WEBVTT 00:00:16.178 --> 00:00:17.470 PHILIP GREENSPUN: Welcome back. 00:00:17.470 --> 00:00:19.600 I hope you've got your coffee. 00:00:19.600 --> 00:00:21.520 I see somebody has a muffin. 00:00:21.520 --> 00:00:23.170 They'll be in a carb coma, Francis, 00:00:23.170 --> 00:00:26.960 I'm relying on you to answer all the hard questions. 00:00:26.960 --> 00:00:29.080 That's not authorized. 00:00:29.080 --> 00:00:34.220 All right, so multi-engine jets-- 00:00:34.220 --> 00:00:37.320 the piston twin, the good news is, 00:00:37.320 --> 00:00:38.820 when both engines are spinning, it's 00:00:38.820 --> 00:00:41.290 easier to fly than a single. 00:00:41.290 --> 00:00:43.530 Because you don't need as much right rudder 00:00:43.530 --> 00:00:44.740 or really any right rudder. 00:00:44.740 --> 00:00:47.290 It doesn't have all those left turning tendencies, 00:00:47.290 --> 00:00:49.170 necessarily. 00:00:49.170 --> 00:00:52.770 The training and rating, especially the Seminole, 00:00:52.770 --> 00:00:54.320 which has counter-rotating props-- 00:00:57.030 --> 00:01:00.120 all your training for a multi-engine airplane 00:01:00.120 --> 00:01:02.550 is flying around on one engine. 00:01:02.550 --> 00:01:04.050 Because flying around on two engines 00:01:04.050 --> 00:01:05.200 is pretty much the same. 00:01:05.200 --> 00:01:07.020 So basically, almost all the flight time 00:01:07.020 --> 00:01:10.350 that you accumulate during your multi-engine training 00:01:10.350 --> 00:01:14.160 will be with one engine pulled back to idle or, in some cases, 00:01:14.160 --> 00:01:15.780 stopped altogether. 00:01:15.780 --> 00:01:21.090 You have six power levers in a twin-engine piston airplane, 00:01:21.090 --> 00:01:25.200 two for throttle, two for mixture, and two for prop. 00:01:25.200 --> 00:01:29.700 You may also have cowl flaps to bring more or less cooling air 00:01:29.700 --> 00:01:30.960 into these piston engines. 00:01:34.040 --> 00:01:35.850 By FAA certification requirements, 00:01:35.850 --> 00:01:37.610 as I think I mentioned earlier, there 00:01:37.610 --> 00:01:39.190 is no required climb rate. 00:01:39.190 --> 00:01:43.020 It may be a truly crummy airplane on one engine. 00:01:43.020 --> 00:01:45.390 So that's why people say that second engine 00:01:45.390 --> 00:01:48.990 either takes you to the scene of the accident. 00:01:48.990 --> 00:01:51.940 One engine expert, Mike Bush, he said-- 00:01:51.940 --> 00:01:54.190 he came to appreciate the Cirrus parachute. 00:01:54.190 --> 00:01:56.940 It's not like having that extra engine out there 00:01:56.940 --> 00:01:59.270 on the wing trying to kill you all the time. 00:01:59.270 --> 00:02:03.390 It just waits there quietly until you need it. 00:02:03.390 --> 00:02:06.020 Piston twins have an illustrious history. 00:02:06.020 --> 00:02:09.840 Here is a Aero Commander piston-driven 00:02:09.840 --> 00:02:14.023 twin that was actually Eisenhower's Air Force One. 00:02:14.023 --> 00:02:16.440 This also tells you something of the growth of government. 00:02:16.440 --> 00:02:18.660 When Eisenhower was president and wanted 00:02:18.660 --> 00:02:20.400 to go to a smaller airport, this is 00:02:20.400 --> 00:02:25.480 how he would go, in an airplane designed for about six people. 00:02:25.480 --> 00:02:27.280 OK, this is probably what you'll be flying, 00:02:27.280 --> 00:02:28.980 which is the Piper Seminole. 00:02:28.980 --> 00:02:32.160 It is unusual in that the props counter rotate. 00:02:32.160 --> 00:02:34.410 And that has some advantages that are 00:02:34.410 --> 00:02:37.040 beyond the scope of this talk. 00:02:37.040 --> 00:02:41.640 It's a design from the '70s based on designs from the '50s. 00:02:41.640 --> 00:02:42.870 Where the problems happen-- 00:02:47.110 --> 00:02:48.130 so have a look here. 00:02:50.930 --> 00:02:55.550 Can anybody immediately see what one problem might be? 00:02:55.550 --> 00:02:58.460 I'd say, the left engine quits, and you 00:02:58.460 --> 00:03:00.198 have to manipulate these. 00:03:00.198 --> 00:03:00.740 What happens? 00:03:03.788 --> 00:03:05.177 AUDIENCE: [INAUDIBLE] 00:03:05.177 --> 00:03:07.410 PHILIP GREENSPUN: You're manipulating the controls 00:03:07.410 --> 00:03:11.040 for the good engine instead of for the failed engine 00:03:11.040 --> 00:03:12.600 inadvertently. 00:03:12.600 --> 00:03:17.250 So it's just an interface that's overly complex 00:03:17.250 --> 00:03:18.450 given human frailties. 00:03:18.450 --> 00:03:21.090 So, what do you have to do if an engine quits? 00:03:21.090 --> 00:03:25.320 You don't want the drag of that propeller 00:03:25.320 --> 00:03:31.090 out there that's not being driven by the engine. 00:03:31.090 --> 00:03:32.952 So you push all of the levers forward 00:03:32.952 --> 00:03:35.160 and try to get maximum power out of your good engine. 00:03:35.160 --> 00:03:37.980 Push everything forward. 00:03:37.980 --> 00:03:41.730 You'll have to put in some rudder to correct the yaw, 00:03:41.730 --> 00:03:44.430 because the airplane is going to be pulled 00:03:44.430 --> 00:03:46.890 to one side or the other depending on which 00:03:46.890 --> 00:03:48.570 engine is still running. 