Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Brakes Vs Reverse Thrust (thinking Of TAM)  
User currently offlineFlybynight From Norway, joined Jul 2003, 1005 posts, RR: 2
Posted (7 years 1 month 6 days 21 hours ago) and read 10291 times:

I'm curious what percentage braking power to stop a jet comes from the actual brakes versus reverse thrust.

Obviously spoilers will make a difference as well, but I would imagine this a marginal percentage.

With accidents like this horrible TAM flight in Brazil, along with AF in Canada last year and AA in the southeastern US a few years ago, it would seem the more stopping power that reverse thrusting can impact versus the brakes the better. Less reliance on wet runways the better in other words.


Heia Norge!
32 replies: All unread, showing first 25:
 
User currently offlineSlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 68
Reply 1, posted (7 years 1 month 6 days 21 hours ago) and read 10283 times:

Can't give you actual percentages as these depend on a wide range of variables but here's the broad strokes:

1. Wheel brakes are by far the most effective component.

2. Depending on the specifics of a "type" aircraft, spoilers are probably next in importance because when deployed they transfer the weight from the wings onto the wheels. Without this, wheel brakes are not very effective.

3. Reverse thrust would eventually stop the airplane but they are not really to be considered primary in the effort. You should think of them more as a device to prolong brake life, reduce brake wear, and reduce heat buildup in the wheels and brakes, especially in a short turnaround.


Under US regulations, use of reverse thrust may be considered in takeoff or landing performance calculations (assuming the system is "safe and reliable") but I've never known an airline to do so. The simple reason is that if they base their calculations on its use then reverse thrust becomes a required system and the plane cannot be dispatched on the MEL without it.

I used to teach the Flight Engineer written test prep and it used some landing distance calculations based on a particular set of charts. These charts which were for a "typical" jet transport of the 1960s, and they clearly showed that not having ground spoilers meant a larger penalty than not having thrust reversers. I just took a look and no longer have these charts handy.

Another reason it is hard to give you actual numbers is, as mentioned above, most common calculations are without the use of reverse thrust. So my chart might show me the penalty for anti-skid inop, or use of manual spoilers vs. autospoiler, but it has nothing to say regarding reverse thrust inop because it was not predicated on the use of that system to begin with. In other words, the stopping distance, as calculated without reverse thrust, is the legally binding stopping distance. Any improvement the crew can realize through the use of reverse thrust is just gravy.



Happiness is not seeing another trite Ste. Maarten photo all week long.
User currently offlineStarlionblue From Greenland, joined Feb 2004, 17017 posts, RR: 67
Reply 2, posted (7 years 1 month 6 days 19 hours ago) and read 10240 times:

Why reinvent the wheel when you can just recycle a truly classic Slamclick post from this thread: http://www.airliners.net/discussions/tech_ops/read.main/109779


User currently offlineSlamClick From United States, joined Nov 2003, 8312 posts, RR: 63
Reply 15, posted Thu Feb 10 2005 12:57:56 your local time (2 years 5 months 1 week 1 day 6 hours ago) and read 6729 times:

One thing I remember from my early days as a light plane pilot was how much wrong information I had about airliners.

Partly it grew out of light plane experience, because light planes are terrible performers when compared with airliners.

Takeoff distance:

A 2000 lb. airplane might take 2000 feet of runway. So a 130,000 lb 737 should take 130,000' right? (almost 25 miles) No way. Landing is similar. So airliners have runway requirements that are only maybe five times that of a light single, but carry a hundred, two hundred, three hundred times the weight.

Compared with a Seneca, the 737 is a STOL airplane.

The brakes on light planes are weak, compared with airliners.

Now as to the original question (disregaring the "THOUSAND TONS" of fuel which is more than a 747 would hold if the filler cap was on top the tail) I think I can put some realistic numbers to it. Using actual weight and balance documents from the last time/place I flew the 737:

72000 lbs BOW of the heaviest 737-300 in the fleet sample I have.
10380 winter weight of 60 passengers
1410 bags of 60 pax at the 23.5 lbs per in use at the time
6400 lbs landing fuel includes alternate at 100 nm away and :45 IFR reserve fuel
90190 landing gross weight of my sample Boeing

For 90K landing weight at Flaps 40 I get VREF of 116 knots. That means stall speed of 89.2 knots. So if I want to do a STOL landing I think I can do the last 200' or so at 1.1 VSO or 98 knots approach speed.

