The Wings Stayed On!

Something for Nothing...

2009-11-17T18:56:00.006Z

Log Entry 1975 - B727 Second Officer-in-training - CYUL - Departure Gate

When I was training as a Second Officer on the Boeing 727 just a few years ago, I learned a neat thing about airflow entrainment. The Trusty Trijet has two air conditioning systems, called "packs." In flight pack 1 draws bleed air from engine 1 and pack 2 bleeds engine 3. Then using the black magic principles of expansion and compression and so on these packs pump air of the desired temperature into our cabin. So far so good.

But what if we're on the ground and the engines are not running? Then we use the auxilliary power unit's (APU) bleed air to do the job. Trouble is one little APU cannot match the flow of two big JT8Ds - the APU just can't produce that much bleed air. So, (now this is the neat part) Boeing engineers equipped the system with a Flow Multiplier. They use the high velocity bleed air from the APU to entrain ambient air from the wheel well and Voila! We now get enough "bleed" air to run two packs. Amazingly, the bleed load on the APU with both packs running is less than with just a single pack.

One surprisingly hot spring day early in my training I was sent on a fam-flight. I had just finished the technical "ground school" part of the 727 course and was awaiting to pass through the bottleneck at the flight simulator portion. Fam-flights were great. We would tag along for a day with an operating crew and see how it all works. Of course not all the line pilots were equally good examples of how the job is to be done. But it sure gave a student the context for how all the parts should finally fit together.

This afternoon we're on the ramp in Montreal and it's a scorcher. The outside temperature is in the mid thirties Celcius. We board the aircraft just ahead of the passengers to discover the interiour is like a suana. Our winged aluminum tube has been sitting in the sun for over an hour baking because the unexpected hot weather caught everyong by surprise. Most of the airport's ground air conditioners are still in winter heating mode wating to be changed over to summer cooling. Whatever the excuse the cabin air is unbreathable.

The pilots shed their formal "blues" and get down to the ramp checks so we can depart on time. I try to be inconspicous as I settle into the observer's seat behind the captain's chair, across from Second Officer Milo. His first priority is starting the APU so he can then get the packs running. The procedures for checking the APU fire protection systems seem to take forever but finally the APU is started and stabilized. Milo flips on the first air conditioning pack watching the electrical load surge as the pack's cooling fan kicks on, followed by the APU exhaust gas temperature needle rising. There is a weak gush of hot air from the overhead grills and a slight change in the background noise. But suddenly the flow stops and the flight deck gets quiet again. The EGT has rapidly spiked to its top limit and the APU's self-protection circuit has tripped the pack off to prevent damage. Milo looks puzzled and goes through the reset drill and tries again. Same results.

Meanwhile the passengers were boarding, the cabin is getting hotter still, and the purser is calling out from the flight deck door - "Air! We need air back here fellas!"

Someone suggests as diplomatically as possible to SO Milo that he might try throwing on the second pack immediately after the first, "So the flow multiplier will kick in and reduce the bleed load..."

"Really?" he asks looking puzzled. He is reassured that this should work. So this time Milo flips on the first pack ... again a weak flow of hot air trickles from the vents and the EGT needle rockets towards the redline. As soon as the electrical surge of the first cooling fan subsides Milo tentatively flips on the second pack. And almost miraculously as the demand for even more bleed air awakens the flow multiplier, the APU EGT slows, stops its climb, and actually reverses down to sit in the middle of the green band. A welcome whoosh of air pours from the vents along with the happy roar of contented packs. In just a few minutes the icy air is having the desired effect. Everyone regains their true cool and we depart on time.

Since then I've always wondered what a flow multiplier looks like and how it works. Today I came across a new consumer product which employs the same principle. I'm sure the ole B-727 flow multiplier did not look nearly so elegant, but it sure did do the trick.

Something for nothing. Now there's a bargain you don't see everyday.

2009-11-15T01:07:00.001Z

I want one of these on my little plane:

But will have to settle for this (for now):

3D Details of Cactus 1549

2009-11-13T00:28:00.002Z

This is an excellent presentation. The crew had so little time to work with. Truly amazing!

Remembrance Day

2009-11-11T17:03:00.005Z

Thanks to all who made the ultimate sacrifice...