00:03:48.570 --> 00:03:53.640 And then there's the old adage, dead foot, dead engine. 00:03:53.640 --> 00:03:58.510 So if your left foot is flat on the floor 00:03:58.510 --> 00:04:00.930 and it's your right rudder that's in, 00:04:00.930 --> 00:04:05.010 then you know that it's the left engine that has failed. 00:04:05.010 --> 00:04:07.770 Then you try to verify the dead engine 00:04:07.770 --> 00:04:09.180 by pulling back that throttle. 00:04:09.180 --> 00:04:11.640 So you'll say, OK, I think the left engine's failed. 00:04:11.640 --> 00:04:14.420 I'm going to try monkeying with the left throttle. 00:04:14.420 --> 00:04:17.670 And if that has no effect on the flight characteristics, 00:04:17.670 --> 00:04:20.700 you verify that it's the left engine. 00:04:20.700 --> 00:04:24.330 Then you feather the dead engine by pulling the prop control 00:04:24.330 --> 00:04:26.210 all the way back. 00:04:26.210 --> 00:04:28.680 If you're in a two-pilot crew, you'll 00:04:28.680 --> 00:04:30.780 get your co-pilot to verify. 00:04:30.780 --> 00:04:34.680 I have my hand on the left prop control. 00:04:34.680 --> 00:04:38.970 And you pull that back, close the cowl flaps. 00:04:38.970 --> 00:04:41.670 And only now do you have any chance 00:04:41.670 --> 00:04:43.470 of getting an actual climb. 00:04:43.470 --> 00:04:46.980 So imagine if this engine failed shortly after takeoff. 00:04:46.980 --> 00:04:49.020 It's a lot of stuff to do very quickly. 00:04:49.020 --> 00:04:50.670 You have to do it all right. 00:04:50.670 --> 00:04:52.860 And if you miss even one of these things, 00:04:52.860 --> 00:04:56.040 you may not be able to clear obstacles 00:04:56.040 --> 00:04:57.300 at the end of the runway. 00:04:57.300 --> 00:05:00.420 Now, of course, your typical piston twin, 00:05:00.420 --> 00:05:03.698 takeoff is a stressful time for an engine 100% power. 00:05:03.698 --> 00:05:05.490 But there's definitely more engine failures 00:05:05.490 --> 00:05:06.900 that occur en route. 00:05:06.900 --> 00:05:11.160 So the generally negative impression of piston twins 00:05:11.160 --> 00:05:13.860 might have to be revised if your primary mission is flying 00:05:13.860 --> 00:05:15.570 around the Caribbean islands. 00:05:15.570 --> 00:05:17.710 You might, in that case, actually say, well, 00:05:17.710 --> 00:05:19.680 I'd rather have that second engine. 00:05:19.680 --> 00:05:22.140 Is this within human capability, that sequence 00:05:22.140 --> 00:05:24.690 that you just saw? 00:05:24.690 --> 00:05:28.140 Yes, in World War II when engines weren't 00:05:28.140 --> 00:05:31.740 being made with as much precision as they are now, 00:05:31.740 --> 00:05:34.230 it would be ordinary to have one out of four engines 00:05:34.230 --> 00:05:37.515 or one out of two engines fail on any given mission. 00:05:37.515 --> 00:05:38.640 But they also got it wrong. 00:05:38.640 --> 00:05:41.670 There is one very famous guy, Louis Zamperini. 00:05:41.670 --> 00:05:44.610 Some of you may have seen a movie about him. 00:05:44.610 --> 00:05:47.130 He floated in a raft for 47 days. 00:05:47.130 --> 00:05:51.540 I think that was a record at the time for survival at sea. 00:05:51.540 --> 00:05:54.660 He was on a four-engined aircraft. 00:05:54.660 --> 00:05:57.000 And one engineer quit. 00:05:57.000 --> 00:06:00.232 And I think there were about four pilots in the cockpit. 00:06:00.232 --> 00:06:02.190 Remember we talked about a flight engineer also 00:06:02.190 --> 00:06:03.693 being an airman. 00:06:03.693 --> 00:06:05.610 So if we count the flight engineer as a pilot, 00:06:05.610 --> 00:06:08.910 there were at least three or four experts up front. 00:06:08.910 --> 00:06:13.320 And as a team, they feathered the wrong engine. 00:06:13.320 --> 00:06:19.590 So they killed a second engine that was actually good. 00:06:19.590 --> 00:06:21.965 And now they had two engines working on only one 00:06:21.965 --> 00:06:22.840 side of the airplane. 00:06:22.840 --> 00:06:24.850 And it was uncontrollable. 00:06:24.850 --> 00:06:27.900 So they went in the water through human error. 00:06:27.900 --> 00:06:30.517 And Cape Air has a great track record. 00:06:30.517 --> 00:06:32.850 They've had a handful of engine failures over the years. 00:06:32.850 --> 00:06:36.242 They fly piston twins all day, every day in the Caribbean 00:06:36.242 --> 00:06:37.200 and around New England. 00:06:37.200 --> 00:06:38.490 And when they have a problem, usually it's 00:06:38.490 --> 00:06:39.448 not a complete failure. 00:06:39.448 --> 00:06:42.630 But maybe there's an ugly indication on one engine. 00:06:42.630 --> 00:06:44.130 So they'll shut it down. 00:06:44.130 --> 00:06:45.900 But they do a lot of recurrent training. 00:06:45.900 --> 00:06:48.330 That's what they fly all day, every day. 00:06:48.330 --> 00:06:53.820 The typical family airplane doesn't get flown as often. 00:06:53.820 --> 00:06:55.830 And the pilot isn't as proficient. 00:06:55.830 --> 00:06:59.190 So the capable twins are very inexpensive now, 00:06:59.190 --> 00:07:02.800 except for the Beechcraft Baron, which is the most sought after. 00:07:02.800 --> 00:07:05.340 They're a little more expensive to insure 00:07:05.340 --> 00:07:07.170 than the comparable single. 