Use of T/R on slippery Runway
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Use of T/R on slippery Runway
Gents, whats your opinion on using T/R on a slippery, partly iced runway, braking actIon medium ?
A/C concerned : Cessna Citation Bravo.
Cessna does not offer a guideline in the manuals, our company manual does neither, I wouldn´t use them to avoid losing directional control....
Any thoughts ?
Edited for troubled fingers....
A/C concerned : Cessna Citation Bravo.
Cessna does not offer a guideline in the manuals, our company manual does neither, I wouldn´t use them to avoid losing directional control....
Any thoughts ?
Edited for troubled fingers....
Last edited by His dudeness; 1st Jan 2005 at 12:32.
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Idle Reverse
I am not familiar with the Citation series. However, would it be feasible to use idle reverse?
While rudder blanking can occur at high reverse levels (on aircraft which have engines mounted on the aft fuselage), I have not seen any degradation at idle reverse. In fact, for one aircraft I flew, the manufacturer specifically directed to select idle reverse if directional control became a problem. My experience with that scenario showed me that directional control can be regained rapidly when reverse is reduced to idle.
While rudder blanking can occur at high reverse levels (on aircraft which have engines mounted on the aft fuselage), I have not seen any degradation at idle reverse. In fact, for one aircraft I flew, the manufacturer specifically directed to select idle reverse if directional control became a problem. My experience with that scenario showed me that directional control can be regained rapidly when reverse is reduced to idle.
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Since your brake efectiveness becomes degradated in slippery runways, aerodinamic braking is welcome to help you to stop the aircraft.
But if you have difficulties with directional control you can always bring the T/R`s to idle and get a more effective directional control imediately and aplly differential braking.
When applying directional braking,try not release the pedals ,instead,press harder the pedal you want to bring the aircraft to.
Hope to have helped you.
Happy New Year Folks
But if you have difficulties with directional control you can always bring the T/R`s to idle and get a more effective directional control imediately and aplly differential braking.
When applying directional braking,try not release the pedals ,instead,press harder the pedal you want to bring the aircraft to.
Hope to have helped you.
Happy New Year Folks
HD
I would recomend the use of symetrical reverse thrust only as using it for steering can get you in all sorts of trouble. If you do not practice it you could easilly end up worst off especially as the anticipation required for spool up times will be really tricky to manage.
I have tried aerodynamic breaking in several diferent aircraft and I think all it does is reduce your control of the aircraft especially as you run out of elevator control at the lower speeds. You are much better off landing normally.
If you are slipping sideways then I feel that gentle breaking and symetrical reverse thrust are th emost suitable. You will often find that once you have deviated from the centre line the friction will vary and you will regain control. It is often water on ice or rubber which causes the problem and the "fresh" ice or snow off the centre line may offer better control.
There is an article on the issue in the December issue of Business and Comercial Aviation, but I can not find a link to it online.
If you PM me I will look for more specific information on the Bravo when I return to work after the New Year break.
If in doubt about breaking action, then there is no doubt!
MM
I would recomend the use of symetrical reverse thrust only as using it for steering can get you in all sorts of trouble. If you do not practice it you could easilly end up worst off especially as the anticipation required for spool up times will be really tricky to manage.
I have tried aerodynamic breaking in several diferent aircraft and I think all it does is reduce your control of the aircraft especially as you run out of elevator control at the lower speeds. You are much better off landing normally.
If you are slipping sideways then I feel that gentle breaking and symetrical reverse thrust are th emost suitable. You will often find that once you have deviated from the centre line the friction will vary and you will regain control. It is often water on ice or rubber which causes the problem and the "fresh" ice or snow off the centre line may offer better control.
There is an article on the issue in the December issue of Business and Comercial Aviation, but I can not find a link to it online.
If you PM me I will look for more specific information on the Bravo when I return to work after the New Year break.
If in doubt about breaking action, then there is no doubt!
MM
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The engines aren't out on the wing, so your directional control would be minimally affected...even with a case of asymetric reverse. If you have reverse, use it at least at idle detent to stop most of the forward thrust as you're trying to slow down.
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Having flown on icy and contaminated runways for longer than I want to remember, use MAX reverse!! If you start having directional control problem, slowly reduce towards idle and steer the aircraft onto the centerline. Then increase reverse.
