Do your seats have some kind of suspension?

I flew into Denver last week and the pilot announced that they were expecting a lot of turbulence. He wasn't lying and as we were descending to land there were several times where the plane lurched and I got that feeling in my stomach. I was reading and had to stop both because of motion sickness and because I actually couldn't hold the book steady enough to read. I would say 3 or 4 of the bumps were far worse than anything I've ever done in a car, despite my share of teens-and-early-20s-male driving.

I actually thought it was pretty fun, though I could have done without feeling sick to my stomach for a few hours. It occurred to me that if I were driving and got tossed like that there'd be no way I could maintain control of the car and that could well be the case for the pilot. This made me wonder if you at least have a seat with suspension or something to stabilize you in turbulence. Even then, the controls are going to be shaking with the plane.

Could you talk about what training you do and steps you take to deal with turbulence so you don't lose control going through it? Any stories you have about it would be interesting.

apologies if this has already been answered but now that they've been busted and fined or whatever they are gonna try and reinstate their licenses - do you think they will succeed?

This apparently happened this weekend.

http://www.ny1.com/8-queens-news-con...e-into-cockpit

Solar powered plane article

Wow, didn't know it had a name. Thanks!

Is it possible to open the emergency exit door (let's say a passenger wants to cause mischief) while at cruising altitude, or are they 'locked'? If so, what would happen (other than, I assume, instant depressurization of the cabin)? Would it have any effect on the flyability of the airplane? How long would passengers have to put on their oxygen masks before being unable to breathe because of the altitude, and if a passenger's mask wasn't working, would a pilot have enough time to descend to a safe altitude for unassisted breathing before the passenger passed out or suffered some other negative effect?

Ever heard of (or read) Touching History? It's the story of what unfolded on 9/11 from the perspective of everyone in the aviation world, from ATC to FAA to DOD to other pilots flying that day, etc. Only heard about it yesterday, bought it on Kindle today and finished half of it; fastest I can remember getting through a book in a long time; really interesting read and I'm sure you'd find it interesting with your background. One claim that I remember hearing about after 9/11, but which never really got much attention in the media (despite its bombshell implications) is that there were 4 Arab men in first class on United Flight 23, a JFK-LAX 767 (hijacked planes were 767's) that was queued for takeoff on 9/11 before the nationwide grounding was announced, who became very agitated when their flight was canceled, and authorities later found copies of the Koran, al-Qaeda docs and box-cutters in the carry-on luggage they left behind. Sounds sensational, but it appeared in a fair amount of media sources, so wonder why we never heard much about it.

.

thx

It's not possible, due to the differential pressure (PSID). A typical cabin will have a PSID of anywhere from 6.5 to 8.5 lbs/sq. in. Emergency exit doors will vary in size, but typical dimensions are in the neighborhood of 20"x30", which is 600 sq. in. At the low end of the PSID above, this would be a force of 3900 lbs holding the door closed.

But if you could open it, this would result in a rapid decompression. The masks would fall and everyone should be ok. Flyability would not be affected and the pilots could descend to breathable altitudes (<15,000') in just a few minutes.

I haven't heard of this book, but I'll put it on my list. That's very interesting about Flight 23...I hadn't heard that either. It's very believable though.

A few months ago, I somehow received the following narrative of what happened on that flight. I can't personally vouch for the authenticity of this, but it's supposedly the story that the Captain related to a friend (who then wrote this account). It all sounds very plausible to me. I have bolded a couple of critical factors leading to the overflight.

From my observations of the guys I fly with, I would say I'm above average...literally (i.e. in the top 50%). But anyone can have a bad landing and I told of my worst one previously itt, flying the MD-88 into LGA. It wasn't pretty.

I had 4 great landings today...in a Cessna 172. I went out to Leesburg and rented a small plane just to stay current in them (actually, I was technically out of currency; my last landings in a light plane were on December 16). But the weather conditions were perfect today and with the slow approach speeds of a Cessna, I feel like I can almost walk it down to a nice landing.

Two things that really increase the chances of a 'greaser': wet runway or snow covered runway. For some reason, both conditions have a great cushioning effect.


