| AVSIM Column "Contrails" A Long Term Love Affair with a Big Hunk of Aluminum!
By Mel Ott |
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When any airplane can give a 58 year old pilot GOOSEBUMPS by simply flying over his head, you do have a work of art!!!
A 747 can hardly be called beautiful, when compared to the Lear, or the Grumman Gulfstream, or even the venerable DC3. However, she is a massive airplane that really put the meaning into "The Aluminum Overcast." This airplane, due to its size, "tricks" the mind while watching it fly an approach that seems to be way too slow for physical flight.
While flying at 160 knots it looks like it is flying at a 80 knots. While landing at that same 160 knot speed, to the pilot, in the cockpit, it looks as if he is landing an airplane only traveling at 60 knots due to his almost 8 story height above the runway at touchdown. Most 747 pilots refer to the 747 as just a "Big Ol Piper Cub"!
With FOUR HUNDRED TONS OF AIRPLANE under his seat belt/shoulder harness, the pilot can use finger tip pressure to change her direction. While in "shirt sleeve" comfort for hours on end, that same airplane is plying her way through temperatures of minus 70 degrees or below and that at times, can cold soak her fuel in the tanks to temperatures that threaten to "gel" that fuel and turn it into slush rather than a burnable liquid.
After a 12 hour ocean crossing with over 400 passengers on board, it can "loiter" for another hour or two, in a holding pattern at the destination—and the Flight Attendants can offer an hitherto unplanned "snack" to those same 400 passengers, (and cockpit crew of 4!) if so authorized by the Captain. <Grin>.
The most visible demonstration of her power and majesty on a fully loaded takeoff is at an airport in the winter. While the runways have been plowed full length and width, and while those runways have been in use for hours by smaller 757s, 737s, 727s, etc., when the "Queen" takes her position onto the far end of the runway for takeoff there's few ground workers, few off duty pilots, and few Control Tower personal who are not watching.
Her initial acceleration from the runway end will be unremarkable, again due to her size. She will begin to "lumber" down the runway at a speed that would allow any old Ford Edsel to easily beat her in the Quarter mile.
However, at about 100 knots she begins to come alive and show her tremendous power!
Her wings have now come to life and they are causing a span-wise flow of air off of the wingtips into a "vortex" that continues out from those wings to the runway edges. This forced swirl of air soon begins to interact with the snow that has been deposited along the runway edges by the snowplows.
Continuing along now at 140 knots her engines have finally been able to get RAM air into their frontal zones, for free, rather than have to SUCK air into that same area. The "ram" of her forward speed allow those engines to now expel tremendous thrust out the tailpipes.
At about 150 knots, and with 8000 feet of runway behind, the airplane is getting very impatient about wanting to fly. Her "groundspeed" at this time is such that she couldn't, even if she wanted to, in the remaining 4000 feet of runway be able to endure an "aborted" takeoff. She is now committed for flight and as the pilot "gently" pulls back on the control column those wings take a bigger bite of that cold and thick air.
By now, on the far end of the runway where she began her takeoff roll an observer can only see a "snowstorm" at her present position. The vortex from her wings is now approaching tornadic force and snow that is more than a 100 feet from either wingtip is now in motion and is creating a cloud that obscures her view from either rear quarter and totally removes her from view to those that are positioned on the runway for departure behind her.
She initially begins her ascent with her nose rising and gaining altitude while her main body remains firmly on the runway. The wings are now at a feeding frenzy with the abundant air and the engines have changed their tone to a deep growl as they ingest tremendous quantities of air for combustion.
She finally rises off of the "tarmac"(!) at an almost impossible angle of climb that will exceed 14 degrees of pitch when at full gross weight. She will seem to hang there, almost suspended in slow motion flight, as she continues to gather speed. The obscured view from behind now changes into a sparkling view of a leviathan taking her rightful place into the atmosphere while leaving behind a visible record of blowing snow and the work that was needed to gain that position and to enable flight.
The "snowstorm" left behind will be her last visible and physical notice at that airport until she returns in about 28 hours and after crossing the Pacific Ocean twice, and while transporting 800 human beings over 12000 nautical miles.
On her return landing she will announce her presence to all of those that have been "ground-bound" since she last departed with the same "snowstorm" on her arrival as those wings relinquish their lift and slow to speeds that finally end their vortex generation.
She will return to her original departure almost as if she is "tip toeing" back home, after being out too late at night. She will almost "whisper" her way back on to the runway. Her engines will be at levels that produce only a fraction of the growl that they were required to generate on her original departure.
She will turn off the runway, most times, onto taxiways that are yet unmarked by other aircraft tires. She will actually land shorter, at her arrival weight, than will many DC-9s and 727s. She will seem to creep to the ramp at a speed that make many think the pilot's are "padding" their flight times and eventually their wallets.
But, that maximum 20 knots taxi speed is to ensure that she does not slide off of that taxiway due to slippery spots created by the "horde" of smaller airliners that have brought into the hub another huge "loading" of passengers for her return to the air.
With over a million and a half dollars, in revenue, generated for each of her two legs, the outbound and the inbound, she will be allowed a maximum of 2 hours on the ground to have her tanks re-filled, her engines topped off with oil, and for the ground cleaners to prepare her interior for a fresh set of passengers, before she is tasked with doing all over again.
After the 12 hour inbound flight, her inbound flight crew will be in various boarding areas, in attempts to "commute" back to their respective homes. If they are lucky enough their "views" from those boarding areas will allow them to watch the next "snowstorm" as she departs and for that same and very tired Captain to experience one more GOOSEBUMP!
In these days of retirement, I do miss my old "Queen". Not the hassle of getting to work, not the hassle of airline delays, not the hassles of checkrides, FAA physicals, and hordes of disgruntled passengers in any major airline terminal. However, I did miss seeing those beautiful CRT screens that provided such a wealth of information to the flying pilot. I miss her sounds, her smells, and her comfort.
Not all is lost however. I am a part of PFD, Inc., and I am now able to fly my old Queen everyday, anyway I want to!!
Thanks for stopping by CONTRAILS!
Mel Ott
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