You can stop most aircraft with reverse thrust with braking action nil, as long as the x-wind is not pushing you off the runway due to lack of lateral traction.
You can stop most aircraft with reverse thrust with braking action nil, as long as the x-wind is not pushing you off the runway due to lack of lateral traction.
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BLE, from my experience, is right on target.
If the reverse causes problems, reduce to idle and try again.
With significant crosswinds, reverse on slippery runways can cause ah.... large problems.
As in, off in the weeds problems.
Not good.
If the reverse causes problems, reduce to idle and try again.
With significant crosswinds, reverse on slippery runways can cause ah.... large problems.
As in, off in the weeds problems.
Not good.
Moderate, Modest & Mild.
Braking action "medium" shouldn't be too much of a concern for you, unless you have landed long and/or fast, on a critical length runway.
The use of auto brakes (at a low-med selection, rather than a higher setting), in conjunction with thrust reverse should be sufficient, and you won't notice a great deal of difference from "good" b/a.
Landing flap selected to give you the min. touchdown speed.
Aircraft manufacturers make adjustments to the max x/wind component, depending on braking action (Good, Medium, Poor), and/or the type of contamination - wet, water, slush, ice, snow -so that "significant crosswinds" are not a factor (for those of us who do follow the O.M.!)
My recommendation is NOT to go playing the reversers like piano keys - from max back to idle, back to max - as you're courting the possibility of encountering an assymetric (unequal) thrust situation.
By not using ANY reverse thrust (as you appear to be inclined to do), the engines will still be producing forward thrust during the landing roll, thereby increasing your landing distance - not desirable.
At least "crack" idle reverse.
The use of auto brakes (at a low-med selection, rather than a higher setting), in conjunction with thrust reverse should be sufficient, and you won't notice a great deal of difference from "good" b/a.
Landing flap selected to give you the min. touchdown speed.
Aircraft manufacturers make adjustments to the max x/wind component, depending on braking action (Good, Medium, Poor), and/or the type of contamination - wet, water, slush, ice, snow -so that "significant crosswinds" are not a factor (for those of us who do follow the O.M.!)
My recommendation is NOT to go playing the reversers like piano keys - from max back to idle, back to max - as you're courting the possibility of encountering an assymetric (unequal) thrust situation.
By not using ANY reverse thrust (as you appear to be inclined to do), the engines will still be producing forward thrust during the landing roll, thereby increasing your landing distance - not desirable.
At least "crack" idle reverse.
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When using Rev Thrust the possibility of weathercocking in crosswinds on a slippery must be considered.
If you aply reverse in calm conditions the thrust vector is applied along the longtitudinal axis of the a/c and the retarding force is therefore at its most efficient.
However, if there is a crosswind, and if the wheels do not have proper grip - the a/c may weathercock into wind. If this happens, the reverse thrust effect will no longer act in the same way. Instead there will be a split in the applied vector, part will act to retard the a/c, but a part will also act to 'slide' the a/c in the downwind (off RWY) direction.
Effectively the reverse thrust acts to drag the a/c off the RWY.
The only cure is to reduce the applied rev thrust and get back on c/l...then re-apply rev.
A diagram would best describe this situation...perhaps someone can provide a link.
If you aply reverse in calm conditions the thrust vector is applied along the longtitudinal axis of the a/c and the retarding force is therefore at its most efficient.
However, if there is a crosswind, and if the wheels do not have proper grip - the a/c may weathercock into wind. If this happens, the reverse thrust effect will no longer act in the same way. Instead there will be a split in the applied vector, part will act to retard the a/c, but a part will also act to 'slide' the a/c in the downwind (off RWY) direction.
Effectively the reverse thrust acts to drag the a/c off the RWY.
The only cure is to reduce the applied rev thrust and get back on c/l...then re-apply rev.
A diagram would best describe this situation...perhaps someone can provide a link.
That is very good advice about tail-mounted engines. As for other winter problems, tonight, the husband of my wife's friend told me about freezing rain at a Canadian airport many years ago. They were stopped in their beautiful Eastern DC-9 (
) and the 25-30 knot wind pushed them several feet on the taxiway. Have no idea what they were told about braking when they taxied out. The Captain turned to the FO (my acquaintance) and said "What do you think?". The FO said "Let's go back to the hotel". They later could clearly see painted shapes on the concrete through a few inches of clear ice.