A day to remember

and long

for peace

for a time when people

are prepared to die

rather than kill

for their beliefs

"Trump" your ride?

2009-11-11T04:13:00.003Z

In case you're getting tired of shlepping around the skies in steerage - here's a good deal on a gently-used B727.

Does self-regulation work?

2009-11-10T19:42:00.004Z

Findings from this bizjet crash continue to challenge Transport Canada's policies regarding air safety. (see my previous posting)...

Inflight Movies You Could Do Without?

2009-11-09T03:29:00.004Z

This is probably not everyone's idea of great in-flight entertainment.

It's from a series that has aired under various names - "Mayday," or "Air Crash Investigations." It's often available on the Discovery Channel or the National Geographic Channel. And happily - Youtube!

Olympic Flight Restrictions

2009-11-07T20:06:00.004Z

For anyone planning to fly in the Vancouver area during the upcoming winter olympics there are several flight restrictions to be aware of. Click Here for a site with the appropriate links:

A Day in the Life (39) Pass-temps

2009-10-29T20:16:00.007Z

A description of a typical day’s flight from Montreal to Vancouver and return - as a backdrop for a detailed, non-technical description of what an airline pilot does. (check left hand column for series index).

Time: CYUL arrival minus …

Pilots are bright-minded action-oriented people. They need to keep busy with meaningful work. But the en-route phase of flight has become so highly automated and the computerized flight plans have become so efficient and the ATC systems so programmed that pilots are reduced to system monitors. Which becomes problematic because research tells us that human beings are good at problem solving, but we suck at monitoring.

Our computer manages speed, altitude and headings more precisely than any human could - nothing to do there. Ask for a direct routing to some downline point? This may take the aircraft away from the best winds. Change altitude for better fuel consumption? Only if the flight plan demands it and traffic permits.

So in an effort to combat en-route boredom here are some strategies I've seen pilots employ:

Getting up frequently and moving around or exercising. Unfortunately, this is harder since our flight deck doors have been welded shut. Also, medium to short range aircraft cockpits are notoriously small. Pilots (or so it seems judging by the evidence) are an expensive necessity that designers would prefer to automate entirely out of the aircraft.

Conversation. But not all pilots are great conversationalists and the chemistry just doesn’t click. Besides, after three days, you've run out of smalltalk anyway. Again, the locked doors limit the frequency of visits by flight attendants. Many pilots once enjoyed giving mini-tours of the flight deck to interested passengers. This was fun but it is no longer an option.

Busy work. I've seen pilots read through the entire logbook history of the aircraft or review work-related flight manuals and complete as much job-related paperwork as possible. But this only lasts so long. And worse, it has a sleep-inducing quality all its own.

More busy work. Some pilots will call up continual streams of weather reports from the data-link system just to have something to read... "So, what's the weather like around the world today?”

Eating! In ‘the day’ we may have had excellent onboard meals to not only energize us but help pass some time. Now as often as not we subsist on "turkey snacks" (i.e. squat 'n gobble) from the airport sandwich shop while running from one flight to the next. Personally, I’ve found nibbling on sunflower seeds keeps the mind active, but this can be messy.

Even more busy work. I've seen pilots create superfluous navigation waypoints just for something to do - to "fine-tune" the flight path. I've seen this taken to a fault such as by one pilot who insisted on building a programmed routing for Laguardia's visual procedure to runway 31. Note - it’s called a “visual procedure” for a reason!

Treasure hunting. That’s the best way I can describe this constant probing for secret information. I've seen pilots delve into obscure and mostly pointless details about aircraft systems. Again I've seen this to a fault. One example: "If we select the flap lever half-way down to the next slot then back to the one we want, we get a different setting on the leading edge flaps and the aircraft then maintains a better attitude during radar vectors..."

Yikes! I'm reminded of a B727 accident many years ago where the crew apparently had developed a "special" procedure to disable the leading edge flaps in cruise then use the alternate flap system to tweak the trailing edge flaps down just a degree or two to get the airplane on the step. Which went disastrously wrong when the flight engineer inadvertently reset a circuit breaker, triggering the sudden deployment of the leading edge flaps in cruise at altitude.

