Why NASA Uses A 1970's Boeing 727 For Zero G Experiments.
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- เผยแพร่เมื่อ 28 ก.ย. 2024
- There's a lot to know about the Boeing 727, why it was built, why it was chosen by Zero G Corporation. Why 3 engines is better than 2 for this application, and... why the exploits of Hijacker DB Cooper forced a design change on the aircraft which would be named after him.
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N794AJ... The last operator was AmeriJet International in Miami, Florida-a freight operator which I happened to work for during the conversion of this 727 to Zero G... the Fedex Stage 3 Hush kits were installed by AmeriJet and so were the winglets... I was there working as a technician for the first Zero G flights... Interesting point is that during weekdays the same aircraft flew as a freighter and on Friday nights we took out the cargo restraining system and retrofitted it for Zero G flights by adding all the padding-seats,oxygen bottles and everything else needed for the operation ( that huge cargo door made this possible and quite easy ) . The hydraulic reservoirs were modified to be bypassed by operating some valves so that no air was at the top of the tank ( known as head pressure ) because the hydraulic fluid would go to the top of the tank during zero gravity and the pumps would cavitate and self destroy... it was quite an interesting experience and am glad that it was part of my aviation career... thanks for the great videos Scott -I always look fwd to your upcoming ones !
That clears several questions I had!
Thanks for the first hand info :-)
The modifications to the hydraulic system makes sense to me now - being used to pressure pumps designed for water, I was assuming that there was a bladder that kept the water / oil and air separate, but I can see why not having one would be a problem.
It was around 1998 as far as I can tell when they added the winglets, Stage III hush kits, of which seem to be FedEx lightweight hush kits since they still use the original tailpipes and not the more common extended tailpipes of the heavyweight hush kits, along with the number 2 engine’s reverser removed.
Some operators Stage III modified their non Stage III jets even prior to the January 1st, 2000 deadline for non Stage III jet aircraft over 75,000 pounds, of which I believe the FAA filed this new regulation in 1994 or so.
Hush kits are the worse, but they are still loud as hell even with them, they primarily eliminate the exhaust crackle.
Interesting to hear that you started working on the conversion on the weekends but kept regular freight operations during the week.
This was the generation of technology coming out when I was studying aerospace engineering. Many of my fellow students were on a track to becoming commercial pilots, the 727 was the hot rod that they wanted to fly back then. High thrust to weight ratio, can land and take off just about anywhere. Only a job flying business jets, especially the Lear 20 series, was more desirable.
Should also note that our drinking game in the dorms was identifying the transports coming in for landings on the north runways of LAX by the sound of their engines. They came in right over our heads at Northrop University.
@@saundby I remember doing the same thing at Embry-Riddle Daytona campus since it was attached to Daytona airport. We joked you could always tell the freshmen since they'd look up and get excited when they heard the Delta jets fly over because of their lower bypass engines.
Lear 23? Nahhhhh. G2SP retrofitted with military surplus Phantom afterburners. Yeah yeah, you got a phone number for me to call, what else is new
When the 727-200s were introduced they were underpowered and pilots nicknamed them the lead sleds. Boeing eventually equipped them with more powerful engines but the nickname stuck.
@@saundby I learned to do that with military jets at my job south of Carswell AFB. Which led to that day leading up to an airshow where I went, "What the HELL is that screaming noise?!" and turned around to see a B-52 on approach.
Hey Scott. Another good video. I want to reiterate NASA had absolutely nothing to do with our company or our FAA certification process. The only connection was that I was employed there through 1999 and Byron Flew as a Payload Specialist on two spacelab missions. Truth be told, if anything it was someone antagonistic. With that said, Bob Williams was the director of operations for the KC-135 for 25 years and he and I worked closely together at NASA MSFC/JSC.
When he retired we consulted for the two sequels of The Matrix, and ZeroG did a week’s worth of research flights for Warner Brothers (our first commercial flights) to in September 2000 to make sure that their concepts of visual effect were accurate. We took master Woo-Ping Yuen and the entire martial arts stunt team (Chad Stahelski was keanu reeves stunt double then) and did a lot of weightless fight scenes in simulated rain storms. We dumped 45 L of water during every parabola and lined the entire plane with a giant “condom” to catch it during pullout and recycled the water for the next parabola.
We validated costumes, ZeroG blood hits, 15 ft flames and other amazing things we had never done or would be able to do at NASA.
The point is that our business started in 1993 and we raised the capital to get it off the ground and flying well before NASA became a client. They didn’t help us with certification and the FAA typically responded - we don’t care what NASA did, you’re flying part 121. The FAA was ultimately supportive, but it took many many meetings and compromises.
Finally on the 727 choice…. The air stairs were a big deal, but if you read our patent the biggest sell was that magic economy of aircraft maintenance ops balancing aircraft take off landing cycles, operation hours, and time in how these things impact A, B, C, and D checks. UPS had a fleet of 200+727s in operation in the 90s as the 727 rolled from high cycle passenger routes (8x Day) to low cycle (2x day) and so there were a lot of them flying and it really fit our business model as is described in the patent. Our plane gets a lot more inspection relative to a standard cargo ops plane hours since we don’t fly as often. Parabolas also don’t stress the plane the way say a hard landing or thunderstorm might (we flight validated a 50,000 node FEM with strain gauges during our early days). There’s no reason we can’t use it for quite a while longer. It’s got a lot of life left.