00:07:07.170 --> 00:07:10.290 Just the other day, I got a quote from my local insurance 00:07:10.290 --> 00:07:12.900 agency called Plane Insurance. 00:07:12.900 --> 00:07:16.380 And we found out that if you look 00:07:16.380 --> 00:07:20.040 at a $200,000 aircraft being flown 00:07:20.040 --> 00:07:23.940 by a pilot that has 250 hours of experience in type 00:07:23.940 --> 00:07:27.135 in that exact aircraft and with a million dollars 00:07:27.135 --> 00:07:29.590 of smooth liability, that means no sublimit. 00:07:29.590 --> 00:07:31.817 So if there's just one passenger, 00:07:31.817 --> 00:07:33.900 they would pay, oh, a million dollars for injuries 00:07:33.900 --> 00:07:35.220 to that one passenger. 00:07:35.220 --> 00:07:40.200 Some policies have, like, $100,000 per person sublimit. 00:07:40.200 --> 00:07:44.310 Anyway, it was about 50% more for the Baron, $3,700 a year 00:07:44.310 --> 00:07:46.930 versus $2,500. 00:07:46.930 --> 00:07:48.460 So there you have it. 00:07:48.460 --> 00:07:51.180 Again, it's not insanely risky. 00:07:51.180 --> 00:07:52.770 You can quantify the risk. 00:07:52.770 --> 00:07:54.540 The insurance company has. 00:07:54.540 --> 00:07:56.340 But it is riskier. 00:07:56.340 --> 00:07:58.110 OK. 00:07:58.110 --> 00:08:01.800 We have a lot of engineering geniuses in this class and one 00:08:01.800 --> 00:08:04.010 physics genius-- 00:08:04.010 --> 00:08:04.510 science. 00:08:04.510 --> 00:08:05.570 Which one was it? 00:08:05.570 --> 00:08:07.710 AUDIENCE: Brain in cog. 00:08:07.710 --> 00:08:09.830 PHILIP GREENSPUN: That's close enough to physics, 00:08:09.830 --> 00:08:10.600 brain in cog. 00:08:10.600 --> 00:08:14.530 It takes a lot of physics to make your neurons fire. 00:08:14.530 --> 00:08:18.820 Obviously, my neurons aren't firing very well. 00:08:18.820 --> 00:08:22.750 So, what's the limit to a piston engine's power? 00:08:22.750 --> 00:08:27.070 Why is it that we can't get 6,000 horsepower out 00:08:27.070 --> 00:08:28.100 of our piston engine? 00:08:28.100 --> 00:08:29.266 What do you guys think? 00:08:29.266 --> 00:08:30.180 AUDIENCE: Cooling. 00:08:30.180 --> 00:08:31.555 PHILIP GREENSPUN: Cooling is one. 00:08:31.555 --> 00:08:33.400 Sure. 00:08:33.400 --> 00:08:33.970 What else? 00:08:33.970 --> 00:08:36.520 What's fundamentally limiting our ability to produce power? 00:08:36.520 --> 00:08:38.145 Remember, all the power that we produce 00:08:38.145 --> 00:08:44.716 is by burning fuel and oxygen. Aziz? 00:08:44.716 --> 00:08:45.650 AUDIENCE: [INAUDIBLE] 00:08:45.650 --> 00:08:46.870 PHILIP GREENSPUN: Size, yeah. 00:08:46.870 --> 00:08:49.600 I think that's a good insight. 00:08:49.600 --> 00:08:51.790 It's the size of the cylinder. 00:08:51.790 --> 00:08:55.270 You only have so much fuel and air that you can combust. 00:08:55.270 --> 00:08:58.150 And once you've blown all of that up, what do you got? 00:08:58.150 --> 00:08:59.540 Nothing. 00:08:59.540 --> 00:09:02.950 So if you want to know why you should never 00:09:02.950 --> 00:09:04.600 be like the Silicon Valley heroes 00:09:04.600 --> 00:09:07.630 and never hire anybody over the age of 30, 00:09:07.630 --> 00:09:12.370 the inventor of the modern jet engine was only 23 years old, 00:09:12.370 --> 00:09:14.920 I believe, at the time that the patent 00:09:14.920 --> 00:09:16.910 was filed over in England. 00:09:16.910 --> 00:09:21.010 He was a cadet when he conceived of the idea 00:09:21.010 --> 00:09:22.850 at the Royal Air College. 00:09:22.850 --> 00:09:25.090 And he said, well, look, these pistons-- 00:09:25.090 --> 00:09:27.940 no matter how high up you go, no matter what you do, 00:09:27.940 --> 00:09:31.390 all you can ever do is burn the volume of air and fuel 00:09:31.390 --> 00:09:33.980 that's inside the cylinder. 00:09:33.980 --> 00:09:37.810 So, what if we just adapt this gas turbine, which 00:09:37.810 --> 00:09:40.660 has already been invented? 00:09:40.660 --> 00:09:44.530 It was kind of invented in 1791 but not really practical 00:09:44.530 --> 00:09:45.920 to fabricate at the time. 00:09:45.920 --> 00:09:47.920 But look, we're just sucking in all of this air. 00:09:47.920 --> 00:09:51.310 We can probably get 20 times as much air in if we just 00:09:51.310 --> 00:09:53.380 vacuum it in, and suck it into a turbine, 00:09:53.380 --> 00:09:55.250 and then light it on fire. 00:09:55.250 --> 00:09:57.550 So that was the idea, the fundamental insight 00:09:57.550 --> 00:10:00.730 for why a gas turbine is going to be a better machine 00:10:00.730 --> 00:10:03.670 for propelling aircraft. 00:10:03.670 --> 00:10:05.170 He struggled with funding. 00:10:05.170 --> 00:10:08.740 So you can see, the patent was filed in 1930. 00:10:08.740 --> 00:10:16.110 And it was only in 1941 that it finally got flown. 00:10:16.110 --> 00:10:18.110 And that's a good lesson for you entrepreneurs. 00:10:18.110 --> 00:10:20.620 A lot of MIT startups have the characteristic, 00:10:20.620 --> 00:10:23.320 but they're a bit too early. 00:10:23.320 --> 00:10:27.430 I remember, in 1994, I built the world's 00:10:27.430 --> 00:10:30.010 first electronic medical record system that 00:10:30.010 --> 00:10:31.700 had a web interface. 