Several years ago, a guy in my Captain class said that during his IOE, he turned slowly off the 'provincial' runway in Michigan or Wisconsin, but told the Check Airman "I got no brakes!!!". The C.A. pulled both reversers up into max reverse and they had to get both engines inspeceted, but the airplane stayed on the taxiway. Only the runway had been de-iced.
Sometimes airport crews throw sand on a slippery runway and use nothing else (i.e. Grand Forks, ND years ago; the Captain had no experience with tail-mounted engines)! When they do spray chemicals on the runway, many turnoff places and taxiways are never sprayed! I saw the two airline 737s off the taxiways years ago in Tulsa. My captain read this in the NOTAMS, and although it delayed us a while, called the TUL tower controller and refused to depart here until another jet landed and gave a braking report to the TUL tower. After we cleared the active, he taxied much slower than anyone else in my life (slower than a golf cart with four fat [..US..] guys near the green) , but it kept us on the taxiways to the gate.
Delays or speed get you into trouble or serious danger if you become 'mission-oriented' all the time.
) and the 25-30 knot wind pushed them several feet on the taxiway. Have no idea what they were told about braking when they taxied out. The Captain turned to the FO (my acquaintance) and said "What do you think?". The FO said "Let's go back to the hotel". They later could clearly see painted shapes on the concrete through a few inches of clear ice.Several years ago, a guy in my Captain class said that during his IOE, he turned slowly off the 'provincial' runway in Michigan or Wisconsin, but told the Check Airman "I got no brakes!!!". The C.A. pulled both reversers up into max reverse and they had to get both engines inspeceted, but the airplane stayed on the taxiway. Only the runway had been de-iced.
Sometimes airport crews throw sand on a slippery runway and use nothing else (i.e. Grand Forks, ND years ago; the Captain had no experience with tail-mounted engines)! When they do spray chemicals on the runway, many turnoff places and taxiways are never sprayed! I saw the two airline 737s off the taxiways years ago in Tulsa. My captain read this in the NOTAMS, and although it delayed us a while, called the TUL tower controller and refused to depart here until another jet landed and gave a braking report to the TUL tower. After we cleared the active, he taxied much slower than anyone else in my life (slower than a golf cart with four fat [..US..] guys near the green) , but it kept us on the taxiways to the gate.
Delays or speed get you into trouble or serious danger if you become 'mission-oriented' all the time.
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Excellent article re this subject produced by Douglas ,originanally for the 'nine',more 'recently' updated in Tri jet,flight crew newsletter.november 94
Covers all aspects of Rev thrust application,cause and effect,on slippery runway ops..aerodynamic.propulsive,inertial,and external forces acting on the aircraft...
Stuff(info)that 's not in the AFM anymore...
Worth reviewing once in a while...
Cheers...
Covers all aspects of Rev thrust application,cause and effect,on slippery runway ops..aerodynamic.propulsive,inertial,and external forces acting on the aircraft...
Stuff(info)that 's not in the AFM anymore...
Worth reviewing once in a while...
Cheers...
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Indeed oldebloke, information that is quite valuable when the chips are down...on slippery runways.
The Lockheed TriStar for example, had complete handling info with reverse on slippery runways, in the AFM.
Can recall a couple of co-pilots who wanted to know about this, so I referred 'em to the big thick manual that said 'Lockheed California Company' on the cover...worked like a charm.
Those that made it up as they went along....ended up in the weeds.
The Lockheed TriStar for example, had complete handling info with reverse on slippery runways, in the AFM.
Can recall a couple of co-pilots who wanted to know about this, so I referred 'em to the big thick manual that said 'Lockheed California Company' on the cover...worked like a charm.
Those that made it up as they went along....ended up in the weeds.
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mxalt - here is a link to a diagram that describes this situation reverse thrust diagram
It comes from "Fly the Wing" Third Edition By: Jim Webb, formerly a captain with Eastern Airlines, and William D Walker. Blackwell Publishing. Ordered a copy on-line for my Xmas present to myself:
http://www.blackwellpublishing.com/b...3808545&site=1
The new third edition (it is dated 2004) comes with a companion CD-ROM, which has the Jetblue A320 Flight Crew Operations Manual and the Honeywell Pegasus Flight Systems Pilot Guide for the A330/340/318-321. Some really interesting stuff - I'm deep into the examples and graphs to determine optimum fuel tankering - the graphs allow you to determine the optimum fuel quantity to be tankered as a function of the fuel price ratio between departure and destination airports, flight level, aircraft takeoff weight, and the air distance to fly. Some good stuff at the ATPL/CPL level.