Hope that helps. I know the weightless part, NASA’s history, and NASA as a currentclient blurs the line, but there wasn’t much overlap or conversation outside of the internal expertise of Bob, Byron, and me. Our extended team was really first class and it’s still unbelievable to me that we pulled it off.
Thanks again for diving into this geek fest. Absolutely LOVE all the comments.
To be clear, one reason I have NASA in the title is because it’s shorthand for ‘space stuff’. I wasn’t clear on how much of the publicly available NASA experience and hardware heritage could apply, but I figured it was more than zero. Anyway, I wish I’d had this information before I recorded this last night.
@@scottmanley it’s remains the best pair of videos on our journey that we’ve done. Can’t wait to take you again one day soon! Let’s figure out when and where. Thank you for doing this and also allowing me to chime in with back stories. Honestly, few believed us in the days of ZeroG, XPrize, and Space Adventures and every day (most often by content on your channel) I’m reminded that we were indeed on the the path that history has shown to be correct. Reach out on one of my social accounts and let’s coordinate making this happen again and we can go even deeper into the rabbit hole. Who knows, perhaps we can pull off an entire flight of channel followers. I’ll toss my hat in the ring to be there. Maybe I can get Peter and Byron to come as well? Another fun fact - other than the FAA flights in the late 90s, the three founders haven’t been on a flight together since. There’s always been one conflict or another. Maybe it’s time to end that track record…23 years later.
It's plain to see you're making these out of pure, genuine enthusiasm. You love to see it.
plane*
missed pun opportunity :(
The smile plastered across his face the entire video is all the evidence of that we need.
In common parlance, one might even call it a shit eating grin.
Aye, he's having fun, but you have to remember Mr Manley is Scottish. :)
There was one other more recent case of someone parachuting from the airstair door of a 727. In 2012, a 727-200 was deliberately crashed in the Mexican desert for a TV production as a test of crash survivability. The aircraft was fitted with a remote control system so a pilot in a nearby chase aircraft could control the final decent but the 727 required a crew onboard for takeoff and flight to the are of the crash because it was flying thru controlled airspace above populated areas. The flight crew bailed out once they were in the test are and the remote pilot had taken over. For the experiment, the air stairs themselves were removed so they had a safe jump space thru the opening. Interestingly, none of the air crew were certified skydivers so they had three professional skydive instructors on board to take them out in tandem jump rigs. All six personnel successfully exited and landed under canopies.
en.wikipedia.org/wiki/2012_Boeing_727_crash_experiment
My wife and I took a ride in this plane out of Houston's Hobby Airport, along with a few actual NASA astronauts in training and a bunch of other folks. I was expecting the experience to be more dramatic, but I actually felt extremely calm and unbothered by the weightlessness. Wife and I were 100% ready to sign up for spaceflight immediately following - we both thoroughly enjoyed it and it was NOTHING like the weird stomach feeling you get in turbulence. TOTALLY would do again.
It makes you wonder what real benefit do astronauts get from this.
The noise was a real surprise to our research team when I did my Zero-G flight. We had to work in tandem to move some things around inside a glove box during the hyper-G maneuver to get ready for the next parabola and between the air noise, engine noise and covid masks, no one could communicate effectively. Headsets are a must for this December's research campaign.
What’s the research? All I can think, fit that little time, it’s crystal growth it something
@@float32 we were trying to validate cratering models in varying gravity levels with regolith simulants. Our profile had 10 mars, 10 lunar, and 10 zero g parabolas. Lots of other experiments are focused on fluid or gas dynamics, human physiological responses to varying gravity etc.
Funny story told to me when I was doing my PPL back in 2000... a 727 had just left the gate (forget the airport) and was taxiing across the apron, when the flight crew received a request to stop and take on another crew who were “deadheading” to another aircraft in another city. The captain stopped the plane and the rear air stairs were lowered so the spare crew could board. As the fully uniformed captain, first officer and flight engineer dashed up the stairs and past the passengers towards the front of the aircraft, one of them was heard to exclaim “My god, I didn’t know the stewardesses even knew how to start the engines!” 😄
Thanks for the laugh, I needed that.
Another bit of 727 trivia: in 1979 a TWA 727 went into a steep dive and reportedly maxed out at Mach 1.012. That airframe is pretty amazing.
It's very interesting to see, that in the US they also use these very old aircraft. The Airbus A300 used in Europe was the first of the line and after the two prototypes were pulled out of service it was the oldest airbus (!) in active service. When I was doing scientific experiments on a zeroG campaign, I was told, that there were two main reasons they used the A300. First, they wanted the computers to stay out of the loop as much as possible and since Airbus very quickly adopted Fly-by-Wire with the A320, the A300 was their only choice. Second, in most other types of Aircraft, as Scott mentioned, zeroG is is explicitly prohibited while it is not for the A300 (hence, it's allowed :D ).
The same logic is true for some military aircraft. In the swiss research team, I was working as a student, there was also a swiss fighter pilot, who was part-time doing research at the university. He realized, that his old Tiger II F-5 jet did not have any explicit restrictions on zeroG either and he was able to use the magazine box of the gun as storage space for biological zeroG experiments. Very cool stuff and the best student job I ever had!
Yeah, the 727 is being operated in it's normal flight envelope and thus can be flown under Part 121. Good luck trying to get the same STC for an FBW aircraft. You could probably still do the same with 737s.