00:10:31.700 --> 00:10:33.700 So that had zero value at the time. 00:10:33.700 --> 00:10:38.620 And about 10 years later, that was a multi-billion dollar 00:10:38.620 --> 00:10:40.510 idea. 00:10:40.510 --> 00:10:44.860 So yeah, Whittle died in relative obscurity in 1996. 00:10:44.860 --> 00:10:47.680 So nobody else liked this idea at the time. 00:10:50.260 --> 00:10:53.120 I'll let you read that quote-- 00:10:53.120 --> 00:10:54.610 not totally wrong, of course. 00:10:54.610 --> 00:10:56.620 Because it did take quite a bit of engineering 00:10:56.620 --> 00:10:58.480 to make it truly practical. 00:10:58.480 --> 00:11:02.950 But that didn't take as long as people thought. 00:11:02.950 --> 00:11:05.620 All right, you saw this figure before. 00:11:05.620 --> 00:11:10.060 This is the modern turbo jet or turbo fan engine, 00:11:10.060 --> 00:11:15.210 where you have this bypass error. 00:11:15.210 --> 00:11:23.220 So the outer ring is devoted to air 00:11:23.220 --> 00:11:25.890 that really never goes through and gets 00:11:25.890 --> 00:11:29.180 burned in the power section. 00:11:29.180 --> 00:11:32.813 And that provides a lot of additional propulsion for not 00:11:32.813 --> 00:11:33.980 a whole lot of extra energy. 00:11:33.980 --> 00:11:37.590 So these are much more efficient than the early pure turbo jet. 00:11:37.590 --> 00:11:41.860 So just to remind you, you have the compressor section, 00:11:41.860 --> 00:11:44.590 where you have air being squeezed. 00:11:44.590 --> 00:11:46.575 Now you introduce some fuel. 00:11:46.575 --> 00:11:49.840 It catches on fire from the extreme heat or the igniters 00:11:49.840 --> 00:11:51.250 if you're just starting up. 00:11:51.250 --> 00:11:53.320 That drives these power turbines. 00:11:53.320 --> 00:11:57.220 And some of the spinning from the power turbines 00:11:57.220 --> 00:12:00.190 goes back to spin the compressor wheels, as well 00:12:00.190 --> 00:12:04.180 as the fan in front, which is kind of like the propeller. 00:12:04.180 --> 00:12:07.913 All right, what about having to turbo jet engines? 00:12:07.913 --> 00:12:10.330 A lot of people like to see two engines on their aircraft, 00:12:10.330 --> 00:12:13.240 especially airline passengers. 00:12:13.240 --> 00:12:16.330 If you have an engine failure, what do you do? 00:12:16.330 --> 00:12:19.840 The answer is, pretty much nothing. 00:12:19.840 --> 00:12:22.690 If it hasn't been done automatically for you already, 00:12:22.690 --> 00:12:25.810 you can advance the thrust levers. 00:12:25.810 --> 00:12:28.090 If the airplane is the yawing, that sometimes 00:12:28.090 --> 00:12:31.870 is automatically corrected for you to a substantial extent 00:12:31.870 --> 00:12:33.460 by the yaw damper. 00:12:33.460 --> 00:12:35.710 You will step on the rudder to do the natural thing 00:12:35.710 --> 00:12:39.950 and bring the nose back pointed to where you want it pointed. 00:12:39.950 --> 00:12:42.070 And you'll keep climbing nicely. 00:12:42.070 --> 00:12:44.525 You've arranged everything both in terms 00:12:44.525 --> 00:12:46.900 of the design of the aircraft and the weight at which you 00:12:46.900 --> 00:12:51.250 took off so that, no matter the environmental conditions, 00:12:51.250 --> 00:12:52.630 you will be able to climb. 00:12:52.630 --> 00:12:54.720 And you will be able to clear the obstacles. 00:12:54.720 --> 00:12:55.720 This can be a challenge. 00:12:55.720 --> 00:12:58.150 If you're taking off out of a mountainous, high altitude, 00:12:58.150 --> 00:13:01.630 hot airport, you're not going to have a full load of fuel 00:13:01.630 --> 00:13:04.408 and a full load of people and bags. 00:13:04.408 --> 00:13:05.950 But by regulation, you're going to be 00:13:05.950 --> 00:13:09.910 able to clear the terrain safely even on one engine. 00:13:09.910 --> 00:13:11.840 Why is it so much easier? 00:13:11.840 --> 00:13:14.950 You don't have a propeller that'll drag back a wing. 00:13:14.950 --> 00:13:19.870 And therefore, there's no urgency about feathering. 00:13:19.870 --> 00:13:23.350 You also have a little bit less of the crazy yaw. 00:13:23.350 --> 00:13:26.410 Because the engines are, in some aircraft, pretty 00:13:26.410 --> 00:13:29.050 close to the fuselage. 00:13:29.050 --> 00:13:32.830 So basically, you can still apply that cardinal rule 00:13:32.830 --> 00:13:34.270 of flying jets. 00:13:34.270 --> 00:13:37.000 If the switch has dust on it, don't touch it. 00:13:37.000 --> 00:13:42.028 So you don't have to take immediate action. 00:13:42.028 --> 00:13:43.570 All right, if it's turbo jet powered, 00:13:43.570 --> 00:13:46.600 though, you do need specific training. 00:13:46.600 --> 00:13:51.700 And you have to pass a check ride specific to that aircraft. 00:13:51.700 --> 00:13:54.190 So most of you guys, except for Francis, 00:13:54.190 --> 00:13:57.940 believe that Captain Sully was all by himself in the A320. 00:13:57.940 --> 00:14:01.720 but actually, anything that's more than about a 10 seater 00:14:01.720 --> 00:14:03.520 almost always requires two pilots. 00:14:03.520 --> 00:14:05.830 And according to the type certificate, 00:14:05.830 --> 00:14:10.060 it's not even legal to operate even the larger business 00:14:10.060 --> 00:14:12.970 jets with one pilot. 