We have "Bitching Betty" calling out altitudes in the 767 ("100", "50", "40, "30", "20", "10"), and some pilots will ask the other guy to call out the radio altitudes below ten feet as it counts down to zero (by twos, for some reason). But while this is a help to some guys, it doesn't guarantee anything and sometimes you'll see -2 before touchdown.

Just recently, flying into Ontario, CA, the Captain asked me to make callouts for him. He slammed it on and as we exited the runway I told him that it was probably my fault for calling out the altitudes too fast.

I don't use callouts myself. I find it distracting and it's easier for me to just find the runway on my own.

I think most of us land with one hand on the yoke and one on the throttles unless it's very gusty.

Just FYI, after having torn throuhg 75% of this book in 24 hours, I can comfortably suggest that you will really enjoy this book. Half of the material to this point consists of in-cockpit conversations among pilots and between pilots and ATC. Just a sampling of what's so tense about the account: no one really knew the extent of anything on 9/11 (i.e. just how many hijacked planes were there?), so every airliner was considered a threat; as such, pilots weren't getting any information about what had happened that day either from ATC or their company's dispatch except instructions which, at that point in history, were unprecedented (i.e. divert, land immediately, armed F-16's appearing out of nowhere on their tails). Very tense throughout. I think you'll enjoy it. Really well-written I've found too.

what avation apps do you use on your iphone? also any general app recommendations? just got an ipod touch with pokerstars fpps

This has been a big sore spot with pilots and I have to agree with the general consensus. What could have been the possible downside of a message to airborne crews to lock down the cockpit, i.e. to not allow access under any circumstances (which was not part of our training in dealing with a hijacking)?

Worst case: the cockpit was already in the hands of hijackers. So what? Does that message somehow empower them?

I'm kind of a lightweight in this regard. I have only 2 aviation apps: AeroWeather, which shows airport METAR and TAF reports (in raw form and also plain English), and NextFlight, which shows all the flights, including status, for all airlines between a city pair (for both today and tomorrow).

Other apps I use:

ACTCurrency and Currency - both are money conversion apps
Yelp - outstanding for finding almost anything you need nearby
Calc 11c - emulates an HP 11c calculator (a little geeky)
Dictionary
Skype
MetrO - shows public transportation routes and stations for every city
TWC - The Weather Channel
Wi-Fi Finder
iDisk - to access my MobileMe iDisk

Bet you also don't miss JK, right?

I know Air Canada used to let their Aeroplan members take 45min "trips" in the flight simulators with an Air Canada pilot. You had to cash in points for it though.

I searched my local library's web site and they have it, so I've put it on request. Thanks for the tip.

Good point, but it seemed too common to me.
I went for the more obscure.

BTW, I don't really see CAVU anymore...now it's always CAVOK. I guess "unlimited" visibility is a thing of the past.

I apologize if this has been asked before (im only on page 75 of this thread ) but my 3 questions are:

If planes have "reverse" why do they need a tug to push back from the gate? I remember being in dallas a few years ago and I remember seeing the Super 80 pop the engines in reverse and he pulled out of the gate alone. Ive never seen it happen again...

My second question is:
Why is it that after takeoff you feel like the pilot pulls out half throttle (and then sometimes puts some more power back in). Since your looking to climb to a reasonable flight level (and since you are moving A LOT of weight from 0 to 500MPH) doesn’t it make sense to keep most the power in until your at cruise?

my last question is: Since turbos have shown to be so useful for cars/semis/boats etc. How come they are not being used for airplane engines?

thanks in advance. You are doing an AWESOME job keeping up with all the questions and I for one GREATLY appreciate it. Its nice to find somebody who is willing to share his knowledge with others!

NorthWest used to do it with their DC-9s at their hubs fairly frequently. There are several reasons why tugs are used more often:

1) Foreign Object Damage -- the engines need to be spooled up quite high to produce enough thrust to move the plane back and it will gobble up any loose trash that accumulates near the terminal. Engines don't like anything that isn't air getting sucked up.

2) Compressor Stalls -- high power and zero forward speed is not the way the fans were designed to operate. This would affect some aircraft type more than others

3) It is probably cheaper in terms of fuel to use a tug

4) Planes don't have rear view mirrors.

5) Enthusiastic braking could stand the plane on its tail.