I am curious, though. The pilots at Novespace told me, that there is nothing special with the A300 (and I assume the B727). They assumed, that Airbus just forget to mention zeroG in their guidelines, while for modern planes, the companies just put a disclaimer in, because they don't want (and don't need) to certify it. This would mean, that there is nothing fundamental prohibiting the use of modern planes for this, except legal issues and probably sensors/Avionics.
@@janusseaman152 I wonder if the computers would allow such manoeuvers or intercept. At least a lot of warnings might be annoying :D
Here's another interesting fact to fuel your new found love for the 727, Scott: the aircraft is capable of JATO (strap solid fuel rockets on the back for assisting takeoff). The 727 is gorgeous.
@@plab0187 so? ...
@@plab0187 Name me another modern commercial airliner (not military strategic transport) that was rated for JATO use.
I'll wait.
I lived right under the approach to DFW in the early 2k’s and would spend lots of time plane watching at a little park right at the end of one of the runways and you could always tell when a 727 was going to come over because of its unique engine sound.
Visited there many times. Always fun to hear the swirls a few seconds after they passed by!
These are my favorite airliner. In NZ, the Airforce had a few, and in the last year before retirement, at the airshows, they gave them hell. I watched the practice over what was then Wigram airfield, And they were doing climbing turns and banking way past 90 degrees. Awesome stuff. Love that plane.
First couple of Avalon Airshows this side of the Tasman, the last of the 727's in comercial service with one of the QANTAS subsidaries was used for flight displays, same sort wing over turns and sone high speed low passes that would make fighter pilots jealous and be agaist show rules now. Was great to see.
The 727's primary advantage is it's 410 KIAS limit speed. Outright legend compared to what's flying now, limited in the 310-360 KIAS range.
The 727 was my favorite commercial plane to be on. My favorite flight was an unscheduled one taking computer geeks back from a computer conference in Santa Cruz to SFO. Lots of geeks but no cargo and not a lot of luggage. We got off the ground really fast. It was mostly taken out of service because you couldn't replace the center engine with a higher-bypass one because it was basically inside the plane body.
Love the rambling. One of the main draws to your channel for me is that you allow your curiosity to get the better of you, and fall straight down that rabbit hole. You share very interesting details that clearly come from a curious mind, which sets you well apart from most of the content on youtube, where curiosity eventually gets crushed by the job of producing regular content.
Thanks for the fascinating detailed content!!
His videos are just so much less scripted than most other science channels and that really makes this channel special.
When I was a kid (70’s) a friend of ours was a 727 pilot. I see to recall him saying that if equipped with the right engines a 727 would have no trouble breaking the sound barrier because it was shown in testing it was pretty stable going through that choppy stage that keeps aircraft from crossing that barrier. I have nothing to back that up.
I remember reading a book back in the '70s about Boeing and the 747, including the history of the aircraft leading up to it. As Scott describes, the 707 set the baseline, but the 727 was able to use much smaller airports and shorter flights. It was referred to as the "Jeep" of airliners, and could almost hit Mach 1 in flight tests. I think it also pioneered "the wing that comes apart", the assortment of slats, flaps, ailerons and whatnot that allowed for a wide range of flight characteristics from low and slow to fast.
Also: _Thanks, Scott!_
And another trivia note: the Boeing 747 test pilot was our test pilot for our FAA test flights.
There was also a a300 flying zero g for the company noves pace. This one was retired in 2014.
Now they have a a310 flying zero g.
Both are twin aisle aircraft, there is a lot more room in them.
Fun fact: the a310 they are using was formerly the "konrad Adenauer", the aircraft used by the German chancellor.
The retired A300 is now located on a public parking lot at Cologne /Bonn Airport (CGN) 😊
@@nicolasblume1046 That A300 in question was MSN 003, an A300B2-103, which was the third Airbus ever built, and until its retirement in 2014 it was the world's oldest flying Airbus. I really wish that aircraft be moved into an indoor display as outdoor storage long term can bring a host of damage to the aircraft including corrosion. The original A300 cockpit is very fascinating and I really wish more people have a chance to see it.
Possibly has much less time on it than most A310s.
@@neilgerace355 You are propably right about flight hours. But I learned that they count each parabola as take-off/landing cycle for maintenance purposes. So those propably add up at least as quickly as in normal transport operations.
16:39 Data is beautiful
Watching yeseterday's video I realized how important the duck is. The only way I think it could be improved is if it was in a vacuum chamber and the logistics of fitting that into a cockpit AND having it be visible to the pilots would be... difficult
Or, automate it.
On a Soyuz launch I saw, they had similar toys hanging from strings. When they reached orbit, the toys flew forward and floated.
@@TaxPayingContributor That's on almost all launches on crewed vehicles. The first crewed Dragon flight had a dinosaur and the recent Starliner test had a Jeb.
@@FastSloth87 i saw that Im so happy Jebediah Kerman managed to get to space and back safely
god knows he dies to much when im playing KSP
edit:didnt remember jebs last name right
The ONLY catch here is that stronger inputs into the pitch will flick the tail up and down faster than the cockpit. So inputs that keep the duck fine up front don't exactly match the rear completely. Small inputs track just fine - but larger ones will definitely see the tail of the plane move around FAR more than the nose, simply because the tail is where the control surfaces/authority is locations.
My dad, brother, and I used to put together the supplemental electrical for tent city for a skydiving convention in our home town. A few years they brought in a 727 for the divers to jump out of and it was always fun watching the post jump videos from those runs. Never got to go up myself but it was always fun watching it fly over the drop zone and see all these little specs get sucked out the back.
