# Zero Flaps or Partial Flaps Landings

## Gulfstream GVII

#### Eddie sez:

Flying a no-flap approach seems easier in this airplane than previous Gulfstreams, but setting it up is definitely harder. You need to remember to turn on the wing anti-ice and consider the autobrakes setting, as well as remember to let the aural warning system know you will be landing with less than 22° of flaps.

If you have to fly this in instrument conditions, you might try setting up the glide path as required for the approach and enter a 2.5° glide path on the HUD/EVS. When you acquire the airport visually, transition to the HUD/EVS path.

Everything here is from the references shown below, with a few comments in an alternate color.

20191019

#### Understanding the no flap landing

Photo: G500 Left flap illustration, GVII-G500 IPC, §27-50-05, figure 1
Click photo for a larger image

To understand the need to nail your speed during a no flap approach and landing, take a look at the airplane from the tail and look at just how much of the trailing edge is taken up by the flaps.

[GVII-G500 AMM, §06-30-00, ¶1

• Wing area: 950.00 ft2
• Flap area: 76.93 ft2

The flaps add just over 8 percent to the wing's area. So how does that translate into numbers? Let's consider landing with a load of passengers and a comfortable margin of gas that translates to 55,000 lbs. gross weight. To make things easy, let's say we do this at sea level.

VREF for 39° flaps is 122 KIAS; that goes up to 138 KIAS with 0° flaps, a 12% increase.

With no wind, no slope, an ISA day, and autobrakes HIGH, you would have a 2,800' landing distance. Without flaps, the distance is 3,600', a 29% increase.

They've hidden the Brake Kinetic Energy chart in GVII-G500 AFM Appendix C. Under our example conditions the BKE after landing will be 38 million ft-lbs, in the normal range, will generate a BTMS temperature of 380°C, and will require a bit less than 3.5 hours to cool. Without flaps, you will have a BKE of 52 million ft-lbs, still in the normal range but a 37% increase. Your peak BTMS temperature goes up to 500°C and your cooling time goes up to just over 3.5 hours.

#### Notes from class:

Due to anti-icing regulatory requirements: with the flaps at 0 degrees, the “High Incidence Protection Function” (HIPF) always assumes there is 'pre-activation icing' on the wing leading edge, which decreases the usable AOA by approximately four degrees, greatly increasing VREF. Therefore, for flaps 0 landing, the procedure will include turning the wing anti-ice ON (regardless of ambient conditions) so the HIPF recognizes warm wings and removes the 'pre-activation icing' penalty, thus reducing the VREF. This is especially significant for emergency return at high gross weights and flaps failed at 6° or less.

Higher VREF = faster approach speeds, longer stopping distance, and higher brake temperatures.

Slower engine response with flaps < 22° because of lower engine idle speed.

Use of Autothrottles is prohibited during approach and landing with flaps less than 12°.

Maximum tailwind component for landing with less than 12° flaps is zero knots.

Significant ground effect will cause exaggerated ballooning resulting in a long touchdown if you attempt to round out or flare. Allow the aircraft descent rate to be slowed by ground effect. If established in a normal descent rate, this will result in an acceptable landing with no further pitch input required until the main gear touchdown. After main gear touchdown, the nose must be positively lowered with some forward pressure on the stick due to the no flap landing attitude.

The GPWS Flap switch is found on TSC 1-4 under Aural Warnings.

The VREF on the POF page of the TSC will reflect the flap handle position, which may not be what you want. When you do the LDG INIT and enter the setting of flaps one notch less than what you have, you will be presented with an accurate VREF and landing distance -- write them down.

[AFM, §03-12-10]

#### Displayed CAS and CA Messages.

Click photo for a larger image

#### System Impacts

• Autothrottle: Use of Autothrottle is prohibited during approach and landing with flaps 10° or less.

• Landing: Maximum tailwind component for landing with flaps 10° or less is zero knots.

• Landing Distance: Zero or partial flap landings will result in increased landing distance required.

Corrective Action

1. Airplane . . . Plan a wide approach and select the longest available runway

2. Approach Winds . . . Plan landing runway and approach that maximize headwinds during approach and landing

3. Approach . . . Plan shallow approach (if possible)

4. Prior to FAF:

1. WAI . . . ON

2. Wing Temperature . . . Verify above 100°F

3. AT Auto-Engage Inhibit (TSC/ Systems/AT Control) . . . Select

4. GPWS FLAP INHIBIT (TSC/Aural Inhibits/TAWS Control) . . . Select

5. Airspeed . . . 200 KCAS minimum (until ready to configure)

Why WAI? Because: reasons. No, actually because of software in the Flight Control Computers that will raise your VREF if the WAI is off as part of AOA protection, because it assumes the wing is contaminated if the WAI isn't on. (This is part of what is called "High Incidence Protection Function.) Not only that, once the airplane gets to 400' AGL, the VREF is set in stone and you are "locked out" of making this change. So you might as well turn the WAI on as soon as you read this in the checklist. So why do you have to do this? Reasons.

I am told the reason for this is that a winglet "flutter" happens when the flaps are up and the airspeed is reduced below 200 KCAS. The fear is that the flutter can be confused for a wing stall and that putting the gear down will mask the flutter. (I was told this my someone who flew on the test of this and witnessed it.)

5. If WAI unavailable:

1. Flaps 0 VREF . . . Increase by a factor of 1.2

2. Flaps 0 Landing . . . Distance Increase by a factor of 1.5

3. CAUTION

LANDING WITH BRAKE ENERGY EXCEEDING 110.90 MFP MAY RESULT IN BRAKE FAILURE AND FIRE AFTER LANDING. CONSIDERATION SHOULD BE GIVEN TO AN ALTERNATE LANDING LOCATION.

4. Refer to 05-11-20, Tire Speed and BKE Limited Maximum Landing Weight.

6. Landing Distance . . . Calculate
7. You will have a choice of Autobrakes HIGH or Autobrakes OFF. In the simulator they will frown upon you for selecting Autobrakes OFF because using HIGH will help lower the nose once the mains are on the ground. With the Autobrakes OFF you need to forcibly lower the nose. I've only done this in the simulator and it wasn't a problem using Autobrakes OFF.

8. LANDING GEAR . . . DOWN

9. Landing Checklist . . . Complete

10. AUTOTHROTTLE . . . DISCONNECT (Flaps 10° or less)

11. Airspeed . . . Establish VREF+ 5 prior to FAF

12. Landing

13. CAUTION

WHEN LANDING WITH PARTIAL FLAPS, MINIMAL FLARE IS REQUIRED. IT MAY BE NECESSARY TO PUSH FORWARD ON THE SIDESTICK TO PUT THE NOSEWHEEL ON THE RUNWAY.

WHEEL FUSE PLUG RELEASE WILL LIKELY OCCUR DUE TO ADDED LANDING SPEED UNDER COMBINATIONS OF HIGH FIELD ELEVATION, NEAR MAX LANDING WEIGHT, AND HIGH OAT. CONSIDERATION SHOULD BE GIVEN TO ALERTING EMERGENCY RESPONSE CREWS DUE TO THE ELEVATED RISK OF BRAKEFIRE AND FUSE PLUG RELEASE.

1. Maximum Touchdown Groundspeed . . . 195 knots

2. Thrust Reversers . . . Apply maximum

14. If a go around is required:

1. Airspeed . . . Execute initial climb at VREF