Games. I've seen pilots tap endlessly through the navigation data-base to find the furthest waypoint from the current spot. I've seen pilots enter made-up waypoints to draw geometric shapes like stars on the screens. With the addition of data-link printers I've seen pilots engage in long "conversations" with other stations or flights. I've even seen pilots resort to solving crossword puzzles to keep mentally active without losing situational awareness.

Perhaps the strangest was the captain who preferred to fly at night. He turned down all the flight deck lighting to the bare minimum and sat with his face right up in the window. He was determined that before he retired he would see a UFO. I'm serious! And so was he.

But usually we have plenty of things to keep us busy.

Some days we are nervously dodging through seas of thunderstorms. Or searching for smoother air at different flight levels and working out the implications on our fuel load and our chances of reaching the destination before the tanks run dry.

System glitches pop up and invoke unfamiliar alternate procedures and reams of paper work and communications with dispatchers and maintenance departments.

And some dark nights the weather systems around us are rapidly shifting and swirling keeping us thinking about alternate plans and strategies. Like tonight.

The data-link printer comes awake and starts pumping out an arm’s length message from our dispatcher. F/O Paula rips the banner into page-sized segments and compiles them into order for our reading pleasure.

Time: CYUL arrival minus 2H00

Miracle on the Hudson - Documentary

2009-10-16T05:28:00.002Z

The Passionate Eye aired this documentary October 5th.

This is a CBC program so it may not play outside of Canada.

Here's one of many clips which are posted on Youtube from the same or a similar program.

It's a good show - well worth viewing.

Be Nice to the Staff...

2009-10-08T17:24:00.005Z

Today I'm feeling philsophical and I love to observe human nature and ponder why we are what we are. I just came across this video featuring the CEO of JetBlue. Near the end I think he offers some very sage advice to travellers:

The rudest passengers in my experience are usually from the largest cities. Maybe it's a tendancy that evolves when the anonymity of the crowd shelters us from the consequences of our behaviour? For example, more than once I've been berated by a swellagantly-attired businessman because I chose to delay the morning departure due to icy runways and crosswinds at his destination. "I have an important business meeting today! You have to get me there! ..." To which my (unspoken) reply is: "If the meeting is that important, then why weren't you smart enough to fly over last night?"

Related to this rudeness is a total lack of awareness that in all competitions between humans and Mother Nature, Nature rules. Many big city dwellers have grown so unaware of our dependence upon nature that they think it's a personal affront when their lives are distrupted by snow, ice, wind, or thunderstorms.

Meanwhile passengers from maritime regions who earn a living from the sea or know someone who does - or passengers from the smaller prairie cities whose livelihood is closely attached to farming - have a different mentality. When informed of weather-related delays, their reaction is usually a shrug and a comment along the lines: "Well, you can't control the weather now, can you. I guess we'll get there when we get there."

Over the years as GooseAir passed off flights into smaller communities to the Feeder Airline, and my schedules became a steady diet of high density airspace and big cities, it was a true downgrade of working conditions in my book.

My conclusions from these meanderings? Be nice to one another. Be aware of the reality we all share. And always know that in the end, Nature rules.

Riding on Risk

2009-10-07T03:40:00.004Z

This CBC investigative journalism show makes some serious allegations about Transport Canada and their effectiveness in policing aviation safety in Canada:

Riding on Risk

September 25, 2009

Disturbing allegations about our safety in the air. How well is our government protecting our safety and security?

the fifth estate

Airplane Hunter

2009-09-30T18:51:00.003Z

The Seattle air museum is certainly on my radar as a must see. Largely due to the work of this gentleman:

One of his latest projects - A TCA Super Connie

Emulating the Right Stuff

2009-08-02T02:45:00.003Z

When we set out to copy nature there's an interesting conundrum that arises. If we emulate form rather than function the results are usually pretty drastic. As this video shows:

For the same reasons that birds can't use propellors, our machines have never done well with "bird-like" structures. I guess this need to differentiate function from form when we learn from what's gone before applies to other fields too...? If you have any good examples that agree or disagree with this statement, please share.

Where the name comes from...

2009-07-30T04:54:00.002Z

A friend checking out in my homebuilt (I'm happy to report that the wings stayed on for him too ;-)

A Non-i-form that will never fly.

2009-07-03T19:16:00.003Z

I won't even begin listing

the reasons why this kind of uniform probably won't catch on.