Skydive Perris has been trying to get their DC-9 operational for like 15 years now also :P
As a retired enroute radar controller I always picked on the 727s in my sector for going fast or slow when spacing was needed. The pilot without hesitation responded "No problem". I rode in a 727 cockpit a few times as an observer and as Mr. Graybill stated the pilots loved this Boeing. Whether its true or not the crew stated it could max out in level flight at Mach .99.
Mmo is 0.90 on the 27 so certainly nobody ever went .99 on a commercial flight, but the difference at 30k feet is only 60mph so it is possible it could achieve .99 in level flight. That's obviously VERY transonic, though so possibly not easy nor a good idea to do it.
I was expecting the plane to have a set of smaller tanks that they could have a bladder to keep the fuel pressurised, so that it could be pumped without gravity.
Any change to critical parts of the plane require extensive testing plus regulator involvement. It seems, it is cheaper to fly with full tanks than to optimize fuel system for zero-G
The main (centre) tank is a bladder tank. They can use it to feed all engines. Probably use the wing tanks for the flight out and back.
Within each fuel tank of the 727 is a collector tank that contains the motive flow jet pumps and electric boost pumps. The collector tank is per it's name a central draining area, essentialy a smaller tank within the larger, that has check valves isolating it from the rest of the tank. This allows for there to be a constant source of fuel regardless of attitude or turbulence. The Engineer would keep all three fuel tank crossfeeds open during low G maneuvers. This way if too much fuel sloshes away from the motive flow pump volutes in one collector tank, then the others will be available to keep the manifolds pressurized.
The motive flow fuel pump (jet pump) is very reliable and needs very little maintenance. The motive flow is pressure fed by the boost pumps or by the return fuel coming from the engine pumps. Whichever has the higher pressure.
@@jpeterman57 Beautifully illustrated by Animagraffs' latest video, although using an Airbus A220, but the system is very similar.
I work at the FBO you departed from, but it was my day off. Sorry I missed you. I gotta say The B 727 is one of my favorites, and we still see them fairly frequently between cargo flights and Zero G. The jt8 engines have a unique sound when they taxi (loud) and the APU positioned in the wing root is about as loud as it gets for the ground people. If you ask someone who has worked around 727 for a while, the answer is "WHAT?" (doesn't matter what the question is) I do however have a different take on how the hush kits work on the older jets, it is most apparent on the G2-G3 biz jets. They work by absorbing noise on takeoff and then releasing it on landing....just makes sense. Science.
Thank You Scott Manley, the video was very interesting and well made. I enjoyed watching it. 👍👍
I love that the Zero-G 727 came from Braniff. My dad worked for them at their St Louis hub in the early to mid-70's.
727 best commercial jet ever, I fell in love with its acceleration when I was a young technician regularly travelling on either Fokker Frightship or 727
The exhaust mixer table is very cool, but I want a coffee table made out of a Falcon 9 grid fin... And a living room large enough to put it in.
There's much smaller grid fins from bombs and such, you could probably find one cheap and it would be a more appropriate size for a table. Not as cool though.
Starship booster grid fin ! You know you've made it when you're living room is big enough for one of those bad boys 🤣
The one at SpaceX HQ is amazing!
I want a GE90 fan blade hanging from my roof! They sold a couple on eBay for like 5k$ like 5 years back!
@@rkan2 I want a whole jet engine to display. Not such a big one but maybe one from a business jet or so. I'm sure it can be found cheap on the scrapyard that's all busted up. And if I have a garden someday an old fighter jet. Sometimes you can find them for the price of materials if it's beyond saving.
The pursuit of DB Cooper is one of my favourite films that I haven't seen in decades!
Your enthusiasm and knowledge always bring a smile to my face.
I'm a student in aerospace engineering, and in my propulsion class we touched on the topic of jet noise.
My understanding that the amplitude of noise generated by a shear flow scales with the magnitude of the velocity gradient to the 7th power (or something around there). That means that the more you can spread out the change in velocity of the flow, the quieter it will be. Turbofans accomplish this by having a layer of medium speed flow around the engine core’s jet, which splits the velocity gradient into two smaller jumps instead of one big one. Also, increasing the bypass ratio of the fan, more energy can be put into accelerating the bypass layer and less into speeding up the core jet, resulting in a lower velocity change overall.
A hush kit like the one you showed, and the chevrons you see on the trailing edge of the cowl on modern turbofans reduce noise by mechanically mixing flows to smooth out the radial velocity profile (and decrease the gradient by doing so). I believe that the mechanics behind the mixing involve the generation of vortices (larger ones than those naturally caused by the shear flow) which help to spread out the change in velocity.
727 has always been my favorite short hop airplane. Flew on them hundreds of times in the late 60's and early 70's. There was a rumor back then that PSA (Pacific Southwest Airlines) had exceeded Mach 1 with one in a dive. Dunno, could happen I think.
Fascinating! A good use of otherwise retired planes (other than being converted into quirky homes!)
I would have liked to hear more about your experience of the zero-g trip and if you suffered anything afterwards...
Thanks to your previous video on the plane, you let your viewers 'experience it' for free... without suffering anything (!)
At least it seemed like I was on the plane in zero-g for a few minutes in my dream last night!
