Challenger crash at KASE

[Capn Bloggs]

That video, and the profile flown by the G3 in 2001, demonstrates all that is wrong with Dive and Drive. No pre-planned profile, bouncing off steps (or going through them) ... a recipe for disaster.

[lifeafteraviation]

It wasn't unusual for chartered business jets to have only one set of approach plates to share with both pilots.

It wasn't just about being cheap and not paying for an extra set. A set of Jepps for the entire USA takes up about seven or eight fully packed volumes. Add to that your nearby countries...Canada, Latin America, Caribbean and regs. Now you're looking at a pretty huge collection of charts to carry around all day in a small jet with limited space. Then think about all the updates!

Most companies now use EFBs anyway and are required to have two.

[ETOPS240]

Wow, that seems like a well-standardized operation!

[thcrozier]

atan((11700-7680+55)/(5.7*6076))=6.71 degrees.

atan((11700-7680+55)/((3.15+2.65)*6080))=6.59 degrees.

The published 6.59 degrees probably eliminates cumulative rounding errors.

So, with the 3.5 degree VGSI also at a TCH of 55 feet, it seems to me you'd be seeing a lot of white lights all the way from DOYPE to the threshold unless you push over into a far steeper descent angle somewhere in between.

Using the same logic, in order to intercept the VGSI 55 feet over the threshold, you would need descent angles of 7.59, 8.23, and 8.94 from the MAP (CEYAG) for Categories A, B, and C, respectively.

In fact, assuming the TDZ is 1000 feet down the runway and TDZE is 20 feet higher than the threshold, from CEYAG it's a 7.26 degree descent angle to the TDZ for Category A.

atan((9840-(7680+20))/((2.6*6076)+1000))=7.26 degrees.

Speculation Alert: Perhaps they maintained MDA all the all the way to CEYAG and then attempted VGSI intercept before reaching the threshold, resulting in excessive speed and a very steep descent angle.

[physicus]

it's pretty standard to be "too high at the MAP" in a non precision approach… the MAP is not the end of the approach, it's the commencement of the missed approach! Big difference...

[acroguy]

I doubt that there is anybody reading this who hasn't seen the runway at the MAP on a non-precision approach but been too high to land. That was the point of a previous poster in this thread. 6.59 degrees from the FAF to the MAP in a jet at +25 tailwind is a problem. Turboprop, doable. Piston doable.

[Capn Bloggs]

Originally Posted by Crozier

Speculation Alert: Perhaps they maintained MDA all the all the way to CEYAG and then attempted VGSI intercept before reaching the threshold, resulting in excessive speed and a very steep descent angle.

This is a circling approach. If you get Visual far enough out to duck down to the PAPI, well and good, but as physicus points out, considering the angles from the MAPt to the threshold is purely academic and a bit meaningless.

[acroguy]

But the Challenger is Category D, so there are no circling minimums.

[thcrozier]

This is a circling approach. If you get Visual far enough out to duck down to the PAPI, well and good, but as physicus points out, considering the angles from the MAPt to the threshold is purely academic and a bit meaningless.

Is it academic and meaningless if it convinces the pilot not to try the maneuver?

From the Approach Plate: Paraphrased - "From DOYPE 6.59 degree descent angle to TCH 55". Exact quote - "VGSI and descent angles not coincident (VGSI Angle 3.50/TCH 55)."

Certainly that information is not intended to be ignored as "purely academic and a bit meaningless."

I no longer fly myself around; but I hope that the pilots in whose hands I place my life, seeing information such as cited above, fully analyze its implications before flying an approach. I always did.

[Capn Bloggs]

Originally Posted by Crozier

From the Approach Plate: Paraphrased - "From DOYPE 6.59 degree descent angle to TCH 55". Exact quote - "VGSI and descent angles not coincident (VGSI Angle 3.50/TCH 55)."

Certainly that information is not intended to be ignored as "purely academic and a bit meaningless."

I agree, but you were talking about angles from the Mapt (CEYAG) to the threshold. That is purely academic. If a pilot needs to get out his calculator to work out the approach angle for 2400ft AGL at 2.6nm from the threshold I strongly suggest you keep away from him.

But the Challenger is Category D, so there are no circling minimums.

So I assume all those nice shiny Cat D speed machines shown parked on Goooogle Earth landed there with VMC below the MSA...