Add to that, automatic ground spoilers that are going to kill the lift upon wheel spin-up, thrust reversers that no one has said I cannot use, and the mind-boggling multi-disc, multi-puck, anti-skid protected brakes and I'm beginning to think that the last thing I'd see before sliding to stop in a cloud of tire and brake smoke is my own paint job sliding off the nose of the airplane.

I have a brake energy chart at hand. It is a "web of death" grid chart with skewed lines and I don't want to blow my whole day staring at that but I believe that I could start at the end with ultimate energy absorbtion (roll the fire trucks) and at the beginning with my weight and solve to the middle to find my runway length required. That is not what these charts are for, but I think I could do it and give the actual feet of runway that would be used up. I just don't want to take the time but I'm pretty sure it will support my claim.

Also, as stated in reply #2, second line, it would require a precise approach and landing and would absolutely not be "normal." but I'd bet my life that I could get it stopped between the first brick and the last brick of a 2400' runway.



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineBoeingfixer From Canada, joined Jul 2005, 530 posts, RR: 0
Reply 3, posted (7 years 1 month 6 days 19 hours ago) and read 10231 times:

Quoting Flybynight (Thread starter):
With accidents like this horrible TAM flight in Brazil, along with AF in Canada last year and AA in the southeastern US a few years ago, it would seem the more stopping power that reverse thrusting can impact versus the brakes the better. Less reliance on wet runways the better in other words.

Both the AF and AA accidents were'nt caused by a lack of reverse thrust or difficiencies in the aircraft. The AF A340 at YYZ landed at the mid-point of the runway and the reverse thrust was not selected for a further 9 seconds. The Little Rock AA DC-9 accident was determined to be caused by the crews failure to discontinue the approach when severe thunderstorms and their associated hazards to flight operations had moved into the airport area and the crew’s failure to ensure that the spoilers had extended after touchdown.

In both casses, additional reverse thrust would have done very little. When aircraft are flown within their performance envelope by competent crews, accidents like these should not happen. Until the accident investigation is complete on the TAM accident, it would be irresponsible to speculate on causes.

Cheers,

John



Cheers, John YYC
User currently offlineViscount724 From Switzerland, joined Oct 2006, 25117 posts, RR: 22
Reply 4, posted (7 years 1 month 6 days 18 hours ago) and read 10209 times:

The TAM crash made me think of a 1993 LH A320 overrun accident at WAW with 2 fatalities. Repeating my related posting from the Civil Aviation forum.



That reminded me of the following LH A320 accident at WAW in 1993.
http://aviation-safety.net/database/record.php?id=19930914-2

The spoilers and thrust reversers didn't deploy immediately since one main gear didn't touch down until 9 seconds after the other due to windshear. The aircraft ran off the end, struck an embankment and caught fire, with 2 fatalities. A320 design features that delayed use of braking systems were considered as a contributing factor in the cause, along with incorrect decisions of the crew. It was also raining heavily.


User currently offlineVikkyvik From United States of America, joined Jul 2003, 9910 posts, RR: 26
Reply 5, posted (7 years 1 month 6 days 18 hours ago) and read 10204 times:
Support Airliners.net - become a First Class Member!

Quoting Starlionblue (Reply 2):
Why reinvent the wheel when you can just recycle a truly classic Slamclick post from this thread: RE: Can A 737 Land On A 2,400 Ft Runway? (by SlamClick Feb 10 2005 in Tech Ops)

Ah man.....I remember that reply!  Smile

Quoting Viscount724 (Reply 4):
A320 design features that delayed use of braking systems were considered as a contributing factor in the cause, along with incorrect decisions of the crew.

Were there any changes to the A320 brake systems implemented as a result?



