Matt D
Topic Author
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Slam Dunking

Sat Jan 12, 2002 5:00 am

Can anyone give me any information on "slam dunking"?

Do pilots like it?
Do passengers hate it?
Why do pilots do it?

Slam dunking, for those that do not know is when a plane is coming in "high" on approach, and then rather than do a "go-around", the last 3 or 4 ground miles of final approach, the pilot almost literally puts the plane into a nose dive (pitched down 30 degrees or more) and then levels off and flares just before or just as he crosses the runway numbers.
 
PanAm747
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RE: Slam Dunking

Sat Jan 12, 2002 5:25 am

That maneuver is called a "slip".

The pilot puts in opposite rudder and aileron and puts the plane into a nose dive aiming for the numbers. This is usually done to correct an error, when you didn't put in the right flap settings or didn't properly reduce power.

The only thing that is different from a normal approach is the steep descent. But as soon as he has the field made and he starts his flare it is the same approach.

Good things:
Doesn't waste fuel/time doing another approach while the pax are waiting for their connections

Bad things:
Pax would probably freak out when they are descending like that.

I have never seen that in commercial flight, but I assume it is very safe.

I've done it many times in my flight training
Pan Am:The World's Most Experienced Airline - P(oor) S(ailor's) A(irline): San Diego's Hometown Airline-Catch Our Smile!
 
EGGD
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RE: Slam Dunking

Sat Jan 12, 2002 5:31 am

Oh yeah, i had my first experience of this 'technique' coming back from YYC at the end of December, after we had 4 White lights on the PAPI. Although we levelled off a long way before the threshold to the runway.

Pretty frightening if you are not a good flyer, but I am used to nose down approaches with KLM anyway so it was really fun!

Regards

Dan
 
mhsieh
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RE: Slam Dunking

Sat Jan 12, 2002 5:43 am

I don't think you can side-slip a jet airliner on final...the engines will flame out
Any airline pilots out there who can verify this?
 
Matt D
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RE: Slam Dunking

Sat Jan 12, 2002 5:59 am

Well we must not be on the same page cuz I've seen lots of planes (for some reason Southwest in particular) on approach to ONT look like they are too high to land without doing a go-around, then right before they cross over the Interstate 15 Freeway (about 2 miles east of the threshold), they just drop like anvils, and the plane is pitched down about 30 degrees.

THAT is what I am referring to.

I don't see why coming in high to ONT should be an issue; it's a flat and level terrain (2 or 3 story tall industrial buildings notwithstanding) approach.
 
PanAm747
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RE: Slam Dunking

Sat Jan 12, 2002 6:02 am

Is it because of noise concerns?

Did you see GWB last week at ONT?
Pan Am:The World's Most Experienced Airline - P(oor) S(ailor's) A(irline): San Diego's Hometown Airline-Catch Our Smile!
 
Matt D
Topic Author
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RE: Slam Dunking

Sat Jan 12, 2002 6:10 am

Noise abatement on (westbound) approach to ONT?

I find that highly unlikely considering that pretty much everything under the flight path for about 20 miles east of the airport is nothing but semi rural and industrial land.

However, in cases (such as yesterday and probably today) when the Santa Ana's are blowing, and the planes run in the "opposite directions" (switch from rwy 24 to 6 ops) THEN I could see that being an issue because almost everything to the WEST of ONT is residential.

I couldn't see G-Bush cuz I had to work.

However, on Saturday or Sunday afternoon (can't remember which) after I got home from work, I saw a c-5 Galaxy depart from ONT. (I live about 5 miles west-south-west of the airport).
 
Tom in NO
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RE: Slam Dunking

Sat Jan 12, 2002 7:14 am

Doesn't 'slam-dunking' take up an entire chapter in Southwest's Pilot Operations Manuals?  Smile They do it here all the time.

Tom in NO (at MSY)

PS: I was on a UA 737-300 at Stapleton one day that did a missed approach to 8R, then came back around and slam-dunked.
"The criminal ineptitude makes you furious"-Bruce Springsteen, after seeing firsthand the damage from Hurricane Katrina
 
TWA717_200
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RE: Slam Dunking

Sat Jan 12, 2002 7:29 am

Taken from Wade H. Nelson's The Gimli Glider:

(http://www.frontier.net/~wadenelson/successstories/gimli.html)

Approaching runway 32L he realized he was too high and too fast, and slowed to 180 knots. Lacking divebrakes, he did what any sailplane pilot would do: He crossed the controls and threw the 767 into a vicious sideslip. Slips are normally avoided on commercial flights because of the the tremendous buffeting it creates, unnerving passengers.

I HIGHLY recommend reading this story at the link above.
 