[thcrozier]

As I said, I threw out a speculation, a hypothesis, a possible explanation for what witnesses described. The investigation will show whether there is any truth to it.

I guess I don't understand the point of your comments. What are you trying to accomplish with them?

[msjh]

Easy

Well, I've just watched Space Cowboys for the 3rd time and I reckon Clint Eastwood could grease it in.

[Capn Bloggs]

Interesting track - seems like a circle to land, followed by a missed, followed by a short approach for the 2nd shot???

Maybe, or one approach broken off early, one missed, and then one close in pattern to touchdown??

I plotted the Flightaware times on the map and as far as I can tell they did a big lazy orbit at high altitude over the area, then did one proper straight-in approach, missed approach at the charted Mapt then did another proper instrument approach. All looks "proper" from what I can see from Flightaware (notwithstanding the cloud and Cat D operation...). No pirouettes or low-level wiffodils...

[hawk37]

No training with less than full flaps??

MFS,

Very interesting. Is there any relief for training situations? I know of a large outfit that for years practiced even flapless landings in the 600 and 601. (Maybe they were only touch and go's for flapless). So would factory pilots be unable to allow in aircraft training for a landing with less that full flap?

I realize most training is accomplished in the sim now, but for years that was not the case.

Can anyone remember Canadair (bombardier) training pilots allowing less than full flap landings?

[lifeafteraviation]

Very interesting. Is there any relief for training situations? I know of a large outfit that for years practiced even flapless landings in the 600 and 601. (Maybe they were only touch and go's for flapless). So would factory pilots be unable to allow in aircraft training for a landing with less that full flap?

I realize most training is accomplished in the sim now, but for years that was not the case.

Can anyone remember Canadair (bombardier) training pilots allowing less than full flap landings?

No, of course you can't fly outside the AFM limitations during training or for any reason other than a test pilot doing certification flights or to handle an emergency.

If you figure out some way to creatively second guess the manufacturer and invent your own techniques that are outside the recommended operating procedures but not directly exceeding any published limitations you will likely still be faulted for an accident if you have one. It won't matter that half the other operators are doing this. If your training center is teaching such practices they may be faulted as well.

Just because people may have done something in the past doesn't mean it's legal or safe, even if it was considered normal behavior at one time.

Lawyers love this kind of crap because it makes them rich...so don't do it.

[acroguy]

Quote:
But the Challenger is Category D, so there are no circling minimums.

So I assume all those nice shiny Cat D speed machines shown parked on Goooogle Earth landed there with VMC below the MSA...

I assume that they shot the LOC DME approach without a 25+ knot tailwind and landed straight in.

[aterpster]

acroguy:

I assume that they shot the LOC DME approach without a 25+ knot tailwind and landed straight in.

That approach doesn't have straight-in minimums for any approach category nor does it have circling minimums for approach category D. So an approach category D airplane cannot legally even begin that approach.

[A Squared]

Originally Posted by lifeafteraviation

No, of course you can't fly outside the AFM limitations during training or for any reason other than a test pilot doing certification flights or to handle an emergency.

What about a type rating checkride in the airplane? IIRC a no flap landing is a required element of a type rating ride. Seems like there's a few other things which would be required in a check ride which may not be approved for normal, non-emergency operations, like OEI maneuvers.

I agree that it appears the AFM would expressly forbid partial flap landings on a normal flight, but there's a lot of non-normal stuff that goes on on a checkride, often with the FAA on board.

[Desert185]

Is there an abnormal procedure in the Challenger book for doing a no flap landing, or will they always come down? Hard to believe there isn't an additive schedule for at least partial flaps.

[Mad (Flt) Scientist]

There is of course an abnormal procedure, the issue is that it for a failure case, not for a "selected" partial flap landing. For some training scenarios there is wording in the AFM to allow for deviation from the "normal operating" AFM limitations and procedures, but I don't know from memory if partial flaps is one such case. Often such things are in a "supplementary procedures" section with explicit permission stated to do the specific task.

edit: the only specific references to training appear to be related to the speed limits, where flight above VMO/MMO or below min speed is allowable under specific training conditions, and a change to the ADG speed limit for testing deployment cases. I don't see anything to allow for intentional reduced flap landings, for training or any other purpose.