"Two and a Half Men" was filmed in front of a live ostrich.
User currently offlineFlybynight From Norway, joined Jul 2003, 1005 posts, RR: 2
Reply 6, posted (7 years 1 month 6 days 16 hours ago) and read 10177 times:

Quoting Boeingfixer (Reply 3):
Until the accident investigation is complete on the TAM accident, it would be irresponsible to speculate on causes.

I'm not speculating on what happened in Brazil. I'm curious about the various stopping powers of airplanes. Obviously on wet or snowy surfaces it would be good to rely on reverse thrust since surface friction has no impact.

Having said that, I think it is OK to speculate. What's wrong with discussion. Either way, I think can we can all agree that was a horrible accident in Brazil and hopefully something good can come out of whatever lessons learned from the incident.



Heia Norge!
User currently offlineStarlionblue From Greenland, joined Feb 2004, 17017 posts, RR: 67
Reply 7, posted (7 years 1 month 6 days 16 hours ago) and read 10175 times:

Quoting Flybynight (Reply 6):
Obviously on wet or snowy surfaces it would be good to rely on reverse thrust since surface friction has no impact.

Well, not for a jet airliner in normal operations. You never rely on reverse thrust. Reverse isn't THAT helpful and if the runway is slippery (or "paved" with snow) stopping distances are waaaay greater simply because the wheel brakes can only do so much.

Remember also that airliners had anti-lock systems way before cars. With any degree of grip, the wheel brakes are eking out the maximum stopping power possible, even with marginal grip. Of course, in the latter case braking will also be marginal in proportion.

Drag chutes. Now There's a cool solution. Or maybe an anchor...  Wink



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineZeke From Hong Kong, joined Dec 2006, 9001 posts, RR: 75
Reply 8, posted (7 years 1 month 6 days 15 hours ago) and read 10155 times:

Quoting Flybynight (Thread starter):
I'm curious what percentage braking power to stop a jet comes from the actual brakes versus reverse thrust.

On the 320 its no difference using reverse or not with autobrake.

Autobrake is a selected deceleration rate, if you use reverse, less brake pressure is applied to achieve the same deceleration rate.

From memory on the 320, 2 reversers reduce landing distance by 12% on a contaminated/wet runway, been a long long time since I have flown one, but thats the QRH number I had in the back of my head.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlineMir From United States of America, joined Jan 2004, 21556 posts, RR: 55
Reply 9, posted (7 years 1 month 6 days 14 hours ago) and read 10139 times:

Quoting Starlionblue (Reply 7):
Drag chutes. Now There's a cool solution. Or maybe an anchor...

Or one of these:  biggrin 



-Mir



7 billion, one nation, imagination...it's a beautiful day
User currently offlineStarlionblue From Greenland, joined Feb 2004, 17017 posts, RR: 67
Reply 10, posted (7 years 1 month 6 days 8 hours ago) and read 10085 times:

Quoting Mir (Reply 9):
Quoting Starlionblue (Reply 7):
Drag chutes. Now There's a cool solution. Or maybe an anchor...

Or one of these: biggrin

"As we prepaper for landing, please use the provided pillow and brace yourself against the seat in front of you. There will be a jolt. Aspirin will be available after landing."



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineSailorOrion From Germany, joined Feb 2001, 2058 posts, RR: 6
Reply 11, posted (7 years 1 month 6 days 7 hours ago) and read 10075 times:

Quoting Vikkyvik (Reply 5):
Were there any changes to the A320 brake systems implemented as a result?

From what I remember, yes. Afaik it's now enough for one sensors to activate ground, plus the required pressure might have been adjusted as well.

SailorOrion


User currently offlineBond007 From United States of America, joined Mar 2005, 5408 posts, RR: 8
Reply 12, posted (7 years 1 month 6 days 7 hours ago) and read 10060 times:

Using real rough figures ..the percentage of increased braking using reverse thrust is something up to 10% maximum on a dry runway. On a contaminated runway, particularly snow/ice, this increases up to 20%.... but as Slamclick mentions - it's extremely variable.

Quoting SlamClick (Reply 1):
You should think of them more as a device to prolong brake life, reduce brake wear, and reduce heat buildup in the wheels and brakes, especially in a short turnaround.

