Re: aborting takeoff AFTER V1

Not at all. I'm as baffled as you are that this discussion is happening. Certainly we can sit and discuss this sort of thing from a theoretical perspective, but out there in the real world a high speed reject is one of the riskier things we do. It's not something you really want to fiddle with on t...

Re: aborting takeoff AFTER V1

Hope you guys aren't aiming any of this shock at me directly. I agree with everything that's been said in this thread.

Re: aborting takeoff AFTER V1

Boeing manuals state the only reason you ever reject above V1 is if in the Captain's judgement the airplane is incapable of safe flight. This is consistent with what the experienced pilots on this thread have stated. Yes, including me. If you read back, I'm giving a vague non specific example of th...

Re: aborting takeoff AFTER V1

Well, "if you've got a really long runway and you know you'll stop..." then V1 = Vr so the point is moot. Point taken but it's still discussed: V1 has been called (and the silent decision to go has been made) and as Rotate is called a fire bell goes off. You've still got 2.5km of runway a...

Re: aborting takeoff AFTER V1

In short, if the aircraft is unsafe or unable to fly. In other words, incapable of sustained flight. Post-V1 rejects should not form part of any normal takeoff brief or considerations. I see a worrying number of discussions between supposedly experienced pilots on this topic, normally starting with ...

Re: Boeing OPT

Are we talking 737? It's quite common to get a small split between the indicated reference N1 and the N1 generated by the OPT. Normally due to differences in actual ambient conditions vs. the data used for performance calculation. For example, if we used an OAT of 18C in our calculations but the act...

Re: Queenstown, NZ operations

Don't forget Qantas, who pioneered RNP-AR into Queenstown. The RNP 0.10 approach for runway 23 will take you down to 250', so very close to ILS minima. A little scary the first time you fly it close to that in IMC, in such a terrain rich environment. ZQN operations always require a full alternate re...

Re: 737 weight restriction on short hop

[url][/url] When flights are short you encounter max landing weight issues. The flight is weight restricted not because it's too heavy for takeoff. It's too heavy for landing. Or the flight isn't long enough to burn the fuel to get the aircraft weight below max landing weight. Our airline for PAP fl...

Re: 737 weight restriction on short hop

I'm confused by all the people saying "especially on short flights", though If I understand it correctly, it's because on a short flight that takes off at MTOW, you're unlikely to burn enough gas during the flight to get you below your Max Landing Weight. So you have to cut the payload. I...

Re: 737 weight restriction on short hop

Not wrong at all. The max takeoff weight is often limited by the max landing weight. Especially on short flights. Actually, I agree with him. Nobody is arguing that TOW is not limited by MLW. I'm confused by all the people saying "especially on short flights", though. On the 738s I operat...

Re: Multiple engine run ups on the runway AA738

Standard cold weather procedure in the 737 in visible moisture (rain etc.) in temps at or below 3 degrees C (37 deg F) is a 30 second runup at minimum 70% N1, at intervals not exceeding 30 min, to "minimize ice buildup". For a normal taxi-out and ATC permitting this will be done at the sta...

Re: 737 weight restriction on short hop

When flights are short you encounter max landing weight issues. The flight is weight restricted not because it's too heavy for takeoff. It's too heavy for landing. Or the flight isn't long enough to burn the fuel to get the aircraft weight below max landing weight. Our airline for PAP flights thoug...

Re: Typical fuel reserves for a 737-800

Haven't seen that thread -- if you're talking about the normal -800W, fixed fuel reserve on most of the flight plans I see is around 1.2 tonne, give or take, (equivalent to 30 minutes), plus a variable reserve of 5% of the trip fuel. Even on the most perfect of perfect days though, we'll never be fl...

Re: About APU start up / Shut down

I knew about the 4 engine airbus', but I'm still surprised about taxying on 1 generator on the 330. It's quite rare in aviation to have no redundancy. But the A320 is well known for its electrical transients. Quite normal to taxi in with one engine shut down and no APU running, we do it all the tim...

Re: About ILS APPR

SINGLE CH - the aircraft has approach mode (I.e. tracking both localiser and glideslope) engaged, but only one autopilot channel engaged. The 737 requires both autopilot channels (A and B) to be engaged prior to 800' for autoland capability. FD - Flight Director. This means the Flight Director is ac...

Re: About ILS APPR

At 300AGL (+/-) should I let the G/S run upwards ? or in case of glide slop you always keep in the middle? Cuz it's hard to keep it in the middle a moment before landing. I know LOC should always be in the middle. Assuming you mean in visual conditions, at 300' you'll naturally transition to a visu...

Re: Tailwinds during takeoff

As above. My operator has the 15 knot tailwind limitation for the 738. If a tailwind exists or is likely to exist (for instance, if the wind is reported as variable) that will be factored in the takeoff performance calculations. Unlike a headwind component where we can accept a reduction in headwind...

Re: question regarding speed at altitude

Bellerophon wrote:

OzzyPirate

At max (certified) altitude with 140 kts between MMO and VLA.

Not a modern jet though!

Best Regards

Bellerophon

Re: Why board from just one door?

My 2 cents, and maybe I'm crazy, but I have always thought airlines should board from the rear door only. Number the boarding passes in order from the outsides of row 1 to the aisle, followed by row 2, etc, ect, and fill the plane from the rear door, but from front to back. Everyone has to line up ...

Re: I once saw Southwest take off, left of the centerline at SAN

Not trying to be too much of a detective here, but you say you were driving when you saw it, so from this can I assume you were only visually "lined up" with the runway for a very short period of time? If this is the case, there could be any number of reasons for a momentary deviation from...

