HS748 Hotel Mode?

[PilotGuy815]

My favorite aircraft, both in real life and the sim, is the HS748. There's a large black lever labeled "Prop Brake" at the pedestal. On the ATR 72, Saab 340, and other small turboprops, the prop brake is used for Hotel Mode Starts. Does the 748 have a Hotel Mode function?

[Garry Russell]

Are you meaning braking the prop so as to use the engine as an APU?...It would help if you said what you mean

If it is that, then no. The prop is on the same shaft as the engine and can't be independently braked.

Darts sometimes had prop brakes on the engine near doors to stop windmilling. Can't say about the 748 specifically.

[PilotGuy815]

Ok, thanks. I'll keep that in mind.

[Charlie Hotel]

Agreed, it's a gem of an aircraft - especially with the new panel

I seem to remember from Fraser's cockpit manual that the prop brake is to stop windmilling and it isolates the ignition circuit when applied.

So no, the engine won't start when the prop brake is on.

CH

[Garry Russell]

Some Viscounts had prop brakes on #2 to stop wind milling, that was the only thing I could think of.

[dfarrow]

A round about answer I'm afraid . The ATR 42/72 has hotel mode , so that on the ground the prop is disconnected / braked with the core engine running to provide elecs , air con , eng start elecs . etc ; with the generator running from the core engine . The ATP with essentially the same engine does not ..... generator comes from propeller gearbox , so until prop is '' upspeeded '' after start , the generator does not come on line . Therefore '' hotel'' mode would involve prop whizzing round ... dangerous ..'' Papa Executioner '' already caught one loader at BRU in 1990 . ATP's battery only start was no problem , but the Budgie [748 ] was a bit fraught , batteries not giving enough power to spin engine over fast enough to always avoid an hot start . Out in the Hebs and Northern Isles a serviceable GPU was a given for Budgie flights , when ATPs took over it was not necessary .Therefore the 748 has no '' hotel mode '' .
Don't think any 748 had an APU , one ATP had one fitted , got to fly her but APU wired off for commonality . And we always saw Budgie crews pulling prop through 4 blades when doing the walk round , so not sure about prop brake . Both types had internal control locks , used on ground to avoid wind / slamming damage to ailerons , rudder , elevators .
Shetland night stops .. we'd fit external ones as well and park into forecast overnight wind [ sometimes in excess of 100 kts ] . ATP's had a '' prop strop '' , a rope slipped over a Port side prop blade and clipped to the airstairs , as prop would windmill and alarm passengers boarding up the airstairs [ couple of feet away ] . If forgotten to remove , it flew off quite spectacularly upon engine start .

Hope this helps .

Dave f .

[Garry Russell]

The Dart has the prop on the same shaft as the engine so it is impossible for that reason alone for the engine to be run without the prop.

Even though Heralds and 748 were both designed to start from batteries, the drain was such that I've never seen either type start without a gpu.

Not sure exactly in this case what the pulling trough four blades means but after 30 mins or so the Dart used to be hand spun to dissipate any pockets of hot gasses that might cause distortion of delicate parts.

If it was a quick turn around, that is remaining hot, that wasn't done.

[TSR2]

Dave's point was that the 748 crews only turned the prop through 4 blades on the ATP,when the ATP had 6

[NigelC]

Seen Battery starts on both 748 and Herald. It's a case of shedding all possible load on the batteries so that the starter gets all the oomph possible! One Radio, min external lighting etc etc etc

[DaveB]

We had to battery start the Vanguard at Brooklands for a number of years and to be honest.. it's not desirable. 2000HPRPM seemed a hell of a long way off most of the time and you don't really want to be seeing 900degC EGT too often either

ATB
DaveB