Yes, although for the first two items you mention, with the newer brakes and the added cost/maintenance of thrust reversers, the latter is probably the main reason today.


Jimbo



I'd rather be on the ground wishing I was in the air, than in the air wishing I was on the ground!
User currently offlineJhooper From United States of America, joined Dec 2001, 6204 posts, RR: 12
Reply 13, posted (7 years 1 month 6 days 1 hour ago) and read 9979 times:

Reverse thrust is very effective at high speeds, but below 60 kts we don't use them because a fan blade inspection is required. And I try to stay off the brakes above approx. 80 knots (runway length permitting) to avoid heating up the breakes.


Last year 1,944 New Yorkers saw something and said something.
User currently offlineSilverComet From Mauritius, joined Apr 2007, 85 posts, RR: 0
Reply 14, posted (7 years 1 month 6 days ago) and read 9963 times:

I'm looking at the A319-112 landing performance figures (config FULL) and I see that using reversers reduces your landing distance by:

3% on a dry runway,
6% on a wet runway,
12% on a water or slush contaminated runway,
and as much as 24% on an ice paved runway.

Which makes sense. The less effective your wheel brakes are, the more the reversers are contributing to stopping the aircraft.

Saw on the BBC today something along the lines of the particular runway (concerning the TAM accident) didn't (yet?) have those 'grooves' on the surface to evacuate water and that might have contributed to the loss of braking performance. All this is, of course, subject to confirmation.


User currently offlineFlybynight From Norway, joined Jul 2003, 1005 posts, RR: 2
Reply 15, posted (7 years 1 month 6 days ago) and read 9963 times:

I guess each pilot has different approaches to slowing down the plane. Sometimes - like a landing I had a week ago at O'Hare on a UA 752 - the pilot was braking very hard. There was plenty of runway left. The only thing that made sense is the he was trying to catch an early ramp away from the runway.
It's always impressive to feel how powerful the braking system is on a large plane.

Three days later I'm landing at SFO on a UA 772 and the pilot seemed to almost let the plane just glide to stop. Very gentle on the brakes.



Heia Norge!
User currently offlineJhooper From United States of America, joined Dec 2001, 6204 posts, RR: 12
Reply 16, posted (7 years 1 month 6 days ago) and read 9955 times:

Quoting SilverComet (Reply 14):
I'm looking at the A319-112 landing performance figures (config FULL) and I see that using reversers reduces your landing distance by:

3% on a dry runway,
6% on a wet runway,
12% on a water or slush contaminated runway,
and as much as 24% on an ice paved runway.

I'm assuming this is based on the pilot performing a maximum anti-skid braking, which isn't usually done. The TRs likely play a much larger role in stopping distance when an average braking effort it used.



Last year 1,944 New Yorkers saw something and said something.
User currently offlineBond007 From United States of America, joined Mar 2005, 5408 posts, RR: 8
Reply 17, posted (7 years 1 month 5 days 21 hours ago) and read 9917 times:

Quoting Jhooper (Reply 13):
Reverse thrust is very effective at high speeds,

I wouldn't say very effective ... maybe somewhat effective  Wink

Quoting Jhooper (Reply 16):
The TRs likely play a much larger role in stopping distance when an average braking effort it used.

I think under normal braking it isn't much more than quoted. I read a NASA report that stated it was under 10% on a dry runway for a variety of aircraft they tested, and this is confirmed by SilverComet's 3% ... even double that at 6% is unremarkable.

Now of course, the less you brake, the bigger role they play in stopping you ...but it ain't much for all that noise  Smile


Jimbo



I'd rather be on the ground wishing I was in the air, than in the air wishing I was on the ground!
User currently offlineVikkyvik From United States of America, joined Jul 2003, 9910 posts, RR: 26
Reply 18, posted (7 years 1 month 5 days 20 hours ago) and read 9915 times:
Support Airliners.net - become a First Class Member!

Quoting Flybynight (Reply 15):
Sometimes - like a landing I had a week ago at O'Hare on a UA 752 - the pilot was braking very hard. There was plenty of runway left. The only thing that made sense is the he was trying to catch an early ramp away from the runway.

