bassslayer

Hey everyone, new to the site. Had a question about a couple of interview questions I read on a gouge for Comair. Not sure if I am understanding the questions correctly. Here goes, what is blueline on the airspeed indicator and does it ever change? My answer would be blue line is the best rate of climb single engine, or will give you the slowest "drift down" speed. It is based on max T/O weight, clean, standard day conditions. As you deviate from these conditions, your rate of climb will in turn change. Rate of climb in terms of ft/min will increase with appox. 50% of the change in weight. For example, A 20% reduction from MTOW will give you Approx a 10% increase in VYSE. On the other had, NO, blueline is always the same indicated airpeed as far as the airspeed indicator is concerned. Which is it?
The other question I had was " Why is adf and radar required on the LGA ils?" My answer would be because you need the adf to navigate LOM/Hold. Radar is required anytime a portion of an approach is not navigable by means of a navaid. At LGA, the plates say the VOR is temporarily moved and to check the Notams. Is this why radar is required or am I retarded?
Thanks for any responses.

rickair7777

Blueline is calculated for certain conditions as you mentioned, so it is not exactly accurate for all conditions but should be good for worst-case when you need it the most.

So Vyse changes, but blueline (Vyse for specified conditions) does not.

In jets the blueline equivalent (V2) is always calculated before flight based on current GW, temp, and PA.

sigep_nm

You are correct in terms of driftdown but remember that to make a complete answer power must be set at max allowable for the operating engine.

cessna126

I think you are trying to make that question too complex. I interviewed at Comair a couple weeks ago and got the job. I also got that question. My answer was that blueline is the best single engine climb speed and that it was 100knots in my current twin. He then asked if it ever changed. I said that depending on conditions it would change a little to either side, but it is best to use the marked line in an emergancy. You dont have to go in depth on any question Comair asks you. They are so relaxed.

bassslayer

Thanks guys. What about the Radar question??

rickair7777

I don't know the answer, but if this is for an interview all you need to do is remember to read that little box with the special requirements and comply with them. They won't ask you why the FAA requires those things.

POPA

I've never flown to LGA, but I'm going to hazard a guess and say they've got more than one ILS there.

sgrd0q

Here's the deal with LGA. ILS Rwy 4 is the only ILS approach at LGA that requires both RADAR and ADF.

Why RADAR? Look closely at the approach plate. There is no IAF. Therefore in a lost comms situation you cannot possibly do this approach. Someone has to vector you in, hence radar is required. As an aside, look at LGA VOR Rwy 6 approach. Colts Neck VOR is an IAF. Guess what? RADAR is not required for this approach. You will see this for all LGA approaches – no IAF, definitely RADAR required.

Why ADF? The missed procedure for ILS Rwy 4 is fly direct ORCHY LOM and hold. You need an ADF to identify ORCHY and hold on a bearing of 224 inbound. You might notice that other approaches (e.g. ILS Rwy 13) also specify hold at ORCHY but no ADF is required.

This is because for the missed procedure for ILS Rwy 13, the inbound course in the hold is 223 (outbound 043) and ORCHY is on the 043 radial from LGA VOR (5.8 DME). So for ILS Rwy 13 your inbound course in the hold is ON the 043 radial of LGA. You can just keep the needle centered in the hold inbound. Not so with the missed procedure hold for ILS Rwy 4. There your inbound course is slightly different – 224, so you are not on the 043 radial the whole time inbound - you are at a small angle relative to that radial.

Note that identifying ORCHY without the ADF is not the problem. ORCHY is on the LGA 043 radial and Deer Park (DPK) 293 radial. Or you can use the DME (D5.8 from LGA). The problem with the hold for ILS Rwy 4 is that once you get to ORCHY you need an ADF to stay on your course inbound as that course does not coincide with any VOR radial.

Pardon my longwinded explanation – I think I am about to fall asleep!

bassslayer

Thanks a lot! No that i look at it, it makes sense.