I was surprised I found myself there just from watching it online and was a bit anxious not knowing when the plane would suddenly get gravity again. Strange things dreams... You never know how you got somewhere or where you'll end up next!
It was as if I could just go to another place by watching it on TH-cam then find myself there, but then when would I find myself transported somewhere else? The zero g plane seemed to take me half way around the world. Obviously travelling is much cheaper and less of an ordeal in dreams - like when I find myself in South Africa without having been queasy (and suffering with the pressure in the ears) on a long-haul flight, then it's so easy to get home - just wake up!
I don't think I ever want to go on a plane again in real life. Free adventures in dreams are much better!
These aviation videos are awesome! I love it! I was just looking through my grandpas pilot log today from the 70s-90s. And the old school map/nav tool
I just noticed how the 3 amber “Low Oil/Filter Bypass” lights under the gear handle come on whenever they’re at zero g. Interesting considering he talks about how oil starvation at zero g can ruin engines really fast 😂
Good catch! I went back and saw that as well.
I noticed that, too. I thought Scott would comment, but he didn't.
In the previous video the captain mentioned that they should worry if the lights *do not* come on. Lol
I think in the last video one of the pilots said it's expected and no warning lights would be the actual problem 😅
The door lights have rather simple proximity switches. They are not connected to the hydraulic system at all. They operate only with very high tension cables, pulleys and bell cranks. Notice also that they are amber, thus they indicate something between completely open or completely closed. Actual "gear position" lights are separate and are either green (down & locked/safe 👍 ), red(not safe/unlocked 👎 ) or OFF (up & locked).
Boeing was ran by engineer people and now by lousy accounting or lobbyist supplication specialists.
727 engineered well, relatively lower cost of operation!
It is not that very well known, but Britain and France were aviation technology leaders in the mid-20th century. E.g. the Sud-Aviation Caravelle was miles ahead and a major reference point for the DC9-MD80 etc... series. Boeing and MD then had their heyday in the 60s and 70s, while what would become Airbus was slowly getting its act together.
re: "Boeing was ran by engineer people and now by lousy accounting or lobbyist supplication specialists."
The old McDonald-Douglas ppl ...
The Picture at 5:32 seems to have been taken during the filming for Apollo 13 (The 1995 movie) with Tom Hanks in the center, Gary Sinise and Kevin Bacon to the left and Bill Paxton in the front left (all in grey)
Two other zero G videos I love are the music vid by OK-Go, and one by a bush/duster instructor/pilot. The OK-Go is obvious, because its a well done vid.
The duster pilot is awesome, because he talks about using zero g maneuvers to avoid stalls. Basically, he points out that it is impossible to stall a wing at zero g, because there's no load on it. So, if in the midst of a tight, low altitude turn, and you start to go into stall, you still nose down to unload the wing. Also interesting rudder use to avoid stalls as well.
The behind the scenes film of the OK-GO video is really good. They had to do something like 200 parabolas to shoot that then splice them all together in time with the music.
Having flown the 727 for 11 years, good accurate discussion about the plane. Those that flew it really enjoyed it. First landings were always done on revenue flights with passengers.
I did a few skydives from 727s at World FreeFall Convention in the 1990s (I wore a black suit with thin tie, used regular skydiving rig and not a NB-8. And it was a nice sunny day). I noticed this 727 was flown by Amerijet and wondered if it was same aircraft I jumped from, looking at photos the Amerijets were N190AJ, N5607, and N495AJ (argg, just one number off). For skydivers they removed the airstair and lined the entire rear exit hallway with plywood so not snag any skydiving rig. I also took opportunity to ride in the cockpit, basically bought another jump ticket and got permission to ride a jump seat. It was interesting to see how the crew flew, something I've never done before or again. Capt does most of the major controls, first officer does some trim and call out numbers, flight engineer does various minor adjustments on throttle in addition to working his station. On another occasion I also spoke with a airline pilot and he said the 727 was a hot rod.
You mentioned CIA... actually they had a role of having operatives parachute out the airstairs back in the 1960s. I'm sure DOD must have done similar with special ops guys. Exception of govt secret stuff, I think first time some legally jumped from a 727 was making the early 1980s movie "Pursuit of DB Cooper." Then in 1992 when it was first flown for skydivers at the WFFC in Quincy, IL. I talked with one of the organizer, Kirran, who said how they managed to get FAA permission was a early series of test flights Boeing did by dropping cargo out the air-stairs during flight. This particular flight test report was key item for the OK from FAA.
Just know, if it makes you excited, it will be a hit with us. You enthusiasm and huge brain are why I am always here.
Nice to see you still bubbly after your zero G experience Scott. Stay safe and I'll catch you on the next one. Thanks for sharing.
Love how the pilots stick reads "Stop screaming I'm scared too".
I think 0g flights would be a perfect task for the precision of a good autopilot. It seems like too much work to never actually get 0g perfectly.
Humans react better to out-of-parameter situations
Think of the tremendous hazzle, Boeing had with the flight-software and certification for the 737 MAX. Programming an autopilot for this task and getting it certified would be a nightmare (in other words: tremendously expensive).
Especially since there's no more than a handful of these planes flying with these parameters, the per unit cost will be even higher
I don't think programming something to essentially nose dive is a good idea
Also, if I recall correctly you literally can't do 0g manoeuvres on modern airliners, the software won't allow It
I graduated from Vincennes University as an A&P Mechanic in ‘89. My first job as an A&P was on B727’s, it was a great job and I still have a soft spot for them. I even kept my B727 books from the B727 classes I took to get me familiar with the systems & engines. I was able to fly as a Flight Engineer on several flights, but decided that wasn’t for me, way too boring.