00:14:12.970 --> 00:14:20.340 There is an old FAR 91.5, I believe, 00:14:20.340 --> 00:14:24.730 that says there has to be a proficiency check annually 00:14:24.730 --> 00:14:28.930 for the pilot in command of a two-pilot aircraft. 00:14:28.930 --> 00:14:31.210 And more recently, the regulations 00:14:31.210 --> 00:14:34.040 were updated for single-pilot turbo jets 00:14:34.040 --> 00:14:36.560 so that a check ride has to be done annually, 00:14:36.560 --> 00:14:39.307 which is not really that different from the insurance 00:14:39.307 --> 00:14:40.640 requirements of annual training. 00:14:40.640 --> 00:14:42.730 They just made it a little more formalized 00:14:42.730 --> 00:14:44.830 with FAA bureaucracy. 00:14:44.830 --> 00:14:46.960 All right, turbo jets that you might own-- 00:14:46.960 --> 00:14:50.350 the single pilot business jet with a straight wing-- 00:14:50.350 --> 00:14:52.150 they said initially, the Cessna Citation 00:14:52.150 --> 00:14:54.760 was so slow that birds were hitting it from behind. 00:14:57.790 --> 00:15:00.700 But sometimes safety and having it 00:15:00.700 --> 00:15:03.610 be easy to operate by people of ordinary skill 00:15:03.610 --> 00:15:06.010 and people of lower skill levels is better than 00:15:06.010 --> 00:15:08.410 getting that last 50 knots of speed. 00:15:08.410 --> 00:15:10.930 And that's what Cessna figured out. 00:15:10.930 --> 00:15:12.910 So they're still kind of a leader in this area. 00:15:12.910 --> 00:15:15.310 They produced the Cessna Mustang, which 00:15:15.310 --> 00:15:18.530 you see there at the right. 00:15:18.530 --> 00:15:20.900 Some of the Microsoft folks, they spun off 00:15:20.900 --> 00:15:22.360 a design called the Eclipse. 00:15:22.360 --> 00:15:25.390 It was supposed to have these new cruise-missile-inspired 00:15:25.390 --> 00:15:27.540 engines from Williams. 00:15:27.540 --> 00:15:28.540 The engines didn't work. 00:15:28.540 --> 00:15:31.030 So the 1500 nautical mile airplane 00:15:31.030 --> 00:15:35.350 became a 900 nautical mile airplane with a Pratt & Whitney 00:15:35.350 --> 00:15:36.730 more conventional designed engine 00:15:36.730 --> 00:15:39.100 that's used on some of these other designs. 00:15:39.100 --> 00:15:41.500 The Embraer Phenom 100 has the same engines 00:15:41.500 --> 00:15:44.050 essentially as the Mustang, same family. 00:15:44.050 --> 00:15:45.640 HondaJet has an innovative engine 00:15:45.640 --> 00:15:48.430 designed by GE and Honda. 00:15:48.430 --> 00:15:51.100 These have all pretty much been business failures. 00:15:51.100 --> 00:15:56.830 And the answer to that is the fixed costs of jet ownership 00:15:56.830 --> 00:16:02.600 are so high you can't just get a T hangar for $800 a month. 00:16:02.600 --> 00:16:06.870 You may have to pay at one of the busier airports 00:16:06.870 --> 00:16:11.260 $40,000 a year to have an FBO hangar it for you. 00:16:11.260 --> 00:16:14.620 The insurance company will require simulator training 00:16:14.620 --> 00:16:15.280 annually. 00:16:15.280 --> 00:16:18.190 And you'll probably have to have two pilots 00:16:18.190 --> 00:16:20.920 as a practical matter go through training. 00:16:20.920 --> 00:16:23.170 Insurance will be expensive, because the whole value 00:16:23.170 --> 00:16:23.710 is high. 00:16:23.710 --> 00:16:25.990 If you wreck a $5 million airplane or a $10 million 00:16:25.990 --> 00:16:29.860 airplane, that's a bad day for the insurance company. 00:16:29.860 --> 00:16:34.450 You get charged a lot more for landing fees 00:16:34.450 --> 00:16:36.190 and parking at airports. 00:16:36.190 --> 00:16:39.483 When you're a little Cessna, they give you a break, 00:16:39.483 --> 00:16:41.900 because they don't want you saying anything bad about them 00:16:41.900 --> 00:16:43.550 on airnav.com. 00:16:43.550 --> 00:16:45.170 But if you show up in a Gulfstream, 00:16:45.170 --> 00:16:49.880 they figure you probably have a credit card somewhere. 00:16:49.880 --> 00:16:52.100 So yeah, the Mustang, they actually 00:16:52.100 --> 00:16:53.930 stopped production of that plane. 00:16:53.930 --> 00:16:56.810 The Phenom 100 is still going from Embraer. 00:16:56.810 --> 00:17:02.320 But basically, I think the Phenom 300 is-- 00:17:02.320 --> 00:17:04.349 it holds about nine or 10 people. 00:17:04.349 --> 00:17:07.790 And I think it weighs somewhere in the 15,000 to 20,000 00:17:07.790 --> 00:17:10.180 pound range. 00:17:10.180 --> 00:17:12.349 At gross, those are the airplanes 00:17:12.349 --> 00:17:15.095 that seem to be popular. 00:17:15.095 --> 00:17:18.829 The Phenom 300 is about $9 million new. 00:17:18.829 --> 00:17:22.650 And $3 to $5 million used applies, including 00:17:22.650 --> 00:17:24.349 the things like the Cessna CJ3. 00:17:24.349 --> 00:17:28.339 A $3 million plane could be a CJ3. 00:17:28.339 --> 00:17:30.590 All right, what about single-engine jets? 00:17:30.590 --> 00:17:35.305 The problem is they're more vulnerable to engine failure. 00:17:35.305 --> 00:17:36.680 Jet engines are a little bit more 00:17:36.680 --> 00:17:40.010 vulnerable to failure from, say, a bird strike or something 00:17:40.010 --> 00:17:41.090 than a piston engine. 