Do standard operating procedures sometimes prescribe flare-less landings in case of areas of standing water/slush/ice on groove-less runways?

Faro

No SOPs that I have seen. On the A320 I fly, a 3 degree glideslope generally gives a rate of descent of about 600 - 700 feet per minute. That's a very firm landing if you don't flare!

In heavy rain or contaminated runways I tend to flare slightly less then normal and avoid a greaser, to touch down positively in the touchdown zone, allowing plently of runway left for stopping.

Well, there is the Navy saying about the AF,

Flare to land, Squat to Pee.

Dan in Jupiter

Quoting faro (Thread starter): Do standard operating procedures sometimes prescribe flare-less landings in case of areas of standing water/slush/ice on groove-less runways?

I've never heard of that in an SOP. You need to flare somewhat to arrest the normal descent rate. What is usually SOP is to *not* attempt to do a greaser and actually positively plant the gear down. That makes sure the autobrakes come on, the spoilers come up, and that your runway landing distance calculation is valid. The landing calculations assume a normal flare regardless of runway condition.

Tom.

I have never heard of something like that as well. When I imagine not to have flared in the MD11 with an approach speed of 175 knots... That would be a hard landing for sure.

wilco737
  

Quoting wilco737 (Reply 4): When I imagine not to have flared in the MD11 with an approach speed of 175 knots... That would be a hard landing for sure.

Not to mention the risk of wheelbarrowing.

Quoting faro (Thread starter): Do standard operating procedures sometimes prescribe flare-less landings in case of areas of standing water/slush/ice on groove-less runways?

Never seen one that has. A "firm" or "positive" touchdown may be advised, but simply driving it on without flaring? No.

Yeah there is nothing more useless than runway behind you!

The C-17 doesn't flare in the traditional sense (by pitching up). It actually flies at a constant angle until touchdown and increases the thrust just prior to touchdown to cushion the impact. This way the aircraft is accurately flown down onto the markers without wasting valuable runway. Of course this is especially important as this aircraft is frequently used on short unprepared strips.

Quoting DrEsteban (Reply 8): The C-17 doesn't flare in the traditional sense (by pitching up). It actually flies at a constant angle until touchdown and increases the thrust just prior to touchdown to cushion the impact.

It's not just thrust, it's also using direct lift control (thank you, Lockheed) with the spoilers to arrest the sink rate without altering pitch.

Tom.

Quoting Kaiarahi (Reply 5): Not to mention the risk of wheelbarrowing.

Well, unless the approach speed is excessively fast, there should still be no real risk of wheelbarrowing, since most airliners approach the runway with some sort of positive nose-up pitch angle. Others, however, could have a bit of trouble (such as the older CRJs, which typically come in nose-down until the flare).

Quoting DrEsteban (Reply 8): The C-17 doesn't flare in the traditional sense (by pitching up). It actually flies at a constant angle until touchdown and increases the thrust just prior to touchdown to cushion the impact. This way the aircraft is accurately flown down onto the markers without wasting valuable runway. Of course this is especially important as this aircraft is frequently used on short unprepared strips

I also recall something re the 747 when first launched in the late sixties; some tidbit about it its ability to land without a flare either i) with no impact on structure or ii) without a big shake-out being felt in the cabin. But then maybe that has more to do with ground effect than anything else; 741's were lighter than later versions.

faro

Quoting faro (Reply 11): I also recall something re the 747 when first launched in the late sixties; some tidbit about it its ability to land without a flare either i) with no impact on structure or ii) without a big shake-out being felt in the cabin. But then maybe that has more to do with ground effect than anything else; 741's were lighter than later versions.

I can positively say that my backside hurt after one arrival on board a 744.

Quoting gingersnap (Reply 12): I can positively say that my backside hurt after one arrival on board a 744.

Strange, as the 744 is one of the easiest plane to land. I am FO on 744 and it is so simple and easy to land that airplane... Simply love it.

wilco737
  

Quoting wilco737 (Reply 13): Strange, as the 744 is one of the easiest plane to land. I am FO on 744 and it is so simple and easy to land that airplane... Simply love it.

It was quite out of the ordinary compared to any other 744 arrival I've experienced. Usually it almost gently rocks itself onto terra firma from what I've experienced.

