15 Degrees Pitch

[TriDriver]

FlyChicaga

As you mentioned, about 18 degrees is a pretty typical pitch attitude for initial climbout. At Delta, we use a max of 20 degrees. What we're really going for is V2 to V2 plus 10 kts. If you get to 20 degrees and exceed V2+10, that's okay, cause at 1000 we lower the nose.

It may be different at other carriers, but our normal cleanup altitude is 1000 ft AGL (unless higher in mountainous terrain, or noise abatement, or some weird airport procedure), at which point we will lower the nose and start accelerating and getting the flaps up. We acellerate to clean speed (flaps up maneuvering speed for our weight, even it exceeds 200 kts) until out of the top of the Class D airspace at 2500 AGL, then we accellerate to 250 til above 10,000.

So, if you're at 20 degrees nose up, it's only for a very limited time - up to 1000 AGL in our case. Then, when you start accellerating, the nose is much lower - even at climb power and 250 kts you're probably well less than 15 degrees nose up.

TriDriver Bob

 

[FD109]

Climb Profile

The climb profile in the previous post is identical to what EAL and every other place I've flown uses.

The reference in Webb's book to reducing power to maintain 15 degree pitch and 250 ias must have been his personal preference, because it wasn't a procedure at EAL where he was a Captain and check airman.

The only airline that I know of that uses something different from the standard profile in the previous post is Northwest--I think they use some sort of "quiet EPR" power reduction profile similar to DCA's procedures.

Maybe somebody from NWA can fill us in on that. Maybe that has changed; I don't know.

 

[banned username 2]

(in normal cruise, for initial climb after departure around 18 degrees is more 'the norm' in my experience)

18° pitch attitude in a normal climb in a 172????

Sorry man, couldn't resist!

 

[Clearsky]

Dumb question for you. Anybody know if the 747 (other airliners also) uses full power at takeoff? There was a story on Air Force One the other night that mentioned they did an unusual takeoff at full power and then climbed out real steep. So, I am left with the thought that maybe this is unique to Air Force One.

Just a curious passenger wondering.

 

[banned username 2]

What about aircraft like a Lear, or something else that can have huge climb rates? Do they operate at over 15 degrees to get those rates?

In the Falcon 50EX and 900EX our typical rotation angle is 18-19°... To hold V2+10 for a noise abatement departure I have seen better than 24° when light and it is cold.... this results in a rate of climb of well over 6,000 FPM...

 

[Starsailor]

Pegging the VSI

Our company operates 20- and 30- series Lears. On a normal departure (passenger or air ambulance), the SOPs ask us to pitch for 200kts until out of the control zone, then 250 to 10k, then 270 or 280 until transition. With initial climb power settings (680 degrees EGT in the 20s, 795 ITT in the 30s), and dependent on temperature and weight, I'll get anywhere from a 12-18 degree pitch angle before entering Class A. On noise abatement departures (though in the 20-series one wonders why one even tries to be quiet, 'cause it's not going to happen), for which we use the NBAA standard, I'll routinely see over 20 degrees nose up before hitting final segment, at which point I'll reduce power and pitch for passenger comfort and for those nice people on the ground who like the convenience of living by an airport but "gosh airplanes are so LOUD, honey; instead of moving why don't we circulate a petition?" [sic]



Then there are the days when it's just the two of you and one little important box, and it's cold out, and Biff and Buffy and their noise sensors aren't anywhere around. . . but if you search you'll find a thread already devoted to Bill Lear's wondrous machine.

Regards,
Starsailor

 

[Groucho]

Pitch etc.

The pitch attitude after takeoff on the newer generation jets is designed into the Flight Director. Some of the first generation digital jets, ie, MD-80 and B737-300 don't have a set pitch attitude. The attitude is set to maintain V2 +10 or 20 after takeoff. This may result in a pitch atitude of up to 20 degrees if the airplane is light with a full power takeoff.

The kicker of this is that it is not required for second segment climb. A fifteen degree attitude maximum will produce an equivaltent required second segment climb requirment in most aircraft. The reason the Flight Directors are programed for this large pitch is noise abatement. The enginers found that they could trim a few decibels off the noise signature of the airplane by increasing the altitude over the standard placement of the sound detectors.