Well, keep in mind that O'Hare is one of the two busiest airports in the country. You'll probably make ATC happy if you spend less time on the runway.

Quoting SailorOrion (Reply 11):
From what I remember, yes. Afaik it's now enough for one sensors to activate ground, plus the required pressure might have been adjusted as well.

Gotcha, thanks.



"Two and a Half Men" was filmed in front of a live ostrich.
User currently offlineSlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 68
Reply 19, posted (7 years 1 month 5 days 20 hours ago) and read 9908 times:

Quoting SilverComet (Reply 14):
reversers reduces your landing distance by:

3% on a dry runway,
6% on a wet runway,
12% on a water or slush contaminated runway,
and as much as 24% on an ice paved runway.

It is important to keep this in mind here; the reductions are in relation to what you'd experience IN THOSE CONDITIONS. So landing on an icy runway might double your stopping distance over a dry runway but reversers might enable you to realize a 24% reduction of that greatly increased distance.

Net effect - an alarmingly increased ground run instead of a catastophically increased ground run.



Happiness is not seeing another trite Ste. Maarten photo all week long.
User currently offlineBond007 From United States of America, joined Mar 2005, 5408 posts, RR: 8
Reply 20, posted (7 years 1 month 5 days 20 hours ago) and read 9907 times:

Quoting SlamClick (Reply 19):
It is important to keep this in mind here; the reductions are in relation to what you'd experience IN THOSE CONDITIONS. So landing on an icy runway might double your stopping distance over a dry runway but reversers might enable you to realize a 24% reduction of that greatly increased distance.

Oh agreed ... on an icy runway there is no question it might save your life ... if you really made the decision to land there (I know, you might not have expected an icy runway ... but you probebly did  Wink)

... they're definitely overrated on dry runways though  Smile

Outside of tech-ops, most people think reverse thrust is 90% of the braking .. they hear the engines spool up, then they are thrown forward ... without realizing the brakes might actually be involved.


Jimbo



I'd rather be on the ground wishing I was in the air, than in the air wishing I was on the ground!
User currently offlineMandala499 From Indonesia, joined Aug 2001, 6841 posts, RR: 75
Reply 21, posted (7 years 1 month 5 days 9 hours ago) and read 9813 times:

The wheels and its brakes are the most effective method of slowing the airplane down...
HOWEVER, it requires the airplane to rest its weight on it...
This is why you have lift dumpers...
Liftdumpers are... self explanatory, they kill the lift by not only spoiling the lift, but also creating a downforce to offset whatever remaining upforce there are from the lower wing surface.
Liftdumpers are now called Ground Spoilers... which are basically, spoilers deflecting at a hideous angle (I call it wall on the wing)... it kills the lift and create aerodynamic drag. This is damn useful on the initial stages of the landing roll... and good to about 80kts or so... albeit its usefulness decreases as you slow down.

So, you can use the wheelbrakes at any speed? No...
The weakness of wheelbrakes is that they have a speed limit, and the tyres also have a speed limit. Some go up to 200kts, but you'd think twice on using it at that speed. If the tyres don't burst on brake application at that speed, you'd melt your brakes... it HAS happened.

A fully loaded 734 should be able to stop in 1200m at MLW... if you throw the lift dumpers, and slam on max brakes and the antiskid works... add 300m from threshold to the touchdown point... it's 1300m... *damn, where's that QRH????*
BUT, a 734 at MLW once landed with no flaps, threw the spoilers and reversers, melted the brakes, and took 3000m of runway and was still at about 20kts when turning off the runway at the very end of the 3300m runway.

The quote on slamclick's braking explanation by starlionblue is a damn good one!

Quoting Zeke (Reply 8):
On the 320 its no difference using reverse or not with autobrake.

it does, but only when if: The reverser can provide a deceleration greater than the autobrake deceleration schedule.
Ie: useful on autobrake LOW, *grin* but then, that's the theory, for the practicality of things, take Zeke's word on it... believe me...  Smile

Mandala499



When losing situational awareness, pray Cumulus Granitus isn't nearby !
User currently offlineCosmicCruiser From United States of America, joined Feb 2005, 2255 posts, RR: 15
Reply 22, posted (7 years 1 month 5 days 6 hours ago) and read 9762 times:

Quoting Mandala499 (Reply 21):
Some go up to 200kts, but you'd think twice on using it at that speed. If the tyres don't burst on brake application at that speed, you'd melt your brakes... it HAS happened.