Even though we were cargo, we still had to preform regular inspections on the Cooper Locks.
The Hush Kits, called them The Cookie Cutter. The purpose of the Cookie Cutter was to mix the bypass air with the turbine air inside the nozzle cutting down on the sound by cutting down on the wind shear. Or at least that is what was explained to us Mechanics is most of the noise from the engines is the wind shear from the turbine air being hot and providing 90% of the thrust compared to the 10-ish% of the cooler bypass air. Back them they were called medium bypass, where as now they would be considered low bypass engines.
Thats exactly what i wanted to know after your last video, thanks for this!
"Stop Screaming - I'm Scared Too" -- very nice. Nice reminder on the yoke.
Making that Cooper device out of stainless seems likely, but making it out of copper so the STC could be entitled the "Copper Cooper clapper caper" would be a fun throwback.
Make out of lead and it is called the "Pb Cooper..."
I guess you know that Thomas Pesquet is part of the team that flies the A310 Zero G in France (where we do not have to comply with FAA by the way ;) ), just as a foot note ! That Airbus also allows for general public to fly OG btw, not only astronauts training :)
The group shot at 5:23 or so...that's the team prepping for the zero gravity shots in the Apollo 13 movie. The back row, from left is Gary Senise and Kevin Bacon. Fourth from left is Director Ron Howard, and sixth from left is the star, Tom Hanks. Front row left is (I think) Bill Paxton, and front row right is Executive Producer Todd Hallowell. Todd is also the guy who pulls up next to Hanks on the street and recognizes him, shouting into his car. That's why his credit says, "noisy civilian."
We used to do zero G maneuvers in the Cessna 172. We called them parabolics--which is what the flight path is, a parabolic arc. Of course you couldn't get as much time in zero G as in a jet. Also the engine would quit from fuel starvation/interruption after about five seconds--it came back immediately once positive g was restored. I also did them in an aerobatic Citabria with inverted fuel system.
Regarding noise level in the jets: Air noise due to airspeed is the larger component of in-flight noise in a rear engine aircraft than engine noise. Notice sometime when you are flying commercial how the sound increases as you level off from climb and begin accelerating to cruise. Fun fact: Eastern Airlines called the 727 "Whisperjet" I guess because the cabin was quieter than the conventional wing mounted engine 707 and 720's of the day.
I wrote this before, but what you call ‘rambling’ is a wonderful delivery that shows your excitement while still delivering all of the tech goods. Don’t worry about it, it’s some of the best content on YuhTuub! Thanks for the entertainment and insights!
I think a 727 was designed (overbuilt), using a slide rule (three digits). Now, they build an airplane with many digits.(fine design margins). 727 is a flying abrams tank.
I love the "STOP SCREAMING... I'M SCARED TOO" checklist holder on the yoke. That's hilarious.
I have read, and watched a lot of video around the "Cooper Story" over the years. This is the first time I've heard mention of the "Cooper Vane"! I vaguely remember something about a 'device', but it was never defined/described. It's very interesting when you think about it, it makes it impossible to "unlock" the air-stares in flight, no matter what. Very interesting!!! Thanks!! --gary
We did notice your fascination and excitement. (Army) We were told the 727 was the hijackers' favourite because on the ground the air stair eliminated the rear blind-spot of other aircraft and it was thus harder for anti-terrorist units to approach and breach.
This was an awesome video, Scott. Thanks for sharing what you learned with us.
Fun fact: In the NASA/Ames simulator I demonstrated that a B727 could do a split-S starting at 16,000 feet and recover at 10,000 feet. Whee!
Of course, I also demonstrated that attempting a dirty roll on takeoff from SFO was a good way to wind up inverted inside Mt. San Bruno.
I love the Jar-Jar button on the instrument panel!
I could tell by that endless grin that you were really having fun with this video. 😁👍
This is exactly the nerdy video I wanted to watch before heading off to work, thanks Scott!
The "hush kit" causes a tempering of the exhaust gas to be a little closer to the temp of the air that did not flow through the engine. It's the heat of the exhaust gasses suddenly meeting the colder air that causes the loud rumble noise you hear from jets, and a low or no bypass engine like the 707/727 and the 20 series Lear CJ610 engines are VERY loud.
Welcome to the pilots life Scott. You will forever be a massive nerd along with the rest of us. Cheers!
I love learning and I feed off the excitement and intrigue. Great work Scott. 😉
As always great technical explanations for the systems and flight control management by the pilots. All very fascinating and great teamwork at the very least.
As a side note, Bob hoover was doing similar types of maneuvers back in the 50's and 60's as filmed adds for the Shrike aircraft alone in the cockpit whilst drinking a glass of water.....and the engines turned off....just makes you think.
RIP Bob.
I remember flying a Cessna 152 as a teenager while working on a private pilot license. My instructor and I felt like goofing off toward the end of a local cross country. After scanning and making a clearing turn we did some micro gravity experiments with a water bottle and later with a ink pen. We climbed up momentarily 10 kts short of stall and flew a parabolic ark for about 8 to 10 seconds. We would make an ink pen levitate off the cockpit dash and catch it with your mouth. So long as we didn’t over G or exceed Vne we weee good.