The problem with this procedure is the V2 cut. It used to be that the V1 cut in the sim was one of the more exciting times of a check ride. Our company has been also using the V2 cut scenario with the pilots told to strictly follow the flight director. It is a real eye opener. In the MD-80 the 20 degree pitch requires an almost slam down to 10 degress, or less if you are slow doing it, and if you go below v2 even momentarily, you will have very little extra rudder control or maybe none at all. With the rudder at the stop and some cross controling the airplane comes back to a normal single engine climb profile with normal controls but very slowly.

If you were to stay at fifteen degrees of pitch and lose an engine it is a walk in the park. The additional speed bleeds off but there is ample rudder available and a slow deliberate pitch down to the single engine attitude and wait for the flight director to come to you, adjusting the control forces as the airplane decelerates. Very much nicer flying but not what the flight directors are signaling. The 20 degree pitch stuff meets all the requirments but doesn't leave much room for any mistakes in an engine
failure situaition.

"These are my principles, if you don't like them I have others"
Groucho Marx.

 

[Purple Haze]

Nice post, Groucho -- my sentiments exactly.

15 degrees: min for obstacle clearance (in some transport aircraft)
15 degrees: comfort
20 degrees: noise abatement

These days we are all about noise abatement -- the gravy is that we get some extra obstacle clearance out of the deal!

 

[Purple Haze]

Let's say you are using (real rough numbers) 95% N1 and 20 degrees for noise abatement. You are getting 220 knots with that arrangement. Wouldn't using 15 degrees of pitch, with 85% N1, considering still getting 220 knots, still conform to noise abatement concerns?

Maybe, but you will be lower, longer (=more ears to hear you and - more importantly - more obstructions). You want to be as high as possible as soon as possible -- accident statistics show particular vulnerability on approach and takeoff (close to the ground), plus: whatever your aircraft's performance data is based on is your required profile. Anything else and you don't know what you're gonna get. As mentioned in an earlier post, many aircraft have max power and standard or reduced epr takeoff power settings. The lower settings, I believe, are based on the lowest takeoff power setting at which you can lose an engine at CEFS, continue the takeoff, and still meet FAA min climb gradient criteria. Than again, I may have heard this in a dream (this happens when you age).

So, make lots of noise at and near the airport, then try to make less.

 

[flywithastick]

Climb Philosphy in Multi Turbine

With (recip) singles, the biggest concern on takeoff is reaching a safe altitude quickly. With recip multis, considering the loss of an engine is still the overriding concern, but the climb to a safe altitude is not quite as urgent.

My question is, with multi turbine power AC, how urgent is the climb to some "safe" altitude? other than getting to cruising alt, stay in the right airspace and keep the flight on schedule.

What made me wonder was noticing evening departures out of HOU with what seemed like a very shallow, low profile. I'm sure this was due to noise abatement procedure. My first thought was that seems like a safety compromise not getting as high as possible quickly. Does it matter?

 

[Purple Haze]

Re: Climb Philosphy in Multi Turbine

With (recip) singles, the biggest concern on takeoff is reaching a safe altitude quickly.
My question is, with multi turbine power AC, how urgent is the climb to some "safe" altitude? other than getting to cruising alt, stay in the right airspace and keep the flight on schedule.

What made me wonder was noticing evening departures out of HOU with what seemed like a very shallow, low profile. I'm sure this was due to noise abatement procedure. My first thought was that seems like a safety compromise not getting as high as possible quickly. Does it matter?

In my experience (only a couple types), I'll answer you by quoting you: "the biggest concern on takeoff is reaching a safe altitude..." They don't fly well when an engine quits -- unless you already have speed and/or altitude. Some airplanes may be more kind. The DC-9-30 has 2 engines and max is 108k; the C-17 has 4 and max is 585k -- either one, if carrying anywhere near max, becomes a handful when one coughs. In the 727, if we lose 2 engines, we actually descend to get enough airspeed to clean up, or it won't continue to fly -- obviously the preferred method would be to have some altitude first.