If for some reason you are on the runway and going that fast you'ld better use them or will find yourself in the dirt still doing 200 very soon. As I posted on another post here in the MD-11 with 2 eng out your Vapp is very high and will approach max tire spedd. When you touchdown you had better get on the brakes and the one reverser because the runway end is fast approaching and if you melt some brakes that's better than going off the end of the runway. I believe at one time a Fedex crew had the heaviest wgt rejected t/o of any DC-10 and yes the brakes melted and the fuse plugs melted but in the end they were still on the runway.


User currently offlineViscount724 From Switzerland, joined Oct 2006, 25117 posts, RR: 22
Reply 23, posted (7 years 1 month 4 days 20 hours ago) and read 9587 times:

It's been announced and confirmed by TAM that one thrust reverser on the A320 involved in the crash had been unserviceable for several days prior to the accident. Apparently the Brazil MEL rules permitted it to fly for 10 days before being repaired.

More discussion on this in the Civil Aviation forum.


User currently offlineKcrwFlyer From United States of America, joined May 2004, 3805 posts, RR: 7
Reply 24, posted (7 years 1 month 4 days 20 hours ago) and read 9580 times:

On a side note.

Wouldnt reverse thrust on an aircraft like a 732, 717, DC-9/MD-80, or even an ERJ, be more effective than that of a newer 737 or an airbus?


25 Post contains links and images Vikkyvik : I assume you're referring to the old "clamshell" reversers that reversed the core AND bypass flow, whereas today's petal, cascade, etc. reversers ten
26 Starlionblue : Interestingly, lots of ERJs don't have reversers.
27 KcrwFlyer : Thats true. I guess airlines that only operate them on longer runways dont see the need for the added MX costs. Thats interesting. Why is the stoppin
28 Flybynight : Interesting, but I don't think it would have mattered all that much. It will be interesting to find out how far down the runway that A320 initially t
29 Vikkyvik : I think the only answer to the first part of your question is simply that airplane wheel brakes are really good. As has been stated, if you slam on t
30 Post contains images PapaNovember : I'll admit that I did not read through each post of the thread to see if this question had already been asked, or answered.... My question is - Do the
31 GivenRandy : Aren't reversers only supposed to be used about 10 seconds or so? Probably at the most effective time, as mentioned above.
32 SilverComet : The criterion defining how long to use the reversers for isn't exactly about 'time' but 'speed'. Below a certain speed the reversers (beyond idle) wi
Top Of Page
Forum Index

Reply To This Topic Brakes Vs Reverse Thrust (thinking Of TAM)
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
Use Of Reverse Thrust posted Mon May 30 2005 13:47:28 by PMN
How Do Diferent Typrs Of Reverse Thrust Work? posted Sat Sep 25 2004 05:19:29 by Kcrwflyer
Reverse Thrust/Brakes posted Fri Dec 15 2000 01:12:04 by Future_Pilot
Why Does JetBlue A320 Seem Not To Reverse Thrust posted Thu Jul 12 2007 06:29:44 by JETBLUEATASW
747 Reverse Thrust Doesn't Stop (Video) posted Sun Feb 11 2007 20:09:53 by HighFlyer9790
Reverse Thrust Before Landing:dangerous? posted Sat Feb 3 2007 11:21:21 by RootsAir
NW Flight -- Sparks During Reverse Thrust? (video) posted Tue Jan 2 2007 13:42:24 by Tweety
Slat Retraction During Reverse Thrust? 747-400 posted Sun Nov 5 2006 00:29:24 by Ajaaron
Reverse Thrust On Props posted Wed Sep 27 2006 06:40:29 by AirWillie6475
Brakes Or Reverse? posted Wed Aug 9 2006 22:05:02 by Frequentflyer

Sponsor Message:
Printer friendly format