Well, there ya go -- there's the first reason right there.

Some things you just don't want getting caught...

First Local Flight - in space!?

2009-07-03T18:40:00.003Z

This story is interesting in that it may be the first ever "local hop" flown in a spacecraft. Earth-bound pilots are familiar with the concept of heading out for a local sight-seeing flight just for the fun of it. Sometimes we'll stop at a local restaurant for a cup of coffee or a "hundred dollar hamburger." Or we'll just motor around the local area on a fine evening to enjoy the experience of flight, then wander back home and tie down for the night.

This sounds like the space equivalent. Albeit there was a purpose - to move the Soyuz lifeboat to another dock. But I can imagine the conversations in the space station leading up to the "flight."

"So, I'm going for a short trip to the other side of the station. Anyone want to come along for the ride?"

Lies, Damn Lies and Instruments...

2009-06-14T04:31:00.003Z

After reading Aviatrix's excellent summary of an Air Caraibe incident related to 'bad' air data and instrumentation malfunctions, I was shocked to discover the following information from a Boeing website:

During the past 10 years, more than 300 accidents and incidents have been reported as a result of erroneous flight deck information, including problems with pitot-static probes and air data computers. Several fatal accidents that involved erroneous flight instrument information and six incidents resulting from lost or erratic air data occurred in 1996 alone.

Some fatal and near fatal accidents have been tracked back to something as mundane as a strip of tape over a sensor port. The Air Caraibe incident involved severe and sudden icing in cruise flight, and may prove to have some common elements with Air France 447.

To a pilot who has become finely tuned and trained to flying by instruments, suddenly having to determine which pieces of conflicting information are right and wrong and how to respond is a huge challenge. During flight in turbulence at high altitude the margins for error can be very small (see previous posts about airspeed envelopes.) A wrong decision and control input can quickly put a jet airliner into a situation from which there is little chance of recovery.

Understanding the causes behind Air France 447's demise is extremely important - making it even more urgent that the 'black boxes' are found.

A Day in the Life (38) Eastward Ho!

2009-06-10T22:36:00.007Z

Time: CYVR Departure minus 0H00

We’re both a little more awake than we were in the Montreal darkness this morning. So the checklists and start up procedures flow even more smoothly - and a little faster.

We’re soon waved off and under way and as our final load figures begin scrolling off the printer F/O Paula confirms that we’re loaded to the gunwales.

We arrive at the button of runway 26L with the checks complete and I make one last check over my left shoulder to ensure no one will try to occupy the same space time coordinates before continuing onto the runway. My plan to use a rolling takeoff is interrupted by a Beaver puttering southbound along the coastline. I recite our take off speeds and confirm our initial climbout altitude as we wait. Then:

“Goose Air, One One Two, you’re cleared take off, runway two six left.”

The thrust levers go up through the clicks to the TOGA slot, there’s a second where it seems as if nothing is happening except for a rise in the noise then slowly the Lumber Jet accelerates.

Rotation speed is 160 kts. and it seems to take forever to get there. A gentle tug on the stick and we leave the rumbling pavement behind and transition into the rich sea-level air. After only a slight pause the altimeter begins a determined run up the scale.

“Positive rate.”

“Gear up.”

The usual thumps and whirrs. Some quick calls and frequency changes and we are soon out over the open ocean west of Vancouver then turning majestically through south towards south-east towards an inspiring view of Mount Baker.

“Goose Air 112, direct to Princeton, maintain flight level 230.” The air is smoother now than when we arrived. It’s often surprising how quickly areas of turbulence can well up, then subside. But up ahead as we near the mountain range again, the clouds convince me to leave the seat belts ‘on’ for a while yet. I ask FO Paula to make an announcement to keep our new flight attendant crew and passengers in the know.

Above ten thousand feet I put Otto back to work and move my chair closer to the windows for a view of the lower mainland and Fraser valley. This time of the year the green-drenched ground is a welcome relief from the December blahs dominant in most of the country.

We’re soon level at FL330 with the cruise checks all done. The countdown to home is underway. The datalink comes alive with an update from our flight dispatcher. South-western Quebec along with parts of Ontario and New York state are rapidly deteriorating into a serious winter wonderland. Visibility continues to drop. Snow continues to fall.