Jan Mogren
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RE: Slam Dunking

Sat Jan 12, 2002 7:40 am

Pitch down 30 degrees or more?
Don't think so..
/JM
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Minuteman
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RE: Slam Dunking

Sat Jan 12, 2002 11:22 am

Slam Dunking has nothing to do with sideslipping.

Basically it's where an aircraft has to lose a lot of energy in a short amount of time and distance.

Picture an aircraft on downwind with ATC keeping his speed and altitude up. Then abruptly clearing him to land while still close in.

As far as I know, the conditions are barely perceptable to passengers, but its a relatively high activity time on the flightdeck. Basically it make a stabilized approach more difficult.
 
redngold
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RE: Slam Dunking

Sat Jan 12, 2002 11:51 am

I one time saw that done by a CO 737-300. The pilot called in as CO9995. It must have been a charter or ferry flight. He said he was "on a high right base" and as he approached, he must have still been at 1,000 ft. only 1/2 mile out. The ATC actually called him and said "are you going to go around?" and the pilot said "no, I'm going to do this." That plane slammed the runway so hard I thought it was going to blow tires!

redngold
Up, up and away!
 
flydeltasjets
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RE: Slam Dunking

Sat Jan 12, 2002 12:20 pm

We would never slip a jet (unless we were in the same situation as the Gimli glider!). We refer to a "slam dunk" when we are on a high and fast downwind, expecting a long final approach, and then are turned base or cleared for the vis. It is actually a lot more fun than the standard vectors for an ils! Basically we pull the power, hang the gear and flaps as quickly as possible, and use spoilers if necessary. If done correctly, we should be stabilized and configured by 1000 AGL, and if not by 500AGL, we go around. If your pilots are still struggling to get it stabilized and configured below 500 feet, he is taking an unnecessary chance. It has bitten many a pilot.
 
cedarjet
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RE: Slam Dunking

Sat Jan 12, 2002 12:20 pm

30 degrees nose-down! Yeah right.
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz
 
ryu2
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RE: Slam Dunking

Sat Jan 12, 2002 12:23 pm

Was that WN 737 that overran the runway at BUR considered "slam dunking"?
 
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lindy field
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RE: Slam Dunking

Sat Jan 12, 2002 12:31 pm

Matt D is right--Southwest pilots "slam dunk" their aircraft very frequently at SAN. I've seen it a number of times--and with the exception of American Eagle and Skywest Commuter props--nobody else is doing it! I had always assumed it's part of the Southwest strategy to turn planes around more quickly.
 
MD88Captain
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RE: Slam Dunking

Sat Jan 12, 2002 12:55 pm

Getting "slam dunked" is pretty common. It basically means that ATC clears you for approach when you are closer to the airport than is normal or higher than normal or both.

Pilots complain about the "slam dunk" because it puts them in a high tempo operation not of their choosing. But I would guess that many (most) pilots enjoy the opportunity to use their flying skills to get the aircraft on the ground comfortably when they get "slam dunked". It is a challenge and most aviators I know love a challenge. And if we dick it up and have to go around we can always blame ATC.

Now pilots can get high close to the airport all by themselves. Sometimes in an attempt to save gas we will keep the speed up and the plane clean until we get very close to the airport. Then we wipe the power to idle and throw out flaps and gear to slow the aircraft. A perfectly flown visual will see the pilot configure at a point that slows the aircraft just right so the plane maintains a 3 degree glideslope and a stabilized approach that has the engines spooled back up below 1000'. This assumes you are cleared number one to the airport, you are comfortable with your aircraft/and situation, and that you can do it safely. I always welcome the chance to try to hit it perfectly. Again it's the challenge thing.

As for slipping a jet. I do it all the time. In cross wind conditions I will typically fly the wing down/top rudder technique. And I believe that is a slip.

30 degrees nose down????????? Never ever in a commercial jet. It's extremely rare to see 10 degrees nose down. Did you know that the B1 bomber cannot go 30 degrees nose down? A B1 pilot told me that the wing will blank out the stab in an extreme nose down condition and the plane becomes unrecoverable. That could be BS, but that's what he told me.
 
flydeltasjets
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RE: Slam Dunking

Sat Jan 12, 2002 1:08 pm

MD,

You are right...I guess I should have been more clear. I would never slip to lose altitude.
 
gocaps16
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RE: Slam Dunking

Sat Jan 12, 2002 1:33 pm

I was on a Continental MD80 on appoach to IAH an the pilot did a slam-dunk approach to the airport. We were descending at like 4000 fpm.

Kevin/DCA
 
MD88Captain
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RE: Slam Dunking

Sat Jan 12, 2002 2:44 pm

Flydeltasjets. I can't imagine slipping to lose altitude either. It would freak out the pax and fa's. I miss the 727 for that kind of stuff. That thing would come down in a big hurry.