It comes from "Fly the Wing" Third Edition By: Jim Webb, formerly a captain with Eastern Airlines, and William D Walker. Blackwell Publishing. Ordered a copy on-line for my Xmas present to myself:
http://www.blackwellpublishing.com/b...3808545&site=1
The new third edition (it is dated 2004) comes with a companion CD-ROM, which has the Jetblue A320 Flight Crew Operations Manual and the Honeywell Pegasus Flight Systems Pilot Guide for the A330/340/318-321. Some really interesting stuff - I'm deep into the examples and graphs to determine optimum fuel tankering - the graphs allow you to determine the optimum fuel quantity to be tankered as a function of the fuel price ratio between departure and destination airports, flight level, aircraft takeoff weight, and the air distance to fly. Some good stuff at the ATPL/CPL level.
Sounds like the simulator is the perfect machine to practice slippery runway crosswind ops. Never seen it done, though. usually the time is wasted on unlikely scenarios that occur in LOFT exercises where most of the time is spent "talking" to the cabin crew, company, ATC and ground crew and of course reading countless pages of checklists - but precious little hands on flying.
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Centaurus,
True words, aptly written.
Forget this CRM/cabin crew nonsense, and fly (as in operating properly) the aeroplane.
CRM will NOT keep you on a slippery runway...reverse or no reverse.
To those who run off with the mouth with CRM, and not pay attention to what they are actually doing.... belong in the weeds.
As in....airmanship right and precisely out the window.
Good grief.
True words, aptly written.
Forget this CRM/cabin crew nonsense, and fly (as in operating properly) the aeroplane.
CRM will NOT keep you on a slippery runway...reverse or no reverse.
To those who run off with the mouth with CRM, and not pay attention to what they are actually doing.... belong in the weeds.
As in....airmanship right and precisely out the window.
Good grief.
Moderate, Modest & Mild.
Forget this CRM/cabin crew nonsense, and fly (as in operating properly) the aeroplane.
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Ah, well, not all of 'em, Kaptin M.
AA just last week ran an MD-80 off into the weeds, and as it is a junior fleet for them, some of their younger guys seem to have rather a few problems handling either...
AA just last week ran an MD-80 off into the weeds, and as it is a junior fleet for them, some of their younger guys seem to have rather a few problems handling either...
Moderator
Clearly, there is a role for all the skillsets which various of us see as being variously useful ... could it be that the problem is not so much one of which skill is more important but not enough time and resource allocation to permit the players to develop the skillsets ... ?
Moderate, Modest & Mild.
Happy New Year, J_T - and of course you too, 411A 
Yes, I'm certain you're correct, j_t - although the company for which I fly issues a LOT of literatural advice at the beginning of every Winter, every year, not much time is devoted during sims to this sort of stuff, in spite of the fact that during the 6 Winters I've been here, there have been runway "excursions" EVERY year - usually by the other airlines, though.
Add to the lack of sim practice, the infrequency of exposure to these (often severe) conditions, by some pilots - or the UNDER-estimation, and/or disregard for strictly adhering to Winter policy ops - and the holes begin lining up.
Well I'm just about to head up to the Deep North again this morning for what has been a relatively "mild" Winter so far - temps only got down to -16C, which is considerably "warmer" than in past years!
Stay outta them weeds!!
Yes, I'm certain you're correct, j_t - although the company for which I fly issues a LOT of literatural advice at the beginning of every Winter, every year, not much time is devoted during sims to this sort of stuff, in spite of the fact that during the 6 Winters I've been here, there have been runway "excursions" EVERY year - usually by the other airlines, though.
Add to the lack of sim practice, the infrequency of exposure to these (often severe) conditions, by some pilots - or the UNDER-estimation, and/or disregard for strictly adhering to Winter policy ops - and the holes begin lining up.
Well I'm just about to head up to the Deep North again this morning for what has been a relatively "mild" Winter so far - temps only got down to -16C, which is considerably "warmer" than in past years!
Stay outta them weeds!!