00:17:41.090 --> 00:17:45.410 And therefore, you need some way of dealing with the consequence 00:17:45.410 --> 00:17:47.330 of having that engine fail. 00:17:47.330 --> 00:17:49.800 The Cirrus jet is pretty slow. 00:17:49.800 --> 00:17:51.950 So it could actually be landed off the airport, 00:17:51.950 --> 00:17:56.010 perhaps, without too much damage. 00:17:56.010 --> 00:17:57.470 But it has a parachute in case. 00:17:57.470 --> 00:18:01.130 And F-16 and other fighter jets that are single engine, 00:18:01.130 --> 00:18:03.920 they obviously have ejection seats. 00:18:03.920 --> 00:18:07.080 Twin turboprops-- let's talk about those. 00:18:07.080 --> 00:18:09.870 So if you want to land on a short runway-- 00:18:09.870 --> 00:18:14.093 we talked about turboprop engines, I think, on day one. 00:18:14.093 --> 00:18:16.010 They can produce a tremendous amount of power. 00:18:16.010 --> 00:18:18.363 So you can have a much bigger, heavier airplane. 00:18:18.363 --> 00:18:20.030 But because they're driving a propeller, 00:18:20.030 --> 00:18:21.488 you get to take off and land short. 00:18:21.488 --> 00:18:26.790 They developed thrust very effectively at low speeds. 00:18:26.790 --> 00:18:29.930 And the prop is a huge drag, so when you land, 00:18:29.930 --> 00:18:33.110 it kind of slows down and stops immediately 00:18:33.110 --> 00:18:34.730 or almost immediately. 00:18:34.730 --> 00:18:40.243 So the King Air from 1964 to the present 00:18:40.243 --> 00:18:41.660 with these Pratt & Whitney engines 00:18:41.660 --> 00:18:46.790 that were developed in the very end of the '50s, the PT6. 00:18:46.790 --> 00:18:49.220 Those have been hugely popular. 00:18:49.220 --> 00:18:51.870 When you hit a bird, it's a problem for the bird 00:18:51.870 --> 00:18:55.970 but not usually for the propeller. 00:18:55.970 --> 00:19:01.100 The King Airs and this ATR, have an auto-feather system. 00:19:01.100 --> 00:19:03.350 If one engine loses power, the propeller 00:19:03.350 --> 00:19:06.890 will automatically go to this knife-edge configuration. 00:19:06.890 --> 00:19:08.810 I should have said what feathering is. 00:19:08.810 --> 00:19:10.220 You twist the propeller blades so 00:19:10.220 --> 00:19:14.250 that they're edge to the wind instead of flat to the wind. 00:19:14.250 --> 00:19:19.700 So you dramatically reduce the drag of the propeller. 00:19:19.700 --> 00:19:22.940 So that airplane actually took care of itself 00:19:22.940 --> 00:19:25.400 or should have taken care of itself pretty well. 00:19:25.400 --> 00:19:27.200 You can read about that crash. 00:19:27.200 --> 00:19:29.820 I think it was in Taiwan. 00:19:29.820 --> 00:19:32.300 But the pilots decided to take heroic, immediate action-- 00:19:32.300 --> 00:19:34.160 or at least, one of the pilots did-- 00:19:34.160 --> 00:19:38.180 and shut down the good engine instead of just leaving 00:19:38.180 --> 00:19:40.380 well enough alone. 00:19:40.380 --> 00:19:42.640 OK, single-engine turboprops-- as these engines 00:19:42.640 --> 00:19:44.650 got more refined and more reliable, 00:19:44.650 --> 00:19:47.370 if you look at the PT6 design, it 00:19:47.370 --> 00:19:49.510 has all kinds of tubes, and hoses, 00:19:49.510 --> 00:19:52.930 and vacuum going from one place to another and bleed air. 00:19:52.930 --> 00:19:55.480 You'd be surprised that it's as reliable as it is. 00:19:55.480 --> 00:19:58.270 But they supposedly don't really have 00:19:58.270 --> 00:20:03.250 to be shut down for a problem or fail more than about 00:20:03.250 --> 00:20:06.380 once every 300,000, 400,000, or 500,000 hours. 00:20:06.380 --> 00:20:13.570 So after that insight, people said, let's just 00:20:13.570 --> 00:20:14.830 put one of them in. 00:20:14.830 --> 00:20:17.020 And we don't need that second engine. 00:20:17.020 --> 00:20:18.990 It'll save a ton of money. 00:20:18.990 --> 00:20:21.250 So the Cessna Caravan is a great example of that. 00:20:21.250 --> 00:20:23.980 That's that sort of boxy cargo plane 00:20:23.980 --> 00:20:27.490 that you saw on floats in the other video. 00:20:27.490 --> 00:20:29.650 For personal planes that are pressurized 00:20:29.650 --> 00:20:34.410 and more comfortable, the Piper Meridian, which is down here-- 00:20:34.410 --> 00:20:39.100 this is my friend Arnold, who is at Hanscom. 00:20:39.100 --> 00:20:42.670 He says he funded his airplanes, because he 00:20:42.670 --> 00:20:47.210 was practicing during the golden age of gynecology. 00:20:47.210 --> 00:20:49.390 And that's what enabled him to afford 00:20:49.390 --> 00:20:54.060 his fancy, pressurized Pipers. 00:20:54.060 --> 00:20:56.470 The TBM is a French design that's 00:20:56.470 --> 00:20:59.090 considerably preferred to the Piper, 00:20:59.090 --> 00:21:00.790 but it's a lot more expensive. 00:21:00.790 --> 00:21:03.640 And the Swiss Pilatus PC-12 is kind 00:21:03.640 --> 00:21:06.640 of a good airplane for a mixture of family use and charter use. 00:21:06.640 --> 00:21:11.470 The Piper and the TBM are too small to justify all 00:21:11.470 --> 00:21:13.270 the machinery around charter. 