Houston is unlike the rest of the U.S. They have no speed restrictions below 10,000. What you see is a very shallow climb while accelerating to best climb speed. You won't see airliners climb that way anyplace else in the U.S. In regard to noise abatement, this would be the opposite of noise abatement, but it helps the schedule. If one of those loses an engine, they have the benefit of speed (=can be traded for altitude if desired).

 

[flywithastick]

If you are talking HOU as in Hobby (which I imagine you are), then you quite possibly could be talking about Southwest. I have noticed at MDW, in visual conditions (read adequate visual references), that they will climb out at a lower pitch angle to provide more forward speed for their climb. This higher groundspeed helps decrease the enroute time, therefore helping on-time arrivals.

I've seen both. Yes it was SWA out of Hobby (about 8 mi south). Generally, during daylight hours they'll come over at their "normal" alt and speed. Occasionally they'll come by low and really hooked up. noticed one come over the house at what looked like <2000' and 300 kts.

What I see at night was them level or only climbing slowly at ~3-4000', moving at 200 kts or less and at a low (quiet!) power setting.

 

[FD109]

...do you climb with pitch above 15 degrees at climb power...

FlyChicago,

If it is of any interest to you, I copied a short excerpt from one operators FCOM where the normal takeoff profile is described. This operator flies DC-9-31, -32, -51, and -81 aircraft. The crews fly them interchangeably.

It describes expected pitch attitudes pretty well for the early part of the climb profile. Once you are above about 10,000 MSL the pitch attitude required varies widely from day to day and flight to flight depending on aircraft weight, OAT, engine power (normal, reduced, max, etc.)

There is a trememdous variation on pilot preference for climb schedules above 10,000. And, of course everybody thinks his personal preference is best.

If I'm really in a hurry for some reason (for instance, getting somewhere before a curfew, where fuel consumption would take second place to preventing a diversion) Barber Pole -10 for climb, descent, and cruise above 10000 seems to be about the "best time" climb/descent schedule in my experience.

One operator's normal climb procedure for the DC-9 and MD-80 follows: (When I OCR'd it none of the pretty graphics or fonts came through, but I think you can follow it okay.)

==============================================

At VR rotate to an initial pitch attitude of 17 degrees for the DC-9 and 20 degrees for the MD-80.

Note: For an engine failure at or after V1 initial pitch target is 13 degrees. Adjust pitch as necessary to climb at V2. See Engine Failure Profiles - Takeoff, Page T-8.

Rotation rate should be approximately 2.5 degrees per second from beginning of rotation to the target pitch.

Liftoff will normally occur at approximately 8 degrees pitch. If liftoff has not occurred by 10 degrees pitch, stop rotation at 10 degrees and hold that pitch until liftoff occurs.

CAUTION: A tail strike can occur with the main gear on the ground at 10.5 degrees pitch. This is especially critical on the DC-9-51.

Climb at V2 to V2+10, maximum pitch 20 degrees

Above 400 feet AGL or Obstruction Clearance Altitude if higher, retract flaps at flap retract speed

At 1,000 feet AGL decrease pitch to approximately 10 degrees and retract slats at slat retract speed.

Set Max Climb Power after slats are retracted and use Max Climb Power as indicated on the Rat/Thrust Indicator or the TRI during climb to cruise altitude.

Climb at 200 knots or minimum maneuvering speed whichever is higher.

Note: Limit bank angle to 15 degrees until at or above minimum maneuvering speed.

Leaving 3,000 AGL accelerate to 250 knots and climb at 250 knots.

Leaving 10,000 MSL transition to either low or high speed climb schedule.

Low speed climb: 290 knots until reaching mach 0.72 and then climb at mach 0.72 (IAS to mach transition will normally be at approximately FL235)

High speed climb: 320 knots until reaching mach 0.74 and then climb at mach 0.74 (IAS to mach transition will normally be at approximately FL235)

Note: The Normal Climb Profile described above ensures compliance with all obstruction clearance criteria unless the Runway Analysis Data for the takeoff runway specifies an alternate procedure.