JBirdAV8r From United States of America, joined Jun 2001, 4472 posts, RR: 21 Reply 1, posted (10 years 8 months 6 days 20 hours ago) and read 6122 times:
You lose speed a bit faster when doing that, and it also gives you a bit more directional control with the rudder I believe. In smaller planes (with no spoilers) it puts more weight on the wheels so your brakes are more effective.
I've seen this done several times. I saw it last on a United 737-322. However, all the airplanes were empty.
MxCtrlr From United States of America, joined Nov 2001, 2485 posts, RR: 37 Reply 4, posted (10 years 8 months 6 days 19 hours ago) and read 6095 times:
Even back with the old 707's, the speedbrakes (spoilers), when armed, automatically deploy as soon as the weight is on the gear (squat switch is set) and the wheel spin up (so as to assist the braking action). Thrust reversers are, like stated above, Captain's discretion but usually deployed as soon as the speedbrakes deploy (speedbrake handle moves aft).
Freight Dogs Anonymous - O.O.T.S.K.
DAMN! This SUCKS! I just had to go to the next higher age bracket in my profile! :-(
Jason McDowell From , joined Dec 1969, posts, RR: Reply 6, posted (10 years 8 months 6 days 19 hours ago) and read 6067 times:
The following is from the Boeing 737 Flight Crew Training Manual:
"Avoid touching down with thrust above idle since this may establish an airplane nose up pitch tendency and will increase landing roll.
If the speedbrakes do not extend automatically, after the airplane settles onto the runway, move the speedbrake lever into the UP position, and initiate reverse thrust. Fly the nosewheel down to the runway smoothly by relaxing aft control pressure. Do not attempt to hold the nosewheel off the runway. Holding the nose up after touchdown for aerodynamic braking is not an effective braking technique.
To avoid the risk of tailstrike, do not allow the pitch attitude to increase after touchdown. However, applying excessive nose down elevator during landing can result in substantial forward fuselage damage. Do not use full down elevator. Apply wheel brakes smoothly with steadily increasing pedal pressure as required for runway condition and runway length available. Maintain deceleration rate with constant or increasing brake pressure as required until stopped or desired taxi speed is reached."
M717 From United States of America, joined Dec 2002, 608 posts, RR: 5 Reply 7, posted (10 years 8 months 6 days 19 hours ago) and read 6008 times:
On the 717, the thrust reversers cannot be deployed until the nose gear is on the ground. They are locked out until the "ground shift mechanism", which is a weight on wheels type switch on the nose gear, senses that the aircraft is in the "ground" mode.
Cedarjet From United Kingdom, joined May 1999, 7815 posts, RR: 54 Reply 8, posted (10 years 8 months 6 days 18 hours ago) and read 6028 times:
M717, you said re the "Boeing" 717 that reverse thrust is locked out on landing due to a "a weight on wheels type switch on the nose gear". Other aircraft have this (not the DC8, which used reverse thrust in the air for a fast descent); but surely not the NOSE gear?
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz
M717 From United States of America, joined Dec 2002, 608 posts, RR: 5 Reply 11, posted (10 years 8 months 6 days 18 hours ago) and read 5957 times:
That is correct. On the B717, the lockout for the thrust reversers is part of the "ground shift" mechanism. There are various functions on the ground shift, and depend on whether the mechanism senses the aircraft is in the "air" or "ground" mode. Pressurization and landing gear handle are a couple. Thrust reversers are another one. They are locked out until the ground shift senses the aircraft is in the "ground" mode, and the ground shift mechanism is on the nose gear. If you ever have the chance to look closely at a 717 nose gear assembly, the ground shift mechanism is a large spring device on the aft portion of the assembly.
M717 From United States of America, joined Dec 2002, 608 posts, RR: 5 Reply 13, posted (10 years 8 months 6 days 17 hours ago) and read 5879 times:
One more thing. The "Boeing" 737-100 and -200 basic also had mechanical lockouts on the thrust reversers (you couldn't pull the thrust levers into the reverse position) until the NOSEWHEEL was on the ground. So, I guess the "wretched" 717 isn't the only "Boeing" with this feature. Sorry to disappoint.
Cx flyboy From Hong Kong, joined Dec 1999, 6454 posts, RR: 56 Reply 15, posted (10 years 8 months 6 days 13 hours ago) and read 5771 times:
When we land, we always land with full flaps and the speed brakes armed. Upon touchdown, we would be in a fairly nose high position, especially on the 777-200 (Compared to the 777-300). Upon touchdown, we also reach for the reversers immediately. However, we do not practise aerodymanic braking by holding the nose up in the air. The problem is when the nose is held too high, either you can lessen the weight on the wheels, and/or when the aircraft slows enough and you don't lower the nose to the ground slowly, it smacks onto the ground causing discomfort and possible damage to the nose area. Our company seriously discourages this sort of practise. Instead, after landing we are to gently, but fairly promptly lower the nose to the ground. This also helps with steering as the aircraft slows.