However, the situation was a 9:15a arrival on a wet morning into LGW onboard a VS bird. I've experienced some pretty rough landings in my time (including my first landing in a C152 ) but safe to say this is the only one that I would say gave me some sort of pain.
I can't be sure on the exact weather conditions of course being down the back so to speak, but it wasn't a sudden drop onto the runway. The descent rate appeared to be consistent, there was just no or very little in the way of a flare. One can only assume that the descent rate was perhaps higher than what may be classed as "normal". However, I've been on countless 747s and nothing seemed out of the ordinary, until touchdown of course.
However, they do say no flight is ever the same.

[Edited 2011-10-13 15:28:42]

[Edited 2011-10-13 15:29:31]

Quoting faro (Reply 11): I also recall something re the 747 when first launched in the late sixties; some tidbit about it its ability to land without a flare either i) with no impact on structure or ii) without a big shake-out being felt in the cabin.

It may not damage the structure, but a not flaring any of the 74 variants will certainly impact the occupants. A late flare, however, can be worse than no flare at all.

Here's the many time's viewed clip of an IL-76 landing in the typical nose gear first fashion. By the looks of it, I would say the flaps are able to extend past the ability of the elevator trim. Hence the need to land on the nose. Thoughts?


http://youtu.be/cclH8ZSDVOM

Another vid: http://youtu.be/C74ZXW2NlSY

The rate of descent seems to high for a normal approach though.
If anyone can tell the full story, I'd really appreciate it, I know it was some sort of test flight, but that is basically it...

[edit] After a brief search, a part of the NTSB report:

"The analysis of the go-around capability showed that if the go-around had been started at 50 feet it would have been completed successfully. During the engineering analysis, as the aircraft descended through 50 feet, the go-around was initiated with a 13.8' TEU elevator deflection followed 0.5 seconds later by the application of go-around thrust. With the elevators held at the position noted above, the aircraft rotated to a 11.8' noseup pitch attitude. The data showed that the aircraft would have descended 43 feet during the maneuver and cleared the runway by 7 feet.

During the DC-9-80 landing performance tests, a test pilot had made an actual go-around from 50 feet because of an excessive rate of descent (912 fpm) at that height. The aircraft was in the 40' flap landing configuration, its landing weight was 124,030 pounds, Vref was 128 KIAS, and the engine EPR's were 1.28 when the pilot began the go-around. At 50 feet, the pilot applied up-elevator and the elevators were deflected to 10 TEU. About 0.5 seconds after the elevator input, the thrust was increased to the go-around thrust, and the aircraft was rotated to a 8' noseup pitch attitude. Comparison of these data with the data derived in the go-around analysis above showed that the test aircraft's engines' thrust was slightly higher at the beginning of the maneuver. The elevator deflection on the test aircraft was the same as that used for the analysis; however, its noseup pitch attitude was 3.8' lower. During the actual go-around, the test aircraft descended 45 feet and it cleared the runway by about 5 feet. The data derived from the actual maneuver in conjunction with the data derived from the engineering analysis indicated that a successful go-around could have been made on the accident approach if the pilot had begun the maneuver at 50 feet."

[Edited 2011-10-14 13:11:14]

WN likes this because it gives you a higher Mach on the turnoff.

Quoting ThirtyEcho (Reply 18): WN likes this because it gives you a higher Mach on the turnoff.

  Good one, I've heard that as well from a Jumpseater or two lol

-2263

Quoting sprout5199 (Reply 2): Well, there is the Navy saying about the AF, Flare to land, Squat to Pee. Dan in Jupiter

What the h*ll does that even mean ?!

Quoting Max Q (Reply 20): What the h*ll does that even mean ?!

He means the Air Force are women...they flare to land (the Navy doesn't, at least on carriers) and they squat to pee (implying that they're women, as compared to the gents who generally pee standing up).

Note: provided for translation/understanding ONLY, not an endorsement of the sentiment.

Tom.

Quoting tdscanuck (Reply 21): He means the Air Force are women...they flare to land (the Navy doesn't, at least on carriers) and they squat to pee (implying that they're women, as compared to the gents who generally pee standing up). Note: provided for translation/understanding ONLY, not an endorsement of the sentiment.

I guess you have to be one of them to understand..

We test failure of the FLARE mode during autoland in the simulator. It is an awful scenario to experience. It has been known to trip the motion off.

I gotta share my favorite video on this subject:
http://www.youtube.com/watch?v=F2PwB5QCISQ

Dang, this looks so cute! .....is what I would say, if I hadnt experienced a similar landing in LCY leaving bruises in my butt