I glance at the estimated fuel overhead Montreal. The first of many such glances over the next few hours.

Time: CYUL arrival minus 4H30

--------------------------

Max weights of interest:

- Maximum taxi weight............................................................75 900 kg (167 329 lb)

– Maximum takeoff weight (brake release) ................75 500 kg (166 447 lb)

– Maximum landing weight .....................................................64 500 kg (142 198 lb)

– Maximum zero fuel weight ................................................60 500 kg (133 380 lb)

High Altitude Airspeed Envelope

2009-06-08T16:33:00.012Z

A friend recently asked me an intresting question, in light of the speculations surrounding the Air France flight 447 disaster:

What would be the stall speed versus the "normal" cruising speed on a plane like this?

At middling altitudes ... like 28,000 there's a ton of spread. Let's say 120 knots stall speed (no flaps) - cruise at 450 knots. But at high altitude cruise it gets a little more complicated because of the speed of sound and incipient shock waves.

As an aircraft climbs above approx. 28,000 feet, the maximum speed the wing can fly gets slower (shock waves start to form). At the same time the lowest speed it can fly at gets faster (thinner air, complicated as well by shock waves).

This phenomenon contributed to some crashes of the original 707 and DC8 jet transport airplanes as the full effects of turbulence and maneuvering on this tightening envelope weren't fully appreciated. At such high altitudes any increase in G-loading, causes these two speed extremes to come even closer together.

The point where they meet, as displayed on a performance chart, has been nicknamed "coffin corner" because of this history.

(Typical Buffet Boundary Chart)
If an A330 is cruising at his maximum altitude for his weight, there could be as little as 10 to 20 knots room to spare on either side of the "envelope". Which is why when we encounter "significant" turbulence or mountain waves, most pilots prefer a lower altitude.

Here is a typical presentation of the speed envelope on a modern "glass" panel. The airspeed tape on the left shows the allowance between high and low speed buffet - about plus/minus 15 knots in this example:

http://en.wikipedia.org/wiki/Coffin_corner_(aviation)

Unfriendly Skies

2009-06-02T07:10:00.009Z

As the investigation into the tragic loss of Air France 447 gets under way thunderstorms are considered a possible cause.

Isolated thunderstorms can be handled fairly easily in the daytime. Under those conditions aircraft actually operate near them on a routine basis:

I spent a summer flying hail suppression in the north end of Thunderstorm Alley at Penhold Alberta, Canada.

But crossing a towering line of tropical thunderstorms in the dark of night is on every pilot's list of least favorite pass-times. Even with the best radar equipment available, encounters with severe turbulence and worst-of-all, hail, are always a possibility.

Were storms a factor in 447's sudden demise? It's way too early to tell. Until the flight data recorders are recovered, we're only guessing. In the meantime investigators will be keeping thunderstorms near the top of the list of suspects.

Common Diversions

2009-05-24T22:42:00.012Z

Welcome Home! Well, almost...

Diversions to alternate landing sites always invoke unwanted costs and complexities. For an airline it's about taking care of the passengers and finally getting them to their destinations and rescheduling crew-members and the aircraft itself to cover ongoing flights.

For NASA it's mainly about getting the Shuttle back to Florida and ready for its next flight. In both cases subsequent flight delays are often the result.

I wonder if passengers are allowed to ride in the Shuttle during transit? I suspect not... too bad. It could help defray the 1.8 Million dollar cost of the diversion. Ouch! And I thought diversions were expensive for airlines!

STS125, You're cleared to hold...

2009-05-22T17:02:00.010Z

An old song from the 70's echoes in my brain ...

"Eight miles high and when you touch down
You’ll find that it’s stranger than known"

Fast forward to 2009 and make that Eighty Miles High and today I'm thinking about Space Shuttle Mission 125 and comparing it's current situation stuck in orbit, to our more familiar experience of an airliner "orbiting" around a holding pattern***.