Re: question regarding speed at altitude

Most modern jets at cruise altitude (could be several thousand feet below max altitude) have less than 20kts of *indicated* airspeed difference between aerodynamic stall and never-exceed speed. Sorry but I can't agree with that, unless you're defining max altitude as certified maximum only. If you'...

Re: question regarding speed at altitude

I am no expert, and you two can probably add something to what I have to say, but what you describe here should probably be put into perspective. AFAIK most passenger airplanes at cruise level are very close to stall speed and maximum speed at the same time, especially when heavy. E.g. a heavy 773 ...

Re: question regarding speed at altitude

What you say in your last sentence would be true if jet engines produced uniform thrust from sea level to cruise. In reality, altitude is a double-edged sword - the air is a lot thinner and thus higher True Airspeeds (and therefore groundspeeds) are attainable, but jet engines have significantly les...

Re: Question about cabin temps

Getting the temperature just right in the 737 involves a fair bit of trial and error, quite often involving the cabin crew calling the flight deck to say the temps are too low or too high. It's one area of control we wish we could hand over to the cabin, like on Airbus types and I'm assuming the lat...

Re: QNH

There are hundreds of military Z and Q signals that have significance when applied to Morse transmission. QNH is one of them... I've heard people say the NH stands for "Nil Height", this terminology isn't technically correct, and it may be untrue (it's nil altitude, not height), but there ...

Re: Circling on approach

Some interesting responses in this thread. To the OP - I've always known those maneuvers as orbits in this part of the world. You may get asked to "conduct one left hand orbit" to delay arrival without entering a formal holding procedure. Or you may request one to lose height if you're too...

Re: Climb Path Angle

Some possible confusion creeping in between the three (edit, four) terms: Flight path angle = the angle of the vertical flight path relative to the ground. Will be expressed in degrees, or percentage. Not to be confused with vertical speed (I.e. rate of climb). An airliner on initial climbout might ...

Re: LETDOWN

Ok. I'd obviously heard the term but never really thought it applied to anything specific or formal, just more of a slang term for an IAP.

Re: LETDOWN

"Letdown" isn't a formal term for anything. Are you talking about types of instrument approaches?

Re: Taxiing speed

Perhaps a stupid question... Is there some kind of wheel speedometer? I'm assuming the airspeed is not live at speeds as low as 30 kts. Thanks. On all modern jets, we just use the groundspeed display on the ND, which is derived from GPS data and will be accurate. 30kts is our company limit too, and...

Re: Engine Fuel burn question

Too many factors for a single answer, but to give you a ballpark figure, in the 738 our cruise fuel flows will generally be around 2.1 to 2.6 tonne/hr (for both engines combined), depending on weight, flight level, temp, cost index etc., with TAS normally around 450-460.

Re: How did the infamous 748 wing wave recover from its stall?

Max Q, Purely from a safety perspective (i.e. forget about whether the maneuver was approved, briefed etc.), I'm curious as to how you see it as any less safe than the video below. Yes, they're most likely test pilots flying the 787 -- but we have no idea who was flying the 748, and I'm guessing tha...

Re: Altimeter

As above, and in this part of the world, we set the altimeters to a hPa scale, which is around 30' per increment, and we can still depart with the Capt and FO altimeters disagreeing by as much as 50'. So they're accurate enough for what they're used for, but nothing more precise than that (such as D...

Re: How did the infamous 748 wing wave recover from its stall?

Well said mmo.

If you want to restore a tiny bit of faith in this forum, just read a few of the expert YouTube comments on the OPs vid.

Re: How did the infamous 748 wing wave recover from its stall?

It amuses me that we're discussing/arguing angle of attack based on a shaky telephoto video from the other end of the runway. It wasn't stalled, and you cannot in any way determine the angle of attack from this video. As for the maneuver itself, it's no different to the B787 Farnborough touch and go...

Re: What we’ve learned from Eastern Air Lines flight 902

The article implies "firewalling" the throttles as SOP when severe wind shear is encountered, and that firewalling damages engines. Is "firewalling" the same as TOGA power? If it is not, is TOGA used in severe wind shear situations? I assume TOGA does not present much of a threa...

Re: Takeoff procedures for different airlines

Everything said above... and also remember there are many legitimate ways of manipulating V speeds, configuration and thrust to achieve a particular performance outcome (look up "improved climb", for instance). Just for a quick example of how much assumed temperature (reduced thrust) takeo...

Re: Vert Nav Correct setup?

A SINK RATE alert is a GPWS alert, it means you're descending too fast for your height above the ground, and it will often precede a hard warning (e.g. a PULL UP alert) if not corrected. A descent rate of 2,500fpm at or approaching 2000' is not acceptable in a jet. And without knowing anything about...

Re: Local coordinates at apron

We generally use the aircraft's present position GPS coordinates to initialize the inertial units. So what is the function these days of the INS if the airplane knows where it is by GPS? The aircraft doesn't navigate off a GPS position, it navigates off the FMC computed position, which just happens...

Re: De-acceleration options at touch down

The Boeing procedure also calls for a callout by the Pilot Monitoring to confirm "SPEEDBRAKES UP" or "SPEEDBRAKES NOT UP" after touchdown. The 787, 747-8, and KC-46 also have a Time Critical Warning with an aural and text on the PFD that says "SPEEDBRAKE" if the speedb...

Re: De-acceleration options at touch down

Are you sure there was zero spoiler deployment? Spoilers/speedbrakes are crucial to braking performance -- losing an entire hydraulic system on the 738 will still leave half the spoilers operational, they're checked as armed during the landing checklist, and they're verified up immediately after tou...