only affected pitch, up and down movement of the nose and that was specifically for a backup system in case we lost control with the primary system and then I could just run the nose down and make sure the aircraft stayed on the range.
When you first heard of this idea, did you say no way we can't do that?
Prof Hansman: I was first approached which was now a number of years ago by some of the television producers, by actually Dragonfly, I had know of the prior experiment that was done by Nasa and the FIA where they attempted to crash large airplanes. It was very difficult and as you probably know they had problems with it, so I discouraged them.
I thought I discouraged them, I told them how hard it would be, how complicated it would be to get the airplane ready, to get the test range to do it and the fact that the one time it had been done before it had not been successful and so I thought I had discouraged them. Three months later they called me back and they said we have some preliminary funding, we're going to do it, so I was actually surprised.
Chip Shanle: We always knew we could do it. The one thing we would not sign on for was to guarantee there wouldn't be a fire. We told them we will do our best but we never guaranteed that it wouldn't catch on fire. That's why we landed it so flat and wings level was in an attempt to minimise fire. It worked but we weren't positive that it wouldn't burn, so other than that we were pretty confident we could do it.
What will be the cause of the plane crash according to your script?
Prof Hansman: The plane crash was simulating a landing accident, so the airplane was in its landing configuration – the wheels were down, the flaps were down. It was simulating an accident where the airplane landed short of the runway. It was similar but not exactly the same as an accident that occurred at Heathrow with a Boeing 777.
What conclusions have you drawn after this experiment?
Prof Hansman: The primary conclusions we drew really regard to passenger survivability and we looked at some factors such as what was the seating position, so the brace position when you're in a crash to put your head down and hold your ankles.
We actually tested whether that made a difference. We looked at how things inside the airplane moved around during the accident and we had some conclusions and recommendations about things like wiring in the panelling, so we probably learned more about what happens in terms of the interior of the airplane than about the external sort of crash dynamics which were fairly standard.
My second question is did you simulate the conditions of a known kind of aircraft crash before it crashed or did you make up your own set of entirely new circumstances?
Prof Hansman: No, it wasn't entirely new. Again the general profile was based on a number of similar accidents that occurred in landing configuration.
When we actually designed the parameters we went to historical data on actually crash tests and one of the things it has done in design is we don't normally crash an entire airplane but we have done a series of experiments where we drop airplanes to simulate crash loads and so we designed and gave Chip the impact parameters to simulate the edge of survivability, so where the loads would be high enough depending on how it happened, it either would be survivable or would not.
What part of the actual crash footage did you find most compelling or interesting or even unusual?
Prof. Hansman: Because of the way we did the flight, the airplane hit a little bit nose
down. One is the way the fuselage failed which is the nose
wheel broke off immediately on impact and then went back into the belly of the
airplane. That caused a buckle, so there now was weakness in the bottom of
the airplane and as it was sliding along the desert, the nose actually buckled
and bent underneath the airplane, essentially the rest of the airplane ran over
the cockpit, twisted it off, the cockpit went in one direction and then the
airplane continued to slide.
The other interesting thing was
that the right main gear swung back, it actually came back around and hit the
fuselage. When we went and did the investigation there was actually a
tyre mark on the fuselage of the wheel going forward and that's again what
caused the airplane to rotate when the airplane slide into that wheel.
Interestingly we did have one camera looking out the right wing and that camera
actually caught ... you can see that wheel hit right next to the window that the
camera was looking out, so in the imagery you can actually see the wheel coming
by, bouncing off the fuselage. At the same time you're seeing the wing
breaking up, the flaps breaking as they slide along the ground.
Chip Shanle: My biggest surprise was also how quickly – and I was just 100 feet away
watching it real time and I was surprised how easily the cockpit came off and
shed since that's normally where I ride; and then I was also very surprised
that two of the engines were still running after that impact. That
surprised me.
What would be your best piece of advice or tips having seen the actual
footage of the plane crash for someone who is going to be flying to maximise
their best chances of survival other than just wearing their seatbelt?
Prof Hansman: Put your seatbelt on really tight and the most important thing is to
know where the emergency exits are in the airplane, both the ones in front of
you and the ones behind you. Then finally if you're going to be in an
impact, assume the brace position.
Has your research changed knowledge about planes or
plane crashes?
Chip Shanle: For me as an airline pilot and a pilot in general the most surprising, I really
thought that the overhead bins would fail. We loaded a few of them
heavily and I thought all the overhead bins would fail and everything would
come out of them, but they held and that surprised me.
How much did the experiment costs?
Prof Hansman: Ultimately it has cost several
million dollars. I don't have the full numbers, operationally it was
about a million and then probably a little bit more; and then you had the
equipment and things like that. Most of us on the science side, we did it
as volunteers. We did it just for the opportunity. We didn’t make
any money off it and then there were obviously a lot of costs having to do with
the television aspects of it.
Curiosity II (Plane crash), Discovery Channel, DStv channel 121, Sunday 4 November, 21:50
(Please note that the text of this interview was edited as well as shortened to enable readability.)
