Engine Magic

Position: Taxiway Echo, radome pointing west, KPHX (Phoenix)
Groundspeed: Zero
Altitude: Zero
Equipment: A321 Enhanced New Metal
Pax-on-Board: 183 plus 3 jumpers
OAT: 111 degrees F
Taxiway temperature: 115 degrees F

Not airborne... Yet

I count ten, twelve... Probably fifteen tails ahead in the shimmering heat. The sun is brutal on my side of the cockpit, not to mention there are four pilots in a space built for two. Number one engine is turning and burning; the APU (small turbine engine in the tail) is providing pneumatics to the packs (air conditioning and pressurization units). The cockpit temperature is 90 F; pax cabin is 86 F.

A heavy three-engine freighter roars past with its nose flying, but the main gear still rolling on the hot concrete... The aircraft ahead of us moves (slowly) forward. I release the parking brake and creep ahead. What a change from this morning...

KSNA/Orange County... 0545 hrs


Third floor, facing south, palm tree rustling in the early morning breeze, sun rising to my left... On the balcony rail, a steaming cup of Starbucks instant coffee. The atmosphere is cool, fragrant, and invigorating. I am relaxing, momentarily, before suiting up for a long day of industrial strength flying.

My brain is starting to compartmentalize... Most of it is enjoying this sweet little moment, but the performance section is worrying about the hot take-off coming in KPHX. The weather section is worrying about the line of thunderstorms building across the center of the Empire. And, of course, the fuel section, always the fuel section...

Taxiway Echo... KPHX


Fuel tank temps are above 40 C... Yeah, it's summer in the desert. A company A319 climbs away from the runway, landing gear doors closing, airframe at a ridiculous nose high angle. It is impressive and I watch it go by until the sun forces me back into the warm shadow of the flight deck.

The co-pilot, after reviewing performance data emailed to us from Mother, informs me that we are looking at a max effort take-off... Thrust levers all the way to the forward stops, APU providing pneumatics to the packs so that the engines are used 100% for thrust. After we set up for max effort, we have one more little trick; bumping, or as I call it, boosting.

It is engine magic, allowed sparingly (a fixed number of times between engine overhauls), that squeezes a little more thrust out of the engines. Each time an engine is boosted for take-off, that event is recorded by Maintenance Control.

Boosting is a double edged sword... It gathers a little more thrust, but it also results in higher temperatures, usually approaching the limits on days like this...

A bright-and-shiny mad-dog 88 goes roaring by, all tires still rolling on the runway. Its engines are loud and smoky, crackling thunder, as it passes. It'll be awhile before they are airborne... They need a lot of runway.

Parking brake released and we creep forward a little more...

Master Caution... "Ding"


Now what? Uh-oh... The APU has quit. Of course it has... The APU system page shows the little turbine spooling down. Yep, it has left the party... Not sure why and I don't really care at this time.

Quickly, I reach overhead and push a few buttons, turn a knob and re-plumb the pneumatic system, drawing bleed air from number one engine to operate the packs. The engine's fuel computer senses the increased demand and automatically raises the idle speed. Not enough, so I move the thrust lever forward watching the fuel flow... About there, I think.

No APU... No problem. We can use number one engine to start number two engine. We can make an unpressurized take-off (we need all available thrust, so the engine bleeds will have to be OFF.  After flaps UP, we can ease the packs back on-line to pressurize the cabin.

iPhone to the rescue...


We are allowed to use personal cell-phones to call Mother as long as the parking brake is ON. My dispatcher and I concur that we can operate without the APU, then  agree to use aircraft email for the remaining communications before take-off; iPhone OFF, parking brake OFF and creep forward...

I promise Maintenance Control that I will...


Yes, of course I will complete the paper trail before we land in KBOS. That promise takes about three feet of mini-printer paper, a trail unto itself. The center jump-seater tears off each message, reads them to us, and then neatly adds to the growing pile of email. Parking brake OFF and creep forward...

Cross-bleed engine start...


I count five vertical fins between us and the runway... Time to start engine two. The co-pilot reaches overhead and opens/closes pneumatic valves to draw air from number one engine to spin the number two starter. I ask the ground controller for clearance to cross-bleed... She allows us to turn onto the parallel taxiway for the start so that we do not blow FOD (trash) into the engines behind us. The co-pilot moves number one thrust lever further forward to increase available bleed air and opens the start valve for number two. The right V2500 A5 begins to spool up... Yeah baby!

There is an old saying about a knife and a cat that is appropriate.

MAX cooling...


