Reverse thrust policy for Fokker F100 landings
 

Was told that Australian operators of the Fokker F100 have a policy to use only idle reverse on all landings - including wet runways. More than idle reverse discouraged although pilot discretion. Request the facts.

If you want the facts then:
(a) buy a ticket on a flight in a Fokker 100, with a landing at an aerodrome that is not 10,000+ feet in length, and experience the use of reverse thrust for yourself
(b) ring the company and ask them

Didn't Qantas have a problem with just using idle reverse and running of the end or am I having a senior moment?

It is common at Port Moresby to see the Fokker 100 and 70's taxi with one reverser deployed at idle thrust to control taxi speed, especially with a tail wind.
Qantas Dash 8-400 crews quite often shutdown the left hand engine at Port Moresby mid way on the taxi to tarmac, to avoid riding the brakes

To reduce fuel burn perhaps?

Jesus Office man, it was a simple question, why the aggro? Ring the company???????????????? Come on mate, get real.

It is these sort of smart-arse comments as demonstrated by responders No 2 and 3 that turn people away from Pprune. There should be no place in Pprune for sarcasm and ridicule.
Use of idle reverse for all landings might be relevant if noise abatement sensors are installed at some airports such as in Europe and noisy reverse thrust could mean withdrawal of slots at certain airports.

What people tend to forget is that if idle reverse is used after touchdown, especially if the surface is wet or even damp, and braking efficiency reduced, then if the decision is made suddenly to change to full reverse when the pilot belatedly realises that he should have used full reverse earlier, by then speed may have dropped off to the extent that full reverse is now ineffective.

There is evidence of many overseas accidents that have been caused by this policy. The landing end of some runways are often contaminated with rubber which when combined with water on the runway significantly reduces braking efficiency and can cause the tyres to skid.

Reverse thrust thrust is most efficient at high airspeeds and drops off significantly below 60-80 knots. A policy that discourages pilots from using full reverse after touchdown has the potential to lead to crew complacency not to mention hotter brakes.

The FCTM of one well known twin engine transport states in part: "For minimum brake heating select maximum reverse thrust as soon as possible after main gear touch down. The intention is to use reverse thrust as the major force that stops the airplane. The use of maximum reverse thrust further minimizes brake heating".

Apart from all the above, Fokker issued a directive as far back as 2005 that the use of more than idle reverse could cause damage to the engines and an inspection was mandated.if used.

Idle reverse is normally quite effective and can be used to reduce taxy speeds as mentioned..

The so called damage was noticed when some operators used reverse to "push back" so to speak i seem to recall.

For an RTO, fill your boots as engines are cheap vs the air frame.

Other types i had the privilage of flying variable from idle to full was SOP depending of all the things you can think of, and some you wont

It's fuel saving, zero to do with brakes.

Greybeard,

Interesting your mention of a 2005 directive …. re use of more than 'idle reverse'
The PX guy's give the reversers a good work out at Madang when the runway is wet.
Recent volcanic activity which closed Hoskins to all traffic due volcanic ash, of course PX did not comply, there is plenty of video footage of Fokkers landing in the ash with hefty amounts of reverse. I think the Tay is very mature and almost indestructible?

They were late for the golf game.

Idle reverse thrust has some advantages, especially with aft mounted engines/T tail combo in that it lessens the potential for rudder blanking. Think DAL 1086

other advantages:
slight fuel savings, GE outlines the savings in their materials, significant on a 4 holer, less so on smaller jets.
potential reduction in FOD events (determined by type)
noise abatement at some sensitive airports

http://www.boeing.com/commercial/aer..._17/brakes.pdf

The Fokker F100 FCOM recommends idle reverse for all landings except in an emergency. If full reverse used, maintenance action is required

There was or is a time limited prohibition range which applied to the smaller F70 engine. Unfortunately the software is the same for both the F70 and F100. The issue is that should this condition be tripped it cannot be cleared by the pilot and cannot continue on until it is, along with any maintenance conditions applied of course in the case of the smaller F70 engine.

Today most dinosaurs have the same problem, there are few if any software engineers who still hold the approvals and skills to make changes to fundamental operational software. Even if there is, since the manufacturer no longer exists who carries responsibility for those changes. It’s not all that simple both software packages must be changed in order to ensure the right software is applied to the right engine. The easier solution is to implement an operating procedure which is less likely to cause the issue. This in itself creates new problems if it’s not though through and most often comes to light literally by accident.

For example for the F50, it came to light that pilots couldn’t be trained reliably to properly reject a takeoff bringing about a significant increase in stop distance. The solution was to lock out reverse and rely on brakes alone. It follows then that the takeoff antiskid inop charts and procedure must be removed also, it wasn’t. I would be curious today as to how many think they can still takeoff with antiskid inop. It will certainly come to light the first time someone rejects a takeoff with no reverse and no antiskid.