When flying gliders on a winch launch we are - or should be - prepared for a cable-break. The momentary situation in that case is similar to the climbing portion of a parabola: You are pointing nose high up and do not have adequate thrust to keep flying like that. In the specific case the thrust has just dropped to precisely zero. Not a sustainable position to stay in.
We train to push over at or near zero G to avoid the possibility of a stall while going over the top. Once the nose points down and sufficient airspeed is regained and confirmed flying continues as usual.
It is always fun to train for that on actual launches, made more interesting by inherent proximity to the ground. Goofing around with vertical G in normal flight when there are no other pressing issues does not have the same urgency and I can very well relate to your experience in the Cessna.
Just don't go negative unless you have personally vacuumed the cockpit before you launch. Or you will eat dirt.
I flew a special acrobatic Cessna 150 a long time ago, that had a G meter installed. The plane was used by the club for teaching spin recovery. But I love the idea of the duck.
The older Pratt & Whitney JT8D engines that were used on all of the Boeing 727’s of any series, were actually called “Low Bypass Turbofan Engines”, not “Low Bypass Turbojet Engines”.
I now have an image in my mind of Scott Manley flying a Cessna 150 in parabolic arcs whilst shrieking with joy.
JumpIng the 727 used to be a staple of the World Freefall Convention in Illinois. Allegedly, if you caught the jet blast, then you could actually gain altitude until you fell too far behind.
I love 727's, I think they are still sleek and futuristic looking. My dad worked for Delta Airlines when I was growing up. At one point in the 80s I think Delta owned something like 200 727's, and as I used to get a discount, I flew on them a lot. I used to keep a mental note of the numbers on the nose gear door, and I think there was one particular 727 which I flew on multiple times. Delta also owned a ton of DC-8's, which is a whole other classy cool old jetliner.
Thanks Scott, for another episode, right up my interest alley.
Nothing wrong with a big smile on your face, especially when sharing KNOWLEDGE!
This adventure went to your head Scott, glad you had a smashing good time !.
Wonderful follow up! Details, details.... ubiquitous gravity vs engineering convenience.
@17:40 surprise Jarjar binks appearance! 😄
One of the current operators of the 727 is a race car driver. Doug Kalitta owns Kalitta Charters for a day job and drives 330 mph dragsters on the weekend
those rubber bands on the yoke remind of the life hack to pan a tripod mount with a rubber band for smooth transitions
The coffee table is really cool and I personally would not mind for a second if you covered airliner technology and the like. Sure Airliners are well figured out and there are countless documentaries on how they work as well as fellow youtubers BUT no one has the recent flight experience and way of explaining thing quite like Scott Manley. I personally, would relish in hearing your perspective on their technologies. After all, airliners are arguably spaceships compared to the atmospheric conditions we experience at sea level in the biosphere.
Really good! Now there's another item out there, which I will never use, but about which I know a ton of fascinating information.
You read my mind... or my comment on the last video. Thanks for explaining the name of the D.B Cooper door and the Cooper vane on the 727 ... They called it the whisper jet at the time !
Great video! Surf the wave. Gaming -> orbital mechanics -> space news -> aviation. It'll be great to have an aviation youtuber who actually understands the flight mechanics.
For example why 4 engines are better than 2. I'm tired of hearing the lazy myth that 2 big engines burn less fuel than 4 smaller ones. Nigel Tufnel logic. If you loose one engine on takeoff on a twin you lose half your thrust, but the plane has to be able to co tinue to accelerate and climb, so the plane has to carry 50% more engine weight and thrust capacity than it needs. But on a quad jet you only lose 25% thrust, so you carry 33% spare capacity. But making and maintaining 2 big engines costs less than 4 smaller ones.
Ref. Nicholas Cumpsty, Jet Propulsion, Cambridge Universtiy Press
@Cancer McAids sure, but a lot of ill-informed journos write that the A340 and A380, both equipped with high bypass engines, fell out of favor because they burned too much fuel. The A340 fuel burn was actually very good, which is how it was able to fly so far. But those engines were expensive to buy and maintain. And ETOPS ratings up to 300 minutes took away almost all the routes that twins couldn't fly. The A380 was just too big of an airplane with too many seats. Fuel furn per passenger mile was actually pretty good, but it's hard to fill 600 seats ..
@Cancer McAids but to your point, and like @Scott Manley says, a high bypass twin 737 is indeed more fuel efficient than a loud, gas guzzling low bypass 727. However, thats a comparison of two, now three different generations of engines.
I probably flew on that aircraft as a kid back in the 70's. Flew quite a few Braniff flights back in the late 70s and early 80s.
Cool. I'm glad 'you' did this, caz other YT'ers have and didn't come back with as much cool info
I wonder if they've looked at getting an L-1011? Similar setup for the centerline engine and you'd get much more space to float around on a widebody. Flip side is that there aren't nearly as many out there and you're going to need a lot more runway. Checking it seems like there's only one left operational but I wonder how many are in boneyards and recoverable.
Being unrelated to the kc-135 would make it hard from a regulatory perspective.The center engine doesn’t have an s duct, it goes straight through, so it would torque the nose down. Plus a bigger plane would increase the risk of having to fly with empty seats, losing money.
@@danthewolf1997 - The L-1011 (Tristar) has the center engine mounted as in the B727, with an S-duct.
Plus the last L-1011's were delivered in the 80's, considerable younger airframes, and are used mostly for longer routes meaning fewer pressurization cycles.
