g5flyer

Greetings, After responding to a post about improper pitch on approach, I decided to give the E175 a quick flight test. The test profile was as follows. 73,000 pounds, standard day temperature and conditions. 1. Depart at 73,000 pounds, climb and maintain 10,000ft at 250kts. Verify 67% N1 and 3.5 pitch attitude: At 10.000ft and 250kts, N1 57.4% and pitch attitude 2 degrees. Shows sign that the aircraft has less than the required drag and a tad bit of too much wing lift in the clean configuration. 2. Select flight level change at 250kts and descend to 5000ft. Verify that achieved VVI is 1300 fpm and pitch attitude is 0: Aircraft descends at 900 fpm with a pitch of 0. Again, the aircraft may need some drag adjustment in the clean configuration. 3. At 5,000ft, slow to a holding speed of 210kts. Verify that the N1 is 59% with a pitch attitude of 5.5 degrees: In holding, the aircraft has N1s at 45% and a pitch attitude of 4.0. Tests shows that in the clean configuration drag is low and lift is a little high as expected. 4. At 5,000ft, slow to 184kts clean for terminal area check. Verify that N1 is 58% and a pitch attitude of 7.5: Aircraft reflected N1 as 46.6% with a pitch attitude of 6.0. As expected, light on drag and 1.5 degrees low on pitch. 5. In the landing configuration of flaps 5, slow to the calculated stall speed of 107kts(132/1.23Vs). Verify that the aircraft stalls near 107kts: Aircraft stalls at 122kts. Stall test shows that flap lift in the flaps 5 position is low. 6. Perform an ILS landing in the flaps 5 position. Verify that N1 is 59% and the pitch attitude is 4 on a 3 degree glide slope: The aircraft had a pitch of 7 to 7.5 and N1at 45% to 50% on the glide slope. Test confirms that flap lift is low and over all drag is low. The aircraft had difficulty stabilizing on the glide slope causing some minor fluxing 7 to 7.5 pitch and 45 to 50% N1. The flight dynamics are not too far off and will make the simulation right on with some minor adjustments. If you are wondering, I utilized the aircraft operating manual for the flight test reference. Below is an example of the data I use. I have owned version 1 and 2 of the feel there series. During the test, I also noticed that selecting APP while the aircraft is tracking the LOC will cause it to engage in basic AP mode instead of arming the GS.

I know what you are saying. Typically, when on vectors to intercept the course, we have LOC armed through selection of the NAV or LOC button depending on the aircraft. Once the aircraft has intercepted the LOC, we then select the APP button. We do this to keep the aircraft from inadvertently descending on a false glides slope or glide slope if we are not on course. This ensures that you are only descending when you are within the obstacle protected area. In the Feel There model, If you have armed the LOC by selecting NAV and you have intercepted the LOC, the aircraft will revert to roll mode when you hit APP. Selecting APP should only arm the GS.

The original poster is correct, but he is speaking of deck angle/approach pitch. I see this also in the 175 when flying the proper approach speed. The 175 has a similar deck angle to the DC-10-30 when flown with flaps 5. It is approximately 4.5 on a 3 degree glide slope. The feel there flight model has it at 10 degrees, which is really high for a 3 degree glide slope. 5 degrees is on the high end of the normal approach pitch that you would find. 10 degrees is what you would find on delta wing type aircraft. These type mainly use the wing for lift, which you find to be typical on a concorde with it's 13 degree deck angle. The pitch of an aircraft during the different phases of flight is an accurate indicator of proper lift of the wing and it's lifting devices. If you need to verify an aircraft's approach pitch, go to it's flight crew training manual and it will display the aircraft's landing geometry. This picture will display view point, glide slope antennae location, no flare touch down point, threshold crossing height, etc for landing flaps at VREF. It will display the body angle (pitch) at different glide slope angles. You may also find touch down pitches at VREF to VREF minus 10. Keep in mind that these pitch angles are at VREF. An aircraft's pitch will change 1 degree per 5 knots. You can also find pitch values in the unreliable airspeed section of the QRH or flight manual. These charts will give you pitch and power values to use when your pitot system or airspeed indications are not reliable. Keep in mind that the approach section of unreliable airspeed charts are created at VREF plus 10 for safety margin. Below is a link to a good video of the 175 on approach. You will notice that the nose reference on the PFD is just below and touching the 5 degree line on the ADI section. When I flew DC10s, we had the same attitude with flaps 35(4.5 pitch). Note that the airspeed is 137 which means his VREF is 132. 132 equates to a weight around 73,000 pounds or so. Also note the pitch behavior at the two different flap settings(3/5) and speeds. When I fly the approach in P3D, I am getting about 9.5 on the PFD ADI section. I hope this helps.