JETPILOT From United States of America, joined May 1999, 3130 posts, RR: 30 Reply 16, posted (10 years 8 months 6 days 13 hours ago) and read 5720 times:
On lightly loaded flights such as I had the other night (727) I popped the spoilers and threw it into reverse thrust when the mains touched, I got 3 lights and I brought the thrust levers up to the second notch of reverse, about 1.93 EPR and the nose will definetly rise unless moderate foward pressure is kept on the yoke. It freaks out new FO's who havent landed light before.
Goboeing From United States of America, joined Jun 2000, 2663 posts, RR: 15 Reply 17, posted (10 years 8 months 6 days 13 hours ago) and read 5704 times:
While the discussion about reverse thrust is active, I have 2 questions:
-Regarding JET's post above, does the engine have several different set "levels" of thrust for reverse, or is it free flowing like it is in forward producing thrust modes?
-When the reverse thrust is at idle, do the reverser panels or whatever they are called still go to the full deployed position, or do they need a little more reverse thrust to go out all the way? Basically, can they be put at say halfway, or are they always either in or out?
JETPILOT From United States of America, joined May 1999, 3130 posts, RR: 30 Reply 18, posted (10 years 8 months 6 days 13 hours ago) and read 5706 times:
The DC8 has a ground shift mechanism....
On the DC8 WITH THE GEAR DOWN only in flight idle thrust uavailable until the ground shift mechanism is compressed. Once compressed max continuous thrust is avaialable. And yeah its on the nose gear.
The procedure in the DC8 for landing is to get the plane firmly on the ground to prevent a main gear spoiler lockout situation which can happen during a soft touchdown. If that happens your spoilers wont automaticly deploy. Then smash the nose gear into the runway to get the ground shift compressed so you can use the marginally effective reversers if they ever open at all.
411A From United States of America, joined Nov 2001, 1826 posts, RR: 9 Reply 20, posted (10 years 8 months 6 days 7 hours ago) and read 5622 times:
Interesting comments about the B707. Which particular model had auto spoilers?
As I personally flew the aeroplane for ten years, don't remember any models equipped as you describe.
Which particular model of the 707 are you referring?
Ljungdahl From Sweden, joined Apr 2002, 902 posts, RR: 38 Reply 21, posted (10 years 8 months 5 days 22 hours ago) and read 5536 times:
Thanks, mate, for plugging my photo!!
While on the subject about use of thrust reversers (sorry if this had been covered earlier in this thread), I have observed frequently in the past that the IL-62 usually had a practice to engage reverse thrust even BEFORE touchdown!
(...sorry, one more plug, but I think this is related to this topic...)
B747skipper From , joined Dec 1969, posts, RR: Reply 22, posted (10 years 8 months 5 days 10 hours ago) and read 5429 times:
I always have used the technique of landing nose up, reversers (thrust as required) flaps and spoilers/speed brakes on the 747 I currently fly, as well as the 707 and 727, same technique... I land on many runways without hard brakes use... most of the time (747) I only start using the brakes when down to 60 knots or even much lower speed, thanks to reversers and all aerodynamic braking.
With the DC8 it is better to land and let nose down early... I flew the DC8s as well, but keeping the nose high after touch down on a long DC8-60 or 70 can easily result in a tail strike... I used to do it in the 62s which have shorter fuselage.
Never heard of auto spoilers in 707s... I flew all major versions of these, 100s, 300 and 720s... none had automatic spoilers/speed brakes, sorry.
Happy contrails to you all
AJ From Australia, joined Nov 1999, 2380 posts, RR: 26 Reply 23, posted (10 years 8 months 5 days 8 hours ago) and read 5410 times:
The 767 has several features that can cause pitching on landing.
First of all the inboard ailerons droop with flap settings of 5 or more to 'flatten' the approach attitude.
The big supercritical wing enters ground effect at about 300'AGL, meaning more nosedown is required to fly to the touchdown zone.
On main gear touchdown the (armed) speedbrake deploys causing a nose up pitch moment.
The autobrakes then engage causing a nosedown pitch.
Due to the engine's forward mounting deploying the reversers causes a decrease in airflow over the wing and an associated nosedown pitch.
Flying the nosegear onto the runway is an art! If not done properly it can cause an embarrassing CLUNK as the nosegear contacts the runway, or worse as an American Airlines B767-300 crew found when they buckled their aircraft just forward of the wing. http://www.aaib.dft.gov.uk/bulletin/oct99/n373aa.htm
Jetskipper From United States of America, joined Jun 2001, 375 posts, RR: 0 Reply 24, posted (10 years 7 months 3 weeks 5 days 9 hours ago) and read 5280 times:
On the EMB-145 we deploy the "buckets" as soon as we have main wheel touchdown, it serves not only to aid in slowing, but also to slow the nose from pitching down rapidly as it tends to do as the speedbrakes are deployed. Even though the buckets may be deployed the N1 is prevented from increasing until there is weight on the nosewheel.