The center mounted engine is a nice benefit of the 727 but not at all required for the STC. The KC-135 and Airbus A300 & A310 have no problems doing the same thing with wing mounted engines. The center thrust is a nice benefit, but it would probably be best to just get the youngest cargo 737 you can get your hands on to do the same stuff. The 737 Classics are not so far away from the 727 either.
@@danthewolf1997 L1011 has an S duct, the DC-10 has a straight through engine.
It will be interesting to see if Zero G Corporation acquires more 727s. Even if there was not enough demand to have two active aircraft as 727s are at the stage of life, “low mileage” planes and parts get harder to acquire every year. So it would make sense to acquire a plane & parts now before need them if you intend to keep flying a 727 in the future.
It's like staying in your lane while driving in one of those 70s police chases down those steep hills where they do huge jumps by accident
Hello Scott (flowers of scotland) , in france , we use Airbus A310 ;)
Juan Browne just did a discussion about offloading the wings and not being able to stall in zero G.
Dan Gryder has a very interesting video that tells the story of D B Cooper and claims to have identified him and interviewed family members. Well worth a watch.
realizing about how they have tight speed margin while diving, lest people fly into nose or tail, is both surprising and obvious in hindsight!! i never flown anything, but thinking about how much a couple m/s extra/deficit can mess you up while docking in KSP puts it a bit in perspective... also i agree that the coffe table looks sick ahah fly safe!
Funny to see it's original Braniff paint job! I probably rode on it! Back in the '70's I was flying Braniff between Dallas and Washington Dulles on a regular basis. I loved Braniff! I got to ride the Concorde between Dallas and Washington three times when Braniff was toying with the idea of flying the Concorde to South America. I knew one United pilot who called the 727 a skateboard! It was fun for him to fly.
I remember reading that from an aerodynamic perspective the 727 wing was a remarkable accomplishment. It was complex but was able to achieve a very high CL (coefficient of lift) with its slats and multi-slotted flaps. By contrast, the Airbus wings were relatively simple in design.
Dangerous to generalize, and not to disagree with the coolness of the 727, but one could argue that the ugly vortex generator tabs on the upper surface of some 737 wings are a bit of a kluge. And for cruise performance the supercritical aerofoil on airbus wings was clearly better L/D at high Mach...so some aerodynamicists might argue Airbus wings (British) were superior....
The '27 was a favorite of mine growing up. It just looked like a hot rod for the air. The wings were swept back, and the body wasn't large. My first flight was on one from Minneapolis to Milwaukee and I remember going in the rear steps.
The D.B. Cooper vane didn't engage pins. It was a one piece unit that simply weather vaned and swung a blocker under the outside of the door. The door could still be unlatched, it just couldn't swing down.
one of the greatest scott manley episodes of all time!
Modern aircraft jet engines are designed to meet various environmental criteria, but when jet engines were a brand-new technology, And when you have a new technology, you start simple and add bells and whistles only after the foundational things have proved themselves. That's why we started with the turbojet engine, because it was the simplest example of air-breathing jet propulsion. And because energy increases by the square of exhaust velocity, the gasses coming out of a turbojet tailpipe were often faster than the speed of sound, making sound pressure levels in excess of 160 dB, and remaining above the threshold of pain for a mile or more aft of the engines. If you had been on Maho Beach on Sint Maarten back when early B707 planes with the JT3C turbojet engine were spooling up for takeoff, you'd be struck deaf almost instantly by the noise. I'm old enough to remember the "daisy" exhaust mixers on early 707 engines that attempted to use the slipstream to reduce noise.
The supersonic exhaust was one reason why turbojet engines weren't ideal for passenger planes; they were most efficient at high speeds (above Mach 2) and high altitudes where the air was cold. The second generation of jet engines, called low-bypass turbofans used some of the engine power to turn a larger compressor section to produce thrust like a propeller. While a prop (or turboprop) makes all thrust from a propeller, a turbofan engine makes some thrust with the turbojet core, and some with the fan. The JT8D engine used in the B727 makes almost as much thrust (96%) from the fan as the core. The air from the fan moves much slower than the super-heated exhaust gasses. In a turbofan engine, this results in a shear zone where the different velocities meet. An exhaust mixer increases the contact area to reduce the speed of the core gasses, while raising the speed of the bypass air, reducing the supersonic shockwave and increasing the overall velocity of the combined core and bypass gasses.
Back in 1964 when the 727 was released, it was a game-changer. Not only did the airstairs eliminate the need for jetways or truck-driven stairs, the 727 had an APU that supplied power on the ground, eliminating the need for ground power, ground A/C and a start cart for starting the engines. The 3-engine design gave superior performance at "hot and high" airports that twins like the DC-9 and 737 struggled to take off from. Unfortunately the trijet was designed before noise abatement rules, and fitting the engines with effective hush kits proved problematic. The better solution was to fit newer models with higher bypass ratio engines, and the #2 s-duct engine couldn't adapt without major redesign. That's a shame, because the 727 was one of my favorite planes to fly as a passenger. Every pilot that flew one felt the same way about being in the front seats.
My father worked for Boeing, in Renton and Seattle. I was 5 years old when this plane was made...
I'm not surprised they hand fly the arc, but I could see them having a display that shows how they need to move to keep the ballistic path.
I remember in the 70s flying on PSA airlines flight in the 727…”Coffee, tea, or bullion?” The rear stairs are the coolest!