Size of a holding pattern

- Airliner: 10 nautical miles long, 6 nm wide

- Space Shuttle: Circumference of the earth plus orbital height: 22,000 nm

Speed in the hold

- Airliner: best speed for fuel economy - typically 200 to 250 knots

- Shuttle: 15,000 kts. - fuel consumption is not an issue

Altitude of the holding pattern

- Airliner: as high as practicable for fuel economy - typically 10,000 to 35,000 feet

- Shuttle: typical orbital heights: 980,000 to 1,700,000 feet - fuel is not an issue

Time to fly one "orbit"

- Airliner: 10 minutes

- Shuttle: 90 minutes

Limitations on holding time

- Airliner: Minimum Fuel on board must not go below that needed to divert to the alternate, plus 30' reserve. A typical maximum holding time is about 1 hour, but usually much less.

- Shuttle: Limited by Life Support systems. The crew of STS-125 have enough supplies to remain in space until Monday.

Alternate airports:

- Airliner: Alternates must have suitable weather forecasts and ground support facilities. They are typically located within an hour of flight time but closer is much better.

- Shuttle: Weather and facility requirements are similar but of course the scale of operations differs. One unique aspect is that an airliner can divert in any compass direction but the Shuttle cannot. An alternate landing site must coincide with the existing orbital path. The shuttle cannot change its ground track until after re-entering the atmosphere.

As a side note - when an airliner takes off in poor weather, a specific Departure Alternate must be designated in case of the need for a quick return to landing. Similarly, the Space Shuttle has designated emergency diversion airports planned during the launch in case it is unable to continue to orbit.

Time to descend:

- Airliner: Typically, from the Top of Descent to touchdown takes 30 minutes.

- Shuttle: The De-Orbit maneuvering occurs about 1 hour before landing, but the spacecraft begins transitioning to an aircraft at about 400,000 feet, 35 minutes before landing.

Descent profile

- Airliner: As a rule of thumb take the altitude to lose and drop the last three zeros (i.e. div. by 1,000). Multiply this number by 3 and add 10. Make adjustments for known wind, and weight of the aircraft (At a heavier landing weight an airliner takes more miles to descend than when it is empty. In descent the forward speed is maintained by gravity. A relatively heavier aircraft maintains the proper speed with a gentler slope.) At busy airports deviations from the ideal profile are often required by ATC. The pilot initiates the descent by reducing thrust and pitching the aircraft slightly downwards (either manually or via the automation).

- Shuttle: Somewhere on the other side of the world, at a point in time and space calculated by means we can't approximate as rules of thumb the De-Orbit Burn is initiated. This requires the Shuttle to face backwards and fire the re-entry engine for about 20 seconds shaving about 150 kts off its orbital speed. Then the craft has to be flipped over and prepared to meet the atmosphere in a flying attitude. As far as I know this is all hand-flown by the pilots. This reshaped orbit will now intersect the atmosphere just short of the landing airport. ATC clearances are not currently an issue.

Approach, Landing and Touchdown

- Airliner: The descent can be interrupted at any time by adding power and levelling off. Adjustments to the descent angle can be tweaked by adding drag via speedbrakes, or adding thrust. Deceleration to 250 knots is usually required by law below 10,000 feet, and slower still nearing the airport. Airliners like to be about 30 miles of flight path from touchdown when they reach 10,000 feet and 250 knots. Wing flaps must be extended within a small window of speeds as the aircraft decelerates to the approach target. Typically airliners fly a stabilized approach of 150 knots for the last 1,000 feet of descent along a 3 degree glide slope. The landing gear and final flap configuration should all be set by this point. Various automatic aids and even automatic landing capability is installed in most modern airliners. Still the vast majority of landings are flown manually to one degree or another by the pilot.

Touchdown speed is just a few knots slower than the stabilized approach speed. If needed, the airliner can quickly be reconfigured into a "Go Around" mode by applying take-off thrust and aiming the nose skyward again. Otherwise the touchdown should occur in the first 1,000 feet or so of a runway that is at least 6,000 feet long. Then wheel brakes, aerodynamic speed brakes and engine reverse thrusters are available to complete the deceleration.

- Shuttle: At some point soon after the de-orbit burn the shuttle is headed for an unavoidable encounter with the earth - no exceptions, no delays. At about 400,000 feet and Mach 25 the Space Shuttle becomes a rapidly descending glider. Someone has described it as not so much gliding as falling with style. As speed reduces to about mach 3 it becomes possible to extend the air data probes and not have them destroyed by the heat of friction. The pilots can now add airspeed to their list of measured flight parameters. Speed brakes and steeply banked turns are used to dissipate excess energy and align with the runway.