I heard from an ATL assistant CPO today that the 727 retirement date has moved up to next summer ('03). And he said it could be quicker than that. Then over at the training center I heard from an initial classmate that I met is the hall that we are taking 11-15 planes from BA that we couldn't defer. 737-800's and 767-400's. Good rumours.
 
flydeltasjets
Posts: 188
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RE: Slam Dunking

Sat Jan 12, 2002 2:48 pm

heard the same thing on the ALPA message boards...seems boing made us take them...heard it was 18...sounds good to me
 
HlywdCatft
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RE: Slam Dunking

Sat Jan 12, 2002 4:15 pm

I've seen Southwest do that a couple times on approach at DTW, they even flew over the runway threshold high and then dropped down
 
L-188
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RE: Slam Dunking

Sat Jan 12, 2002 7:15 pm

Are there bad neighborhoods on the final?

I ask because the last time I read stories about pilots flying a landing like that was in the book "Tiger Tales".

In their case they where flying rice into Cambodia in the late 1960's. They where flying that approach to keep from gettin extra holes in the aircraft.
OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
 
cv640
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RE: Slam Dunking

Sun Jan 13, 2002 1:10 am

We get them all the time in the Saab. ATC loves us in that we can really hussle on down and slow down, although 30 degree nose downs are not going to happen. That is extremely steep. What we can do it hold 250 knots longer then any jet. All we have to do is push the props up and those are the most efficient speed brakes ever created, will slow you down in a herat beat. We usally do that and follow with gear and flaps on speed, you'd be shocked with how fast a turboprop can slow down. Had a new controller at MEM once, approach told us to keep our speed up, so we kept 250 to inside the outer marker. We got handed over to tower and he freaked, said we were 110 knots faster then a Lear in front of us and be prepared to go around. As stated above, we just configed for landing and wound up with plenty of space.
 
mhsieh
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RE: Slam Dunking

Sun Jan 13, 2002 10:18 am

Forward slipping to compensate for crosswind is done by everyone on short finals. But side-slipping to lose altitude is not a usual practice in a jet airliner ( I do it in my Cessna but I tried it in a United Flight Center 767 simulator in Denver with disaterous results. Rate of descent becomes too high to recover from ...GPWS starts to sound "pull-up, pull-up"
It's very uncomfortable and dangerous b/c your rate of descent could become excessive.
If you fly a 767 and need to side-slip on short final to get down, you should be going around!! Key is stabilized approach.
I hate to say this, but except for the couple of posts by pilots, most of the posts in the topic is completely bogus.
 
Goldenshield
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Joined: Sun Jan 14, 2001 3:45 pm

RE: Slam Dunking

Sun Jan 13, 2002 12:25 pm

Working at ONT, I see that a lot as well.

It is mostly the northerly arrivals that slam dunk in, since they have to cross the san bernardino mountains, which top off at 10,000 on that approach, then they dive in, and they cross PETIS at around 6,000 feet. This does not give them much room for error.

I have flown Over petis in a 152 inbound to ONT, and the glideslope intercepts at 4,000 so you have to lose altitude FAST in order to make it.

The C-5's you saw were there for a convention with Dubya himself. They brought in/out all his things.

When AF1 was within 10 miles of ONT, they shutdown the airport, and NOTHING on the AOA was allowed to move, not even the ops personnel.

Two all beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame seed bun.
 
redngold
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RE: Slam Dunking

Mon Jan 14, 2002 1:17 pm

One of the reasons a jet might slam dunk after passing over the threshold a bit high is to avoid wake turbulence from traffic.

I see a lot of WN slam dunking at KCLE as well. It seems to be their style. But I've also been on greased landings flying with WN (like the last two flights I took) so I think they're still somewhat sane up front.  Big grin

redngold
Up, up and away!
 
mhsieh
Posts: 327
Joined: Thu Jul 20, 2000 2:28 pm

RE: Slam Dunking

Mon Jan 14, 2002 2:29 pm

I don't think you can "slam dunk" after crossing threshold...by that time, your fate is pretty much determined ie. airspeed, rate of descent, and altitude has to be within an acceptable range for a safe landing.
If you are still too high or fast, the only thing you can do is GO AROUND.
Slam dunking refers to losing a lot of altitude or speed on the approach by increasing drag (ie speedbrake, landing gear or flaps) ....NOT side-slipping or nosediving as described by the others previuosly
If any commercial pilot side-slips or nose dives (in normal op)to lose altitude, the passengers will be very scared!
Smoothness and precision (and safety) is paramount in commercial flying! NOBODY not even Sounthwest does what you guys are talking about!

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