Both engines are at high idle, all pneumatics returned to normal configuration before take-off. Each engine is feeding its on-side pack, each pack demanding HI FLOW, trying to cool the cabin further. We are next for take-off... I take one more look at the overhead panel. We have been pushing buttons and turning knobs up there; need to be sure that everything is back to normal configuration.

Arm the boost, please...


There ya go... The co-pilot pushes a little red button, hidden by a thumbnail sized flap.


A little "B" appears over each N1 gauge... Boost is armed. Have I said that I love this aircraft yet? No I don't believe I have...

One more time; I review the engine failure scenario. Nose to 12 point 5 degrees, landing gear UP clear of the runway, lots of rudder into the good engine. If it is on fire, let it burn until the flight path is under control... Maintain control of the aircraft first and foremost.

KPHX Tower: Wind two thirty at five knots... Cleared for take-off runway seven left.


Checklists are done as I oversteer the A321 to line up on the centerline. One last glance at the OAT shows 45 degrees C on the runway... That would be about 113 F.

The co-pilot closes the engine bleed valves for an unpressurized take-off... Amber FAULT lights illuminate in each pack button. Perfecto...

Captain's silent runway checklist: flaps set at 50%, trim set, fuel adequate... We are good to go here.


Thrust levers forward enough to stabilize the engines before moving the levers quickly to the forward stops. Hardly any engine noise in the 321 cockpit, mostly visual cues on the engine gauges and the feeling of thrust.

Engine temperatures spike at about 545 C, and then roll back to about 500 C before starting their climb toward the red line. The long fuselage starts to wiggle in the way that only a 321 does... It freaked me out the first time I felt it, but now it's cool.

80 knots...


Everything looking good with engine temps crossing the 600 C mark. The acceleration is strong for such hot weather.

120 knots...


Engine temps 620 C and still climbing... Boost envelope temperatures.

140 knots...


Engine temps 630 C and climbing... I can feel the wings loading. The nose wheels want to fly. Not yet... Hang on just a little bit more. The cockpit temperatures are rising from the unpressurized take-off.

Vee one...


We are past the reject point. Not enough runway ahead to stop. Get ready for an engine failure el cap-i-tan.

Rotate...


Using two fingers, increase back pressure a tiny bit on the control stick and the nose gear leaves the runway. A super-quick glance at the engine temps show #1 at 634 C and #2 at MAX of 635 C. The main gear follows... We are airborne. Positive climb rate and the co-pilot selects the landing gear handle to UP.

Everything is looking good; both engine temperatures are at 633 C as the gear doors slam shut covering her folded legs and hot Michelin Aeros... Got 18 point 5 degrees nailed on the $65,000 primary flight display; the $200 stand-by artificial horizon next to it, also shows exactly 18.5 degrees. Loving it!

1,000 feet above the ground...


Ease the thrust levers back from MAX; watch the engine temps and fuel flows roll back into friendlier territory. That's better... Now ask the co-pilot to raise the flaps from 50 to 25%. Fi-Fi likes that and leaps ahead more than twenty knots. She climbs at 700 fpm as the speed trend arrow points at the top of the instrument case. Flaps UP speed rolls past the pointer; the co-pilot raises all slats/flaps. The Electric Jet wallows a little as the wing goes sleek and clean, but quickly recovers and increases climb rate and airspeed.

The co-pilot opens number one engine bleed and the rush of cool, pressurized air feels wonderful. After we are comfortable with the behavior of the left pack, he opens number two engine bleed and the right pack comes back from its nap. I can feel cabin pressurization in my ears as well as see it on the pressure display.

3,000 feet above the ground...


The critical climb envelope is now below us. I push a button and turn airspeed control over to the flight management computers. The NAV computers turn further left to a heading of 45 degrees tracking the departure's course. Indicated airspeed is 250 knots and climb rate is holding steady at 2,800 feet p/min. The outside air temperature is 28 C (82 F), so the temp dropped 31 F in 3,000 feet. That definitely falls into the cool category.

10,000 feet above sea level...


I reach overhead and stow the lights, cycle the seat-belt sign to let the flight attendants know they can un-buckle... Fi-Fi NAV rolls the speed bug to 309 knots and begins to get serious about climbing into the cold blue.

Pulling up the wheel-well display shows temperatures steady at 200C... We could bake bread down there. In the movies, there would be a hatch to get into the wheel well.

Flight Level One Eight Zero (18,000 feet)...


Set all altimeters to 29.92 inches... And relax. The Electric Jet is climbing at a steady 1,800 feet p/min. I start composing a message to dispatch asking about the growing line of thunderstorms ahead... Still over the horizon. After we get through that mess, it will be a straight shot to KBOS.

Life on the Line continues...