An initial flare begins at 10,000 feet where plummeting is converted to plummeting gently and airspeed begins to reduce towards a more survivable touchdown level. A shuttle typically passes through 10,000 feet 8 nms from landing and continues down a 20 degree glideslop. At 3,000 feet it continues flaring and decelerating to reach 190 kts at the runway threshold. The landing gear is extended during the final flare just before reaching the runway. The time to deal with landing gear malfunctions is zero - or close enough. The option to go-around does not exist. Various automatic aids and even automatic landing capability is installed in the shuttle. Still the vast majority of landings are flown manually to one degree or another by the pilot.

After touchdown, usually about 2,500 to 3,000 feet into a 15,000 foot runway, a drogue chute aerodynamic speed brakes and wheel brakes are used to dissipate the remaining kinetic energy.

Ground holds and airport congestion are not currently an issue for the Space Shuttle.

***Notes:

The holding numbers I'm giving are gross generalizations. To see just how detailed holding airspace and procedures get when they are officially calculated, see this paper.

As for numbers related to Space Shuttles, I'm using gross generalizations gleaned from the NASA internet site. These units are all given in Nautical Miles - multiply by 2 for an approximate conversion to Kilometers.

Here's a more detailed explanation of Space Shuttle re-entry.

Congratulations to the crew of STS125 and happy landing whenever it occurs!

I bought a ticket - I'm getting OFF the plane!

2009-04-23T20:41:00.001Z

A little comic entertainment for fun...

Crabby Old Captain?

2009-04-03T17:09:00.008Z

Sam at Blogging at FL250 recently posted an excellent article about our mutual love of flying and how over the years many professional pilots seem to lose it. His thoughts inspired a response that was getting too long for his comments page - so I've posted it here instead:

----------------

Sam, I don't know if I avoided becoming a Crabby Old Captain... but there are certainly some parts of the job that never become tedious.

You mention the Lift Off as a great point where the fun really begins. Over the years I've discovered a few more break points. The first occurs after clearing all the noise and activity of the flight planning room, the security checks etc.. and actually walking towards the aircraft with nothing else in the way. "Now it just keeps getting better and better," I think to myself.

The next great moment (which I discovered after moving to the Captain's seat) is when all the preparations are finished, and I can finally push up the power and feel the aircraft begin to roll under my control ... that is a sweet feeling.

There's the anticipation as we move into the takeoff position. Followed by the risks and thrills of the takeoff roll and yes - that sweet instant of transition to the air! Then the joy of efficiently cleaning up the gear and flaps and getting headed in the right direction.

I enjoy the moment of "letting her rip..." once clear of the 250 knot speed restriction. Best of all is when we "happen" to do this just on top of a cloud layer where we can see the speed!

And finally there's that moment of locking into cruise level, clicking my seat back a notch and settling in for what will hopefully be an uneventful few moments or hours.

All the ancillary issues that increasingly surround the job are unfortunate and endemic to our society - our world. But over and through all this I've also found one other thing that keeps the job always fresh and interesting. People.

Once you've mastered a piece of machinery it's always that same piece of machinery. Always with the same repetitive sets of inputs/outputs. But people are always different, growing, challenging and worthwhile. More and more I find that the real satisfaction in life comes from learning about people, how to understand and communicate with and enjoy them.

Getting a good performance out of a piece of machinery is one challenge but once learned, it is easily repeatable. As an airline captain, inspiring a good performance out of a flight crew and surrounding support teams - consistently -in all sorts of conditions. That is the real and never-ending challenge. And it comes with an even deeper satisfaction when achieved.

Thanks for a fine article and for reminding me to think of all the good points in a day's work. They do so easily get buried by the "ancillary Bravo Sierra!"

And finally, Anonymous@9:14 said: "I love my wife, not my job. I need a job I can tolerate."

I agree completely with this thinking. We all need to decide if we Live to work - or Work to live. The world seems to be run by the Type A personalities who fall into the first category. I believe that ultimately this mindset causes many of the problems we face as a society. Those who discover we have a greater purpose to life than "just working," who discover the true importance of family, friends and community, will find a satisfying life no matter what career they need to work at to put food on the table.

Fly Safe! Thanks again, Sam.