Well, actually, turbochargers were in aircraft way before cars. Many WWII era aircraft were turbocharged, like the B-17 and P-47. Superchargers were more common because the size of the tubes associated with the turbos was a problem and no one cared about fuel efficiency back then. Early gas turbine engines were essentially just glorified turbochargers.

I believe that some modern piston-aircraft still use turbos if they are designed for high altitude flight, but I don't know much about which ones.

They don't. But most airlines don't allow this practice for safety reasons. American Airlines was one that did it for a while and only on the MD-80 aircraft to my knowledge. I haven't seen it done by them in many years, so it may be a practice they finally stopped. (If so, this may have been a decision based solely on rising fuel costs, or it might be they had an incident or two. I don't know.)

The safety considerations involved in powering back: (1) the thrust itself will blow loose objects (or baggage carts) around; (2) the crew cannot see where the airplane is going and is completely dependent on ground personnel for ensuring the operation is safe; and (3) applying brakes while going backward can, if they are applied suddenly or with great force, cause the plane's tail to strike the ground (the CG is somewhere forward of the main landing gear; brake application, coupled with the plane's momentum, will cause a pivot about that CG, raising the nose and lowering the tail).

Although it's not half throttle, we do reduce power after climbing to a safe altitude, usually about 1000' AGL (sometimes referred to as "acceleration height" because we lower the nose slightly to speed up at this point). This power reduction prolongs the life of these extremely expensive engines while still delivering the climb performance we need.

We usually don't even takeoff at full power (unless we have ice protection on or there is windshear in the vicinity or the weight of the plane requires it). We use a reduced thrust takeoff power setting, designed to provide single engine climb performance (in case of an engine failure) for our takeoff weight, density altitude, runway length and winds. When using this reduced power setting, we still reduce even further upon reaching acceleration height.

Ah, but they are! However, this is strictly a piston engine thing. A normally aspirated piston engine will start pooping out somewhere above 10,000' due to the lower air density (and thus less oxygen for the engine to use). A turbo-charger is a small compressor that provides the engine with denser air and allows it to perform as if it's still down near sea level. (That's why jets don't have turbo-chargers; a jet engine has a compressor which does the job of providing dense air to the combustion chamber. In a sense, every jet engine is "turbo-charged.")

My old Turbo Arrow, N36067, would give sea level performance up to altitudes higher than I would fly it (because we didn't have supplemental oxygen on board). Where a normally aspirated Arrow might only go up to 13-14,000', the Turbo Arrow could get to the low 20's. I rarely flew our Arrow above 12,500', but it was nice to have the performance there; in a normally aspirated Arrow, it would be a struggle just to claw your way up to that altitude.


You're welcome, but I'll take this opportunity to state again that the "facts" included in this thread are often kind of "off the cuff" and may, in some cases, even by tainted by opinion or faulty memory.

Well, I should have read this before responding. You've covered just about everything I mentioned.

I finally read the book...finished it yesterday. Very well written and informative. Makes me wonder how any of the conspiracy theorists can cling to their belief that it wasn't a plane that struck the Pentagon.

crosspost from Golf subforum. Hoping your aerodynamic knowledge can help answer this question. Thanks!

You just leased Iron Byron, the mechanical golf hitting machine that will give you a nearly identical shot again and again.

It's clear in the first part of the afternoon, and Mr. Byron hits 5 perfectly solid PWs averaging 125 on the dot.

Two hours later there's a brisk 20 mph wind and you set Mr. Byron directly downwind and hit five more and averages _____ yards

Then, you set up Mr. Byron directly into the wind and hit five more, resulting in an average of ______ yards

So here's the issue. It seems like a headwind hurts your shot's distance more than an equal tailwind helps you. I'm pretty sure you have to be a serious golfer to notice this slight difference, but I'm wondering if anyone with a physics background can help me to understand.

If I had to guess, I'd say it has to do with the lift generated as the ball goes through the air. Sort of like how a plane can take off momentarily if it's not tied down and there's a sustained 100 mph wind over the wings (headwind)...the plane is going 0 mph, but it's airspeed (speed over the wings) is the speed of the wind over the wings which is 100 mph.

so as the ball flies through the air with the headwind, it's airspeed is higher than it would be if it were going downwind. higher airspeed means higher drag and higher drag means the wind has a more significant wind effect on the ball in a headwind compared with downwind.