Thrust reverse...

[G21Agoose]

Did squat switches allow that? The DC-8 was the only one I had ever heard of reversing in flight.

I did know of an idiot that used to do it in a E-90. Scared the crap out of me.

I believe the Lauda 767 had reversers deploy in flight.

In the Falcon we stick our head out the window and blow backwards.

 

[Munga]

It would also depend on the type of brakes you have. Some work better and last longer if you use them when hot, so the technique would be to use them most of the time during landing so they heat up quick and not bother with the TRs. This way you reduce wear while taxing at some of the bigger airports/ I don't like that technique or policy, but it makes sense if you replace brakes more than maintain the TRs.

 

[Jeff Helgeson]

Squat switch vs. ground shift mechanism

Did squat switches allow that? The DC-8 was the only one I had ever heard of reversing in flight.

I did know of an idiot that used to do it in a E-90. Scared the crap out of me.

DC9/MD80 has a squat switch on the mains, but the ground shift mechanism works on the nose wheel (compression on the nose strut).

As far as I know it does not effect the TRs. I have never used that techinique. However, when I was an F/O I saw a Captain deploy the TRs before main wheel touch down and spoiler deployment. The plane was floating in ground effect with a down sloping rwy. It worked out fine, but it got my attention.

 

[LJ45]

In the Falcon we stick our head out the window and blow

LMFAO

 

[hawker]

I know from my maintenance background ual 737 had an option to deploy reversers 10ft agl (works off ra) for short runway landing. One crew did this and put the mains through the wings OUCH!!

 

[TXDA2000]

I used to fly with a guy in a Sabre 40 that deployed them in the flare on really short runways. Worked really well in that aircraft. A no-no in the 60.

There are as many TR techiniques as there are aircraft. Use what works best for yours.

In the 2000, there is a sw on the nose gear, so it has to be down.

 

[ultrarunner]

717 limitation might be a DC-9 carry over... anyone??

Nope, not a limitation on the DC-9 series. I'd have to dig out the rules book however. I seem recall TR deployment was authorized as long as the nose was on it's way down. Some airlines however has SOP's against it.

If I recall, U was a big advocate of operating that way for brake longevity. The also pretty much as autobrakes as an SOP.

 

[Archie Bunker]

Real pilots deploy the TR with the nose wheel UP!!

Not in the last couple of jets I've flown....

From the Citation X pilot training manual.....
Caution: Thrust reversers should not be deployed until the nosewheel is on the ground. Airplane pitch up may occur.

At NJA, we are trained not to deploy the TRs until the NW is on ground.

When I flew the MD-88/90 at Delta, it was the same deal. No TRs until the NW was on the ground. The 88 had big buckets that you could easily drag with the nose in the air....it was a major preflight item to check the buckets and make sure the dork before you didn't drag them on the rollout. While the MD-90 didn't have buckets (it had sliding cuff TRs), as a matter of standardization we didn't deploy them either until the NW was on the ground.

I can't remember what we did on the 727 (standardizationwise), but I remember popping in idle reverse a couple of times with the NW still in the air. The nose would pitch up, and you would really have to shove the nose over....not real comfortable, or smooth. I stopped using that technique after a couple of attempts.

 

[MikeMD80]

[quote=Rez O. Lewshun;1163904]717 limitation might be a DC-9 carry over... anyone??

Having flown both the -80 and the 717 (briefly), I can still remember what the company policies were for both A/C. We could open the buckets on the -80 upon main wheel touchdown, but were restricted from applying reverse thrust until the nose wheel was on the ground. This was to due to rudder "block out" where the rudder lost effectiveness due to the reversers being deployed . we were also restricted to 8 degrees of pitch attitude with the buckets deployed.

The 717 policy was not to deploy the reversers at all until the nosewheel was on the ground. This was due to the size of the buckets and their close proximity to the ground with the nose up. Not a real issue as the buckets helped in slowing the plane. Also the 717 had FADEC, so the motors spooled up together very nicely.

In regards to the DC9's. The Ozark drivers were famous for opening the buckets while in the flare just prior to main wheel touchdown. I saw it once holding short of the runway. Amazing how they could time that! I also have flown with a pilot who has about 14,000 hrs on Gulfstreams and he could do it too. Never did get used to it, but it was VERY effective. As a note, the G-II has a Ref speed of 141 knots at MLW. FAST!

And finally, in regards to the debate, brakes over reversers.... there are many circulars out there, based on tests, that show reversers are more effective above 100 kts, and brakes are more effective below 100 kts. So alot of this debate depends on your speed at touchdown,.... and your interest in saving the brakes I guess.

 

[GravityHater]

(it had sliding cuff TRs)

I am looking for a pic or diagram of these.

 

[Archie Bunker]

I am looking for a pic or diagram of these.

Sliding cuff TRs was probably a poor choice of words on my part to describe the system.

From the Volume 2 (ops manual): The TR system on the MD-90 consists of cold-ducts (C-ducts), translating sleeves, blocker doors, and cascades. As the translating sleeve moves aft, it moves the blocker doors down and uncovers the cascades, which direct the flow of fan air outward and forward through the cascades. The doors are are shaped to fit together to form a complete barrier across the air duct and block the flow of air through the duct.

There....clear as mud?

Bottom line.....you're not going to drag a bucket on the MD-90 (because they didn't have any) like you could on the MD-88. Like I said, for the sake of standardization we (at Delta) didn't deploy the TRs on either aircraft until the NW was on the ground.

 

[Rez O. Lewshun]

Good info on the DC9 series....

Any thoughts on Boeing.. 757 or 747? How about airbus??

 

[gear_guy]

I used to fly with a guy in a Sabre 40 that deployed them in the flare on really short runways. Worked really well in that aircraft.

Exactly what do you think would happen if only one bucket opened while airborne?

Also 400A, in regards to "it depends on the runway length". Landing distance is not even including T/R's. So how could you justify an accident to the FAA if you lost directional control b/c you didnt have the nosewheel down.

Again, we are risk managers and I can't find a reason to take that risk.

 

[Donsa320]

Good info on the DC9 series....

Any thoughts on Boeing.. 757 or 747? How about airbus??

The A-320 requires the respective main gear squat switch to be compressed to get reverse...which is only cold stream anyway and not very effective. The DC-9 had no provision to prevent inflight reverse selection, just procedure. As to the reversers blocking the rudder some how, I say poppy cock. With about 15,000 landings in DC-9's in Northern Wisconsin, Michigan and Minnesota with wild crosswinds on icey runways I can assure anyone the rudder works just fine with lots of reverse applied. After the Little Rock accident American's school house came up with that lame excuse and the NTSB and Boeing bought it. If it had not been an MD-80 it would have departed the side of the runway long before the end with the technique that was used. No auto-brakes armed, no auto-spoilers armed and steering the ailerons like a car. ARG! Rant over.

 

[Beechjetr]

I saw a global express land in MTH once and the reversers were deployed almost coincident with touchdown. Do globals have auto-reversers? Someone told me they pull up the levers prior to touchdown and when the ground safe switches close they deploy??? Is this true?