Thanks pacplyer. Indeed, the color differences between the smaller and larger part of the lake in the sat picture are deceptive.

Regards,
Green-dot

There is a strange contradiction in the crash site pictures.
The length of the debris field seems what one could expect from an aircraft crashing at climb-out speed.
However the picture of two engines sitting side by side and both pointing the same direction implies low fwd speed.:confused:

The fact that all three engines seen in the pictures show little to no rotational damage has me puzzled.
Even at idle RPM I would expect to see more damage done, either by flattening of the fan case on impact, or by dirt and debris being ingested.

The cockpit interior pictures are a grim reminder of what Murphy will do given the oppertunity.

Thoughts with all affected :(

Did you note the severe fan damage to the 4th engine as well? That appears to be the cacass without a fan case visible.

So what does hitting a house do to an engine?

Huck:

KSEA-FAJS direct on a delivery flight with pre-cooled fuel IIRC.

Standardization of audio controls
 

Some guys on the line can't comment for obvious reasons.

Question to retired guys:

High altitude 747 t/o's are essentially semi-unpressurized, packs off, (which is different than some jets that allow a pack to run at t/o on apu, IIRC

I can't get to my books out here, but I seem to remember a high altitude procedure & charts where all bleeds are kept off until clean up. This ensures extra power for first, second, and final segment climb capabilities.

Operational profiles are different at different carriers but, we used to typically call for climb power at 1500ft AGL and then level off to accelerate at 3000 feet AGL. After flps 1 call, IIRC, the bleeds would be re-opened as to provide PDU function for the slats retract call typically at around 220kts according to weight.

Bogota's 8400 ft field elevation plus 3K equals 11,400 meaning a cabin altitude warning horn would go off at cabin altitude of before 10K, right? Did you don masks before t/o?

We have a second-hand report from a cab driver that the crew were wearing Oxygen Masks when found. My reason for focusing on this is that we had at least five different types of audio selector in our fleet of 747's when I flew it. It was not a simple thing in the dark to don the mask and wrestle with a dirty, poorly lit, confusing unit that was different than the simulator. Some you flipped a switch, others you flipped two switches, some you lifted and turned a knob and flipped a switch, some you depressed a button and turned two knobs .... and if you didn't get the speaker volume and selector volume up, you just wasted your time and had to start over again. I just can't see how anybody could do a good job navigating or communicating with this damn impediment in play.

Back before de-regulation, carriers had the money and the safety culture to attempt to standardize fleet cockpits. Not saying that this had anything to do with the Bogota accident. But this could have been a factor. JMHO's only.

It's clear to me at least, that deregulation of airlines, banks and oil just hasn't worked out at all!

pac

pacplyer . . .
 

One pack goes on at 400AGL, it's included in the performance criteria, including 3-eng climb. Nobody wears oxygen masks at BOG [8360], unless perhaps you're a heavy smoker and have difficulty breathing.

Pax 74s had been operating into BOG [AV- Avianca] way back in the 70s; bleeds are not kept off during the inital climb. It's an elementary certification criteria; if the airplane couldn't climb on 3-eng with pressurization capability, then it wouldn't be certified to operate at this high altitude airport.

By the way, 74s also operate into UIO - Quito, where the elevation is 9226 feet. :ooh:

74 classic bleeds are on for take off-they run the adp's to help gear retraction. As previously stated first pack on at 400 feet. Take off is always unpressurized. The Connie birds are actually very well equipped. Glass adi/hsi, dual fms, in all a/c; electronic flight bags in most soon to be all. Not typical of the "bottom feeders" as many are ignorantly trying to assert. Take off performance is computer based for each specific runway and of course always takes into account an engine loss on take off. That was a very experienced crew and I really don't see this event as being as simple as a single engine loss on departure.

No Bleeds = No Packs
 

glueball & Junkflyer (man, you gotta change that screen name!),

Isn't there a field in Lima Peru or someplace in Peru that has a Takeoff above 10,000 ft field elevation? Maybe that's where a "bleeds off" t/o is required in the performance charts in ground school. The supplemental procedure would be part of the individual airline's AOM as approved by the POI. The data it is derived from would come from Boeing performance data/charts in Seattle. I don't think its a case of a binary question of: are bleeds off required or not required by certification data. At certain high gross weights if an operator wishes to avail himself of that higher weight capability he must find a way in the already certified master 747-200 performance data at boeing to allow that heavy-high operation. The gain might be another 8,000 lbs of permited TOGW for example if all four bleeds are selected off until after cleanup.

I could have sworn there was a (packs off & three bleeds off then?) procedure and charts for this but maybe you guys don't do this anymore. If I can find it I'll have to post it up here in about three months when I get back to the states. In the meantime, I'll just have to take your word for it guys. :O

Cheers & thanks for the insight.

74s are not certificated to operate from fields above 10,000 feet.

In South America, the highest major commercial airport is at La Paz, Bolivia [LPB/SLLP] 13,313 feet; In Peru there is Cuzco [CUZ/SPZO] at 10,855'

That's it. And agreed, 10,000 ft is the absolute limit for certification t/o and landing. (But now I'm positive that there's a two bleeds off t/o performance chart, now that I think about it..... ) Right?

Just thinking about operating this high is giving me a nosebleed though! :uhoh:

747 classic bleeds are open for take off not just for air driven pumps.Leading edge flaps are also air driven. Many years ago [LH I think] did a bleeds off departure [in error] = no leading edge flaps =crash.

Manley,

Not to pick nits, but the leading edge flaps (e.g. inboard krugers) are actually hydraulically operated. They droop open on the ground until ADP's (air driven hydo pumps) are turned on or engine-driven hydro pumps start up. The fiberglass leading edge slats, however, are air-driven, activated by the PDU's (Pnematic Drive units.) But you don't need those until the "Slats retract call." It won't crash loosing air because the PDU has an internal locking mechanism. It is well known that inop bleeds can be defered and wired shut. MEL restrictions then apply.

Agreed, some bleed is needed to pressurize the air "head" on the hydro reservoirs, ADP gear service assist etc. So I guess the 4 bleeds off was the 146 or something.... my apologies.

I remember that you can t/o with the apu running (you actually get 600 lbs extra thrust out of it! But can't count that.) Refresh my memory here.... can the APU supply any elect or pnem demands during t/o (per ops procdrs)? Maybe it was just for back up....

I'm doing pretty good on this oral, huh?

Hand me a bigger shovel so I can dig deeper.... :}

One regular destination of the -400F is LTX with an elevation of 9200ft.
3 Packs-off take-off can be done, but normally not needed over there.
In NBO it's often a necessity. After thrust reduction in climb-out one by one the packs on again. Gives indeed some gain. Bleeds always remain on, though.

pacplyer,

I'm not sure which A/C you are talking about (727?) but the 747 LE krueger and variable leading edge flaps are all pneumatic with electrical back up.

Manley, & SMOC,

You are right, they are air driven, my mistake. Manley, you may also be right about the 747 crash, but I am not aware of the leading edge device accident you refer to.

Thanks guys for keeping me honest.

Cheers

Excuse the human diversion from this important analysis:rolleyes:

Does NO-ONE have news of the recovery of the injured?

BOAC,

Fruitless Analysis over. I yield the floor.

Most of the injured will be returning home shortly. Kalitta flew families there to be with the crew and to bring them home.

Link to 747 crash Nairobi:
ASN Aircraft accident Boeing 747-130 D-ABYB Nairobi-Jomo Kenyatta International Airport (NBO)

Regards