00:21:16.360 --> 00:21:18.490 All right, so actually, old King Airs 00:21:18.490 --> 00:21:20.600 are cheaper than these single-engine airplanes, 00:21:20.600 --> 00:21:22.620 but they cost a little more to run. 00:21:22.620 --> 00:21:24.370 All right, when you're maintaining a jet-- 00:21:24.370 --> 00:21:25.930 I think I mentioned this earlier-- 00:21:25.930 --> 00:21:29.950 the manufacturer's guidance will supersede those catch-all rules 00:21:29.950 --> 00:21:35.170 of a 100-hour inspection for an airplane operated commercially 00:21:35.170 --> 00:21:39.490 or the annual inspection for an airplane operated privately. 00:21:39.490 --> 00:21:40.750 It can get expensive. 00:21:40.750 --> 00:21:42.790 On one of those Cessna Citation jets 00:21:42.790 --> 00:21:45.760 that I mentioned, coming out with $100,000 00:21:45.760 --> 00:21:51.040 bill from the annual would not be unexpected. 00:21:51.040 --> 00:21:56.935 You usually have a time limit on the whole airframe. 00:21:56.935 --> 00:21:59.140 And if it's pressurized, it's getting 00:21:59.140 --> 00:22:00.880 expanded and contracted, expanded 00:22:00.880 --> 00:22:03.310 and contracted and a little bit of metal fatigue 00:22:03.310 --> 00:22:04.030 on every flight. 00:22:04.030 --> 00:22:06.170 So you may have a limit on the number of cycles, 00:22:06.170 --> 00:22:08.140 the number of times that's happened, 00:22:08.140 --> 00:22:10.220 and also on the number of hours. 00:22:10.220 --> 00:22:15.380 So a 12,000-hour or 20,000-hour airframe life limit might be 00:22:15.380 --> 00:22:15.880 common. 00:22:15.880 --> 00:22:18.510 For the Pilatuses, it's 20,000 hours. 00:22:18.510 --> 00:22:20.260 And then they have life extension programs 00:22:20.260 --> 00:22:23.410 where they tear the whole thing apart and replace 00:22:23.410 --> 00:22:26.410 some structures or, at least, look at every structure. 00:22:26.410 --> 00:22:29.860 People have extended them out to about 32,000 hours, I think, 00:22:29.860 --> 00:22:31.420 now. 00:22:31.420 --> 00:22:33.590 There's cycle limits, also, on the jet engines. 00:22:33.590 --> 00:22:37.150 So the turbine blades and stuff and disks, every time 00:22:37.150 --> 00:22:38.860 they're started and shut down, there's 00:22:38.860 --> 00:22:40.570 a huge amount of thermal cycling. 00:22:40.570 --> 00:22:43.810 So they say, look, after you've done that 15,000 times, 00:22:43.810 --> 00:22:45.400 you got to throw that wheel out. 00:22:45.400 --> 00:22:50.830 And that wheel inside the turboprop could be $100,000. 00:22:50.830 --> 00:22:53.170 If you guys ever-- 00:22:53.170 --> 00:22:55.630 it may seem hard to believe now that MIT has stripped you 00:22:55.630 --> 00:22:57.700 of all of your savings, but if you 00:22:57.700 --> 00:23:00.190 do have a little bit of money at some future date 00:23:00.190 --> 00:23:02.860 and you want to get a type rating for your airplane, 00:23:02.860 --> 00:23:04.510 by far the cheapest type rating you 00:23:04.510 --> 00:23:07.732 get will be for a big airplane. 00:23:07.732 --> 00:23:09.190 So it turns out, if you want to pay 00:23:09.190 --> 00:23:11.320 flight safety for the Gulfstream rating, 00:23:11.320 --> 00:23:14.020 or a Cessna Mustang rating, or whatever, 00:23:14.020 --> 00:23:15.170 those are pretty expensive. 00:23:15.170 --> 00:23:16.990 They're relatively rare. 00:23:16.990 --> 00:23:20.500 Boeing 737s and Airbus A320s, so many 00:23:20.500 --> 00:23:25.030 were made that there's just a wide variety of simulators 00:23:25.030 --> 00:23:25.960 all over the world. 00:23:25.960 --> 00:23:32.200 And for about $10,000, you can jump in and get your instrument 00:23:32.200 --> 00:23:36.700 proficiency back up to snuff, as well as have a lot of fun. 00:23:36.700 --> 00:23:39.610 All right, so as a summary, it's a good challenge 00:23:39.610 --> 00:23:42.100 to get that multi-engine rating. 00:23:42.100 --> 00:23:45.190 I wouldn't recommend practicing it 00:23:45.190 --> 00:23:47.920 unless you have an unusual application, like you 00:23:47.920 --> 00:23:49.630 live in the Caribbean, and you want 00:23:49.630 --> 00:23:50.850 to get from island to island. 00:23:53.560 --> 00:23:57.180 If you're nervous and somebody says, 00:23:57.180 --> 00:24:01.000 I don't feel comfortable depending on this 00:24:01.000 --> 00:24:06.790 five-year-old, 1,000-hour piston engine that's in front of us, 00:24:06.790 --> 00:24:10.150 the answer I think these days is it's better to get an airplane 00:24:10.150 --> 00:24:14.710 that has a ballistic parachute as your backup than to have 00:24:14.710 --> 00:24:17.320 the second engine as a backup. 00:24:17.320 --> 00:24:21.910 And while you're formulating your questions, I'll show you. 00:24:21.910 --> 00:24:24.490 On the top left is a French design. 00:24:24.490 --> 00:24:26.506 That's called a Cri-Cri. 00:24:26.506 --> 00:24:27.940 It seats one person. 00:24:27.940 --> 00:24:29.555 And it's, I believe, fully aerobatic. 00:24:29.555 --> 00:24:31.930 So you can do all kinds of crazy maneuvers in the Cri-Cri 00:24:31.930 --> 00:24:33.130 if you want. 00:24:33.130 --> 00:24:36.280 Each of those engines might be only 30 horsepower or 15. 00:24:36.280 --> 00:24:37.870 You can look it up. 00:24:37.870 --> 00:24:39.820 It's a truly crazy design. 00:24:39.820 --> 00:24:44.577 Here is an AirCam that's an open cockpit. 00:24:44.577 --> 00:24:45.910 Although, this one has a canopy. 00:24:45.910 --> 00:24:48.790 That's from the Oshkosh seaplane base, a great airplane 00:24:48.790 --> 00:24:53.860 for flying low and slow over remote, somewhat wet locations. 00:24:53.860 --> 00:24:58.180 Here's an L-39 Czech military trainer. 00:24:58.180 --> 00:24:59.620 And there's a company called-- 00:24:59.620 --> 00:25:01.330 I think it was called Code 1 Aviation. 00:25:01.330 --> 00:25:03.310 They had that at Oshkosh, where they 00:25:03.310 --> 00:25:06.910 took a regular American business jet engine out of a Hawker, 00:25:06.910 --> 00:25:09.400 and they stuffed it into the L-39 00:25:09.400 --> 00:25:12.010 because it's cheaper to operate and maintain it 00:25:12.010 --> 00:25:15.770 as a lower fuel burn than the military engines. 00:25:15.770 --> 00:25:18.670 So you end up getting a lot longer range out of your L-39 00:25:18.670 --> 00:25:19.780 if you want to-- 00:25:19.780 --> 00:25:22.030 those L-39s are only a couple hundred thousand dollars 00:25:22.030 --> 00:25:22.720 for a nice one. 00:25:22.720 --> 00:25:25.360 So you can actually own a jet that's fully aerobatic, 00:25:25.360 --> 00:25:26.950 and cool, and look like-- people will 00:25:26.950 --> 00:25:32.050 think it's an F-16 for less money than buying a Cirrus. 00:25:32.050 --> 00:25:34.380 On the left is the ramp at Teterboro. 00:25:34.380 --> 00:25:37.390 I said I was talking about it. 00:25:37.390 --> 00:25:39.265 If you're working for Bernie Sanders 00:25:39.265 --> 00:25:41.140 and you want to start a revolution in the US, 00:25:41.140 --> 00:25:43.690 I would recommend starting it right at the Teterboro 00:25:43.690 --> 00:25:46.055 airport and just film the people getting in and out 00:25:46.055 --> 00:25:46.930 of their Gulfstreams. 00:25:46.930 --> 00:25:47.805 And this is Meridian. 00:25:47.805 --> 00:25:51.820 This is the lowest-cost FBO at Teterboro. 00:25:51.820 --> 00:25:53.770 And that's what the ramp looks like. 00:25:53.770 --> 00:25:57.520 If you want to combine two piston engines in a jet, 00:25:57.520 --> 00:26:03.250 I believe each of these of is a Yak-55. 00:26:03.250 --> 00:26:07.930 And some airshow performer at Oshkosh glued them together 00:26:07.930 --> 00:26:14.700 and put a jet engine in the middle and calls it a Yak-110. 00:26:14.700 --> 00:26:15.660 So there you have it. 00:26:15.660 --> 00:26:18.047 That combines everything from this talk. 00:26:18.047 --> 00:26:18.630 Any questions? 00:26:18.630 --> 00:26:21.340 Or should we jump right into night? 00:26:21.340 --> 00:26:23.410 Who wants to fly a jet? 00:26:23.410 --> 00:26:26.818 Excellent. 00:26:26.818 --> 00:26:29.746 AUDIENCE: So you said Cessna Caravans are single engine. 00:26:29.746 --> 00:26:32.109 I know they fly those commercially in Hawaii 00:26:32.109 --> 00:26:33.075 island to island. 00:26:33.075 --> 00:26:34.880 How do you think they justify that? 00:26:34.880 --> 00:26:35.838 PHILIP GREENSPUN: Yeah. 00:26:35.838 --> 00:26:40.030 The question is, is it OK to fly a single engine over water 00:26:40.030 --> 00:26:46.135 in Hawaii in a Cessna Caravan with only one engine? 00:26:46.135 --> 00:26:51.550 Well, first of all, the last crash of a Caravan in Hawaii 00:26:51.550 --> 00:26:54.430 from an engine failure, they operated it just a few hours 00:26:54.430 --> 00:26:58.240 beyond the manufacturer's TBO under a special program 00:26:58.240 --> 00:26:59.635 they had approved by the FAA. 00:26:59.635 --> 00:27:02.560 They were not doing anything illegal. 00:27:02.560 --> 00:27:04.690 Everybody survived the crash. 00:27:04.690 --> 00:27:05.860 One person was killed. 00:27:05.860 --> 00:27:08.890 Does anybody remember who was killed in that crash, 00:27:08.890 --> 00:27:12.510 and what was special about that person? 00:27:12.510 --> 00:27:14.010 AUDIENCE: It was a flight attendant. 00:27:14.010 --> 00:27:15.718 PHILIP GREENSPUN: Not a flight attendant. 00:27:15.718 --> 00:27:22.520 It was a woman who was a state of Hawaii employee. 00:27:22.520 --> 00:27:25.250 What was special about her? 00:27:25.250 --> 00:27:28.820 She was the person who certified Barack Obama's birth 00:27:28.820 --> 00:27:29.930 certificate as genuine. 00:27:32.510 --> 00:27:34.970 Think about that. 00:27:34.970 --> 00:27:37.670 So anyway, if you really open up the PT6 00:27:37.670 --> 00:27:40.170 and the manually would say, no, I'm not going to allow this. 00:27:40.170 --> 00:27:41.128 And I think in Europe-- 00:27:41.128 --> 00:27:44.510 Europe wouldn't even allow a single-engine charter IFR 00:27:44.510 --> 00:27:46.620 until just a year or two ago. 00:27:46.620 --> 00:27:48.740 They said, no, this is too much. 00:27:48.740 --> 00:27:50.530 So I don't know. 00:27:50.530 --> 00:27:51.840 It's a balancing of risk. 00:27:51.840 --> 00:27:54.320 I don't think it's an unacceptable risk. 00:27:54.320 --> 00:27:58.100 People with Pilatuses, they will go back and forth to Europe 00:27:58.100 --> 00:28:00.980 regularly as individuals. 00:28:00.980 --> 00:28:04.140 But yeah, maybe there should be a warning to passengers. 00:28:04.140 --> 00:28:05.330 We only got one engine. 00:28:05.330 --> 00:28:07.510 Thanks for buying a ticket.